UNIVERSITY OF GRONINGEN

Bio-impedance vector analysis in Malawian children with

severe acute malnutrition A diagnostic study in a low- income setting

Report written by Jacintha Kool (s2099837) under supervision of Dr. P.F. van Rheenen,

Pediatric Gastroenterologist at the University Medical Center Groningen (UMCG) and Dr.

W.P. Voskuijl, Paediatrician and Senior Lecturer at the Department of Paediatrics, College of

Medicine, Queen Elisabeth Central Hospital (QECH).

2

SUMMARY

Background/objectives: Severe acute malnutrition (SAM) is diagnosed according the criteria

of the WHO guidelines. Measurement of weight, length/height and mid upper arm

circumference (MUAC) and determination of edema is required to distinguish between two

phenotypes: kwashiorkor and marasmus. Bio-electrical impedance vector analysis (BIVA) is a

known method to measure body composition but it has not been investigated yet whether this

method can help to assess the nutritional status of children with SAM. This study aims to

identify changes in body composition during the stabilization of children with SAM.

Methods: Firstly the use of BIVA in correlation with de traditional anthropometry was

analyzed in a cross-sectional study design. Secondly the changes in bio-electrical impedance

between the start and end of the stabilization treatment phase were recorded in a longitudinal

design.

80 participants with SAM (43 male), between 6 months and 8 years old, were admitted to a

Nutritional Rehabilitation Unit (NRU). The BIVA parameters , normalized by height, are:

resistance (R/H), which reflects body fluids and reactance (Xc/H), which reflects the amount

of soft tissue.

Results: A sufficient negative correlation is seen between MUAC and R/H ratio in patients

with kwashiorkor (r = -0,440, p = 0,003) and a stronger correlation in patients with marasmus

(r=-0,644, p = 0,001) during the stabilization. The Z-scores of weight-for-height/length only

correlates with the R/H value of children with kwashiorkor (r=0,621, p= >0,001). Secondly,

BIVA demonstrated the difference between marasmus and kwashiorkor at the start (p<0,001)

and end (p<0,001) of the stabilization phase. Kwashiorkor (p<0,001) as well as marasmus

(p<0,001) show a significant change in BIVA parameters after the stabilization.

Conclusion: BIVA can detect significant changes in body composition during the stabilization

of children with SAM. Further studies should evaluate whether BIVA is a useful add-on to the

traditional anthropometry to guide therapy SAM in a low-income setting.

SAMENVATTING

Achtergrond: Ernstig acute ondervoeding (SAM) wordt gediagnostiseerd volgens de criteria

van de WHO richtlijnen. Het vaststellen van gewicht, lengte, midden-arm omtrek (MUAC)

en oedeem is noodzakelijk om onderscheid te maken tussen de twee fenotypes van SAM:

kwashiorkor en marasmus. Bio-elektrische impedantie vector analyse (BIVA) wordt al

gebruikt om lichaamscompositie te meten. Het is echter nog niet onderzocht of deze methode

gebruikt kan worden bij het inschatten van de voedingstoestand van kinderen met SAM. Deze

studie tracht verschillen in lichaamscompositie vast te stellen, tijdens de stabilisatie van

kinderen met SAM.

Methode: Allereerst werd in een cross-sectional study design de relatie tussen het gebruik van

BIVA en klassieke antropometrie geanalyseerd. Daarnaast wordt de verandering in BIVA

gedurende de stabilisatiefasen een longitudinaal design vastgelegd.

80 deelnemers met SAM (43 mannelijke) in de leeftijd van 6 maanden tot 8 jaar werden

opgenomen op een hervoedings afdeling (NRU).

De BIVA parameters, genormaliseerd voor lengte, zijn: weerstand (R/H) die de

vochthuishouding weerspiegeld en reactantie (Xc/H) die de hoeveelheid zacht weefsel

weerspiegeld.

Resultaten: Een duidelijke correlatie is te zien tussen MUAC en R/H ratio in patiënten met

kwashiorkor (r = -0,440, p = 0,003) en een sterkere correlatie in patiënten met marasmus r=-

0,644, p = 0,001). De Z-scores van gewicht voor lengte/hoogte correleren alleen met de R/H

waardes van de kwashiorkor kinderen.

BIVA toonde ten tweede aan dat er verschil zit tussen kwashiorkor en marasmus aan het

begin (p<0,001) en eind (p<0,001) van de stabilisatie fase. De BIVA parameters van

3

patiënten met zowel kwashiorkor (p<0,001) als marasmus (p<0,001)zijn na stabilisatie

significant veranderd.

Conclusie: BIVA kan tijdens de stabilisatie significante verschillen vaststellen in

lichaamscompositie van kinderen met SAM. Verdere studies moeten onderzoeken of BIVA

een bruikbare aanvulling is op de huidige klassieke antropometrie om de behandeling met

SAM te kunnen volgen.

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TABLE OF CONTENTS 1. INTRODUCTION ............................................................................................................................... 5

1.1. Background/ rationale .................................................................................................................. 5

1.2. Objective ...................................................................................................................................... 6

2. METHODS .......................................................................................................................................... 6

2.1. Setting and study design ............................................................................................................... 6

2.2. Participants ................................................................................................................................... 7

2.4. Statistical methods ...................................................................................................................... 10

3. RESULTS .......................................................................................................................................... 11

3.1. Participants ................................................................................................................................. 11

3.2. Descriptive data .......................................................................................................................... 13

3.3. Main results ................................................................................................................................ 13

4. DISCUSSION ................................................................................................................................... 16

4.1. Key results of research questions ............................................................................................... 16

4.2. Methodological limitations ......................................................................................................... 16

4.3. Comparison with other studies ................................................................................................... 16

4.4. Implications for paediatric practice ............................................................................................ 17

5. CONCLUSION ................................................................................................................................. 18

6. ACKNOWLEDGEMENT ................................................................................................................. 18

7. REFERENCES .................................................................................................................................. 18

Appendix A. Standard Operating Procedure ......................................................................................... 21

Appendix B photo report information sheet for guardians .................................................................... 24

Appendix C BIVA-CRF ........................................................................................................................ 28

5

1. INTRODUCTION

1.1. Background/ rationale

1.1.1. Epidemiology and topical underlying causes of Severe Acute Malnutrition

Despite the first millennium development goal (MDG) target 1 c: “cut the proportion of

people who suffer from hunger in halve between 1990 and 2015”, childhood malnutrition is

still a major global health problem. It is contributing to childhood morbidity, mortality,

impaired intellectual development, suboptimal adult work capacity, and increased risk of

diseases in adulthood. (1) It is estimated that 19 million preschool-age children, mostly from

the WHO African Region and South-East Asia Region, are suffering from severe wasting

(weight for Height/length <-3SD)

Globally, nearly half of under-five deaths are attributable to malnutrition. In 2013 3.1 million

deaths – half of under-five deaths worldwide- occurred in Sub-Saharan Africa (2). Malawi, a

sub-Saharan African country with 16 million inhabitants, is one of the world’s poorest

countries. It ranks 174 out of 187 countries in the 2013 Human Development Index(3). 1/7th

of the children younger than 5 years is malnourished. For every 1000 live births 68 children

were dying before the age of 5 in 2013. The global mortality rate is 46 children per 1000 live

births(2).

Malawi is experiencing frequent food shortages due to the vulnerable agriculture sector, the

most important sector in the economy. More that 80 percent of Malawians are smallholder

farmers. (4) Food security can be easily effected by natural disasters such as annual dry spells

and flooding. At the start of this year, 2015, heavy floods destroyed about 25000 of hectares

of crops. It is estimated that 695 600 people experienced acute food insecurity during the

previous lean season, December to March 2015(3). It is expected that this number will be

much higher next lean season. Children between six months and five years old are especially

vulnerable to changes in food intake. Those who also live in households with lack of

environmental hygiene and unequal gender relations are of high risk to get severe acute

malnutrition (SAM)(5).

1.1.2. Measuring Severe Acute Malnutrition

Traditionally, the severity of malnutrition is determined with the use of anthropometry (which

includes the measurement of weight, height, en mid upper arm circumference (MUAC)). This

method is based on historical data of the World Health Organization on nutrient requirements.

Few of the recommendations are supported by evidence from clinical trials.(6,7)

Anthropometric observations in children with Severe Acute Malnutrition (SAM) are

frequently not correctly reflecting the actual nutritional status. Disturbances are seen when

edema is present and this causes overestimation of body weight. Secondly, dehydration can

lead to underestimation of bodyweight, while the presence of dehydration is often difficult to

recognize.(8,9) Dehydration is a common feature in children with SAM, caused by impaired

gut function (carbohydrate malabsorption) and osmotic diarrhea. Currently, simple bedside

clinical observations are the only tools to assess hydration status, but these signs are difficult

to interpret in children with SAM (4,5). Sunken eyes and wrinkled skin can been seen in a

malnourished child with and without dehydration. Signs that that are typical for dehydration

in a malnourished child are also seen in septic shock, for example cold hands and feet and

diminished urine flow (7).

It has been proven that the early identification and treatment of SAM could improve long term

as well as short term outcomes and it is vital to identify and manage underlying clinical

conditions during treatment of SAM as well (10).

6

A method that more accurately distinguishes between nutritional status and hydration status

would assist health workers in deciding what treatment is needed to stabilize children with

SAM. Those that are admitted with dehydration need rehydration with ReSoMal first, while

those without dehydration can be treated with therapeutic formula straight from the start(7).

1.1.3 Bio-electrical impedance

Bioelectrical impedance vector analysis (BIVA) allows to differentiate between soft tissue

mass and fluid mass, and might be able to give information about the body composition. It

measures electrical properties of the different body tissues at the bedside. (11-13) The use of

BIVA to diagnose SAM children in a low-income setting is not yet described in recent

published studies.

1.2. Objective

This study aims to evaluate the use of BIVA in the assessment of body composition in

children with SAM in Malawi. BIVA is compared with the traditional clinical assessment of

the nutritional status. The following research questions will be answered:

(A) Is the improvement in nutritional status measured by traditional anthropometry in

agreement with the changes in body composition measured by BIVA?

(B) Is the clinical distinction between kwashiorkor and marasmus reflected in differences in

bio-electrical impedance between those groups?

(C) Does the bio-electrical impedance within one person change between the start of

treatment and the moment of transition?

2. METHODS

2.1. Setting and study design

2.1.1. The F75 study

The present study is an add-on study to the “F75 trial”. The F75 trial is a multicenter

randomized double-blind intervention trial that is currently being executed in two hospitals in

Kenya and one hospital in Malawi. The BIVA-study is only performed on the nutritional

rehabilitation unit (NRU) in Queen Elizabeth Central Hospital (QECH) in Blantyre (Malawi).

This unit is one of the biggest malnutrition wards in Africa where up-to-date clinical care is

combined with research that varies from basal to clinical-epidemiological (10,16-18).

The standard clinical care for children with SAM in a NRU consist of three distinct phases. In

‘phase 1’ or ‘stabilization phase’ a low protein, liquid diet (F75) is introduced with a reduced

energy intake (80-100 kcal/kg/day). Once a child has stabilized, it moves up to the ‘transition

phase’. In this phase a child will either get therapeutic foods (RUTF) with supplemental F75

or a milk formula known as F100. F100 is a liquid formula with a higher energy density and

protein content than F75. The caloric intake is increased daily to a maximum of 130

kcal/kg/day. Recovery mainly takes place in phase 2, or the rehabilitation phase. The focus is

to achieve catch-up growth with either RUTF or F100. The total amount of days to recover

varies per patient (6).

The F75 trial wants to evaluate the outcome of a revised formulation of F75 milk with

reduced carbohydrate composition and without lactose, compared to the current formulation

of F75 during the initial stabilisation period amongst children with SAM.

7

Figure 1: implementation of BIVA-study in F75-study, illustrated by patient X. The patient is

admitted to the hospital on day 0 and gets stabilized the with F75-milk. The first BIVA test

takes place the next day and de second BIVA test takes place when clinical signs show

improvement and the patient is ready to receive more calories in the transition phase: F100

of RUTF with supplemental F75. When no complications occur, the patient can rehabilitate

in phase 2.

2.1.2. Design of the BIVA-study

The BIVA study consists of two parts:

In the first part a cross-sectional design is used in order to compare the pattern of impedance

of SAM children with the anthropometric measurements. The measurements are performed on

day 1 as shown in table 1.

The second part of the BIVA-study is performed in a longitudinal design. BIVA patterns,

measured on the first day of stabilization, are compared with those measured on the last day

of stabilization. 2. The follow-up stopped as soon the patient died or when the participation of

the F75-study ended.

The Malawian research site of the F75-trial in the NRU started recruiting patients as of

December 2014. The aim is to recruit 320 patients. The BIVA study recruited patients

between February 9 and April 9, 2015. The follow up of patients ended April 18 when the last

participant was discharged from the QECH. The sample size was based on a convenience

sample. It was anticipated that approximately 100 children with SAM could be included in the

F75 trial in a 10 week period.

2.2. Participants

All of the children admitted to the NRU suffered from SAM. The WHO guideline (7)

distinguishes two clinically phenotypes:

- Marasmus: weight-for-length/height ≤ -3 Z-scores OR - a mid-upper-arm circumference

of <11.5 cm (WHO growth standards).

- Kwashiorkor: nutritionally induced bilateral edema. Other features of kwashiorkor can

include fatty infiltration of the liver and hepatomegaly, discolored sparse hair, flaky

desquamated, discolored skin and anorexia.

All children between 6 months and 8 years old with SAM were screened on the eligibility

criteria for the F75 study. They had to have medical complications as defined in the current

WHO guideline for the management of SAM (6) or had to fail an appetite test in absence of

complications. A known allergy to milk products was a reason to exclude the patient.

Patient

nummer

Day 0 Day 1 Day 2 Day 3 Day 4 Day 5 Day6 Day 7 Day 8

X Phase

1

BIVA

test 1

BIVA

test 2

Transition

phase:

F100 or

RUTF

(+F75)

Phase

2

F100

or

RUTF

discharge

F75 F75 F75

8

After receiving informed consent from the guardian the patient was enrolled in the F75 trial.

A F75 study patient was excluded from the BIVA-study when one of the following was found

during physical examination:

1. open skin lesions on the sticker placements

2. inability to stretch the limbs due to a cerebral palsy

3. significant body asymmetry as in amputations, unilateral hemiparesis, and

neuromuscular conditions that produce localized changes in perfusion or tissue

atrophy(19)

After enrollment of the patients in the BIVA study they were followed as long as they were

part of the F75 study. Participation of the F75 study stopped as soon as they were discharged

from the hospital.

2.3 Data source & measurement

Figure 2A: image of BIVA device in practical use, Figure2B: graphical interpretation of the BIVA

parameters.

2.3.1. Interpretation of BIVA

Resistance (R) and reactance (Xc) are the output variables of interest in bio-impedance vector

analysis (figure 2A and B) (20). R gives information about ionic solutions of soft tissue that

represents the total amount of intra- and extracellular fluid. Xc gives information about cell

membrane integrity that represents the lean tissue mass. The combination of these two

components is Impedance (Z-vector). An RXc graph allows an evaluation of the soft tissues

trough patterns based on percentiles of their electrical properties without prior knowledge of

body weight. As described in figure 2B, vector shortening or lengthening indicates a change

in hydration status, while upward or downward bending of the vector indicates a change in

soft tissue mass.

As a relatively short duration of the stabilization phase is anticipated, we expect the R

component to show bigger absolute differences from baseline compared to Xc. We therefore

2B

9

decided to use the R component divided by height (R/H ratio) as the primary outcome of the

analysis

See appendix A for a detailed description of the Standard Operating Procedure (SOP) and

additional appendix B for a illustration of the BIVA procedure that was used to inform the

guardians and patients.

2.3.2. F75-CRF

Four trained clinicians completed a Case Report File (CRF) on a daily basis for all study

patients of the F75-trial. The BIVA-CRF is based on these reports and additional BIVA data

were added by the author of this report. (see appendix c for the complete BIVA-CRF). Table

1 shows the source of each variable.

F75 trial day 0 BIVA-study

day 1

BIVA study

transition *1

Discharge

F75-CRF

- age

-gender

- date/time of

admission

- Upper arm

circumference

- length(49-84 cm) height (85-110 cm)

-weight (kg)

- edema score *2

- clinical hydration

status *3

-Weight (kg)

-edema score

- Upper arm

circumference

- clinical

hydration status

- date

- admission

pathway:

moved back to

phase 1:

yes/no

- HIV-status

- medical history

- complications at

admission *4

- number of days

with diarrhoea

- number of days

requiring

rehydration fluids

(ReSoMal of IV

fluids)

- total days of

stabilization

phase *5

- study outcome

- Numbers of

episodes of

new-onset

severe clinical

deterioration

*6

BIA-device

- Number of

feeding

moments*7

- BIVA-output 1

*8

- Number of

feeding

moments

BIVA-output 2

Table 1: BIVA-CRF variables were collected on four moments of the inhospital treatment, out

of two different sources.

10

Definitions of variables in BIA Case Report File

1. The criteria for stabilization and ready to move to ‘transition phase’ (WHO

guidelines):

- Absence of any WHO danger or emergency signs: obstructed breathing, respiratory

distress, cyanosis, shock (delayed capillary refill plus fast & weak pulse plus

temperature gradient), severe anaemia (Hb<5g/dl), congestive cardiac failure,

impaired consciousness, convulsions, severe dehydration, profuse watery diarrhea,

vomits everything, hypothermia.

- If there is edema at baseline, loss of edema Tolerating full prescribed volume of F75

feeds and observed to be completing the feeds.

2. Edema score: If there is edema at baseline, loss of edema is defined as improving from

a severe +++ edema (severe: generalized bilateral pitting edema including feet, legs,

arms and face) to ++ edema (moderate: no upper arm or upper leg edema and no facial

edema) or from ++ edema to + (mild: only feet/ankle edema) or none;

3. Hydration status is based on the frequency of diarrhea (3 or more loose/watery stools

in last 24) and/or vomiting, the AVPU-consciousness score: alert, response to Voice,

response to Pain, Unconsciousness, and the component is the capillary refill >2 in the

fingernail:

4. Complications at admission: shock, severe pneumonia, diarrhea, malaria, febrile

sepsis, or other.

5. Total days that a patient was treated in the stabilization phase: excluding number of

days when the child is moved back to the stabilization phase (from the 'transition

phase') during a clinical deterioration;

6. New-onset severe clinical deterioration accompanied by one or more of the following

features: shock (fast and weak pulse and limb versus core temperature gradient and

capillary refill time>3 seconds), respiratory distress (severe sub- or intercostals

recessions/in drawing, hypoxemia (SaO2 < 94% in room air) or requiring oxygen;

impaired consciousness (Blantyre coma score<4) or hypoglycemia (<3.0 mmol/l);

7. Feeding moments on a NRU take place every three hours.

8. BIVA output variables: Reactance (Xc), Resistance (R), Phase angle (PhA).

2.4. Statistical methods

Pearson’s correlation is used to evaluate the relationship between the BIVA parameter R/H

ratio and MUAC. The correlation between the R/H-ratio and he weight-for-length/height Z-

score is calculated with the Spearman’s correlation. The weight-for-length/height Z-score is

calculated with the NCHS/WHO normalized reference values(21). The difference in BIVA

output variables between kwashiorkor and marasmus and between the beginning and end of

the stabilization phase is calculated with a BIVA software package (Piccoli 2002) (22). This

software package plots the two mean components R/H and Xc/H in a confidence ellipse. Two

mean vectors have a significantly (P , 0.05) different position in the R–Xc plane when the

95% confidence ellipses are not overlapping. The independent Hotelling’s T2 test is used for

the difference between kwashiorkor and marasmus and the paired one-sample Hotelling’s T2

test will be used to calculate the difference between the start and end of the stabilization

phase. Hotelling’s T-test is a multivariate extension of the Student-T test.

11

3. RESULTS

3.1. Participants

In a total period of 9 weeks 80 patients could be tested at baseline and 60 patients at the end

of the stabilization phase.

86 participants were seen between the 5th

feeding moment and the 7th

feeding moment and

could be examined for eligibility for the BIVA study. 5 patients were excluded due to two

reasons: 4 patients were not able to stretch their limbs due to a cerebral palsy and 1 patient

with kwashiorkor suffered from desquamated skin. These exclusion criteria are displayed in

figure 3A en 3B.

Out of 81 eligible patients who were recruited 80 patients underwent the first BIVA test. One

guardian refused because her child was too upset. Figure 4 displays a flow diagram that gives

an overview of the inclusion of participants.

A B

Figure 3A: Not able to stretch the limbs due to cerebral palsy. Figure 3B: open skin lesions on

sticker placement.

12

Figure 4: enrolment of participants in BIVA-study

F75 study -recruitment n = 95

Assessed for eligibility n = 86

Total recruited n = 81

Not assessed for eligibility: n=9

Researcher not available

n = 9

Excluded n = 5:

Unable to stretch limbs n=4

Open skin lesions n = 1

Data available for cross-sectional

analysis n = 80

Withdrawal n = 1

Child was too upset

Data available for cohort analyses

n=60

Lost to follow-up n = 20

Died in phase1 n =9

Absconded n =1

Withdrawn n =1

No researcher n = 9

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3.2. Descriptive data

Demographic and

Clinical Characteristics

Total

(n=80)

Marasmus

(n=37)

Kwashiorkor (n=43)

Male gender, n (%) 43 (53,8) 22 (59,5) 21 (48,8)

Age at enrolment

in months, median (IQR)

20,0 (13) 19 (6) 22 (7)

HIV reactivity, n (%) 23 (28,7) 15 (40,5) 8 (18,6)

Cerebral palsy, n (%) 7 (8,8) 6 (16,2) 1 (2,3)

Weight-for-Height z-

score, median (IQR)

-2 (1) -3 (0,75) -1 (0,5)

MUAC in cm, mean (SD) 11,35

(1,77)

10,35(1,45) 12,3 (1,46)

Complications at

admission n(%):

Shock

3 (3,8)

1 (2,7)

2(4,7)

Severe

pneumonia Freq (%)

11

(13,8)

5 (13,5) 6 (14,0)

Diarrhea 39 (48,8) 19 (51,4) 20 (46,5)

Malaria 5 (6,3) 2 (5,4) 3 (7,0)

Febrile 37 (46,3) 19 (51,4) 18 (41,7)

Sepsis 33 (41,3) 18 (48,6) 15 (34,9)

Other 17 (21,3) 12 (32,4) 5 (11,6)

Table 2: Characteristics of the study sample at enrolment

3.3. Main results

(A) Is the improvement in nutritional status measured by traditional anthropometry in

agreement with the changes in body composition measured by BIVA?

There is a strong inverse correlation between R/H-ratio and MUAC in both kwashiorkor and

marasmus cases, although the correlation is substantial stronger in the children with

Marasmus (r=0,644), table 3A. A similar agreement is seen in the second measurement of the

R/H-ratio and the MUAC on the day of transition, table 3B.

Traditional

anthropometry

Kwashiorkor

correlation r

P-

value

Marasmus

correlation r

p-value

MUAC 1(cm) -0,440 0,003 -0,644 >0,001

z-score 1weight

for height/length

-0,621 >0,001 0,246 0,142

Table 3A : correlation Bio-electrical impedance parameter R/H-ratio and traditional

anthropometry on day 1 of stabilization phase.

A strong correlation of -0,621 and -0,592 (p>0,001) is seen between the R/H-ratio and the Z-

score weight-for-length/height in children with Kwashiorkor. This also applies to both the

start as well as the end of the stabilization phase. No similar correlation is seen in the children

with Marasmus (Table 3A, 3B).

14

Traditional

anthropometry

Kwashiorkor

correlation r

P-

value

Marasmus

correlation r

p-value

MUAC2 -0,499 0,004 -0,623 >0,001

z-score 2 weight-

for-length/height

-0,592 >0,001 0,248 0,204

Table 3B: correlation Bio-electrical impedance parameter R/H-ratio and traditional

anthropometry at the end of the stabilization phase.

(B) Is the clinical distinction between kwashiorkor and marasmus reflected in differences

in bio-electrical impedance between those groups?

At admission (figure 5A) BIVA measures a significant difference between vector position of

children with kwashiorkor and children with marasmus (p<0,001). At transition (figure 5B)

the difference in vector position between kwashiorkor and marasmus is smaller but still

significant (p<0,001).

Figure 5A: Bio electrical impedance of patients with kwashiorkor (blue vector) and

marasmus (black vector) at admission. Both ellipses show the 95% confidence interval

(n=80.)

Figure 5B: Bio electrical impedance of patients with kwashiorkor (blue vector) and

marasmus (black vector) at the end of stabilization phase. Both ellipse show again the 95%

confidence interval which are slightly bigger due to a smaller group (n=60).

A B

15

(C) Does the bio-electrical impedance within one person change between the start of

treatment and the moment of transition?

The paired one sample Hotellings T test calculates the difference between the BIVA results

from the start and the end of the stabilization treatment phase. The null hypothesis (H0) shows

that no vector trajectory was observed between start and end of the stabilization phase. The

RXc graph will displays the mean difference at the origin (0,0), figure 6. In marasmic children

the R-Xc vector position is seemingly unchanged between baseline and the end of the

stabilization phase (figure 5AB). However, as the 95% confidence interval of the vector

trajectory in figure 6 does not overlap the origin of the graph (point 0,0), it can be concluded

that there is a significant change in vector position (p<0,001 in both as Kwashiorkor and

Marasmus). In children with kwashiorkor the R-Xc vector position moves closer to the

marasmus vector position. Overlap of the two confidence intervals in figure 6 shows that the

change in body composition of children with kwashiorkor during the stabilization phase is not

significant from the change in body composition from children with marasmus.

Figure 6: Vector trajectories shows the change in mean bio-electrical impedance between

start and end of the stabilization treatment phase. The ellipses reflecting mean and 95%

confidence interval of patients with Kwashiorkor (blue vector ) and Marasmus (black vector).

16

4. DISCUSSION

4.1. Key results of research questions

We studied the use of BIVA to assess body composition in children with SAM, and compared

its results with traditional clinical anthropometry. It is found that the resistance-to-height ratio

correlated strongly with the mid upper arm circumference in both marasmus and kwashiorkor

cases. The R/H ratio correlated strongly with the weight-for-length/height z-score in children

with kwashiorkor, though lack of agreement was seen in marasmic children. The reason for

this non-correlation cannot be explained yet.

Secondly, we found that the two phenotypes of SAM (kwashiorkor and marasmus) have

distinct patterns of bio-electrical impedance at baseline, and that these patterns tend to overlap

at the end of the stabilization phase. This means that the loss of edema, that is seen in children

with kwashiorkor during the stabilization phase, can be made visible with the BIVA-method.

Their initially distinct body composition tend to become more similar to the marasmic body

composition at the end of the stabilization phase.

Unlike the R/H ratio, a reliable detection of an absolute change of the Xc/H value in the very

short period of stabilization is questionable. Figure 6 shows an higher increase of Xc/H ratio

in patients with Kwashiorkor comparable with Marasmus during stabilization. This is

probably not due to more growth of lean mass. The density of the cells can also increase due

to the loss of fluids in children with kwashiorkor. This gives a relative increase of the Xc /H-

ratio.

4.2. Methodological limitations

The traditional anthropometric measurements were taken by different staff workers of the

NRU. We frequently observed unrealistic values for which remeasurements were done.

Nevertheless, observer bias is probably not completely prevented.

Although we strictly followed the standard operating procedure for BIVA measurement to

gather reliable results, the resistance (R) value can easily be disturbed by the passage of urine,

sweating or breastfeeding during the test. The magnitude of this potential instrument bias is

unknown as it was not possible to quantify the volume of urine, sweat and breast milk.

4.3. Comparison with other studies

There is a paucity of information on BIVA measurements in malnourished children. In 2003,

reference values of BIVA-parameters from healthy children were published. These reference

values for every age groups were established in two Italian studies in children in the first year

of life (15)and in children between 2 till 15 years old(14). In 2009, a survey in a local health

program also used to reference values to compare 4 to 14 year old Moroccan children (23).

For the current study, it is decided not to follow this example. First of all because reference

values for children between 12 and 24 months do not exist yet. This age group is most

frequently seen in the current study as shown in table 2. Besides that, 41% of Malawian

children is stunted (-2SD height-for-age)(3). The body composition of a 2 year old stunted

child will already be different from the mean value of a reference population from a

developed country, even after normalization for height.

The agreement between anthropometry and BIVA parameters has already been evaluated in

2000. Phase Angle (calculated from Xc and R) did correlate with body weight (r=0,818) and

MUAC (r =0,901) in well-nourished Japanese children (24). This study also predicts that it

should be possible to distinguish between weight gain caused by an increase in body cell mass

and weight gain caused by edema. Severe malnourished children, however, were not included

17

in the study. In 2013, a study on critically ill patients evaluated the effect of hydration status

on the BIVA measurements. BIVA was able to differentiate between mild, moderate and

severe dehydration, but these patients were adults in ICU. In other words, the results cannot

be extrapolated to malnourished children in a low-income setting(25).

An unpublished study gives limited information about the use of BIVA in 350 children with

SAM (Girma (26)). A short summary confirms the presumption of the Japanese study from

2000(24): BIVA parameters should able to distinguish tissue- vs hydration related weight

changes in Ethiopian children during the whole inpatient treatment of SAM. This study also

analyzed the change in R/H ratio and Xc/H ratio during treatment.

There is a notable difference in design: the current Malawian BIVA measured only during the

stabilization period instead of during the whole inpatient treatment. Girma took more time to

measure the difference in Xc/H-ratio. Among marasmic children the R/H ratio decreased and

the Xc/H increased. In other words: both the amount of fluids and lean mass increase.

Therefore, is it very likely that this Ethiopian study detect an absolute change in the Xc/H

value.

4.4. Implications for paediatric practice

Nowadays nutritional status is only assessed by traditional clinical anthropometry (weight-

for-height/length, MUAC, height-for-age). The limitations of these methods were described in

paragraph 1.1.2. There is need for a method that more accurately distinguishes between

nutritional status and hydration status. In this study it is showed that BIVA can be used to

distinguish marasmic from kwashiorkor cases, and that body composition of kwashiorkor

cases changes to the marasmus type at the end of the stabilization phase. This information in

itself is not enough to recommend the use of BIVA in the assessment and management of

children with SAM.

There is a need for a healthy reference population of Malawian children to evaluate whether a

combination of traditional anthropometry and BIVA is more reliable than anthropometry

alone. As described in paragraph 4.1, it was not possible to explain why BIVA parameter R/H

and Z-score weight-for-height/length did not correlate due to lack of reference values. Further

studies should analyze the bio-impedance vector position in well-nourished Malawian

children.

In order to detect both the overestimation of bodyweight due to edema and the

underestimation of bodyweight due to dehydration, there is a need for reference values of the

bio-impedance vector position of well-nourished children with dehydration.

This vector position should be compared with the vector of children with SAM and

dehydration. For this report it was decided not to quantify a hydration status due to limited

variables that could indicate dehydration. Besides the limitations that were described in

paragraph 1.1.2, losses can easily be underreported or overestimated by guardians. It will be

challenging for further studies to analyze the vector position of children with SAM with

confirmed dehydration.

BIVA measurements in dehydrated children, and children with kwashiorkor and marasmus

should take place during the whole inpatient treatment on a daily basis. The quicker change of

the R/H ratio as opposed to the slower change of the Xc/H ratio as described in paragraph 4.1.

justifies a daily record.

Apart from the theoretical validity of BIVA as a suitable to monitor therapy in children with

SAM, it needs to be evaluated whether BIVA is applicable in a daily routine in a low resource

setting.

18

First of all, in many ways the current used NRU is a typical ward in a resource poor setting,

but because of the different research projects that have been going on in this NRU its

resources are far above many other wards. There is a need for both a solid patient file system

and for financial resources. The electrode stickers are priced at €0,80 per test and a set of lead

wires has to be replace once a year (€35,- per set)(27).

Furthermore, the size of the intervariability of BIVA parameters taken by different health care

workers should be analyzed. The execution of the test itself is relatively simple and it asks for

the same precision as using a MUAC- tape. The health care worker only needs to have enough

time and patience to inform the guardian about the procedure and to comfort the child. The

reliability of the results depends on willingness and understanding of the participants to

follow the exact instructions.

5. CONCLUSION

This study concludes that BIVA can distinguish changes in body composition during the

stabilization of children with SAM.

At this moment we cannot recommend the use of BIVA as a useful add-on to the traditional

anthropometry to guide therapy in children with Severe Acute Malnutrition in a low-income

setting.

Further studies that include measurements of bio-electrical impedance in a healthy Malawian

reference population and in patients with confirmed dehydration are essential before a final

recommendation can be made.

6. ACKNOWLEDGEMENT

First of all I want to thank my supervisors. Dr. Patrick van Rheenen was involved from the

very early start until the final report as the supervisor at the UMCG. He introduced me to dr.

Wieger Voskuijl who became my supervisor from the ground on the NRU.

Natasha Lelijveld and Emmanuel Chimwezi also played an important role in my study by

providing me the BIVA device, by answering all my questions during the rest of my study and

providing the BIVA software.

I am grateful to the F75-trial clinicians who allowed me to look over their shoulders and

informed me about new study recruitments.

This also goes for the The NRU staff nurses who enrolled me in the Malawian culture, and

taught me how to deal with the native language, religion, and mournfulness.

7. REFERENCES

(1) Black RE, Victora CG, Walker SP, Bhutta ZA, Christian P, De Onis M, et al. Maternal and child

undernutrition and overweight in low-income and middle-income countries. The Lancet

2013;382(9890):427-451.

(2) Danzhen Y., Hug L., Chen Y., et. al. Levels and trends in child mortalitly. 2014.

(3) World Food Program. Malawi, current issues and what the world food program is doing. 2015;

Available at: https://www.wfp.org/countries/malawi. Accessed 07,29, 2015.

19

(4) Trading Economics. World Bank Indicators - malawi - Nutrition. 2010; Available at:

http://www.tradingeconomics.com/malawi/malnutrition-prevalence-weight-for-age-percent-of-

children-under-5-wb-data.html. Accessed July/23, 2015.

(5) Sassi M. Short-term determinants of malnutrition among children in Malawi. Food Security

2012;4(4):593-606.

(6) World Health Organization. Guideline: updates on the management of severe acute malnutrition in

infants and children. 2013;ISBN 978 92 4 150632 8:14-15-20.

(7) World Health Organization. Management of severe malnutrition: a manual for physicians and other

senior health workers. ISBN 9241545119 ed. Geneva: WHO; 1999.

(8) World Health Organization. THE TREATMENT OF DIARRHOEA :A manual for physicians and

other senior health workers 2005;ISBN 92 4 159318 0:22-24.

(9) Heikens GT, Manary M. Wasting disease in African children: the challenges ahead. Malawi Med J

2009 Sep;21(3):101-105.

(10) Kerac M, Bunn J, Chagaluka G, Bahwere P, Tomkins A, Collins S, et al. Follow-up of post-

discharge growth and mortality after treatment for severe acute malnutrition (FuSAM study): a

prospective cohort study. 2014.

(11) Kyle UG, Bosaeus I, De Lorenzo AD, Deurenberg P, Elia M, Gomez JM, et al. Bioelectrical

impedance analysis--part I: review of principles and methods. Clin Nutr 2004 Oct;23(5):1226-1243.

(12) Barbosa-Silva MC, Barros AJ. Bioelectrical impedance analysis in clinical practice: a new

perspective on its use beyond body composition equations. Curr Opin Clin Nutr Metab Care 2005

May;8(3):311-317.

(13) Norman K, Smoliner C, Kilbert A, Valentini L, Lochs H, Pirlich M. Disease-related malnutrition

but not underweight by BMI is reflected by disturbed electric tissue properties in the bioelectrical

impedance vector analysis. Br J Nutr 2008;100(03):590-595.

(14) De Palo T T. Normal values of the bioelectrical impedance vector in childhood and puberty.

Nutrition 2000-6;16(6):417-24.

(15) Savino F, Grasso G, Cresi F, Oggero R, Silvestro L. Bioelectrical impedance vector distribution

in the first year of life. Nutrition 2003 Jun;19(6):492-496.

(16) Kerac M, Bunn J, Seal A, Thindwa M, Tomkins A, Sadler K, et al. Probiotics and prebiotics for

severe acute malnutrition (PRONUT study): a double-blind efficacy randomised controlled trial in

Malawi. Lancet 2009 Jul 11;374(9684):136-144.

(17) Bunn J, Thindwa M, Kerac M. Features associated with underlying HIV infection in severe acute

childhood malnutrition: a cross sectional study. Malawi medical journal 2009;21(3).

(18) Colman S, Stewart RC, MacArthur C, Kennedy N, Tomenson B, Creed F. Psychological distress

in mothers of children admitted to a nutritional rehabilitation unit in Malawi–a comparison with other

paediatric wards. Maternal & child nutrition 2013.

(19) Bioelectrical impedance analysis in body composition measurement: National Institutes of Health

Technology Assessment Conference Statement. Am J Clin Nutr 1996 Sep;64(3 Suppl):524S-532S.

20

(20) Piccoli A, Codognotto M, Piasentin P, Naso A. Combined evaluation of nutrition and hydration in

dialysis patients with bioelectrical impedance vector analysis (BIVA). Clin Nutr 2014 Aug;33(4):673-

677.

(21) World Health Organization. NCHS/WHO normalized reference values for weight-for-

height/length by sex. 2005; Available at: http://helid.digicollection.org/en/d/Js8234e/8.3.html.

Accessed 07-24, 2015.

(22) Piccoli A. PG. Guideline BIVA software 2002. 2002.

(23) Buffa R, Baali A, Lahmam A, Amor H, Zouini M, Floris G, et al. Assessment of nutritional status

in the Amazigh children of Amizmiz (Azgour Valley, High Atlas and Morocco). J Trop Pediatr 2009

Dec;55(6):406-408.

(24) Nagano M, Suita S, Yamanouchi T. The validity of bioelectrical impedance phase angle for

nutritional assessment in children. J Pediatr Surg 2000 Jul;35(7):1035-1039.

(25) Basso F, Berdin G, Virzi GM, Mason G, Piccinni P, Day S, et al. Fluid management in the

intensive care unit: bioelectrical impedance vector analysis as a tool to assess hydration status and

optimal fluid balance in critically ill patients. Blood Purif 2013;36(3-4):192-199.

(26) Girma Nigatu T. Bioimpedance in severely malnourished children : An emerging method for

monitoring hydration of children with severe acute malnutrition. 2014; Available at:

http://nexs.ku.dk/english/calendar/2014/phd_tsinuel-girma-nigatu/. Accessed 07-28, 2015.

(27) Bodystat. Quadscan4000 Specifications, prices on request. 2015; Available at:

http://www.bodystat.com/products/quadscan. Accessed 07-24, 2015.

21

Appendix A. Standard Operating Procedure

1.0 PURPOSE

This SOP describes the Bio impedance analyses (BIVA) procedure.

2.0 SCOPE/RESPONSIBILITY

- This SOP applies to clinicians of the F75 trial

- The principal investigator retains the overall responsibility on implementation of the

SOP

3.0 ABBREVIATIONS

None

4.0 MATERIALS

4.1 BIVA device inclusive all items

4.2 Ruler tape

4.3 Hand gel and cotton wool

4.4 Toys etc: funny movie on phone, music instrument, bubbles, book

4.5 Stickers (reward)

5.0 METHODOLOGY

Start up:

- Start each day with the calibration of the BIVA-device.

- Check the enrolment log (black hardcover) on new admissions to the study. Code: E

- Make a planning for new admission patients regarding their ‘admission time’ that is

written down in the enrolment log. They must be tested preferably after 5 or 6 feedings

after admission.

- For example: Patient X was admitted to the ward at 20.00u. 5 feedings later: (21-24-03-

06-09) you test the patient between 11.00u en 12.00u. Feeding influences the results of the

test! Test in the last hour before the next feed. When a child is still breastfeeding, you can

test the child directly after feeding. Record this exception in CRF.

- Meanwhile: follow the phase 1-study patients during the ward round. Patients ready for

the Transition phase must be tested preferably before they start receiving the actual

Chiponde.

BIVA -test

- Use the plastified demonstration sheet to show the guardian about BIVA and outlight the

safety, non-invasive aspect of the test and emphasize that the help of the mother is very

important. If you need to convince the mother: give a demonstration on your own hands.

Be aware that consenting to the F75 trial, we already have permission to do BIVA. If the

surrounding area is very noisy, you can choose to use the bed behind the last the bay of

the ward. It is better to leave the child on its own bed.

22

- Check before testing:

o Left side is free of clothes or any decorative items. If for some reason the

procedure must be done on the right side, then make a note of this on the CRF.

o All remaining clothes including diaper (!) are dry

- Clean the child ’s hands and feet with some cotton wool and hand gel on the spot where

the stickers will be placed

- Attach the electrodes as follows: (See photograph 1 and 2 for clarification).

1. Hand: Place just behind the knuckles on the fingers. Tab facing away from the body.

2. Put the second electrode minimal 5,5 cm away from the first one. In an older child, it

can be more: measure the distance between the stickers and make a note on the CRF in

order to place the stickers on the same spot during the second reading.

3. Ankle: Place on an imaginary line between the protruding ankle bones straight across

to the lateral of the ankle. Doing so, the tab of the electrode is lateral (facing away

from the body).

4. Foot: Place just behind the toes below the knuckles of the right foot with tab facing

away from the body (lateral position).

5. Attach the leads to the electrodes. (NOTE: The black clip on each lead goes proximal

and red clip goes distal). See photographs

- Wait untill the child feels comfortable with the electrodes and then ask the mother to

put her child in the right position: the child should lie on its back on the bed, with

arms by his/her sides and both arms and both legs must not be touching (Figure 3).

The mother can touch her child if she puts the blanket in-between her hands and the

child. Allow this if it truly necessary to prevent the child from moving.

- Turn the BIVA analyser “on”. When the analyser asks for it, there is no need to enter

the child’s gender, age, height and weight.

- Make sure the subject refrains from movement on the moment that the device says

“measuring”. Movement will influence the BIVA analysis. When you are happy with

the position of the subject, read and record the displayed Impedance at 50kHz, and

Resistance (R), Reactance (Xc) and Phase angle for three times.

- Accept not more difference than a 1% variation in Resistance (R) or a 5% variation in

Reactance (Xc) and Phase Angle. If so, please check the child’s position and electrode

position and repeat until variation is acceptable. Normal range of R: (400 – 1400

ohm), Reactance: (60 – 10 ohm) and Phase Angle: (1,3 -4,0 degrees).

- Remove and dispose of the electrode stickers and offer the child its own sticker.

- Record time of measurement, position of the child, body side of the electrodes,

describe any movement, and earlier physical/feeding activity.

- End of the BIVA assessment.

Tricks to prevent a child from moving:

- Cover the child with their blanket to calm down the child.

- Very upset child under age 2 years: Make sure the child is focused on its mother. If

necessary put a Chitenje between you and the child.

- Very upset child above 2 years old: ask the mother to attach the stickers and

electrodes.

- Count down together with the child.

23

Images from bodystat Photograph 1

24

Appendix B photo report information sheet for guardians

25

26

27

English translation of the information sheet in Chichewa

“No worries, I don’t use injections”

Sticker Test

Thank you for joining the F75 trial!

With this we would like to give you additional information about a potential diagnostic

instrument of malnutrition that is part of the F75 trial.

This instrument can measure the fluids and tissue in the body. A lot of research has been

done already with this instrument. It is considered completely safe and it is not invasive or

hurt your child in any other way.

How does it work?

1. You are very important for this test! You can calm down your child when he or she afraid of

upset.

2. Two stickers will be placed on a hand and two stickers will be placed on a foot.

3. The child needs to lie down as shown on the picture. No rush, we should not force the child.

4. For about 10 sec your child needs to lie very still without touching you.

!! Movement / touch of the child during these 10 seconds will give unreliable results!!

5. Does your child like to watch a movie?

6. Your child can pick its own sticker afterwards.

28

Appendix C BIVA-CRF

CASE RECORD FORM

1. Study Number: F75 | _ | _ | _ | _ |

2. Participant name +

surname:_______________________________________________

3. DATE OF BIRTH |__|__|/|__|__|/| 2 0 |__|__| (dd/mm/yyyy)

4. AGEgroup* |__|

*1 = 0-1 yr, 2 = 2-3 yr, 3 = 4-5 yr, 4 = 6-7 yr, 5 = 8 yr

5. SEX (M/F) |__|

6. DATE OF admission: |__|__|/|__|__|/| 2 | 0 | 1 |__|

7. TIME OF admission: |__|__|:|__|__|

(24 hour clock)

ANTHROPOMETRY 1:

8. Weight: |__|__|.|__|__| kg

9. Height: |__|__|__|.|__| cm

10. MUAC: |__|__|.|__| cm

11. Edema: none / + / ++ / +++ (circle one)1

MEDICAL HYSTORY

1 + = mild, only feet/ankle, ++ moderate: no upper arm or upper leg edema and no facial edema, +++ = severe generalized

bilateral pitting edema including feet, legs, arms and face

29

12. HIV antibody test: Negative Positive

13. Other:

…………………………………………………………………………………………

………………

14. COMPLICATIONS AT ADMISSION:

14.1 SHOCK

(cold hands and capillary refill time longer than 3 seconds and fast

weak pulse)

Yes No

14.2 SEVERE PNEUMONIA (WHO severe or very severe

pneumonia)

Yes No

14.3 DIARRHOEA (3 or more loose stools in 24 hours) Yes No

14.4 MALARIA (confirmed by slide or RDT positive) Yes No

14.5 ANY OTHER FEBRILE ILLNESS Yes No

14.6 OTHER _____________________________________________ Yes No

HYDRATION STATUS 1

15. Number watery stools in last 24 h ___

16. Number vomiting episodes in last 24 h, ___

17. AVPU score ___

18. Cap refill >2: Yes/No ___

19. DATE OF TEST 1: |__|__|/|__|__|/| 2 | 0 | 1 |__|

20. TIME OF TEST 1: |__|__|:|__|__|

21. Number of feedings between admission and testing moment:

30

o 5

o 6

o 7

o Other, because:

BIVA OUTPUT 12:

definitive

22. R(ohm

23. Xc(ohm)

24. PhA

(degrees)

25. Notes (physical activity, (breast) feeding, urine output, body side)

26. Breastfeeding: Yes/No

27. DATE OF TEST 22: |__|__|/|__|__|/| 2 | 0 | 1 |__|

28. TIME OF TEST 2 |__|__|:|__|__|

ANTHROPOMETRY 2:

29. Weight: |__|__|.|__|__| kg

30. MUAC: |__|__|.|__| cm

31. Edema: none / + / ++ / +++ (circle one)3

2 1= onset of stabilisation phase

2= onset of transtition phase 3 + = mild, only feet/ankle, ++ moderate: no upper arm or upper leg edema and no facial edema, +++

= severe generalized bilateral pitting edema including feet, legs, arms and face

31

HYDRATION STATUS 2

32. Number watery stools in last 24 h ___

33. Number vomiting episodes in last 24 h ___

34. AVPU score ___

35. Cap refill >2: Yes/no ___

BIVA OUTPUT 2

definitive

36. R(ohm

37. Xc(ohm)

38. PhA

(degrees)

39. Notes (physical activity, (breast) feeding, urine output, body side)

40. SEVERE ADVERSE EVENT

Name of Event Date of onset End date

40.1 Profuse Watery Diarrhoea

40.2 Vomits everything

40.3 hypothermia

40.4 shock

40.5 Metabolic asidosis

40.6 Hypoxia

40.7 Impaired consciousness (BCS<4)

40.8 WHO severe or very severe pneumonia

40.9 Severe anaemia (Hb<5g/dl)

40.10 Other:

32

HYDRATION SUMMARY: Number of days during stabilisation phase: ___

41. diarrhea (>3 Watery stools) ___

42. requiring ReSoMal ___

43. requiring IV-fluids ___

44. study conlusion date: |__|__|/|__|__|/| 2 | 0 | 1 |__|

45. OUTCOME

o Absconded

o in hospital death

o refused further participation

o full participation