S Grantham-McGregor Centre for International Health and Development Institute of Child Health...

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S Grantham-McGregor Centre for International Health and Development Institute of Child Health University College London Early child development in developing countries : the role of nutrition and stimulation
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Transcript of S Grantham-McGregor Centre for International Health and Development Institute of Child Health...

S Grantham-McGregorCentre for International Health and Development Institute of Child Health University College London

Early child development in

developing countries:

the role of nutrition and stimulation

Ackowledgements

Jamaica

• S Walker, S Chang, C Powell,

• H henningham, J Meeks Gardner

Bangladesh

• J Hamadani, F Tofail, S Huda

Childpoor early development

poor school achievementbehavioural problems

Implications: Intergenerational transmission of poverty

adultlow educational level

low skilled job / no work high fertility

stressed

Poor nutrition,care &stimulation

Natio

Focus on early childhood

Sensitive period when experience has maximum

effect on brain development (conception- 5 yrs)

Effects of insults and interventions can be lasting

Ability on entry school progress productivity

Early interventions more cost effective than later

• > 200 million children < 5years in

developing countries are failing to

reach their potential in cognitive and

socio-emotional development

The Problem

(Lancet child development series 2007)

% of disadvantaged children <5yrs by region

0

10

20

30

40

50

60

70

S-S Africa Mid East & NAfrica

S Asia E Asia &Pacific

La America &Caribbean

Central & EEurope

Grantham-McGregor et al 2007;Lancet series

Poverty

>60 X-sectional studies showed associations with wealth and school achievement or cognition

Cumulative Effects: Vocabulary scores by SES quartiles in 3 to 6 yr old children in Equador

age in months ( Paxson and Shady 2005)

Timing of cognitve gap: Timing of cognitve gap: Mental Mental development by wealth quintiles at birth in development by wealth quintiles at birth in 1,579 children in rural Bangladesh

-0.8

-0.6

-0.4

-0.2

-0

0.2

0.4

0.6

0.8

7 18 63 Age in Months

Z scores

Hamadani unpublished

Problem BayleySolving MDI

WPPSI IQ

• What is the role of nutrition and lack of stimulation in decline in developmental levels in the first 5 years?

Prevalence of nutritional deficits in children <5 years in developing countries 9 (Black et al 2008; UNICEF 2110)

Stunting = 192.5 million (34%)

Wasting = 73.6 million (13%)

LBW =16% - IUGR = 11%

Iron deficiency anaemia = 158.6 million (28%)

Iodine deficiency ?35% of total population

Intra-uterine growth

restriction

(11% of births)

Consistent evidence for poorer development up to age 3 years.

Limited evidence from developing countries at later ages

• 8 longitudinal studies of anaemia in early childhood followed to 4 – 19 years

• All but one showed sustained deficits

Iron deficiency anaemia 158.6 million (28%)

Cantwell 1974, Palti 1983, Lozoff 2000, De Andraca1991,

Wasserman 1994,Dommergues 1989, Hurtado 1999, Sherriff 2001

Longest follow-up: Cognitive scores to 19 years Longest follow-up: Cognitive scores to 19 years by iron status and SES, Costa Ricaby iron status and SES, Costa Rica

Age, years

Cognitive scores

Lozoff et al 2007

8 robust RCTs with iron supplementation in children <3 years (lasting 2 months)

• 6/8 benefited motor development

• 2/7 benefited mental development

Moffatt 1994, Freil 2003, Black 2004, Lind 2004, Olney 2006, Stoltzfus 2001, Idjradinata 1993, Aukett 1986,

7 RCTs with multiple micronutrients

• 5/7 benefited motor development

• 1/3 benefited mental development (not randomised)

Black 2004, Olney 2006, Abdu-Afarwuah 2007, Faber 2005, Dhingra 2004, Katz 2010, Chen 2010

Effects of multiple micronutrient & iron supplementation

• Usually benefits motor development

• Insufficient evidence for effect on mental development

• treatment duration insufficient OR irremediable?

• Insufficient evidence to show that multiple micronutrients better than iron alone

Stunting (192.5 million)

4 Longitudinal studies up to ≥ 5 years

8 longitudinal >5yrs

Effects of stunting (height/age ≤ -2SD) <3yrs on later cognition or grades attained

-1.5

-1.1

-0.7

-0.3

0.1

0.5

cognition z scores

grades

S Africa Indonesia Peru Jamaica

z scores/ grades

9yrs 17-18yrs 21- 41 yrs

Grantham-McGregor et al Lancet 2007, Martorell et al 2010

7yrs 9 yrs Guatemala, Pelotas,

Philippines, India

Comprehensive deficits: Jamaican children stunted before 2 yrs

at 17 & 22 yrs

• IQ, cognitve function

• Reading/ maths/ school drop out

• Depression, anxiety, self esteem, hyperactive, attention

• School suspension/ expulsion

Walker et al 2005, 2007,2010

9 RCTs of macronutrient supplementation9 RCTs of macronutrient supplementation

Pregnancy

Bangladesh

Taiwan

Pregnancy + early childhood

Guatemala

Bogota

Early childhood

Ghana

Jamaica

Indonesia

Indonesia

Cali

Adu-Afarwuah 2007

Grantham-McGregor 1991

Pollitt 2000

Husaini 1991

McKay 1978No effect

Pollitt 1993

Waber 1981

Tofail 2009

Joos 1983

Timing of supplement (months)

Age of Follow up (years)

Effect

P for 1m Bangladesh 5 -P+lactation Taiwan 1.5 -P + 6m Bogota 3 -P + 24m (Guatemala) 32 ++P + 36m (Bogota) 7 ?

6-20 for 4m (Indonesia) 8 +/- 1 test

9-24 for 24m Jamaica 17 -20-60 for 4m Indonesia 8 ->36 to 84m Guatemala 32 -

Sustained benefits from supplementation

Benefits from supplementation in Guatemala

age 25-42years

• Increased wage/hour (males)(supplement from birth to 36 months)

• Improved reading comprehension and reasoning (supplement from birth to 24 months)

Stein et al 2008, Hoddinot et al 2008

Timing: Effect (SE) of 1 z-score of birth weight & growth in weight <4 years on grades attained in 4

cohorts, controlling for SES

0

0.2

0.4

0.6

grades

Birthweight

Growth 0-24m

Growth24-48m

p<0.001

p<0.001

p=0.04

Martorell et al 2010. J Nutr 140

(n=7025) Brazil, Philippines, Guatemala, India

Conclusion from stunting

• Undernutrition contributes to the decline in development

• Most sensitive period 1st 24 months

• Some evidence of a sustained effect of supplementation

• Stunted children will not catch up with food alone

Inadequate cognitive stimulation or

learning opportunities

A biological insult

Low licking /grooming High licking /grooming

Length of dendrites in hippocampus related to treatment in 1st postnatal week

ApicalApical

BasilBasil

Champagne et al J Neurosci. 2008 Jun 4;28(23):6037-45.

Mean Corticosterone Levels Pre & Post Stress in Non-handled, Handled and Maternally-separated Rats

0

5

10

15

20

25

30

35

40

0 60 120

non-handled

maternal separation

handled

0

5

10

15

20

25

30

35

40

0 60 120

non-handled

maternal separation

handled

Plotsky & Meaney 1993

µg/dl

Pre-Pre-stressstress

Time (min)Time (min)

(n= 8 per group)

20

25

30

35

40

45

0 1 2 3 4 5 6

Language comprehension score at 18 months by number of play activities (n=786)

p=0.001

Hamadani, Tofail, 2009Hamadani, Tofail, 2009

20

25

30

35

40

45

1 2 3 4 5 6 7 8 9

Language comprehension score at 18 months by number of play materials (UNICEF n=786)

p=0.001

Hamadani TofailHamadani Tofail

Home visiting or centre based approaches Effect size 0.5-1 SD (Lancet child development series Paper 2)

15 of 16 intervention studies providing cognitive

stimulation show benefits to child development

• Focus on mother Focus on mother

• Paraprofessionals

Home made toysHome made toys

Effects of visiting frequency in Effects of visiting frequency in disadvantaged children: Jamaicadisadvantaged children: Jamaica

94

98

102

106

110

pre-test post-test

DQ

Powell, 1989

weeklyweekly

fortnightlyfortnightly

monthlymonthly

no visitsno visits

75

80

85

90

95

McKay et al, 1979McKay et al, 1979

Cognitive abilityCognitive ability

Cognitive ability at 7 years by Cognitive ability at 7 years by duration of intervention; Colombiaduration of intervention; Colombia

0

1 2 3 4

periods of interventionperiods of intervention

RCT of 20 Community Nutrition Centres in Bangladesh (Hamadani et al, 2006)Hamadani et al, 2006)

RCT of stimulation with malnourished Bangladeshi RCT of stimulation with malnourished Bangladeshi infants: Effect on mental development index (MDI)infants: Effect on mental development index (MDI)

78

80

82

84

86

88

90

92

94

Pre-test

Post-test

intervened malnourishedcontrol malnourishedadequately nourished

Rx p< .05

Hamadani et al, 2006Hamadani et al, 2006

MDI

Severely Malnourished Children in Hospital

65

70

75

80

85

90

95

100

105

Enrolment After 6 months

control n=39

Intervention n=43

Raw mental score

Rx p < .001 Rx p < .001 0.57SD0.57SD

Raw Mental Score at Enrolment & 6 Months After Leaving Raw Mental Score at Enrolment & 6 Months After Leaving Hospital in Severely Malnourished Bangladeshi ChildrenHospital in Severely Malnourished Bangladeshi Children

Nahar et al,2008Nahar et al,2008

Primary Health Care: Effect of Intervention Primary Health Care: Effect of Intervention by PHC Staff on Children’s Development by PHC Staff on Children’s Development

JamaicaJamaica

90

95

100

105

pre-test post-test

Control n=69 Control n=69

Intervened n=70Intervened n=70

Rx p<.001Rx p<.001

Powell et al, 2004Powell et al, 2004

DQ

Integrated interventions: stunted Integrated interventions: stunted Jamaican children aged 9-24mthsJamaican children aged 9-24mths

85

90

95

100

105

110

Baseline 6 mo 12 mo 18 mo 24 mo

85

90

95

100

105

110

Baseline 6 mo 12 mo 18 mo 24 mo

DQDQnon-stuntednon-stunted

controlcontrol

Grantham-McGregor et al, 1991Grantham-McGregor et al, 1991

both Rxs

supplemented

stimulated

Sustainable stimulation benefits at 17 & 21 years

• Full IQ, verbal and performance IQ

• Reasoning, analogies, vocabulary,

• Reading comprehension & sentence completion

• Depression, anxiety, self esteem,

• Attention deficit, oppositional behavior

• Aggressive behaviour, social inhibition, general knowledge, grades

attained, exams passed, depression

Walker 2007, 2010

Mothers’ BenefitsMothers’ Benefits

•Child development and child rearing knowledge

Stimulation provided in the home

•Depression

Powell et al 2004

Change in Maternal Depression With Change in Maternal Depression With InterventionIntervention

16

20

24

28

Pre-test Post-test

Baker et al , 2005Baker et al , 2005

Intervened

Control

DepressionDepression

Summary for Stimulation

• Nearly all trials have concurrent benefits

• Malnourished/LBW children can improve

• Benefits related to intensity and duration

• Can have sustained & comprehensive benefits

• Mothers benefit

Timing of cognitve gap: Timing of cognitve gap: Mental Mental development by wealth quintiles at birth in development by wealth quintiles at birth in 1,579 children in rural Bangladesh

-0.8

-0.6

-0.4

-0.2

-0

0.2

0.4

0.6

0.8

7 18 63 Age in Months

Z scores

Hamadani unpublished

Problem BayleySolving MDI

WPPSI IQ

Timing: Effect of 1 z-score of birth weight & growth in length on IQ at 5 years, controlling for SES

(n=1579)

0

0.05

0.1

0.15

0.2

Birthweight

Growth 0-24m

Growth24-64m

Hamadani Tofail unpublished MINIMat

**p<0.01 *p<0.05

IQ Z scores

*

**

*

*

Timing: Effect of preschool on IQ at 5 years, (controlling for SES, nutritional status and Bayley scores at 18 months)

(n=1579)

0

0.1

0.2

0.3

0.4

0.5

Kindergarten Non-formal

Primary school

Hamadani, Tofail unpublished

IQ Z scores

Growth 24-64

Maktab

***88***

**

** *

**p<0.01* p<0.05

Urgent need to prevent enormous wastage Urgent need to prevent enormous wastage in individual and national developmentin individual and national development

Well evaluated projects Well evaluated projects at scaleat scale with long with long term follow upterm follow up

Explore ways of Explore ways of integratingintegrating stimulation stimulation with other services for<3yearswith other services for<3years

Implications for Future Policy

health and nutrition services.health and nutrition services.

• cash transfer/ women’s groups/ faith cash transfer/ women’s groups/ faith groups/microcredit groupsgroups/microcredit groups

• Upgrade preschoolsUpgrade preschools

Implications for Future Policy

The End

Thompson, Nelson 2001