CORRELATES OF EXECUTIVE FUNCTION IN ADOLESCENTS WITH

TYPE 1 DIABETES

Katia Perez, MEd; Niral Patel, MPH; Jade Lord, BA; Kim Savin, BA; Sarah Jaser, PhD

Department of Pediatrics, Vanderbilt University School of Medicine, Nashville, TN

INTRODUCTION

TYPE 1 DIABETES & ADOLESCENCE

• Type 1 Diabetes

• 18,000 new cases annually in the U.S.1

• Highest incidence among 10-14 year olds2

• Requires adhering to complex treatment regimens to achieve optimal glycemic control

• Long-term health complications include nerve damage

and kidney, eye, and heart disease3

• Adolescents with Type 1 Diabetes4-7

Glycemic control

Treatment adherence

Depressive symptoms

Quality of life

1 CDC National Diabetes Statistics Report, 2014; 2 SEARCH for Diabetes in Youth Group, 2007; 3 Wood et al., 2013; 4 Hilliard et al., 2013; 5 Clements et al., 2015; 6 Varni et al., 2003; 7 Grey, Whittemore & Tamborlane, 2002

EXECUTIVE FUNCTION

• Ability to plan, organize and monitor

goal-directed behavior

EXECUTIVE FUNCTION &DIABETES CARE

When did I last use my glucometer?

Where is that thing…

So if my blood sugar is high, and I eat 50g

of carbs, and I’m going for a run, and I feel a cold coming

on… How much insulin do I take right

now?

Sure, I can dine out! I just need to bring my

supplies, a snack for the wait, look up carbs, time

my insulin dose…

PREVIOUS STUDIES

• EF Impairment in youth with type 1 diabetes

• Brain changes as a result of glycemic dysregulation1,2

• Subtle cognitive differences compared to healthy youth3

• EF and adherence4-7

• Worse EF worse adherence

• Adherence measured through self-report

• Limited evidence in this age group

1 Ohmann et al., 2010; 2 Lin et al., 2010; 3 Duke & Harris, 2014;4 Bagner et al., 2007; 5 Berg et al., 2014; 6 Smith et al., 2014; 7 McNally et al., 2010

PREVIOUS STUDIES

• EF and glycemic control1-3

• Mixed findings

• Direct or indirect relationship?

• Limited evidence on sex differences4

• EF associated with adherence & glycemic control in males

1 Berg et al., 2014; 2 Smith et al., 2014; 3 Nylander et al., 2013;4 Graziano et al., 2010

STUDY AIMS

• Aim 1: Examine the relationships between EF &

several measures of adherence

• Parent-report, child-report, glucometer data

• Aim 2: Examine the relationship between EF &

diabetes-related outcomes

• Glycemic control (i.e., A1c)

• Psychosocial outcomes (i.e., depression, quality of life)

• Aim 3: Explore sex-related differences in these

associations

METHODS

STUDY DESIGN & PROCEDURES

• Design: cross-sectional analysis of

baseline data from intervention study

• Eligibility criteria:

• 13-17 years old

• > 6 months since diagnosis

• No other major health problems

• A1c between 8-12%

• Not currently in intervention studies

• Procedures:

• Electronic questionnaires

• 28-day glucometer data downloads

• A1c (%) from enrollment date from

medical record

Assessed for eligibility (n=361)

Approached (n=185)

Enrolled (n=120)

Declined to participate

(n=64)

Excluded (n=177)

MEASURES

Parent- Reported

• Sample characteristics

• Diabetes history

• Demographics

• Executive Function

• Behavior Rating Inventory

of Executive Function

(BRIEF) – Parent Form

• Adherence

• Self Care Inventory

Adolescent-Reported

• Adherence

• Self Care Inventory

• Quality of Life

• Pediatric Quality of Life Inventory (PedsQL) 3.0 –

Diabetes Module

• Depression

• Patient Health

Questionnaire (PHQ-9)

EXECUTIVE FUNCTION MEASURE

Global Executive Composite

Metacognition Index

InitiateWorking Memory

Plan/Organize

Organization

of MaterialsMonitor

Behavioral Regulation Index

Shift InhibitEmotional

Control

Behavior Rating Inventory of Executive Function (Parent Form)1

1 Gioia, Isquith, Guy & Kenworthy, 2000

RESULTS

SAMPLE CHARACTERISTICS

Range Mean (SD)

Age (years) 13-17 14.83 (1.44)

Duration of Diabetes (years) 1-16 5.84 (3.64)

N (%)

Sex

Male

Female

57 (47.5)

63 (52.5)

Race, % White, Non-Hispanic 105 (87.5)

Annual Family Income (USD)

<39,000 32 (26.7)

40,000-79,000 45 (37.5)

>80,000 43 (35.8)

Treatment type

Insulin pump

Injections

61 (50.8)

59 (49.2)

SAMPLE CHARACTERISTICS

Range Mean (SD)

A1c (%) 8-11.5 9.16 (0.90)

Mean Daily BGM 0.21-9.30 3.29 (1.75)

PHQ-9 0-24 4.14 (4.02)

P-SCI 1.29-5.0 3.53 (0.73)

C-SCI 1.71-4.86 3.50 (0.74)

PedsQL 26.85-97.22 70.87 (12.05)

EXECUTIVE FUNCTION IMPAIRMENT ACROSS BRIEF SCORES

N (%)1 Normative Sample2

GEC 16 (13.6) 7-11 %

MI 18 (15.3) 9-12 %

Initiate 22 (18.6) 7-10 %

WM 21 (17.8) 5-9 %

P/O 15 (12.7) 5-9 %

Org. of Materials 22 (18.6) 5-10 %

Monitor 9 (7.6) 4-7 %

BRI 13 (11.0) 7-11 %

Inhibit 13 (11.0) 7-9 %

Shift 19 (16.1) 4-9 %

EC 17 (14.4) 5-8 %1 Percentage of adolescents with BRIEF scoresat or above the clinical cutoff (T-scores of ≥ 65)2Gioia, Isquith, Guy & Kenworthy, 2000

GEC= Global Executive Composite, MI= Metacognition Index, WM= Working Memory, P/O= Planning and Organization, BRI= Behavioral Regulation Index, EC= Emotional Control

BIVARIATE ASSOCIATIONS BETWEEN EXECUTIVE FUNCTION, ADHERENCE, AND

OUTCOMES

GEC MI BRI

Age -.11 -.06 -.19*

Duration of Diabetes -.06 -.05 -.06

P-SCI -.32** -.29** -.29**

C-SCI -.10 -.09 -.10

Daily BGM .06 .08 .02

A1c .06 .04 .07

PHQ-9 .15 .14 .13

PedsQL -.31** -.26** -.33**

* p < 0.05

** p < 0.01

BIVARIATE ASSOCIATIONS BETWEEN EXECUTIVE FUNCTION, ADHERENCE, AND

OUTCOMES

GEC MI BRI

Age -.11 -.06 -.19*

Duration of Diabetes -.06 -.05 -.06

P-SCI -.32** -.29** -.29**

C-SCI -.10 -.09 -.10

Daily BGM .06 .08 .02

A1c .06 .04 .07

PHQ-9 .15 .14 .13

PedsQL -.31** -.26** -.33**

* p < 0.05

** p < 0.01

BIVARIATE ASSOCIATIONS BETWEEN EXECUTIVE FUNCTION, ADHERENCE, AND

OUTCOMES

GEC MI BRI

Age -.11 -.06 -.19*

Duration of Diabetes -.06 -.05 -.06

P-SCI -.32** -.29** -.29**

C-SCI -.10 -.09 -.10

Daily BGM .06 .08 .02

A1c .06 .04 .07

PHQ-9 .15 .14 .13

PedsQL -.31** -.26** -.33**

* p < 0.05

** p < 0.01

PREDICTORS OF PARENT-REPORTED ADHERENCE

Teen Age

P-SCI

GEC

Race/Ethnicity

*p < .05; **p<.01; ***p < .001

Teen Sex

Family Income

1.

2.

F (5, 113) = 3.99**

PREDICTORS OF QUALITY OF LIFE

Teen Age

PedsQL

GEC

Race/Ethnicity

*p < .05; ***p < .001

Teen Sex

Family Income

1.

2.

F(5, 113) = 4.40***

BIVARIATE ASSOCIATIONS BY SEX

1 2 3 4 5 6 7 8 9

1. Age - .30* -.18 -.11 -.12 -.10 .10 .31* -.16

2. Duration of Diabetes .09 - -.17 -.40** -.13 -.19 .09 .07 -.09

3. GEC -.09 .07 - -.18 -.27* .04 .16 .02 -.35**

4. P-SCI -.07 .06 -.56** - .47** .18 -.44** -.09 .27*

5. C-SCI -.15 .00 .13 .20 - .26* -.66** -.37** .43**

6. Daily BGM -.43** -.21 .14 .11 .30* - -.33** -.01 -.03

7. A1C .14 .13 -.10 .25 .00 -.13 - .22 -.39**

8. PHQ-9 .20 -.12 .30* -.30* -.20 -.07 -.12 - -.30*

9. PedsQL -.15 -.10 -.30* .25 .04 .16 -.09 -.53** -

Note. Correlations for male sex are presented below and correlations for female sex are

presented above the diagonal line.

* p < 0.05

** p < 0.01

BIVARIATE ASSOCIATIONS BY SEX

1 2 3 4 5 6 7 8 9

1. Age - .30* -.18 -.11 -.12 -.10 .10 .31* -.16

2. Duration of Diabetes .09 - -.17 -.40** -.13 -.19 .09 .07 -.09

3. GEC -.09 .07 - -.18 -.27* .04 .16 .02 -.35**

4. P-SCI -.07 .06 -.56** - .47** .18 -.44** -.09 .27*

5. C-SCI -.15 .00 .13 .20 - .26* -.66** -.37** .43**

6. Daily BGM -.43** -.21 .14 .11 .30* - -.33** -.01 -.03

7. A1C .14 .13 -.10 .25 .00 -.13 - .22 -.39**

8. PHQ-9 .20 -.12 .30* -.30* -.20 -.07 -.12 - -.30*

9. PedsQL -.15 -.10 -.30* .25 .04 .16 -.09 -.53** -

Note. Correlations for male sex are presented below and correlations for female sex are

presented above the diagonal line.

* p < 0.05

** p < 0.01

DISCUSSION

EXECUTIVE FUNCTION AND ADHERENCE

• Greater EF deficits associated with poorer parent-

reported adherence, but not child-reported

adherence

• EF not significantly related to meter download data

• Other diabetes tasks on the SCI may carry higher cognitive

demands

• Tasks requiring more skill/planning may be more sensitive to

EF deficits

EXECUTIVE FUNCTION AND DIABETES-RELATED OUTCOMES

• Executive function was associated with health-

related quality of life

• Adolescents with deficits in EF may struggle to face

stressors related to their diabetes, negatively impacting

quality of life

EF deficitsLower

adherence

Poor glycemic control

• A significant direct relationship between EF and

glycemic control did not emerge in this sample

• Proposed indirect relationship1

1 Smith et al., 2014

A CLOSER LOOK AT EXECUTIVE FUNCTIONING

• Evidence for greater than normal impairment in

working memory, and ability to initiate and shift

behavior

• Consistent with neurocognitive studies in T1D youth1

• Evidence of sex differences in correlates of

executive function

• Working memory and inhibition develop slower in males2

1 Naguib, Kulinskaya, Lomax & Garralda, 2008; 2 Boelema et al., 2014

LIMITATIONS & FUTURE DIRECTIONS

• Participants targeted

for poor glycemic

control (A1c > 8.0%)

• Longitudinal models

could not be tested

• EF measured through

questionnaire data

• Expand use of

objective measures of

adherence (e.g., insulin

pump data)

• Measure EF through

neuropsychological

assessments

• Investigate whether

specific EF skills are

stronger predictors of

adherence and

diabetes outcomes

CONCLUSION

• Current study demonstrates that EF is related to

adherence and certain diabetes outcomes

• May be further influenced by adolescent sex

• Adolescents with T1D should be studied

comprehensively, with the focus expanding beyond

traditional outcome measures (e.g., complications,

A1c)

• Consider maturity of EF skills and which aspects of diabetes

care are problematic for adolescents

ACKNOWLEDGEMENTS

Collaborators:

• Sarah Jaser, PhD

• Robin Whittemore,

PhD

• Jadienne Lord, BA

• Niral Patel, MPH

• Kimberly Savin, BA

• Bill Russell, MD

Funding:

• This research was

supported by grants from

the National Institute of

Diabetes and Digestive

and Kidney Diseases

[DP3DK097678-01]