1. Household chaos and infant adiposity
Sara Benjamin Neelon, PhD, MPH, RD
Associate Professor
Department of Health, Behavior and Society
AND
Aastha Khatiwada, MS
Doctoral Student
Medical University of South Carolina

2. Background and training
Academic training: PhD, MPH, RD
UNC-Chapel Hill – nutrition intervention and policy
Postdoctoral training
Harvard Medical School – nutrition epidemiology
Current position
Associate Professor, Department of Health, Behavior & Society
Director, Lerner Center for Public Health Promotion
Johns Hopkins Bloomberg School of Public Health
Visiting Senior Fellow
Centre for Diet and Activity Research
University of Cambridge

3. Background and training
Academic training
MS in Mathematics (East Tennessee State University)
BS in Math and BA in Economics (Minnesota State University Moorhead)
Current position
Second year PhD student in the Biostatistics
Graduate research assistant
Working with Dr. Donjung Chung
Developing a Bayesian framework incorporating pleiotropy and functional annotation on GWAS dataset

4. Nurture study Observational study of 666 mother/infant dyads
Goal is to examine effect of caregivers on infant weight gain trajectories from birth to 12 months
Mothers recruited during pregnancy
Infants followed monthly for first year of life
Funding: R01DK NIH

5. Nurture recruitment Mothers recruited during pregnancy
Recruited women at one of 2 prenatal clinics: Duke Medicine and local Health Department
2 out of every 3 women agreed to participate
Women received up to $200 for participation from pregnancy to 12 months postpartum
Funding: R01DK NIH

6. Nurture recruitment Frequent assessments over 1st year of life
Home visits at 3, 6, 9, and 12 months
IVR calls in months 1, 2, 4, 5, 7, 8, 10, and 11
Home visits lasted approximately 2 hours
Data collectors drove up to 1.5 hours
Data collectors traveled if women moved out of state
Funding: R01DK NIH

7. Nurture study aim Primary Aim:
Evaluate longitudinal associations of effect of different caregivers throughout first year of life and offspring adiposity at 12 months
Considering potential mediators of:
Feeding
Physical activity and inactivity
Stress
Sleep

8. Nurture schedule of assessments

9. Nurture Incentives

10. Study population and sample
666 mothers consented to participate with their infants post-birth
468 mothers completed the home visit when infants were 12 months
401 had complete data for exposure, outcome, covariates

11. Data Management and Cleaning
Data cleaning/refining
Producing summary statistics to detect and correct inaccurate and out of range data values (e.g. screen time and sleep time)
Producing graphs to look at outliers/time trends
Looking at bivariate associations
Thinking about apriori covariates

12. Background
Household chaos, defined as chaotic living with high levels of disorganization, overcrowdedness, noise, lack of routine associated with:
Household poverty and economic vulnerability
Maternal caregiving and parenting behaviors
Poor glycemic control in adolescents
Nighttime sleep disturbances in adolescents
Social and emotional developmental problems in preschool
Executive function in parents and adolescents

13. Exposure: Household chaos
Confusion, Hubbub, and Order Scale
Mothers completed when infants were 6 and 12 months during home visit
15 items scored on 4-point likert scale
Validated against direct observation of household
Higher scores indicate greater disorganization and confusion in home environment

14. Exposure: Household chaos

15. Exposure: Household chaos
Item
We can usually find things when we need them
We almost always seem to be rushed
You can’t hear yourself think in our home
It is a real zoo in our house
No matter how hard we try, we always seem to be running late

16. Outcomes: Infant adiposity
Birth weight for gestational age z-score
Calculated using Intergrowth-21st newborn birth weight standards
12-month weight-for-length z-score
Calculated using World Health Organization age- and sex-specific reference data
12-month skinfolds
Subscapular, tricep, abdominal

17. Potential mediator: Sleep
Measured at 3, 6, 9, and 12 months via maternal report
Calculated mean number hours per day of sleep
Also collected but not yet used:
Also measured using ActiSleep monitor at 3, 6, 9, and 12 months
Infants wore monitor continuously on ankle for 4 days

18. Potential mediator: Screen time
Mothers reported total screen time: videos, tv, mobile interactive technologies
Questions adapted from Children’s Media Use in America survey
Calculated mean number of minutes per week of any screen time

19. Household chaos, infant sleep and screen time, and infant adiposity
Infant adiposity at age 12 months
Infant sleep
Infant screen time

20. Household chaos, infant sleep and screen time, and infant adiposity
Infant adiposity at age 12 months
Infant sleep
Infant screen time

21. Analysis
Conducted multivariable linear regressions to assess chaos and infant adiposity
Included potential covariates of a priori interest in models:
Infant age, race, sex, birth weight for gestational age z-score;
Maternal age, education, marital status, pre-pregnancy BMI;
Number of adults in household, number of children in household, and household income.

22. Participant characteristics
Infants
Total sample (n=666)
Mean (SD)
Birth weight for gest. age z-score
-0.3 (0.9)
Weight-for-length z-score 12 months
0.6 (1.0)
Any breastfeeding in months
3.7 (4.6)
Percent (number)
Race
Black / African American
69.7 (457)
White
15.2 (100)
Other / multiple race
15.1 (9)

23. Participant characteristics
Infants
Total sample (n=666)
Mean (SD)
Birth weight for gest. age z-score
-0.3 (0.9)
Weight-for-length z-score 12 months
0.6 (1.0)
Any breastfeeding in months
3.7 (4.6)
Percent (number)
Race
Black / African American
69.7 (457)
White
15.2 (100)
Other / multiple race
15.1 (9)

24. Participant characteristics
Mothers
Total sample (n=666)
Mean (SD)
Maternal age in years
27.3 (5.8)
Maternal pre-pregnancy BMI
29.9 (9.2)
Percent (number)
Race
Black / African American
71.4 (472)
White
19.2 (127)
Other / multiple race
9.4 (62)
Education
≤High school
>High school
47.8 (317)
52.2 (346)

25. Participant characteristics
Mothers
Total sample (n=666)
Mean (SD)
Maternal age in years
27.3 (5.8)
Maternal pre-pregnancy BMI
29.9 (9.2)
Percent (number)
Race
Black / African American
71.4 (472)
White
19.2 (127)
Other / multiple race
9.4 (62)
Education
≤High school
>High school
47.8 (317)
52.2 (346)

26. Participant characteristics
Households
Total sample (n=666)
Mean (SD)
Number adults
3.7 (2.9)
Number children
1.3 (1.6)
Percent (number)
Income
<$20,000 per year
50.4% (233)
≥$20,000 per year
49.6% (229)

27. Participant characteristics
Households
Total sample (n=666)
Mean (SD)
Number adults
3.7 (2.9)
Number children
1.3 (1.6)
Percent (number)
Income
<$20,000 per year
50.4% (233)
≥$20,000 per year
49.6% (229)

28. Results Estimate (95% CI) p value 12-month weight-for-length z-score
Chaos
0.104 (0.002, 0.206)
0.047
Sleep duration, hours
0.024 (-0.154, 0.202)
0.202
Screen time, minutes
(-6.886, )
0.124

29. Results Estimate (95% CI) p value 12-month weight-for-length z-score
Chaos
0.104 (0.002, 0.206)
0.047
Sleep duration, hours
0.024 (-0.154, 0.202)
0.202
Screen time, minutes
(-6.886, )
0.124

30. Results Estimate (95% CI) p value 12-month weight-for-length z-score
Chaos
0.104 (0.002, 0.206)
0.047
Sleep duration, hours
0.024 (-0.154, 0.202)
0.202
Screen time, minutes
(-6.886, )
0.124

31. Conclusions
Greater household chaos associated with increased infant weight-for-length z-score at 12 months
Some indication that not operating through sleep or screen time

32. Study limitations
Nurture sample not representative of larger US population
Nearly 30% of sample did not complete 12-month home visit
Chaos measure may reflect maternal perception only
No measures of maternal or infant executive function

33. Next steps
Assess associations between chaos and other adiposity outcomes (skinfolds)
Include MI data for sensitivity analyses due to loss to follow up

34. Thank you