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

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

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

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: R01DK094841 NIH

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: R01DK094841 NIH

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: R01DK094841 NIH

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

Nurture schedule of assessments

Nurture Incentives

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

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

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

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

Exposure: Household chaos

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

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

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

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

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

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

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.

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)

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)

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)

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)

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)

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)

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 24.852 (-6.886, 56.590) 0.124

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 24.852 (-6.886, 56.590) 0.124

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 24.852 (-6.886, 56.590) 0.124

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

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

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

Thank you