Introduction

1. JAMA Pediatrics Journal Club Slides:Responsive Parenting Intervention and Rapid Infant Weight Gain Savage JS, Birch LL, Marini M, Anzman-Frasca S, Paul IM. Effect of the INSIGHT responsive parenting intervention on rapid infant weight gain and overweight status at age 1 year: a randomized clinical trial. JAMA Pediatr. Published online June 6, 2016. doi:10.1001/jamapediatrics.2016.0445.

2. Introduction • Background • Rapid weight gain and overweight in infancy are associated with later risk for overweight/obesity and numerous comorbidities. • Modifiable factors that promote or prevent infant obesity have been identified, but interventions to prevent rapid infant weight gain are lacking. • Responsive parenting is defined as developmentally appropriate, prompt, and contingent on infant’s needs. • Responsive parenting promotes a range of adaptive outcomes in children including secure attachment, emotion regulation, cognitive and language development, and aspects of self-regulation including inhibitory control and executive function. • Study Objective • To evaluate the effect of the Intervention Nurses Start Infants Growing on Healthy Trajectories (INSIGHT) responsive parenting intervention on rapid infant weight gain and overweight status at age 1 year and whether effects differed between breastfed and formula-fed infants.

3. Methods • Study Design • The INSIGHT study is an ongoing randomized clinical trial comparing a responsive parenting intervention with a safety control. • The INSIGHT parenting intervention used a responsive parenting framework, with messages addressing infant feeding, sleep, emotional regulation/soothing, active play, and growth chart education. • Nurses delivered the intervention curriculum at home visits at infant ages 3 to 4 weeks, 16 weeks, 28 weeks, and 40 weeks. • Infant weight and length were measured at home visits by nurses and at a clinic visit at 1 year by a researcher blinded to the study group.

4. Methods • Setting • Recruited from a single maternity ward in central Pennsylvania. • Home visits (3-40 weeks) and pediatric clinic (1 year). • Patients • Primiparous mothers and their healthy singleton newborns (n = 291) were randomized 2 weeks after childbirth. • Major eligibility criteria included full-term (≥37 weeks’ gestation), singleton newborns delivered to English-speaking, primiparous mothers aged ≥20 years residing within 50 miles of the medical center. Infants born at <2500 g were excluded. • Sample size calculations indicated that 276 participants, defined as those completing the home visit at 3 weeks, would have 90% power to detect a 0.67 difference in body mass index zscore at 3 years, with an anticipated attrition rate of 30%.

5. Methods • Outcomes • Conditional weight gain from birth to 6 months. • Standardized residuals from linear regression of weight for age at 28 weeks on weight for age at birth, with length for age at birth and 28 weeks and actual infant age at the 28-week assessment entered as covariates. • A conditional weight gain score of 0 represents population mean; positive scores indicate faster than average weight gain; and negative scores indicate slower weight gain. • Overweight status at 1 year (weight for length ≥95th percentile on World Health Organization growth charts). • Limitations • Homogeneous sample: limited minority participation, highly educated, higher income. • Limited to first-time mothers.

6. Results • Of 279 participants completing the first home visit at 3 weeks, 253 (91%) completed the clinic visit at 1 year. • No difference in attrition by study group. • No differences in demographic characteristics by study group.

7. Results Effect of Responsive Parenting Intervention on Rapid Weight Gain • Responsive parenting group infants had lower (negative) conditional weight gain scores, reflecting slower than average weight gain, whereas control group infants had higher (positive) scores, reflecting faster, more rapid weight gain. • No difference in intervention effect between breastfed or formula-fed infants.

8. Results Study Group Weight-for-Length Percentiles at 1 Year • Among responsive parenting group infants, 5.5% were overweight at age 1 year compared with 12.7% of control group infants.

9. Comment • Infants in the INSIGHT responsive parenting intervention grew less rapidly during the first 6 months after birth, had a lower mean weight-for-length percentile at age 1 year, and had a lower prevalence of overweight status at 1 year. • Intervention was equally effective for breastfed and formula-fed infants. • In addition to INSIGHT, 3 other trials that focused on preventing obesity in infancy have reported beneficial effects on growth/weight status: SLIMTIME, Healthy Beginnings, and NOURISH. • All limited to primiparous mothers. • All except NOURISH were delivered by nurses during home visits. • Intervention dose higher than trials showing null effects. • All provided guidance on aspects of responsive parenting.

10. Comment • Unique feature of INSIGHT: “stealth” approach. • Framed as a responsive parenting program across all infant behavioral domains (drowsy, sleeping, fussy, alert) rather than explicitly focusing on obesity prevention. • These findings in combination with other trials suggest that interventions beginning early in infancy can have effects on growth and weight status by providing responsive parenting guidance for first-time mothers.

11. Contact Information • If you have questions, please contact the corresponding author: • Jennifer Savage, PhD, Center for Childhood Obesity Research, 129 Noll Laboratory, The Pennsylvania State University, University Park, PA 16802 (jfs195@psu.edu). Funding/Support • This research was supported by grant R01DK088244 from the National Institute of Diabetes and Digestive and Kidney Diseases. Additional support was received from the Children’s Miracle Network at Penn State Children’s Hospital. US Department of Agriculture grant 2011-67001-30117 supported graduate students. Research Electronic Data Capture support was received from The Penn State Clinical and Translational Research Institute, Pennsylvania State University Clinical and Translational Science Award, and National Institutes of Health/National Center for Advancing Translational Sciences grant UL1 TR000127. Conflict of Interest Disclosures • None reported.