Abstract P119: Positive and Negative Aspects of Social Relationships are Differentially Associated with Longitudinal Increases in Body Mass Index and Waist Circumference: The Coronary Artery Risk Development in Young Adults (CARDIA) Study
Authors: Kershaw Kiarri N , Hankinson Arlene , Lewis Cora E , Liu Kiang , Loria Catherine M , Reis Jared P , Carnethon Mercedes R 
Published: July 2021

Background:
Few studies have examined longitudinal associations between close social relationships and weight gain. While supportive relationships may minimize weight gain by providing a healthy alternative to maladaptive stress coping behaviors, adverse relationships may act as chronic stressors and lead to weight gain, particularly via central fat accumulation. We assessed whether positive and negative social relationships were differentially associated with 10-year increases in overall and central adiposity.

Methods:
CARDIA participants (ages 33-45 in 2000) with complete covariate data were included (n=2,686). Individuals were asked 4 questions about positive social interactions and 4 questions about negative interactions. Participants were grouped into 3 categories based on positive and negative close relationships reported in 2000 and 2005: persistently high (highest tertile in both years); persistently low (lowest tertile in both years); and intermediate (all other combinations). Overall and central adiposity were estimated with measured BMI and waist circumference (WC), respectively. Separate logistic regression models were used to assess whether cumulative exposure to positive and negative relationships were associated with a >10% (clinically meaningful) increase in BMI and WC between 2000 and 2010.

Results:
The prevalence of persistently high and persistently low positive relationships were similar (20.0% and 18.2%), but more participants reported persistently high negative relationships (25.7%) than persistently low negative relationships (14.7%). Approximately 28.2% and 27.9% of participants experienced a >10% increase in their BMI and WC, respectively. Participants with persistently high positive relationships were 0.68 (95% CI: 0.52, 0.90) times less likely to increase their BMI by ≥10% over 10 years compared to those with persistently low positive relationships after adjusting for age, sex, race, field center, and marital status. Persistently high positive relationships were not significantly associated with a ≥10% increase in WC (OR: 0.81; 95% CI: 0.61, 1.08). Persistently high negative relationships were not associated with a >10% increase in BMI (OR: 1.21; 95% CI: 0.91, 1.60). However, those with persistently high negative relationships were 1.40 (95% CI: 1.05, 1.86) times more likely to experience a ≥10% increase in WC compared to participants with persistently low negative relationships. These findings persisted after further adjustment for education, income, employment status, depressive symptoms, current smoking, physical activity, and 2000 BMI. Results did not differ by sex or race.

Conclusions:
Supportive social relationships were more strongly associated with lower levels of clinically meaningful overall weight gain, while adverse relationships were more strongly related to meaningful increases in central weight gain.