Abstract
IMPORTANCE: Disparities by race and socioeconomic status in cardiometabolic diseases are prevalent, and social determinants of health (SDOH) are significant contributors to these disparities. However, SDOH research often focuses on negative factors. OBJECTIVE: To examine associations of volunteering, a potentially positive SDOH, with metabolic syndrome and diabetes across 2 samples of Black adolescents from lower-income households, and to assess mediators of associations. DESIGN, SETTING, AND PARTICIPANTS: This cohort study used data from 2 studies. Study 1 was a cross-sectional study of Black adolescents (ages 14-19 years) in households with less than 2 times the poverty threshold from 2018 to 2022. Study 2 was a 14-year longitudinal study of Black adolescents (ages 11-20 years) from low-income families from 1994 to 2008. Data were analyzed from April 2024 to November 2025. EXPOSURE: Study 1 examined volunteering as a binary yes/no as well as volunteering frequency; study 2 examined volunteering from ages 12 to 18 years. MAIN OUTCOMES AND MEASURES: Study 1: metabolic syndrome (counts of the number of metabolic syndrome components above clinical cutoffs; composite z scores of each metabolic syndrome component). Study 2: diabetes diagnosis at age 29. RESULTS: Study 1 included 400 Black adolescents (256 [64.0%] female; mean [SD] age, 16.39 [1.56] years). Study 2 included 979 Black adolescents (570 [58.2%] female; mean [SD] age, 15.87 [1.71] years). In study 1, a higher frequency of volunteering was associated with a lower metabolic syndrome composite score (b = -0.06; SE, 0.03; P = .03). Purpose in life, but not physical activity or depressive symptoms, statistically mediated associations between volunteering and metabolic syndrome. In study 2, participants who volunteered during adolescence had lower odds of adult diabetes (odds ratio, 0.48; 95% CI, 0.24 to 0.94; P = .03). CONCLUSIONS AND RELEVANCE: These results suggest that encouraging adolescents to volunteer may represent a novel approach to improving cardiometabolic health earlier in life and in groups that have been historically marginalized. The notion that volunteering might help not only the recipients of volunteering efforts, but also the volunteers themselves, suggests the possibility of creating a 2-way street of benefits through a single activity that could promote health across groups while also strengthening the social fabric across communities.