The association between baseline acculturation level and 5-year change in adiposity among Puerto Ricans living on the mainland United States.

While it is recognized that acculturation influences adiposity risk, the direction and magnitude of this relationship remain unclear. Previous studies' use of proxy acculturation measures and exclusively cross-sectional study designs have limited understanding of this research question. The aim of this study was to examine associations between acculturation and adiposity among Puerto Ricans (45-75 years) living on the mainland United States. We analyzed data from the longitudinal (baseline, 2-year, 5-year) Boston Puerto Rican Health Study (n = 1114). Language-based and psychological-based acculturations were assessed at baseline using questionnaires. Acculturation scores were divided into tertile categories; higher tertiles indicate greater English- and U.S.-based acculturation. Adiposity was assessed using BMI and waist circumference at baseline and each follow-up. Linear mixed effects regression models were fit with baseline acculturation tertile as the predictor and baseline or change in adiposity as the outcome. When examining baseline associations with language acculturation tertiles, participants in the middle acculturation tertile (bilingual) had 2.48 cm (95%CI: -4.64, -0.31) lower waist circumference compared to the more Spanish-based acculturation tertile. When examining the associations between baseline language acculturation tertiles and change in adiposity, those in the more English-based acculturation tertile had higher annual gains in BMI (0.13 kg/m (95%CI: 0.01, 0.25)) and waist circumference (0.44 cm (95%CI: 0.01, 0.88)) over 5-years compared to those in the more Spanish-based acculturation tertile. No significant differences in adiposity were found across psychological-based acculturation tertiles. In conclusion, English language-based acculturation at baseline influences long-term adiposity. Psychological-based acculturation may capture distinct acculturation processes from the language-based construct.