Dietary patterns, socioeconomic disparities, and risk of type 2 diabetes in the Sister Study.

AIMS: We investigated the role of socioeconomic disparities in the association between diet and risk of type 2 diabetes (T2D). METHODS: We used prospective data from 40,243 Sister Study participants aged 35 to 74 years who were enrolled in 2003-2009. Scores for healthy eating indices (alternate Mediterranean diet, Dietary Approaches to Stop Hypertension, alternative Healthy Eating Index, and Healthy Eating Index 2015 (HEI-2015)) were calculated using data from a 110-item food frequency questionnaire completed at enrollment. Incident T2D was defined based on self-reported physician's diagnosis or use of anti-diabetic medications. Multivariable-adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) were estimated using Cox proportional hazards models. RESULTS: We observed inverse associations between all four dietary indices and incident T2D after multivariable adjustment. These associations were most pronounced among women with higher educational attainment, higher income, and lower area deprivation index (ADI) (e.g., for the HEI-2015: low ADI, aHRQ4vsQ1: 0.44, 95% CI: 0.35, 0.56 vs high ADI, aHRQ4vsQ1: 0.75, 95% CI: 0.63, 0.90; pinteraction: 0.0007). CONCLUSIONS: Weaker associations among women with lower socioeconomic status and higher neighborhood deprivation suggests that other factors play a larger role in T2D incidence than diet quality among individuals with low SES.