Diet Quality Indices and Risk of Type 2 Diabetes Mellitus: The Singapore Chinese Health Study

Abstract

We aimed to test whether predefined dietary patterns that are inversely related to risk of type 2 diabetes (T2D) in Western populations were similarly associated with lower T2D risk in an Asian population. We included 45,411 middle-aged and older participants (ages 45-74 years) in the Singapore Chinese Health Study who were free of diabetes, cancer, and cardiovascular disease at baseline (1993-1998). Participants were followed up for T2D diagnosis through 2010. Dietary information was collected using a validated food frequency questionnaire. Dietary pattern scores were calculated for the alternate Mediterranean diet (aMED), Alternate Healthy Eating Index 2010 (AHEI-2010), the Dietary Approaches to Stop Hypertension (DASH) diet, an overall plant-based diet index, and a healthful plant-based diet index. During a median of 11.1 years of follow-up, 5,207 incident cases of T2D occurred. After adjustment for multiple potential confounders, the 5 dietary pattern scores were significantly associated with 16% (for aMED) to 29% (for DASH) lower risks of T2D when comparing the highest score quintiles with the lowest (all P-for-trend values < 0.001). These associations did not vary substantially by baseline age, sex, body mass index, or hypertension status but were limited to nonsmokers (aMED: P for interaction < 0.001; AHEI-2010: P for interaction = 0.03). Adherence to a high-quality diet, as reflected by several predefined diet quality indices derived in Western populations, was significantly associated with lower T2D risk in an Asian population.

Figure 1.

Relationship between components of the Dietary Approaches to Stop Hypertension (DASH) diet index and risk of type 2 diabetes mellitus in the Singapore Chinese Health Study, 1993–2010. Foods and beverages were analyzed in 1-serving/day increments and sodium in 500-mg/day increments. Hazard ratios (HRs) were adjusted for the potential confounders listed for model 2 in Table 2, and results were mutually adjusted for other DASH components in quintiles. Results for several dietary components (fruit, vegetables, nuts and legumes, red/processed meat, and sodium) that were substantially correlated with dietary energy intake (correlation coefficients ≥0.30) were further adjusted for total energy intake using the residual method. P-for-trend values were calculated by fitting median intakes for quintiles as continuous variables in statistical models. Bars, 95% confidence intervals (CIs). SSBs, sugar-sweetened beverages.

Figure 2.

Radar chart showing energy-adjusted Pearson correlation coefficients for correlations between dietary pattern scores and their components in the Singapore Chinese Health Study, 1993–2010. AHEI, Alternate Healthy Eating Index; aMED, alternate Mediterranean diet; DASH, Dietary Approaches to Stop Hypertension; hPDI, healthful plant-based diet index; MUFA, monounsaturated fatty acids; PDI, plant-based diet index; PUFA, polyunsaturated fatty acids; SFA, saturated fatty acids; SSBs, sugar-sweetened beverages.