Abstract P479: Whole Grain and Refined Grain Intake and Associations With Adiposity, Inflammation, and Incident Type 2 Diabetes Among Adults of South Asian Ancestry in the MASALA Cohort

Abstract

Background: Although growing evidence has suggested that whole grain over refined grain consumption is associated with lower measures of adiposity, no studies have examined these relationships in South Asians, who are at higher risk of less favorable adipose tissue distribution and risk of type 2 diabetes (T2D). Objective: We evaluated the associations between whole and refined grain intake with cross-sectional measures of adiposity (waist circumference, visceral, subcutaneous, hepatic, and pericardial adipose tissue), markers of inflammation (CRP, adiponectin), and incident T2D. Methods: We included 891 South Asians who completed the baseline visit in the Mediators of Atherosclerosis in South Asians Living in America (MASALA) study for cross-sectional analyses and 715 participants who completed exam 2 (~5 y after baseline). Whole and refined grain intake were determined using data from semi-quantitative food frequency questionnaires. We used multivariable linear and logistic regression models to evaluate associations between whole and refined grain intake with adiposity, inflammation, and incident T2D (among n=542 participants free of diabetes at baseline; n=48 incident cases), adjusting for several demographic, health, and lifestyle factors. Results: At baseline, participants (45% female) were on average 55 ± 9.2 (mean ± SD) years old with a BMI of 25.3 ± 3.9 kg/m 2 . Cross-sectionally, we observed that higher consumption of whole grains was associated lower pericardial fat (Beta ± SE: -2.3 ± 0.81 cm 3 , p-value=0.005) and higher refined grain intake was associated with higher percent difference in CRP (10.2 ± 4.65%, p-value=0.03) even after adjustment for BMI and other dietary factors (legumes, fruits, vegetables, and dairy). Substitution models also showed that replacing 1 serving/d of refined grain with whole grain was associated with lower pericardial fat (-3.2 ± 1.27 cm 3 , p-value=0.01) and CRP (-11.4 ± 5.38 % difference, p-value=0.02) in the fully adjusted models. Whole grain intake was also associated with greater attenuation of hepatic fat (0.71 ± 0.35 HU, p-value=0.04), but this did not remain significant after adjustment for BMI. Neither whole nor refined grain intake was associated with 5-year incident T2D. Conclusions: Higher intake of whole grain was associated with lower pericardial fat, while higher refined grain intake may be associated with higher inflammation. These observations support recommendations to consume whole grains over refined grains, especially among high-risk groups such as South Asians.