Refined grain consumption and the metabolic syndrome in Urban Asian Indians (Chennai Urban Rural Epidemiology Study 57)

Abstract

The objective of the study was to evaluate the association of refined grains consumption with insulin resistance and the metabolic syndrome in an urban south Indian population. The study population comprised 2042 individuals aged ?20 years randomly selected from the Chennai Urban Rural Epidemiology Study (CURES), a cross-sectional study on a representative population of Chennai, southern India. The metabolic syndrome was defined according to modified Adult Treatment Panel III guidelines; and insulin resistance, by the homeostasis assessment model. The mean refined grain intake was 333 g/d (46.9% of total calories) in this population. After adjustment for age, sex, body mass index, metabolic equivalent, total energy intake, and other dietary factors, higher refined grain intake was significantly associated with higher waist circumference (8% higher for the highest vs the lowest quartile, P for trend < .0001), systolic blood pressure (2.9%, P for trend < .0001), diastolic blood pressure (1.7%, P for trend = .03), fasting blood glucose (7.9%, P for trend = .007), serum triglyceride (36.5%, P for trend < .0001), low high-density lipoprotein cholesterol (-10.1%, P for trend < .0001), and insulin resistance (13.6%, P < .001). Compared with participants in the bottom quartile, participants who were in the highest quartile of refined grain intake were significantly more likely to have the metabolic syndrome (odds ratio, 7.83; 95% confidence interval, 4.72-12.99). Higher intake of refined grains was associated with insulin resistance and the metabolic syndrome in this population of Asian Indians who habitually consume high-carbohydrate diets.