Association of physical inactivity with components of metabolic syndrome and coronary artery disease-the Chennai Urban Population Study (CUPS no. 15)

Aim The aim of the study was to assess the influence of physical activity on the components of metabolic syndrome (MS) in an urban south Indian population in Chennai. Methods The Chennai Urban Population Study (CUPS) is an epidemiological study involving two residential areas in Chennai in South India. Of the total of 1399 eligible subjects (age >= 20 years), 1262 individuals participated in the study. MS was diagnosed based on modified Adult Treatment Panel (ATP) III guidelines. Details about the physical activity were collected using questionnaire, which included job-related and leisure-time activities, and specific questions on exercise. Study individuals were then graded as light, moderate and heavy using a scoring system. We assessed the relationship between the grades of physical activity and the components of MS and coronary artery disease (CAD). Insulin resistance was calculated using the homeostasis assessment model (HOMA-IR). Results Prevalence of most of the components of MS (diabetes P < 0.001, obesity P = 0.003, abdominal obesity P < 0.001 and hypertension P < 0.001) and MS per se (P < 0.001) increased significantly with decrease in physical activity. Among non-diabetic subjects, HOMA-IR was significantly higher in subjects who did light-grade activity compared with heavy-grade activity (P = 0.041). Logistic regression analysis revealed physical activity to be significantly associated with MS [heavy activity: reference, moderate activity, odds ratio (OR) 1.639, (P = 0.017); light activity: OR 2.289, (P < 0.001)]. Subjects in the light-grade activity group also had higher odds of CAD (OR 2.42, 95% confidence interval 1.40, 4.24, P = 0.011), compared with the heavy-grade activity group. Conclusion Physical inactivity is associated with the components of MS and CAD in this urban south-Indian population. Lifestyle changes focusing on increasing physical activity could help to prevent the exploding epidemic of MS and CAD in India.