Physical inactivity and glucose intolerance in the multiethnic island of Mauritius

The island nation of Mauritius, located in the southwest Indian Ocean, has a high prevalence of non-insulin-dependent diabetes mellitus (NIDDM) among all of its ethnic groups (Hindu and Muslim Indians, African-origin Creoles, and Chinese). These high rates of NIDDM among groups of varying genetic background provide strong support for the importance of environmental components in the etiology of the disease. Research in Mauritius using a simple activity scale has suggested that physical inactivity may be one of these components. The current investigation further examined the association between glucose tolerance and physical activity in middle-aged nondiabetic residents of Mauritius using a more extensive physical activity questionnaire (the Modifiable Activity Questionnaire). Excluding individuals with NIDDM, a statistically significant (P < 0.05) inverse relationship between physical activity and 2-h post-load glucose concentration was found for both males (rho = -0.14) and females (rho = -0.11). Stratifying by ethnic group, similar inverse correlations were observed in Hindu, Creole, and Chinese males, and in Hindu females (P < 0.05), as well as weaker relationships in Muslim males and Creole females (P < 0.10). Total physical activity remained an independent predictor of 2-h post-load glucose concentration after controlling for body mass index, waist-hip ratio, age, and family history of NIDDM. These data are supportive of a potentially important role of physical activity in the prevention of NIDDM in middle-aged inhabitants of Mauritius.