THE ASSOCIATION OF PHYSICAL-ACTIVITY WITH OBESITY, FAT DISTRIBUTION AND GLUCOSE-INTOLERANCE IN PIMA-INDIANS

The relationships between physical activity, obesity, fat distribution and glucose tolerance were examined in the Pima Indians who have the highest documented incidence of non-insulin-dependent diabetes. Fastin g and 2-h post-load plasma glucose concentrations, body mass index, an d waist-to-thigh circumference ratios were determined in 1054 subjects aged 15-59 years. Current (during the most recent calendar year) and historical (over a lifetime) leisure and occupational physical activit y were determined by questionnaire. Current physical activity was inve rsely correlated with fasting and 2-h plasma glucose concentrations, b ody mass index and waist-to-thigh ratios for most sex-age groups even when diabetic subjects were excluded. Controlled for age, obesity and fat distribution, activity remained significantly associated with 2-h plasma glucose concentrations in males. In subjects aged 37-59 years, individuals with diabetes compared to those without reported significa ntly less leisure physical activity during the teenage years (median h ours per week of activity, 9.1 vs 13.2 for men; 1.0 vs 2.2 for women). Controlled for body mass index, sex, age and waist-to-thigh ratio, su bjects who reported low levels of historical leisure physical activity had a higher rate of diabetes than those who were more active. In con clusion, current physical activity was inversely related to glucose in tolerance, obesity and central distribution of fat, particularly in ma les. Subjects with diabetes were currently less active and reported le ss historical physical activity than non-diabetic subjects. These find ings suggest that activity may protect against the development of non- insulin-dependent diabetes both directly and through an influence on o besity and fat distribution.