The negative association between traditional physical activities and the prevalence of glucose intolerance in Alaska Natives.

The once low prevalence of non-insulin-dependent (Type 2) diabetes (NIDDM) in Eskimos and Indians has risen approximately fourfold over the past 30 years, suggesting the presence of a non-genetic factor affecting NIDDM prevalence. At the same time, traditional physical activities required of a subsistence (self-sufficiency) lifestyle have diminished. Since physical activity has been shown to prevent NIDDM in other populations, we performed a case-control study of physical activity and glucose intolerance in 666 Yup'ik Eskimos and Athabaskan Indians > or = 40 years old in 15 villages in the Yukon Kuskokwim Delta in Alaska. Self-administered questionnaires were used to determine whether subjects participated in a number of traditional activities and/or their modern counterpart (for example, dog sledding and riding motorized vehicles). Intensity values and a score were defined for the activities. Cases included known or newly discovered impaired glucose tolerance or NIDDM. Newly discovered cases were defined by oral glucose tolerance testing of those individuals were screening blood glucose values > or = 6.7 mmol l-1 by random capillary blood glucose testing. Cases included 11 newly discovered (1 with a history of IGT) and 26 known cases of NIDDM, and 17 newly discovered and 1 known cases of IGT. The results showed that, compared to a reference group with low-level physical activity, moderate level physical activity (odds ratio, OR, 0.7, 95% confidence interval [CI] 0.4-1.3) and high level activity (OR 0.2, CI 0.1-0.6) were associated with a lower prevalence of glucose intolerance, adjusted for age, ethnicity, body mass index, and sex.