Impaired glucose tolerance: influence by environmental and hereditary factors

The influence on impaired glucose tolerance (IGT) by obesity, physical leisure time activity (PLTA), family histories of diabetes mellitus (DM) and other characteristics were evaluated in a health survey of 807 middle-aged females and males, with the rate of IGT 8.4% (WHO-criteria). Independent (adjusted for covariates) odds ratios concerning IGT were estimated. The ratios were 5.3 with the presence of obesity and 2.2. (ns) with low compared to high PLTA. In a subgroup of summarized environmental factors (obesity and low PLTA versus no obesity and high PLTA, n = 339), the independent odds ratio for IGT was 9.6 with obesity and low PLTA. With one 1st degree DM relative the odds ratio for IGT was 3.1. The ratio was increased both with the presence of relatives with non-insulin-dependent diabetes mellitus and with the presence of relatives with insulin-treated diabetes. Diabetic mothers yielded a higher ratio for IGT than diabetic fathers. In conclusion, the independent relative risk for IGT in this Swedish middle-aged urban sample was about two times higher with environmental factors (obesity only/obesity with low PLTA) than with one 1st degree DM relative.