RATE OF WEIGHT-GAIN, WEIGHT FLUCTUATION, AND INCIDENCE OF NIDDM

The relationships of rate of weight gain and weight fluctuation to inc idence of non-insulin-dependent diabetes mellitus (NIDDM) were examine d in Pima Indians. The 1,458 subjects were participants in a prospecti ve study with examinations approximately every 2 years, Rate of weight gain was defined as the slope of the regression line of weight with t ime for two or more consecutive examinations greater than or equal to 2 years apart and weight fluctuation as the root-mean-square departure from this line for four examinations, Among men, incidence of NIDDM w as strongly and significantly related to rate of weight gain (e.g., ag e-adjusted incidence = 56.7/1,000 person-years in those with weight ga in greater than or equal to 3 kg/year and 16.9/1,000 person-years for those losing weight [P-trend < 0.01]). In women, weight gain was signi ficantly related to diabetes incidence only in those who were not init ially overweight (body mass index < 27.3 kg/m(2)). In contrast to the relationship with weight gain, weight fluctuation was not associated w ith incidence of diabetes in either sex. These findings suggest that w eight control in overweight individuals may be a more effective strate gy for prevention of NIDDM in men than in women, whereas prevention of obesity may prevent diabetes in both sexes. Concern about a diabetoge nic effect of weight fluctuation should not deter weight control effor ts.