Adipose Tissue Fat Cell Size in Relation to Metabolism in Weight-Stabile, Physically Active Men

Abstract

The degree of filling of adipose tissue associated with a close caloric balance was examined by measuring adipose tissue fat cell size in three groups of weight-stabile, physically active men. These groups consisted of men who had survived a myocardial infarction and had reached weight-stability on a supervised physical training program during periods up to 18 months, a group of middle-aged active endurance athletes, and a group of young athletes. Appropriate controls for these three groups were the myocardial infarction patients before training, middle-aged randomly selected men, and young sedentary men, respectively. The three sedentary groups had more body fat and larger fat cells than corresponding physically active men. Fat cell size in the gluteal region of the latter was found within a narrow range (0.2-0.5 µgm), apparently independent of age and body fat of these men. This small fat cell size was associated with low fasting plasma triglyceride and insulin values. Fasting blood glucose apparently did not follow this pattern. Cholesterol was low in the athletes, but not in the training myocardial infarction patients. It was suggested that the degree of adipose tissue filling (fat cell size) may in certain connections be a more meaningful way to define obesity than the amount of body fat, because of its associations with carbohydrate and lipid metabolism. 1 Supported by grant B71-19X-251008 from the Swedish Medical Research Council.