Serum growth hormone was studied during a mild exercise load of 350 kgm. per minute for twenty minutes in four groups of subjects: nonobese normal subjects, obese normal subjects, nonobese maturity-onset diabetics and obese maturity-onset diabetics.
It was found that (1) the fasting pre-exercise serum growth hormone level was higher and the exercise response occurred earlier and was greater in diabetics than in normal subjects; (2) in the nonobese groups, the basal values and exercise responses in diabetics were significantly different from those of normal individuals. In the obese groups, the mean exercise response was higher in diabetics than in normals, but this difference was not significant; the basal values were identical in the two groups; and (3) the basal values and exercise responses were higher in nonobese diabetics than in obese diabetics. In normal subjects, the exercise responses were higher in the nonobese group than in the obese group.