Cardiovascular response to exercise in young women with insulin-dependent diabetes mellitus.

To evaluate the cardiovascular response to exercise in diabetes, a graded maximal exercise test was performed on 50 women with insulin-dependent diabetes mellitus, aged 15-40 years, and on 15 healthy women in the same age group. The diabetic subjects were divided into 3 groups according to the duration of disease: group 1: 0-5 years, group 2: 6-14 years, group 3: 15-29 years. The maximal work load was lower in the diabetic subjects than in the controls. The difference was most marked between the controls and group 3 (167 +/- 14 W vs 132 +/- 23 W, p less than 0.001). The maximal heart rate was lower in groups 2 and 3 than in the controls (173 +/- 16 vs 187 +/- 11, p less than 0.05). The diabetic women with long-standing disease had a slightly higher blood pressure response to exercise resulting in comparable rate-pressure products in the study groups. Two diabetic women in group 3 and one healthy woman had 1 mm ST depressions during the test without appearance of arrhythmias or chest pain. These studies suggest that exercise tolerance is reduced in young diabetic women, especially in patients with long-standing disease. The frequency of pathological exercise ECGs does not, however, seem to be increased.