Effect of the exercise test on albuminuria, blood pressure and blood glucose in type I (insulin-dependent) diabetic patients.

Twenty-nine male type I diabetic patients (age range 16-46 years) and thirteen healthy men (age range 18-43 years) were exercised on a cycling ergometer at 75 W and 100 W after having achieved a steady state of water diuresis. Diabetic patients were subdivided into Group A (n = 19, resting urinary albumin excretion rate - UAER less than or equal to 16 micrograms/min) and Group B (n = 10, 16 less than resting UAER less than 126 micrograms/min). The groups were comparable in weight, serum creatinine, duration of diabetes and glycosylated hemoglobin. Group B showed the highest elevation of UAER at the work load of 100 W, with no correlation between increase in UAER and increase in systolic blood pressure (SBP) at both work loads. The only correlation between these parameters was found in Group A at the work load of 100 W (p less than 0.05). No correlation was found between exercise UAER and actual blood glucose in either group. The difference in UAER between healthy subjects and Group B patients (p less than 0.001) remained on the same level during exercise as at rest, but the difference between Group A and Group B (p less than 0.001) decreased with increasing work load (p less than 0.05). The highest exercise-induced systolic and diastolic blood pressure (DBP) was found in Group B, although there was no difference between the diabetic groups in pre-exercise blood pressure and in mean SBP and DBP from previous outpatient check-ups. Blood glucose did not change significantly during exercise in either diabetic group. Working capacity of diabetic patients was lower than that of healthy subjects. The test revealed some diabetic patients with strong elevation of UAER and with abnormally raised systolic and diastolic BP during exercise. The value of the findings reported is to be clarified in a further longitudinal study.