Abstract

The development of functional changes in the kidney in juvenile diabetes was studied by the use of two provocative tests, physical exercise and lysine injection, that increase urinary protein excretion. Thirty-seven male diabeticpatients were studied before and after two bicycle-ergometer exercise sessions(75 Wmin for 20 min and 100 Wmin for 20 or 30 min). No increase in albumin excreation was found in 11 normal controls or in six patients who had diabetesfor less than 1 yr. Increases in albumin excretion were found in patients withdiabetes of 2-12 yrs duration and even higher exercise-induced increases werefound in patients with diabetes for 16-20 yr. No increase in beta-2-microglobulin or light chain excretion was noted in any of the subjects. The lysinetest was conducted in 32 male diabetics and 9 normal controls. After lysine injections (0.4 gkg body weight, iv), abnormally high values in albumin excretion were found only in patients with diabetes for more than 15 yr. No significant changes were found in the peak excretion values of beta-2-microglobulin and light chains after lysine injection in any of the diabetic groups. It is concluded that the exercise test is the more sensitive of the two tests, since it allows detection of abnormalities early in the course of diabetes. Verf.-Referat