Changes in diabetic urinary transferrin excretion after moderate exercise.

ABSTRACT

Microalbuminuria following submaximal exercise testing has been proposed for detecting renal abnormalities in diabetic patients. We compared urinary transferrin and albumin excretion between eight adults with insulin dependent diabetes mellitus and eight nondiabetic controls without microalbuminuria before and after a standardized exercise challenge of only moderate intensity for 20 min. Both groups were similar for age, sex, and METs expended during treadmill walking. Urinary excretion ratios of transferrin (UTER) and albumin (UAER) did not significantly increase for nondiabetic subjects. After exercise, UTER increased on average 207% in diabetic subjects (P = 0.009) and UAER increased 209% (P = 0.046). The percent increase in UTER appears to be a function of workload intensity, while the percent increase in UAER appears less dependent on the duration of exercise. A standardized treadmill challenge of moderate intensity easily differentiated changes in urinary transferrin excretion ratios between diabetic and nondiabetic subjects. Measuring transferrin excretion may be a more sensitive parameter than albumin in studies using urinary protein excretion as a response to a provocative exercise challenge.