The increase in albuminuria induced by exercise is not associated with preferential excretion of glycated albumin in type 1 (insulin-dependent) diabetic patients.

The increase in urinary albumin excretion induced by acute exercise in Type 1 (insulin-dependent) diabetic patients is associated with the urinary excretion of cationic proteins. To test whether the renal excretion of glycated albumin (more anionic than non-glycated albumin) is affected by exercise, we submitted seven normoalbuminuric (albumin excretion rate less than 30 mg/24 h) Type 1 diabetic patients and six well-matched healthy subjects to an exercise test (600 kpm/min for 20 min) on a bicycle ergometer, preceded and followed by a 1-h resting period. The selectivity index (renal clearance of non-glycated/glycated albumin) was not significantly different among the pre-exercise, exercise and post-exercise periods, either in the normal subjects (1.01 +/- 0.03 vs 1.08 +/- 0.06 vs 1.08 +/- 0.05) or in the diabetic patients (1.25 +/- 0.09 vs 1.20 +/- 0.07 vs 1.20 +/- 0.06), whereas it was significantly higher (p less than 0.05) in diabetic patients compared to healthy subjects during pre-exercise. These results are not consistent with the hypothesis that acute exercise may induce a preferential excretion of glycated albumin.