Abnormal albuminuria and blood pressure rise in incipient diabetic nephropathy induced by exercise

Abstract

The aim of the study was to evalutate the influence of light to moderate dynamic work (450 kpm/min followed by 600 kpm/min during 20 min each) on the blood pressure and renal protein handling in insulin-dependent diabetic patients with incipient nephropathy (D3) (elevated baseline albumin excretion but without clinical proteinuria). Fifteen male diabetic patients (D3) with a mean age of 26.5 ± 4.8 years (SD) and a diabetes duration of 15.6 ± 3.4 years (SD), 11 comparable diabetic patients with normal urinary albumin excretion (D2), and ten non-diabetic subjects (C) were studied. In D3 baseline diastolic blood pressure was elevated [92.1 mm Hg ± 6.0 (mean ± SD)] compared to D2 (80.9 mm Hg ± 4.8, 2P = 0.003%) and C (79.5 mm Hg ± 12.4, 2P = 1.2%). Baseline systolic blood pressure was not significantly different in the three groups, but systolic blood pressure was more elevated at 600 kpm/min in D3 (193.0 mm Hg ± 23.0) compared to D2 (170.5 ± 17.3, 2P = 1.2%) and C (157.5 mm Hg ± 20.9, 2P = 0.07%). Baseline albumin excretion in D3 was 82.6 μg/min x/-2.5 (geometric mean x/- tolerance factor) and during exercise the maximal albumin excretion rose to 195.0 μg/min x/- 2.6 (2P = 0.01%). In D2 albumin excretion rose from 3.3 μg/min x/- 1.9 to 7.9 μg/min x/- 1.5 (2P = 0.02%). The albumin excretion in C did not change during exercise. A highly significant correlation between maximal exercise induced albumin excretion was demonstrable in D3. It is concluded that exercise increases the already abnormal baseline albumin excretion and unmasks hyper-responsiveness in systolic blood pressure in patients with incipient diabetic nephropathy.