Glomerular filtration rate, autonomic nerve function, and orthostatic blood pressure in patients with diabetes mellitus.

Glomerular filtration rate (GFR) measured by the 51Cr-EDTA clearance method, autonomic nerve function evaluated by the heart rate reaction to deep breathing (E/I ratio) and to tilting (acceleration and brake indices), and orthostatic blood pressures were followed up after 5-7 yr in 43 patients with Type 1 diabetes. At follow up, 20 patients showed a decrease in GFR greater than expected. In the first study, these patients showed low E/I ratios and brake indices indicating vagal neuropathy, while the acceleration index fell, indicating sympathetic denervation, between the studies. Accordingly, vagal neuropathy preceded decreases in GFR and sympathetic denervation favoured deteriorations in GFR. The present report provides evidence that sympathetic denervation might be behind the development of diabetic kidney complications.