ALTERED BLOOD-PRESSURE PROFILE, AUTONOMIC NEUROPATHY AND NEPHROPATHY IN INSULIN-DEPENDENT DIABETIC-PATIENTS

evaluate the relationship between autonomic neuropathy (AN) and nephro pathy we measured 24-h blood pressure (BP) and overnight urinary album in excretion (UAE) in 38 patients with insulin dependent diabetes mell itus (IDDM). Autonomic function was evaluated by the heart rate respon se to deep breathing, Valsalva maneuver, heart rate at rest and BP var iation with posture. Sympathetic cutaneous reflex was also tested in b oth inferior and superior limbs, Patients with mean day diastolic BP ( DDBP) less than or equal to 90 mmHg without AN (N = 15) compared to 12 normal controls had similar BP values, but compared to those with DDB P less than or equal to 90 mmHg and AN (N = 12) they had lower night d iastolic BP (NDBP) (66 +/- 4.8 vs 72 +/- 8.8 mmHg; p < 0.05) and UAE ( 9.8 +/- 2.3 vs 107.2 +/- 3.5 mu g/min; p < 0.001). No difference in DD BP was observed between these two diabetic groups (80 +/- 3.9 vs 83 +/ - 6.1 mmHg). Of the 11 patients with DDBP > 90 mmHg, only three were f ree of AN and only two of the eight with AN where free of diabetic nep hropathy. The percentage day/night changes in systolic BP were lower i n patients with AN (13 vs 7.9%; p < 0.05) and were inversely related t o autonomic score, used as an index of the degree of autonomic dysfunc tion (r = -0.48; p < 0.01) and to UAE (r = -0.39; p < 0.05), Furthermo re, UAE correlated with autonomic score (r = 0.69; p < 0.0001) and wit h NDBP (r = 0.44; p < 0.01). Our results show that AN in IDDM patients is associated with a reduced nocturnal fall in BP and suggest a patho genic role of autonomic dysfunction in the development of diabetic nep hropathy, possibly favoring both BP elevation during the night and inc reases in intraglomerular pressure.