[Nyctohemeral arterial pressure profile and heart rate in autonomic diabetic neuropathy].

Autonomic failure reduces the physiological nocturnal decline of blood pressure (BP) and heart rate (HR). To assess the effect on circadian hemodynamic rhythms of sympathetic (s) and parasympathetic (ps) impairment in diabetic autonomic neuropathy (DAN), we measured BP automatically every 15 min and HR continuously for 24 hour in 11 diabetic patients. They were divided into 3 groups according to the results of cardiovascular reflex tests: a) DAN s + ps, b) DAN ps, c) no DAN. Nine of the patients were hypertensive. Eleven non-diabetic hypertensives served as controls. The disturbance of the circadian BP profile was related to the severity of the DAN, nocturnal BP tending to rise in group a, to fall in group b, and falling markedly in group c and in the control group. FC fell to a similar extent in all the groups. We conclude that the circadian BP profile is more affected by DAN than the FC profile, and that study of the circadian BP profile could reveal the presence of predominantly nocturnal hypertension.