Previous studies have shown an increased incidence of sudden deaths and lower survival in diabetics with autonomic neuropathy. In hypertensive non diabetic patients a direct correlation has been found between nocturnal blood pressure levels and left ventricular hypertrophy. We have shown in diabetics with autonomic neuropathy a flattening in nocturnal blood pressure reduction and increased 24 hours blood pressure values compared to diabetics without autonomic neuropathy and controls. Our results suggest that abnormalities in 24 hours blood pressure profile might play a role in the increased incidence of cardiovascular morbidity and mortality in diabetics with autonomic neuropathy.