[The impact of dipper and non-dipper characteristics in the fluctuation of arterial blood pressure. A study of a population of 484 diabetic patients].

Abnormal pattern of circadian blood pressure variations carries a high risk of cardiovascular complications. The aim of this study was to assess the frequency of abnormal blood pressure rhythm in diabetes and its consequences on micro and macrovascular complications. 484 diabetes mellitus patients were submitted to 24-h ambulatory blood pressure monitoring. They were divided into two groups according to the absence (non-dipper: group 1; n = 167) or presence (dipper: group 2; n = 317) of nocturnal BP reduction = 10% of daytime BP. Following data were collected and compared between these two groups: body mass index, glycated haemoglobin, urinary albumin excretion, research of retinopathy by fundoscopy, tests for presence of a macrovascular disease. There were no significant differences among the two groups in sex, body mass index, type and duration of diabetes and glycemic control. Clinical SBP and DBP did not differ from significant manner between non-dipper and dipper (140 +/- 18/81 +/- 1 versus 138 +/- 19/81 +/- 10 mmHg). Non-dipper 24-h SBP and 24-h DBP were higher than those of dipper (129 +/- 16/76 +/- 9 versus 122 +/- 15/73 +/- 8 mmHg; p < 0.001). Non-dipper were older than dipper (59.9 +/- 13 versus 55.8 +/- 15 years; p < 0.001) and there was more hypertensive patients in group 1 than in group 2 (50% versus 39%; p < 0.01). Macro- and microvascular diabetes complications were more common in non-dipper. In conclusion high blood pressure is frequently observed in diabetic patients. Its association with a diminished nocturnal BP fall could explain a higher risk of complications, especially retinopathy, nephropathy and cardiac events.