DIURNAL BLOOD-PRESSURE AND BLOOD-PRESSURE VARIABILITY IN DIABETIC NORMOTENSIVE AND HYPERTENSIVE SUBJECTS

Purpose: Ambulatory blood pressure monitoring has helped to identify different patterns of diurnal blood pressure variability in hypertensive patients. This review examines the available data, with special reference to diabetic hypertensives. Data identification: The diurnal rhythm is absent or abnormal in certain disease states, including diabetes mellitus, Cushing's syndrome, hyperaldosteronism and renal failure. Lack of a nocturnal decline in blood pressure is clinically significant, as it is associated with a greater prevalence of hypertensive target-organ disease. Study selection: Clinical studies were assessed, in which casual and 24-h blood pressure measurements were available from normotensive and hypertensive patients with insulin-dependent or non-insulin-dependent diabetes mellitus. Results of data analysis: Studies comparing the diabetic with the non-diabetic normotensive (based on casual, or office blood pressure measurements) have shown that 24-h mean blood pressures are higher in diabetics. In insulin-dependent diabetics, the incidence of elevated nocturnal pressure appears to be greater than in non-insulin-dependent diabetics. Furthermore, recent reports have shown that ambulatory blood pressure is more closely correlated than casual blood pressure with urinary albumin excretion in type 1 diabetic hypertensives. Conclusions: Ambulatory blood pressure monitoring reveals certain characteristic blood pressure variability in the diabetic patient with hypertension and allows an assessment of the effects of antihypertensive drug therapy in order to ensure blood pressure control.