Antihypertensive Treatment Efficacy in Type II Diabetes Mellitus

Abstract

AbstractWhole-day ambulatory blood pressure monitoring is used to confirm the diagnosis of hypertension and assess the response to antihypertensive therapy. Neither of these has been applied to patients with type II diabetes mellitus, in whom it has been proposed that the desirable blood pressure should be lower than in nondiabetics. This multicenter study was designed to examine whether there are differences in the efficacy of a first-line antihypertensive drug when assessed by casual and ambulatory blood pressure determinations in patients with type II diabetes mellitus in whom 24-hour ambulatory monitoring confirms or fails to confirm the diagnosis of hypertension. Forty-three patients (mean age, 57.7 years) with stable type II diabetes mellitus and mild hypertension (casual diastolic pressure, 90 to 104 mm Hg on at least two visits) were treated with an angiotensin-converting enzyme inhibitor (benazepril, 10 to 20 mg, once a day) for 8 weeks. Antihypertensive drug efficacy was assessed by casual (trough) and 24-hour ambulatory blood pressure monitoring. Diabetic patients were classified as nonconfirmed hypertensive if the mean 24-hour ambulatory diastolic pressure was below 85 mm Hg. Antihypertensive treatment significantly decreased both systolic and diastolic pressures when determined by either casual measurement (from a mean of 162.7/98.0 to 153.9/89.2 mm Hg;P<.001) or ambulatory monitoring (from a mean of 143.1/84.4 to 137.0/81.5 mm Hg;P<.05). Twenty-one patients (49%) were classified as confirmed hypertensive and 22 as nonconfirmed hypertensive. In confirmed hypertensive patients benazepril significantly reduced systolic and diastolic pressures when assessed by either casual or 24-hour ambulatory monitoring. In contrast, in nonconfirmed hypertensive patients benazepril significantly decreased casual diastolic pressure (mean decrease, 10.0 mm Hg) but did not substantially modify 24-hour ambulatory diastolic pressure (mean decrease, 1.3 mm Hg;P<.001). At the end of antihypertensive therapy the number of patients with diastolic pressure equal to, above, or below 90 mm Hg was remarkably different when assessed by casual versus 24-hour ambulatory determinations (κ, 0.348; 95% confidence interval, −0.020 to 0.716;P>.1). The results indicate that whole-day ambulatory blood pressure monitoring identifies a substantial number of type II diabetic patients with nonconfirmed hypertension. In these patients the discrepancy in diastolic pressure reduction between casual and 24-hour ambulatory monitoring suggests that the method of blood pressure assessment is important when evaluating antihypertensive drug efficacy.