Antihypertensive effect of irbesartan and predictors of response in obesity-associated hypertension : a prospective, open-label study.

BACKGROUND

Obesity-associated hypertension is difficult to treat and puts patients at a substantially increased risk of cardiovascular events. Irbesartan has previously been shown to effectively lower blood pressure (BP) in high-risk groups including patients with type 2 diabetes mellitus or nephropathy, and may therefore also be suitable for the treatment of obesity-associated hypertension. In this study we aimed to: (a) assess the efficacy and tolerability of irbesartan alone and in combination with hydrochlorothiazide in patients with obesity-associated mild-to-moderate hypertension; and (b) investigate patient-associated determinants of poor BP control in this patient group.

PATIENTS AND METHODS

This was a 3-month, prospective, open-label, multicentre, phase IV study in 72 479 hypertensive patients in 6989 general practices across Germany. Main outcome measures were BP reduction (primary parameter of effectiveness) and BP response rates after 3 months, as well as adverse events (AEs). Independent predictors of poor control were identified in a multivariate proportional odds model.

RESULTS

All of the patients were Caucasian, 50.5% were females, mean age was 62.1 +/- 11.1 years, mean bodyweight was 88.6 +/- 15.4kg, and mean body mass index (BMI) was 30.7 +/- 4.8 kg/m(2). Almost all the patients were overweight or obese (92.3%). From a baseline value of 162/94mm Hg, systolic and diastolic BP were reduced by a mean of -23/-12mm Hg after 3 months. 66.1% of the patients were responders (reduction of diastolic BP >/=10mm Hg), and 48.0% achieved BP normalisation (i.e. <140/90mm Hg). 79% of patients met their individual treatment goals as defined by the treating physician (mean 135/80mm Hg). AEs were reported in only 322 patients (0.4%). Factors requiring special attention in patients not achieving BP control were age (>55 years), high BMI category (>25 kg/m(2)), and increased waist circumference.

CONCLUSION

Treatment with irbesartan (+/- hydrochlorothiazide) appeared to be effective and well tolerated in the study population of patients with obesity- associated hypertension. Easily recognisable characteristics allow physicians to identify patients whose BP is likely to be difficult to control.