Sibutramine is safe and effective for weight loss in obese patients whose hypertension is well controlled with angiotensin-converting enzyme inhibitors
Sibutramine treatment in obesity results in significantly greater weight reduction compared with placebo, although weight loss with sibutramine may be accompanied by small but statistically significant mean increases in blood pressure (BP). This 52-week, placebo-controlled, double-blind, randomised study investigated the effects of sibutramine 20 mg once daily or placebo on body weight in 220 obese (body mass index (BMI) 27–40 kg/m2), hypertensive patients. At randomisation, hypertension was well controlled (⩽95 mm Hg diastolic blood pressure (DBP)) with an angiotensin-converting enzyme (ACE) inhibitor, with or without concomitant thiazide diuretic therapy. Therapy for hypertension continued for the 52 weeks of the study. Sibutramine 20 mg produced significantly greater weight loss compared with placebo: 4.5 kg with sibutramine compared with 0.4 kg with placebo (last observation carried forward (LOCF); P ⩽ 0.05). A total of 62 patients (42.8%) treated with sibutramine lost ⩾5% of their body weight compared with six patients (8.3%) treated with placebo; 19 patients (13.1%) treated with sibutramine lost ⩾10% of their body weight compared with two patients (2.8%) treated with placebo (LOCF; P⩽ 0.05 for both comparisons). Hypertension remained well controlled for the 52 weeks of the study with both sibutramine and placebo treatment. After 52 weeks, the differences between placebo treatment and sibutramine treatment for both mean supine systolic blood pressure (SBP) and DBP were approximately 3 mm Hg: mean DBP was 82.8 mm Hg with placebo treatment compared with 85.5 mm Hg with sibutramine treatment (LOCF; P = 0.004) and mean SBP was 130.4 mm Hg with placebo compared with 133.1 mm Hg with sibutramine (LOCF; P = 0.0497; both comparisons, sibutramine vs placebo). The mean increases in SBP and DBP did not appear to change the overall risk category for coronary heart disease end points. Changes in pulse rate at week 52 were a decrease of 0.3 beats per minute (bpm) for placebo treatment compared with an increase of 5.7 bpm for sibutramine treatment (P < 0.001). Mandated withdrawals from the study due to protocol-defined changes in BP were not statistically different between the two treatment groups. Greater favourable changes in lipid profile, serum glucose, and uric acid could be accounted for by greater weight losses occurring in the sibutramine treatment group. Sibutramine was well tolerated. This study indicates that in obese patients whose hypertension is well controlled at the outset with an ACE inhibitor, with or without concomitant thiazide diuretic therapy, sibutramine safely and effectively achieves weight loss without compromising good BP control.