Effect of rimonabant on blood pressure in overweight/obese patients with/without co-morbidities: analysis of pooled RIO study results

OBJECTIVE: Rimonabant, the first selective cannabinoid type 1 (CB1) receptor blocker, has been shown to improve multiple cardiometabolic risk factors in overweight/obese patients. This analysis assessed the impact of rimonabant on blood pressure in the pooled population from four large trials with similar design - the Rimonabant-In-Obesity (RIO) programme. METHODS: RIO-Europe (n = 1507) and RIO-North America (n = 3040) recruited overweight/obese patients, and RIO-Lipids (n = 1033) and RIO-Diabetes (n = 1045) recruited overweight/obese patients with untreated dyslipidaemia or type 2 diabetes, respectively. At study entry (screening), 37.2% (n = 2463) of patients had hypertension, 71.4% (n = 1757) of whom were taking an antihypertensive treatment. RESULTS: After 1 year of treatment, mean change in systolic blood pressure (SBP) from baseline was -0.8 mmHg for rimonabant 20 mg versus +0.3 mmHg for placebo (P = 0.007); diastolic blood pressure (DBP) decreased by -0.8 versus -0.3 mmHg (P = 0.029) respectively. In the subgroup of patients with high blood pressure at baseline, SBP change was -7.5 mmHg for rimonabant 20 mg versus -4.7 mmHg for placebo (P = 0.005); DBP change was -5.2 versus -3.0 mmHg (P < 0.001). Reductions were more pronounced in patients with dyslipidaemia and type 2 diabetes. There was no effect of rimonabant 20 mg on blood pressure beyond that expected from weight loss alone. Overall, there was a similar incidence of adverse events (AEs) at 1 year in the placebo (81.8%) and rimonabant 20 mg (86.0%). The most common AEs occurring with rimonabant were nausea, dizziness, arthralgia and diarrhoea. A slightly higher proportion of patients in the rimonabant 20 mg group discontinued as a result of AEs (13.8%) versus placebo (7.2%). CONCLUSIONS: Rimonabant 20 mg led to modest, but significant SBP and DBP reductions in overweight/obese patients. The effect of rimonabant on blood pressure appears to be mediated by weight loss.