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 ( CB(1)) 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 -0.8mmHg for rimonabant 20mg versus +0.3mmHg for placebo ( P=0.007); diastolic blood pressure ( DBP) decreased by -0.8 versus -0.3mmHg ( P=0.029) respectively. In the subgroup of patients with high blood pressure at baseline, SBP change was -7.5mmHg for rimonabant 20mg versus -4.7mmHg for placebo ( P=0.005); DBP change was -5.2 versus -3.0mmHg ( P< 0.001). Reductions were more pronounced in patients with dyslipidaemia and type 2 diabetes. There was no effect of rimonabant 20mg 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 20mg ( 86.0%). The most common AEs occurring with rimonabant were nausea, dizziness, arthralgia and diarrhoea. A slightly higher proportion of patients in the rimonabant 20mg group discontinued as a result of AEs ( 13.8%) versus placebo ( 7.2%). Conclusions Rimonabant 20mg 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.