ObjectiveTo compare the effects of rilmenidine with those of amlodipine on blood pressure, glucose metabolism, plasma lipid concentration and fibrinolysis parameters.DesignA four-month randomized double-blind, parallel group study.Patients and methodsObese hypertensive patients with hypertriglyceridaemia (≥ 2.3 mmol/l) and impaired glucose tolerance (OMS-ADA) were included (n = 52). A placebo run-in period of 2 weeks was followed by 4 months of double-blind treatment with either rilmenidine or amlodipine. Blood pressure was recorded using a mercury sphygmomanometer. Glucose metabolism was evaluated by an oral glucose tolerance test.ResultsOf the 52 patients recruited, 47 (21 rilmenidine and 26 amlodipine) completed the 4-month treatment period. The intention-to-treat analysis showed a comparable reduction in systolic and diastolic blood pressure (SBP, DBP) with the two anti-hypertensive treatments (rilmenidine –13.9/–13.5 mmHg; amlodipine —17.6/–15.0 mmHg). Insulin concentrations under basal conditions and 2 h after a standard oral glucose load did not change significantly after treatment in both groups. Plasma glucose under basal conditions and 2 h after a standard oral glucose load as well as the area under the plasma glucose concentration curve tended to decrease in the rilmenidine group and to increase in the amlodipine group so that the changes in these parameters were significantly different between the two study groups (P= 0.041,P= 0.042 andP= 0.015, respectively). Plasminogen activator inhibitor type 1 (PAI-1) antigen and PAI-1 activity were only decreased in the rilmenidine group (not statistically significant).ConclusionOur results demonstrate that rilmenidine and amlodipine have a comparable anti-hypertensive effect but only rilmenidine is able to improve glucose metabolism.