Long-term effects of glimepiride or rosiglitazone in combination with metformin on blood pressure control in type 2 diabetic patients affected by the metabolic syndrome: a 12-month, double-blind, randomized clinical trial.

BACKGROUND: Some evidence suggests that antihyperglycemic drugs might have a small but clinically significant beneficial effect on blood pressure in patients with diabetes mellitus. Based on a literature search, few direct comparisons of different antihyperglycemic treatments on blood pressure have been reported. OBJECTIVES: The primary aim of the present study was to compare the effect of long-term (12-month) combination treatment with glimepiride or rosiglitazone plus metformin on blood pressure in patients with type 2 diabetes mellitus (DM-2) and the metabolic syndrome. Secondary end points were glycemic control and improvement in insulin sensitivity. METHODS: This randomized, double-blind study was conducted at 2 centers in Italy. Patients aged > or =18 years with DM-2 and the metabolic syndrome and poor glycemic control (insulin resistance) with monotherapy with the maximum tolerated dose of an antihyperglycemic agent (eg, a sulfonylurea, metformin) were enrolled. All patients received 12 months of oral treatment with metformin 500 mg TID plus glimepiride 2 mg QD (G + M) or rosiglitazone 4 mg QD (R + M). Blood pressure, heart rate (HR), and body mass index (BMI); plasma levels of fasting and postprandial glucose and insulin (FPG, PPG, FPI, and PPI, respectively) and glycosylated hemoglobin (HbA(1c)); and homeostasis model assessment (HOMA) index were determined at 0 (baseline), 3, 6, 9, and 12 months of treatment. Adverse effects (AEs) were assessed using spontaneous reporting, patient interview, and laboratory analysis. RESULTS: Ninety-nine patients were enrolled in the study; 95 completed it (48 men, 47 women; mean age, 54 years [range, 47-58 years]; G + M, 47 patients; R + M, 48 patients). Four patients did not complete the study due to noncompliance (2 patients in the R + M group), protocol violation (1 patient in the G + M group), and loss to follow-up (1 patient in the G + M group). Mean blood pressure values were not significantly improved in the G + M group at any time point, whereas these values were significantly improved at 12 months in the R + M group. Mean BMI, HbA(1c), FPG, and PPG were significantly decreased from baseline in both groups at 12 months (all, P < or = 0.05). Mean FPI, PPI, and HOMA index were significantly improved at 12 months only in the R + M group (all, P < or = 0.05 vs baseline); these changes were not found in the G + M group. No significant changes in HR were found. Headache and flatulence were reported in both groups (G + M, 2 patients each; R + M, 1 and 2 patients, respectively), but these AEs were mild and transient. In the R + M group, liver enzyme levels were increased to 1.5-fold the upper limit of normal in 3 patients, but were normalized by study end. CONCLUSIONS: In this study in patients with DM-2 and the metabolic syndrome, long-term (12-month) combination treatment with R + M, but not G + M, was associated with a significant improvement in blood pressure control. Improvements in glycemic control and insulin resistance-related parameters were found at 9 months with R + M, compared with 12 months with G + M. Both treatments were well tolerated.

Antithrombotic effects of rosiglitazone-metformin versus glimepiride-metformin combination therapy in patients with type 2 diabetes mellitus and metabolic syndrome.

STUDY OBJECTIVE: To evaluate the differential effect on coagulation and fibrinolysis parameters of combination therapy with glimepiride-metformin and with rosiglitazone-metformin beyond their effect on glucose metabolism in patients with type 2 diabetes and metabolic syndrome. DESIGN: Multicenter, double-blind, randomized, controlled trial. SETTING: Two university-affiliated medical centers in Italy. PATIENTS: Ninety-five patients with type 2 diabetes for at least 6 months without glycemic control by diet and oral hypoglycemic agents to their maximum tolerated dosage and who also had metabolic syndrome. INTERVENTION: All 95 patients received metformin 1500 mg/day. In a randomized manner, 47 patients received glimepiride 2 mg/day and 48 patients received rosiglitazone 4 mg/day. MEASUREMENTS AND MAIN RESULTS: Body mass index (BMI), glycemic control, and coagulation and fibrinolysis parameters were evaluated at 3, 6, 9, and 12 months of treatment. Compared with baseline values, significant decreases in BMI, fasting plasma glucose, postprandial plasma glucose, and hemoglobin A1c were observed at 12 months in both the glimepiride and rosiglitazone groups (p<0.05 and p<0.01, respectively). Decreases in fasting plasma insulin and postprandial plasma insulin were observed at 12 months (p<0.05 and p<0.01, respectively) compared with baseline values in the rosiglitazone group. Furthermore, improvement in the Homeostasis Model Assessment index was observed only at 9 and 12 months (p<0.05 and p<0.01, respectively) compared with baseline in the rosiglitazone group. Significant improvement in plasminogen activator inhibitor (PAI)-1 was present in the rosiglitazone group after 9 months (p<0.05), and significant PAI-1 improvement was observed in the glimepiride and rosiglitazone groups after 12 months (p<0.05 and p<0.01, respectively). CONCLUSIONS: The rosiglitazone-metformin combination significantly improved the long-term control of all insulin resistance-related parameters compared with the glimepiride-metformin combination. However, both combinations were associated with a slight but statistically significant improvement in PAI-1 value, related to a similar reduction in insulin resistance.

Thiazolidinedione effects on blood pressure in diabetic patients with metabolic syndrome treated with glimepiride.

The aim of our study was to compare the long-term effect of pioglitazone and rosiglitazone on blood pressure control of diabetic patients with metabolic syndrome treated with glimepiride. We evaluated 91 type 2 diabetic patients with metabolic syndrome. All were required to have been diagnosed as diabetic for at least 6 months, and to have failed to achieve glycemic control by dietary changes and the maximum tolerated dose of the oral hypoglycemic agents sulfonylureas or metformin. All patients took a fixed dose of 4 mg/day glimepiride. We administered pioglitazone (15 mg/day) or rosiglitazone (4 mg/day) for 12 months in a randomized, double-blind fashion, and evaluated body mass index (BMI), glycemic control, blood pressure and heart rate (HR) throughout the treatment period. A total of 87 patients completed the study and were randomized to receive double-blind treatment with pioglitazone or rosiglitazone. An increase in BMI was observed after 12 months (p < 0.05) in both groups. After 9 and 12 months, there were significant decreases in glycated hemoglobin (HbA(1c)), mean fasting plasma glucose (FPG), postprandial plasma glucose (PPG), fasting plasma insulin (FPI), and postprandial plasma insulin (PPI) in both treatment groups (p < 0.05 at 9 months and p < 0.01 at 12 months for all parameters). Furthermore, homeostasis model assessment index (HOMA index) improvement was obtained at 9 and 12 months (p < 0.05 and p < 0.01, respectively) in both groups. Significant systolic blood pressure (SBP) and diastolic blood pressure (DBP) improvement (p < 0.05, respectively) was observed in both groups after 12 months. There were no significant changes in transaminases at any point during the study. We can conclude that the association of a thiazolinedione to the glimepiride treatment of type 2 diabetic subjects with metabolic syndrome is associated to a significant improvement in the long-term blood pressure control, related to a reduction in insulin-resistance.