Background: Mexican Americans, the fastest growing ethnic group in the United States, have a 2- to 3-fold higher prevalence of type 2 diabetes mellitus relative to the non-Hispanic white population. It is estimated that 10% of Mexican Americans greater than or equal to20 years of age have diabetes. Objective: The goal of this study was to evaluate the efficacy and safety of glimepiride, a long-acting sulfonylurea, as an adjunct to diet/exercise in Mexican Americans with type 2 diabetes mellitus. Methods: This was a multicenter, randomized, double-blind, placebo-controlled study. Mexican Americans with uncontrolled type 2 diabetes, defined as a fasting plasma glucose (FPG) level between 120 mg/dL and 225 mg/dL and glycated hemoglobin (HbA(1c)) values between 8.0% and 10.5%, after greater than or equal to3 months of diet/exercise were enrolled. Patients were randomized in a 2:1 ratio (using the lowest available treatment assignment number when eligibility was established) to receive 14 weeks of glimepiride or matching placebo once daily with continued diet/exercise. The starting glimepiride dose was 1 mg, with titration to 2 mg and 4 mg for FPG levels >120 mg/dL. The primary efficacy variable was change in HbA(1c) from baseline to study end point. Secondary efficacy variables were HbA(1c) response (rated as excellent, good, or marginal) and changes in FPG, fasting insulin, fibrinogen, and plasminogen activator inhibitor-1 (PAI-1) levels from baseline to study end point. The tolerability of glimepiride in this study population was determined by evaluating adverse events, hypoglycemic episodes, and physical examination as well as laboratory findings. All analyses were performed on an intent-to-treat basis. A per-protocol analysis also was conducted to support the primary efficacy analysis. Results: Seventy patients were randomized to treatment with glimepiride (n = 48) or placebo (n = 22). The glimepiride and placebo groups were similar with respect to mean (SE) age (48.4 [11.7] and 50.7 [10.0] years, respectively) and sex (56.3% [27/48] and 50.0% [11/22] were male, respectively). However, the glimepiride group had a higher mean body weight (83.3 [17.0] vs 76.3 [18.5] kg) and a significantly higher mean fasting insulin level (23.8 [17.7] vs; 17.8 [19.7] muU/mL; P = 0.031). The mean (SE) HbA(1c) values at study end point were 7.8% (0.2%) and 9.9% (0.7%) in patients receiving glimepiride and placebo, respectively The adjusted mean difference in HbA(1c) reduction from baseline to end point was statistically significant in favor of glimepiride (-1.8% [0.4%]; P < 0.001). More pronounced HbA(1c) impairment at baseline was associated with greater glimepiride-placebo differences in HbA(1c) reduction. Glimepiride-treated patients also achieved a significantly greater improvement in FPG, with an adjusted mean (SE) treatment difference of -46.7 (16.7) mg/dL (P = 0.007). Glimepiride did not appear to affect fibrinogen and PAI-1 levels but was associated with significantly greater mean increases in fasting insulin (10.2 vs -2.1 muU/mL; P = 0.002) and body weight (2.3 vs 2.1 kg; P < 0.001) compared with placebo. Glimepiride was well tolerated, with an adverse-event profile similar to that of placebo. Conclusions: These results indicate that once-daily glimepiride plus diet/ exercise was effective in Mexican Americans with type 2 diabetes whose disease was inadequately controlled with diet/exercise alone. It appeared to be well tolerated in the population studied. More weight gain was seen with glimepiride compared with placebo. Given the high prevalence of type 2 diabetes among Mexican Americans, further clinical studies of glimepiride and other glucose-lowering therapies are needed in this ethnic subset. Copyright (C) 2003 Excerpta Medica, Inc.
