Black/African American patients with type 2 diabetes mellitus: study design and baseline patient characteristics from a randomized clinical trial of linagliptin

Objective: In the United States, black/African American individuals are more likely than whites to develop type 2 diabetes mellitus (T2DM), and have higher rates of complications, but are under-represented in clinical trials. The design of a trial comparing the efficacy and safety of the dipeptidyl peptidase-4 (DPP-4) inhibitor linagliptin 5 mg/day with placebo in this patient group, and the characteristics of the patients enrolled are reported. Research design and methods: This United States, multicenter, 24-week, randomized, double-blind study enrolled adults with T2DM who self-reported their race as black or African American, were receiving ≤ 1 oral antidiabetes drug, had a body mass index ≤ 45 kg/m2 and glycosylated hemoglobin (HbA1c) of 7.5 – 11% at screening. Main outcome measures: The primary efficacy endpoint is the change of HbA1c from baseline to week 24. Baseline data: A total of 226 patients were randomized and received ≥ 1 study drug dose. The mean age was 54 years (standard deviation: 9.9 years), and 54% were men. The mean HbA1c was 8.75% (standard deviation: 1.10%). Approximately half the patients (52%) had mild or moderate renal impairment and the majority (72%) had hypertension. Conclusions: To the authors' knowledge, this is the first trial of any oral antidiabetes drug specifically conducted in black/African American patients.