Effect of Linagliptin on Glycemic Control in Chinese Patients with Newly-Diagnosed, Drug- Naïve Type 2 Diabetes Mellitus: A Randomized Controlled Trial

Background: This study aimed to evaluate the efficacy and safety of linagliptin (a novel dipeptidyl peptidase (DPP)-4 inhib-itor) on glucose metabolism and b-cell function in Chinese patients with newly-diagnosed, drug-naïve type 2 diabetes mellitus (T2DM). Material/Methods: Newly-diagnosed and drug-naïve T2DM patients were enrolled. After 4-week lifestyle modulation and 2-week placebo run-in, 57 patients were randomized to double-blind treatment with linagliptin (n=34) or placebo (n=23). The primary endpoint was the change from baseline in glycosylated hemoglobin A1c (HbA1c) after 24 weeks. Fasting plasma glucose (FPG), 2-h postprandial plasma glucose (2h-PPG), fasting insulin, proinsulin-to-insulin ratio, homeostasis model assessment of insulin resistance (HOMA-IR), and homeostasis model assessment of b-cell function (HOMA-b) were also evaluated. Results: Baseline characteristics were similar between the 2 groups. Compared with placebo, linagliptin therapy re-sulted in a significant decrease in HbA1C (–1.2±0.7 % vs. –0.4±0.4%, P<0.001), FBG (–0.98±1.17 vs. –0.32±0.51 mmol/L, P=0.011, and 2h-PPG (–2.02±0.94 vs. –0.97±0.63 mmol/L, P<0.001). Significant differences were ob-served for the proinsulin/insulin ratio (P<0.001) and HOMA-b index (P=0.001). Rates of adverse events were similar between the 2 groups (30.3 % vs. 27.3%). All adverse events were mild. One patient discontinued par-ticipation due to pregnancy