Clinical efficacy of Huanglian Wendan decoction in treating type 2 diabetes mellitus: A systematic review and meta-analysis

Background: Huanglian Wendan decoction (HLWDD) is a traditional Chinese prescription, which has been used to treat type 2 diabetes mellitus (T2DM) in recent years. However, no studies have evaluated its underlying clinical efficacy. Therefore, we used systematic review and meta-analysis to explore the clinical efficacy of HLWDD in treating T2DM. Methods: The randomized controlled trials of HLWDD on T2DM were retrieved from Chinese and foreign databases. The primary outcomes included fasting blood glucose (FBG), 2-hour postprandial blood glucose (2hPG), and glycosylated hemoglobin, type A1c (HbA1c). The secondary outcomes included fasting serum insulin, homeostasis model assessment of insulin resistance (HOMA-IR), total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-c), and high-density lipoprotein cholesterol (HDL-c). Statistical analyses were performed using Review Manager and Stata software. Mean difference (MD) with 95% confidence intervals (CI) were used to describe results. The grades of recommendation assessment, development and evaluation approach was used to rate the quality of the evidence; and trial sequential analysis was used to evaluate the required information size and treatment benefits. Results: Twenty-three randomized controlled trials were included in this study. We showed that HLWDD can improve FBG (MD = −0.99, 95% CI: −1.10 to −0.88), 2hPG (MD = −1.57, 95% CI: −1.97 to −1.17), HbA1c (MD = −1.11, 95% CI: −1.42 to −0.80), HOMA-IR (MD = −0.80, 95% CI: −1.80 to −0.51), TC (MD = −0.65, 95% CI: −0.88 to −0.42), TG (MD = −0.32, 95% CI: −0.38 to −0.27), LDL-c (MD = −0.54, 95% CI: −0.66 to −0.41), and HDL-c (MD = 0.08, 95% CI: 0.02–0.15) levels in T2DM patients. Trial sequential analysis suggested that the eficacy of HLWDD in improving FBG, 2hPG, HbA1c, HOMA-IR, TC, TG, LDL-c, and HDL-c was sufficient to draw a firm conclusion. Grades of recommendation assessment showed that HLWDD only has high or moderate quality of evidence in improving FBG, and TG. Conclusion: HLWDD can improve blood glucose and blood lipid levels in T2DM patients, and may be a potential drug to treat T2DM.