Effects of Urtica dioica on Metabolic Profiles in Type 2 Diabetes: A Systematic Review and Meta-analysis of Clinical Trials.

Abstract

Several studies have investigated the effect of Urtica dioica (UD) consumption on metabolic profiles in patients with type 2 diabetes mellitus (T2DM); however, the findings are inconsistent. This systematic review and meta-analysis of clinical trials were performed to summarize the evidence of the effects of UD consumption on metabolic profiles in patients with T2DM. Eligible studies were retrieved from searches of PubMed, Embase, Scopus, Web of Science, Cochrane Library, and Google Scholar databases until December 2019. Cochran (Q) and I-square statistics were used to examine heterogeneity across included clinical trials. Data were pooled using a fixed-effect or random-effects model and expressed as weighted mean difference (WMD) and 95% confidence interval (CI). Among 1485 citations, thirteen clinical trials were found to be eligible for the current metaanalysis. UD consumption significantly decreased levels of fasting blood glucose (FBG) (WMD = - 17.17 mg/dl, 95% CI: -26.60, -7.73, I2 = 93.2%), hemoglobin A1c (HbA1c) (WMD = -0.93, 95% CI: - 1.66, -0.17, I2 = 75.0%), C-reactive protein (CRP) (WMD = -1.09 mg/dl, 95% CI: -1.64, -0.53, I2 = 0.0%), triglycerides (WMD = -26.94 mg/dl, 95 % CI = [-52.07, -1.82], P = 0.03, I2 = 90.0%), systolic blood pressure (SBP) (WMD = -5.03 mmHg, 95% CI = -8.15, -1.91, I2 = 0.0%) in comparison to the control groups. UD consumption did not significantly change serum levels of insulin (WMD = 1.07 μU/ml, 95% CI: -1.59, 3.73, I2 = 63.5%), total-cholesterol (WMD = -6.39 mg/dl, 95% CI: -13.84, 1.05, I2 = 0.0%), LDL-cholesterol (LDL-C) (WMD = -1.30 mg/dl, 95% CI: -9.95, 7.35, I2 = 66.1%), HDL-cholesterol (HDL-C) (WMD = 6.95 mg/dl, 95% CI: -0.14, 14.03, I2 = 95.4%), body max index (BMI) (WMD = -0.16 kg/m2, 95% CI: -1.77, 1.44, I2 = 0.0%), and diastolic blood pressure (DBP) (WMD = -1.35 mmHg, 95% CI: -2.86, 0.17, I2= 0.0%) among patients with T2DM. UD consumption may result in an improvement in levels of FBS, HbA1c, CRP, triglycerides, and SBP, but did not affect levels of insulin, total-, LDL-, and HDL-cholesterol, BMI, and DBP in patients with T2DM.