Efficacy and Safety of Curcumin Supplement on Improvement of Insulin Resistance in People with Type 2 Diabetes Mellitus: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
Tianqing Zhang, Qi He, Yao Liu, Zhenrong Chen, Heng-Jing Hu
Abstract
Background. Diabetes is a major public health concern. In addition, there is some evidence to support curcumin as part of a diabetes treatment program. Methods. Data from randomized controlled trials were obtained to assess the effects of curcumin versus placebo or western medicine in patients with type 2 diabetes mellitus (T2DM). The study’s registration number is CRD42018089528. The primary outcomes included homeostasis model assessment-insulin resistance (HOMA-IR), glycosylated hemoglobin (HbAlc), total cholesterol (TC), and triglyceride (TG). Results. Four trials involving 453 patients were included. The HOMA-IR of curcumin group is lower in Asia (WMD: −2.41, 95% CI: −4.44 to −0.39, <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" id="M1"> <a:mi>P</a:mi> <a:mo>=</a:mo> <a:mn>0.02</a:mn> </a:math> ) and the Middle East subgroups (WMD: −0.60, 95% CI: −0.74 to −0.46, <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" id="M2"> <c:mi>P</c:mi> <c:mo><</c:mo> <c:mn>0.00001</c:mn> </c:math> ). The HbAlc in the curcumin group is lower than that in the control group (WMD: −0.69; 95% CI: −0.91, −0.48; <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" id="M3"> <e:mi>P</e:mi> <e:mo><</e:mo> <e:mn>0.0001</e:mn> </e:math> ). The TC and TG levels of the curcumin group are lower in the Asia subgroup (TC: WMD: −23.45, 95% CI: −40.04 to −6.84, <g:math xmlns:g="http://www.w3.org/1998/Math/MathML" id="M4"> <g:mi>P</g:mi> <g:mo>=</g:mo> <g:mn>0.006</g:mn> </g:math> ; TG: WMD: −54.14, 95% CI: −95.71 to −12.57, <i:math xmlns:i="http://www.w3.org/1998/Math/MathML" id="M5"> <i:mi>P</i:mi> <i:mo>=</i:mo> <i:mn>0.01</i:mn> </i:math> ), while in the Middle East the difference was of not statistically significant (TC: WMD: 22.91, 95% CI: −16.94 to 62.75, <k:math xmlns:k="http://www.w3.org/1998/Math/MathML" id="M6"> <k:mi>P</k:mi> <k:mo>=</k:mo> <k:mn>0.26</k:mn> </k:math> ; TG: WMD: −4.56, 95% CI: −19.28 to 10.16, <m:math xmlns:m="http://www.w3.org/1998/Math/MathML" id="M7"> <m:mi>P</m:mi> <m:mo>=</m:mo> <m:mn>0.54</m:mn> </m:math> ). Conclusion. Based on the current evidence, curcumin may assist in improving the insulin resistance, glycemic control, and decreased TG and TC in patients with T2DM.