Effects of sitagliptin on serum lipid levels in patients with type 2 diabetes: a systematic review and meta-analysis

Aim Lipid abnormalities often occur in patients with diabetes mellitus and the coexistence of diabetes mellitus and dyslipidaemia will increase the risk of cardiovascular diseases. However, the specific effects of sitagliptin on lipid control remain elusive in diabetic patients. The aim of this meta-analysis is to investigate the effects of sitagliptin alone or with other antidiabetic agents on serum lipid control. Methods PubMed, Cochrane Library, Embase and the ClinicalTrials.gov website were systematically searched from 2006 (the first year that sitagliptin entered market) to 16 January 2021. Eligible studies were randomized clinical trials (RCTs) of sitagliptin including outcomes of serum total cholesterol (TC), triglycerides, high-density lipoprotein cholesterol (HDL-C) or low-density lipoprotein cholesterol (LDL-C). Results A total of 14 RCTs with 2654 patients were identified. Treatment with sitagliptin alone or in combination with other antidiabetic agents significantly reduced serum TC [mean difference (MD) = -5.52 95% confidence interval (95% CI), -7.88 to -3.15; P < 0.00001] and LDL-C (MD = -0.07; 95% CI, -0.14 to 0.00; P < 0.00001) in patients with type 2 diabetes. No statistical significances were found in serum triglycerides (MD = 1.53; 95% CI, -8.22 to 11.28; P = 0.76) or HDL-C (MD = 0.65; 95% CI, -1.59 to 0.29; P = 0.18). Subgroup analyses suggest that sitagliptin can significantly decrease serum LDL-C, TC and triglyceride levels compared with placebo alone, and no statistical significance was found in comparison with the serum HDLC levels. Conclusion Sitagliptin alone or in combination with other antidiabetic agents significantly reduces serum TC and LDL-C in patients with type 2 diabetes mellitus, while no significant difference was observed in serum triglycerides or HDL-C.