Effects of Basal Insulin on Lipid Profile Compared to Other Classes of Antihyperglycemic Agents in Type 2 Diabetic Patients

Objective: The lipid profile represents a driver of cardiovascular risk in type 2 diabetes. The effect of chronic insulin therapy on cholesterol levels is unclear. We aim to evaluate the effect of basal insulin on lipid profile compared to other classes of antihyperglycemic agents in type 2 diabetic patients. Design: We performed a meta-analysis of randomized controlled trials reporting changes of lipid parameters in type 2 diabetic patients randomly assigned to basal insulin or other classes of anti-hyperglycemic agents. Results: The levels of total (TC) and low-density lipoprotein cholesterol (LDL-C) appeared to be significantly reduced by therapies with glucagon-like peptide-1 receptor agonists (GLP-1RA) in comparison to basal insulin (mean difference [MD] -3.80; 95% CI [-6.30 to -1.30] mg/dL, P < .001 and -4.17; 95% CI [-6.04 to -2.30] mg/dL, P < .0001), whereas no difference was detected between basal insulin and dipeptidyl peptidase-4 inhibitors (DPP4-I) or standard therapy (sulfonylurea +/- metformin). Thiazolidinediones (TZD) produced a significant improvement in high-density lipoprotein cholesterol (HDL-C) (MD 3.55; 95% CI: 0.55 to 6.56 mg/dL, P = .02) but were associated with an increase in TC and LDL-C (MD 16.20; 95% CI: 9.09 to 23.31 mg/dL, P < .001 and 5.19: 95% CI: -3.00 to 13.39 mg/dL, P = .21). Basal insulin was superior to standard therapy in triglyceride reduction (MD 3.8; 95% CI: 0.99 to 6.63 mg/dL, P = .008). Conclusions: GLP-1RA were superior to basal insulin in the control of TC and LDL-C. Basal insulin effectively reduced serum triglycerides. TZD led to improvement in HDL-C. DPP4-I and standard therapy did not have any significant effect on lipid levels.