Effects of pioglitazone therapy on blood parameters, weight and BMI: a meta-analysis

Type 2 diabetes mellitus (T2DM) is one of the most common diseases worldwide and insulin insufficiency and insulin resistance are two main metabolic issues connected with it. The dyslipidemia associated with insulin resistance and T2DM is characterized by higher triglycerides (TGs), higher very-low-density lipoprotein cholesterol and lower apo A1. Pioglitazone, a member of the thiazolidinedione class, with a proven antihyperglycemic effect, is known to positively influence insulin sensitivity and β-cell function and to have the potential to alter the lipid profile.

The aim of our meta-analysis is to summarize and determine the influence of pioglitazone on the glycemic profile and lipoprotein metabolism as well as on weight and BMI in order to highlight the benefit of pioglitazone therapy in patients with T2DM. A comprehensive literature search was conducted through the electronic databases PubMed, MEDLINE, Scopus, PsyInfo, eLIBRARY.ru (from 2000 until February 2016) to identify studies that investigate the effect of pioglitazone on the glycemic and lipid profile and on the weight and BMI. We chose the random-effects method as the primary analysis. Forest plots depict estimated results from the studies included in the analysis and funnel plots are used to evaluate publication bias. Sensitivity analyses were performed in order to evaluate the degree of influence of the consequent elimination of each individual study on the final result.

Of the 1536 identified sources only 15 randomised trials were included in the meta-analysis. Pioglitazone treatment was associated with improvement in the glycemic profile. It reduced FPG levels by a mean of 1.1-2 mmol/l and HbA1c by a mean of 0.9-1.3%. Our results reaffirmed the hypothesis that pioglitazone has a positive influence on the lipid profile of T2DM patients with increase in TC and HDL, no significant changes in LDL and notable decrease in TGs. Results also showed that pioglitazone therapy led to increase in both weight and BMI (WMD 1.755, 95% CI 0.674 to 2.837 and 1.145, 95% CI 0.389 to 1.901 respectively).

Our results prove that the PPAR γ agonist pioglitazone has the potential to be beneficial to patients with T2DM.