Sitagliptin added to previously taken antidiabetic agents on insulin resistance and lipid profile: a 2-year study evaluation

The aim of this study was to evaluate whether the positive effects of sitagliptin on glycemic control and insulin resistance were maintained also after 2years of therapy and whether sitagliptin could be effective also in improving lipid profile. In this randomized, double-blind, placebo-controlled trial, 205 patients with type 2 diabetes in therapy with different antidiabetic drugs were randomized to add sitagliptin 100mg once a day or placebo to their current therapy. We evaluated at the baseline and after 6, 12, 18, and 24months the following parameters: body mass index, glycated hemoglobin (HbA(1c)), fasting plasma glucose (FPG), postprandial plasma glucose (PPG), fasting plasma insulin (FPI), homeostasis model assessment insulin resistance index (HOMA-IR), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (Tg). Sitagliptin, added to previously taken antidiabetic agents, proved to be effective in improving glycemic profile, reducing HbA(1c) by -17.5%, FPG by -12.7%, PPG by -20.5%. Regarding insulin resistance, sitagliptin decreased FPI by -8.3% and HOMA-IR by -20.0%, confirming that what have been already reported in short-term studies can be applied also after 2years of treatment. Sitagliptin also reduced body weight by -4.3%. Our study also showed the positive effect of sitagliptin on lipid profile; in particular, sitagliptin decreased TC by -13.3%, LDL-C by -20.4%, and Tg by -32.3%, and also increased HDL-C by+13.6%. Sitagliptin proved to be effective on glycemic profile and insulin resistance even after 2years of therapy and to be effective in improving body weight and lipid profile.