Metformin monotherapy significantly decreases epicardial adipose tissue thickness in newly diagnosed type 2 diabetes patients

INTRODUCTION: Imbalance between pro- and anti-inflammatory cytokines secreted from visceral adipose tissue (VAT) contributes to the pathogenesis of certain cardiovascular and metabolic disorders, including insulin resistance. Epicardial adipose tissue (EAT) is a form of VAT mainly concentrated along the coronary arteries. It has been shown in various studies that EAT thickness is positively correlated with cardiovascular disease. Due to its high worldwide prevalence, prevention and management of type 2 diabetes (T2D) has become a major public health challenge. Metformin, the most widely prescribed drug to treat T2D, has favorable effects on VAT and body weight. As metformin decreases VAT mass, in this prospective study we analyzed the possible positive effect of metformin on EAT mass, which is organ-specific VAT, and body mass index (BMI). METHODS: Subjects were selected from patients admitted to the internal medicine outpatient clinic. Newly diagnosed T2D patients treated with metformin monotherapy were analyzed and 40 patients were included. EAT thickness in the included patients was measured echocardiographically. BMI and EAT thickness were analyzed at the beginning (BMI0 and EAT0) and after three months of metformin monotherapy (BMI3 and EAT3). RESULTS: There was a statistically significant decrease in EAT thickness after three months of metformin monotherapy (EAT0=5.07±1.33 mm vs. EAT3=4.76±1.32 mm; p<0.001). Furthermore, BMI was also significantly decreased (BMI0=28.27±2.71 vs. BMI3=27.29±2.10; p<0.0001). CONCLUSIONS: In this study we show that metformin monotherapy significantly decreases EAT thickness and BMI in T2D patients. This suggests that metformin could reduce the frequency of coronary atherosclerosis.