Abstract: Objective The aim of this study was to investigate the short-term impact of metformin and simvastatin combination therapy on blood glucose and lipid parameters in patients with nonalcoholic fatty liver disease (NAFLD) with concomitant diabetes mellitus type 2 (T2DM). Methods 168 patients with NAFLD and T2DM were encountered in our hospital between January 2018 and June 2020, and 75 patients were treated with metformin and another 93 patients received metformin and simvastatin combination therapy. The observation lasted for three months. Blood biochemical parameters, glycosylated hemoglobin (HbA1c) and fasting insulin (FINS) were detected, and the homeostasis model assessment of insulin resistance index (HOMA—IR) was calculated. Results There were no significant differences as respect to baseline materials such as age, gender, body mass index, serum FINS levels, concomitant hypertension, metabolic syndrome, or nonalcoholic steatohepatitis between the two groups(P>0.05); at the end of three month observation, the HOMA—IR in the combination group was 1.8(1.0, 2.7), significantly lower than [2.1(1.3, 3.5), P<0.05] in metformin-treated group, and there were no significant differences in blood HbA1c and FINS levels [(6.4(6.0,7.0)% vs.(6.5(6.2,7.5)%, and (5.5(2.2,7.6)μU/ml vs. (5.7(2.9,8.5))μU/ml,P>0.05] between the two groups; the blood triglyceride level in the combination group was 2.1(1.9,3.3)mmol/l, significantly lower than [(2.7(2.1, 3.5))mmol/l, P<0.05], and blood total cholesterol level was 4.3(3.7, 5.0)mmol/l, significantly lower than [5.4(5.0, 6.2)mmol/l, P<0.05], while blood high-density lipoprotein cholesterol level was 1.7(1.5,2.6)mmol/l, significantly higher than [1.4(1.0,1.7)mmol/l, P<0.05] in metformin-treated patients, and there were no significant differences respect to serum alanine aminotransferase levels [54(26, 62)U/L vs. 55(32, 65)U/L, P>0.05], serum aspartate aminotransferase levels [57(47, 72)U/L vs. 57(46, 64)U/L, P>0.05] and serum low-density Lipoprotein cholesterol levels [2.5(2.2, 3.3)mmol/l vs. 2.6(2.1, 3.4)mmol/l, P>0.05] between the two groups. Conclusion The combination of metformin and simvastatin in treatment of patients with NAFLD and T2DM could improve blood glucose and lipid metabolism, and what it impact on liver steatosis needs further investigation.

Key words: Nonalcoholic fatty liver disease, Diabetes mellitus type 2, Metformin, Simvastatin, Therapy