OBJECTIVETo compare and explore metabolic risk factors related to type 2 diabetes mellitus (T2DM) and the development of nonalcoholic fatty liver disease (NAFLD).

METHODSA total of 389 in-patients with T2DM (DM group, 204 cases) and T2DM with NAFLD (DM+NAFLD group, 185 cases) were enrolled in the study between October 2012 and July 2013. Clinical data collected for analysis included levels of blood lipids, liver function markers, uric acid (UA) and insulin, as well as results from the oral glucose tolerance test (OGTT) and C peptide releasing test. Improvements in insulin level, C peptide secretion index [HOMR-IR(CP)] and whole body insulin sensitivity index (ISIcomp) were used to estimate insulin sensitivity. Improvements in insulin level, C peptide secretion index [HOMR-islet(CP)], early insulin secretion index (delta I₃₀/delta G₃₀), correction of the islet beta cell function index (MBC1) and glucose disposition index (DI) were used to evaluate the function of pancreatic islet 1 beta cells. The t-test and repeated measures ANOVA were used for statistical analyses. Risk factors of T2DM with NAFLD were assessed by using logistic regression analysis.

RESULTSCompared with the DM group, the DM+NAFLD group had higher body mass index (BMI) and levels of triglycerides, alanine aminotransferase (ALT), aspartate aminotransferase, gamma glutamine transferase and UA (all P < 0.05), but lower age and level of high density lipoprotein cholesterol (both P < 0.05). Moreover, the DM+NAFLD group had higher postprandial blood glucose levels at 30 min (10.88 ± 2.87 mmol/L vs. 12.18 ± 2.79 mmol/L, t =-3.32), 60 min (14.65 ± 3.69 mmol/L vs. 15.99 ± 3.12 mmol/L, t =-3.46), 120 min (16.56 ± 5.11 mmol/L vs. 17.65 ± 4.29 mmol/L, t =-2.81) and 180 min (13.92 ± 5.10 mmol/L vs. 14.71 ± 4.91 mmol/L, t=-2.02) (all P < 0.05). The DM+NAFLD group had higher postprandial insulin levels at 60 min (28.62 ± 23.51 muIU/ml vs. 36.91 ± 33.47 aIU/ml, t =-3.46) and 120 min (36.36 ± 25.60 muIU/mL vs. 44.38 ± 34.95 muIU/mL, t =-3.35) (both P < 0.05). The DM+NAFLD group had higher postprandial C peptide levels at 30 min (2.74 ± 1.70 ng/mL vs. 4.30 ± 6.51 ng/ml, t =-4.97), 60 min (4.17+/-2.49 ng/ml vs. 5.19 ± 2.96 ng/ml, t =-3.29) and 120 min (6.08 ± 2.79 ng/ml vs. 6.76 ± 3.10 ng/ml, t =-2.19) (all P < 0.05). The DM+NAFLD group had higher HOMA-IR(CP) (1.505 ± 0.004 vs. 1.507 ± 0.005, t =-2.208, P less than 0.05), but lower ISIcomp (90.09+/-69.31 vs. 59.93 ± 24.52, t =5.608), MBCI (4.68 ± 4.31 vs. 3.83 ± 2.41, t =2.365) and DI (35.40 ± 71.83 vs. 15.37 ± 13.93, t =3.730) (all P < 0.05). Logistic analysis showed that BMI, ALT, postprandial level of C-peptide at 30 min, and UA were the major risk factors of T2DM with NAFLD (OR =1.208, 2.080, 1.041, and 1.005, respectively; all P < 0.05).

CONCLUSIONPatients with a propensity for developing nonalcoholic fatty liver disease may experience earlier open of type 2 diabetes. T2DM patients with NAFLD have more severe glucose metabolism disorders.