LIVER FAT IS INCREASED IN TYPE 2 DIABETIC PATIENTS AND UNDERESTIMATED BY SERUM ALT COMPARED TO EQUALLY OBESE NON-DIABETIC SUBJECTS

Abstract

Objective: To determine whether type 2 diabetic patients have more liver fat than age-, gender-, and BMI matched non-diabetic subjects, and whether liver enzymes (S-ALT, S-AST) are similarly related to liver fat in type 2 diabetic and normal subjects.

Methods: 70 type 2 diabetic patients and 70 non-diabetic subjects matched for BMI, age and gender were studied. Liver fat (¹H-MRS), body composition (MRI), and biochemical markers of insulin resistance were measured.

Results. The type 2 diabetic patients had on the average 80% more liver fat and 16% more intra-abdominal fat than the non-diabetic subjects. The difference in liver fat between the two groups remained statistically significant when adjusted for intra-abdominal fat (p<0.05). At any given BMI or waist circumference, the type 2 diabetic patients had more liver fat than the non-diabetic subjects. The difference in liver fat between the groups rose as a function of BMI and waist circumference. FS-insulin (r=0.55, p<0.0001), fP-glucose (r=0.29, p=0.0006), HbA_1c (r=0.34, p<0.0001), fS-triglycerides (r=0.36, p<0.0001), and fS-HDL cholesterol (r=-0.31, p=0.0002) correlated with liver fat similarly in both groups. The slopes of the relationships between S-ALT and liver fat were significantly different (p=0.004). Liver fat content did not differ between the groups at low S-ALT concentrations (10-20 U/l), but was 70-200% higher in type 2 diabetic patients as compared to controls at S-ALT concentrations of 50-200 U/l.

Conclusions: Type 2 diabetic patients have 80% more liver fat than age-, weight-, and gender- matched non-diabetic subjects. S-ALT underestimates liver fat in type 2 diabetic patients.