We read with great interest the recent article by Targher et al. (1) reporting the prevalence of nonalcoholic fatty liver disease (NAFLD) and associated cardiovascular disease (CVD) risk factors in patients with type 2 diabetes.
Proper identification of patients with NAFLD is of major importance for adequate treatment and reduction of CVD risk in type 2 diabetic patients. However, routine ultrasound examination of the abdomen for the screening of hepatic steatosis in combination with serologic tests for hepatitis infection in patients with type 2 diabetes may not be feasible in common practice in most countries; it is certainly not performed on a routine basis, even in university hospitals, in the Netherlands.
Furthermore, the authors comment on the use of alanine aminotransferase (ALT) as a marker of NAFLD and confirm previous studies demonstrating the limited use of this marker in clinical practice (2,3). However, even mild elevations of ALT or other liver enzymes, in combination with clinical characteristics including a waist circumference and fasting triglyceride levels suggestive of the metabolic syndrome, may prompt the clinician to initiate further diagnostic work-up for the presence of NAFLD in patients with type 2 diabetes. In addition, they cite a very interesting cross-sectional study by Ioannou et al. (4), who demonstrated that elevated ALT is associated with an increased CVD risk as calculated by the Framingham Risk Score. Because of low specificity and sensitivity, ALT is of limited use in clinical practice. Still, it might provide more insight in the mechanisms that link NAFLD to CVD. We have recently extended the cross-sectional data by Ioannou et al. (4) and demonstrated in the population-based Hoorn Study that ALT levels in the high range of the normal distribution are associated with an increased 10-year risk of coronary heart disease in elderly individuals. This association was independent of classical CVD risk factors and components of the Adult Treatment Panel III–defined metabolic syndrome (5), indicating that ALT may be a useful marker in the assessment of CVD risk in patients who may have NAFLD.
Despite the diagnostic difficulties of NAFLD in clinical practice, the increased CVD risk in type 2 diabetic patients with NAFLD necessitates the design and implementation of optimal treatment strategies. However, consensus on the optimal treatment does not yet exist.
