Diabetes mellitis: risk factor for advanced liver disease

The study by Porepa and colleagues confirms something most hepatologists have always known: diabetes mellitus is a risk factor for advanced liver disease.1 I congratulate the authors for taking on this methodologically difficult task, but they missed a few opportunities for addtional knowledge translation.

Hemochromatosis, a genetic disease of iron overload that, if not recognized, leads to diabetes and cirrhosis, should have been in the exclusion and censoring criteria. After all, the prevalence of hemochromatosis may be as high as 5/1000 people of northern European descent.2

In addition, hepatocellular carcinoma, a known complication of cirrhosis, should have been included in the list of serious liver disease outcomes as a surrogate marker for cirrhosis because ICD (International Classification of Diseases) coding of liver disease and its complications is not always comprehensive.3 Some patients with primary liver cancer would have been included in the analysis because either cirrhosis was mentioned in the discharge abstract database or the patient underwent liver transplantation for hepatocellular carcinoma.

Obesity, diabetes and metabolic syndrome are risk factors for nonalcoholic fatty liver disease and advanced fibrosis (metabolic syndrome confers an odds ratio of 3.5 for advanced fibrosis).4 In addtion to the risk of serious liver disease in patients with diabetes alone, hypertension alone, dyslipidemia alone and obesity alone, it would have been helpful to identify, from this large population database, the additional cumulative risk for serious liver disease in patients with metabolic syndrome.