Newly Diagnosed Diabetes May Increase Risk for Liver Disease

From Medscape Medical News

Laurie Barclay, MD

June 21, 2010 — Adults with newly diagnosed diabetes are at increased risk for advanced liver disease, known as diabetic hepatopathy, according to the results of a population-based, matched, retrospective cohort study reported online June 21 in the Canadian Medical Association Journal.

"The negative impact of diabetes mellitus is well recognized, yet little is known about the effect of this disease on the liver, an organ susceptible to nonalcoholic fatty liver disease related to insulin resistance," write Liane Porepa, MD, from the University of Toronto in Ontario, Canada, and colleagues. "We evaluated whether adults with newly diagnosed diabetes were at increased risk of serious liver disease."

The investigators used administrative health databases for the province of Ontario from 1994 to 2006 to identify 438,069 adults with newly diagnosed diabetes. A comparison group of 2,059,708 individuals without known diabetes were matched 5:1 to exposed persons by birth year, sex, and local health region. Persons with preexisting liver or alcohol-related disease were excluded. The main study endpoint was incident serious liver disease, defined as cirrhosis, liver failure and its complications, or receipt of a liver transplant.

Among persons with newly diagnosed diabetes, the incidence rate of serious liver disease was 8.19 per 10,000 person-years vs 4.17 per 10,000 person-years among those without diabetes, yielding an unadjusted hazard ratio (HR) of 1.92 (95% confidence interval [CI], 1.83 - 2.01). After adjustment for age, income, urban residence, healthcare utilization, and preexisting comorbid conditions (hypertension, dyslipidemia, obesity, and cardiovascular disease), the HR was 1.77 (95% CI, 1.68 - 1.86).

"Adults with newly diagnosed diabetes appeared to be at higher risk of advanced liver disease, also known as diabetic hepatopathy," the study authors write. "Whether this reflects nonalcoholic fatty liver disease or direct glycemic injury of the liver remains to be determined."

Limitations of this study include possible misclassification of persons with diabetes, inability to distinguish between newly diagnosed type 1 and type 2 diabetes, and the possibility that diabetes developed as a complication of cirrhosis. In addition, the investigators could not rule out subclinical preexisting liver disease, nonalcoholic fatty liver disease, or steatohepatitis.

"[A]lthough diabetic hepatopathy is potentially less common, it may be appropriate for addition to the list of target-organ conditions related to diabetes, such as glomerulopathy, retinopathy and neuropathy," the study authors conclude. "Annual screening for liver disease might be accomplished by means of a simple biochemical analyte such as alanine aminotransferase. However, before screening can be considered, the efficacy of primary and secondary preventive measures, such as weight loss and glycemic and lipid control, must be validated by good evidence akin to that completed for adults and children with isolated fatty liver and no diabetes."

The Banting and Best Diabetes Centre at the University of Toronto supported this study. The study was also supported by the Institute for Clinical Evaluative Sciences (ICES), which is funded by an annual grant from the Ontario Ministry of Health and Long-Term Care (MOHLTC). No endorsement of the study authors' opinions by ICES or the Ontario MOHLTC is intended or should be inferred. The study authors have disclosed no relevant financial relationships.

CMAJ. Published online June 21, 2010.