Newly diagnosed diabetes mellitus as a risk factor for serious liver disease

Abstract

Background: 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. We evaluated whether adults with newly diagnosed diabetes were at increased risk of serious liver disease.

Methods: We used administrative health databases for the province of Ontario (1994-2006) to perform a population-based matched retrospective cohort study. The exposed group comprised 438 069 adults with newly diagnosed diabetes. The unexposed comparison group--those without known diabetes--consisted of 2 059 708 individuals, matched 5:1 to exposed persons, by birth year, sex and local health region. We excluded individuals with pre-existing liver or alcohol-related disease. The primary study outcome was the subsequent development of serious liver disease, namely, liver cirrhosis, liver failure and its sequelae, or receipt of a liver transplant.

Results: The incidence rate of serious liver disease was 8.19 per 10 000 person-years among those with newly diagnosed diabetes and 4.17 per 10 000 person-years among those without diabetes. The unadjusted hazard ratio was 1.92 (95% confidence interval [CI] 1.83-2.01). After adjustment for age, income, urban residence, health care utilization and pre-existing hypertension, dyslipidemia, obesity and cardiovascular disease, the hazard ratio was 1.77 (95% CI 1.68-1.86).

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

Figure 1

Risk of serious liver disease according to participants’ characteristics at study entry, comparing those with newly diagnosed diabetes mellitus and matched individuals without diabetes mellitus. Hazard ratios (HRs) were adjusted for age (continuous, in years); income quintile; urban residence; presence of hypertension, dyslipidemia, obesity or cardiovascular disease within 36 months before study entry; number of hospital admissions within 36 months before study entry; and number of primary care visits within 12 months before study entry. With the exception of the age stratum, adjustment was not performed on the variable being stratified. CI = confidence interval.