Diabetes may increase cirrhosis mortality risk
Having diabetes appears to increase the risk of cirrhosis-related mortality, according to results from the Singapore Chinese Health Study (SCHS).
Individuals with diabetes had an almost threefold elevated risk of death due to cirrhosis (hazard ratio [HR], 2.80, 95 percent confidence interval [CI], 2.04─3.83). This association applied to both viral and nonviral hepatitis-related cirrhosis mortality (HR, 2.20, 95 percent CI, 1.18─4.11 and HR, 3.06, 95 percent CI, 2.13─4.41, respectively). [Liver Int 2016;doi:10.1111/liv.13241]
Individuals with a higher body mass index (BMI ≥23 kg/m2) had a higher risk of cirrhosis-related mortality; however, this increased risk only applied to individuals without diabetes at baseline (HR, 1.53, 95 percent CI, 1.03─2.28) and only affected those with nonviral hepatitis or cryptogenic cirrhosis-related mortality.
The association between diabetes and the risk of nonviral hepatitis-related cirrhosis mortality was stronger in individuals with a lower BMI (<23 kg/m2, HR, 7.11, 95 percent CI, 3.42─14.79) compared with those with a higher BMI (HR, 2.28, 95 percent CI, 1.20─4.35).
“This was an unexpected result as we normally assume that nonviral cirrhosis would be mostly due to nonalcoholic fatty liver disease [NAFLD] and NAFLD is usually associated with obesity and metabolic syndrome,” said study author Dr George Goh Boon-Bee, consultant at the Department of Gastroenterology and Hepatology at Singapore General Hospital.
“However, we also know that there is a nonobese NAFLD entity which has been reported more in the Asian setting. Some studies suggest that the severity of NAFLD can be the same regardless of BMI. In Asians, complications tend to occur at lower BMIs compared to their Western counterparts at corresponding BMIs, which is why our BMI cutoffs are lower compared to the West,” he said.
Among the theories put forth by the authors to explain the link between diabetes and cirrhosis in participants with a lower BMI include genetic reasons that increase the risk of more aggressive liver disease in normal weight individuals with diabetes, or BMI being an ineffective measure of body weight or fat.
While previous studies have demonstrated a higher risk of chronic liver disease-related mortality in patients with diabetes, [Am J Gastroenterol 2014;109:1020-1025] knowledge of this association in Asian populations has been limited.
To assess the impact of diabetes on the risk of cirrhosis mortality, researchers analysed data from 63,275 individuals in the SCHS who were aged 45─74 years upon enrolment in the study (1993─1998). Data was followed-up until December 2014.
There were 133 deaths due to cirrhosis in the mean 16.9-year follow-up period, of which 34 individuals had chronic hepatitis B, two had chronic hepatitis C, 16 had chronic alcoholic liver disease, and three had biliary cirrhosis, while the remaining 78 had unspecified or cryptogenic cirrhosis, which the authors suggest were mostly due to NAFLD.
The authors acknowledged that the lack of information on diabetes medication use and potential underreporting of viral hepatitis were among the study limitations.
According to Goh, awareness is key in reducing the risk of cirrhosis-related mortality among diabetic patients. “The recognition and awareness of NAFLD as a potentially serious liver complication of diabetes/metabolic syndrome and obesity needs to be increased. Similar to regular eye, kidney, and neurologic screening in diabetic patients, experts in both endocrinology and hepatology are now starting to recommend screening for NAFLD in this at-risk population,” he said.