While it is unclear whether diabetes directly causes liver disease, or if changes in liver function cause diabetes, Dr. Hashem El-Serag, study author from the Houston Veteran Affairs Medical Center, sees this study as an important warning for patients with diabetes. Because liver disease can often go unnoticed, as it causes no discernible symptoms, he recommends "regular testing of liver enzymes for patients with diabetes."
In a related study, published in the journal Gut, 2,061 patients with liver cancer were compared to over 6,000 patients without liver cancer from a Medicare database. The researchers found that 43 percent of the patients with liver cancer also had diabetes, while only 19 percent of the cancer-free control group had diabetes.
When other factors that contribute to liver cancer risk, like alcoholism, were taken into account, the researchers found that patients with diabetes had three times the risk of developing liver cancer as the general population.
"Our results indicate that diabetes is associated with an increased risk of [liver cancer] among people 65 years and older," wrote El-Serag.
Chronic liver diseases, caused by hepatitis B, hepatitis C, heavy alcohol consumption and fatty liver disease have previously been shown to be major risk factors for developing liver cancer, but this is the first time that diabetes alone was seen as a risk factor for liver cancer. This correlation may explain why rates of liver cancer have been on the rise in the United States.
"The incidence of liver cancer is rising in the developed Western world at a time when obesity is also emerging as a major public health threat," said DiBisceglie. "What is the link between these two phenomena?"
