Garvan InstituteHepatitis C is said to be an infectious disease affecting the liver, apparently caused due to hepatitis C virus (HCV). It is known for many years that Hepatitis C, a general cause of liver cirrhosis and cancer, may also make people three to four times more liable to suffer from Type 2 diabetes.

While examining the insulin resistance of roughly 29 people with Hepatitis C, Australian scientists have verified that they seem to encompass high insulin resistance, a predecessor to diabetes. Nevertheless, nearly all insulin resistance appears to arise in muscle, with little or none in the liver, an extremely astonishing discovery since Hepatitis C is a liver disease.

Insulin, a hormone produced by the pancreas, seems to aid the body use glucose for energy. The two most significant organs that react to insulin are said to be the liver and muscle. A healthy liver apparently reacts to insulin by not generating glucose, while healthy muscle retorts by using glucose. An insulin resistant liver is said to produce unwanted glucose, while insulin resistant muscle may not absorb it from the bloodstream, thereby resulting in elevated levels of sugar in the blood.

Dr Kerry Lee Milner and Professor Don Chisholm from Sydney’s Garvan Institute of Medical Research, in partnership with Professor Jacob George from the Storr Liver Unit, University of Sydney at Westmead Hospital apparently conducted this study.

Professor Don Chisholm, commented, “Contrary to all expectations, not only did we find no significant insulin resistance in the liver of the patients in the study, half of them suffered from a strain of Hepatitis C that causes about three times the normal level of fat to accumulate in the liver. The fifteen people with very high levels of fat in the liver had the same degree of insulin resistance as the fourteen that didn’t have fatty livers. A number of important investigators around the world have been arguing that fat in the liver is an extremely important determinant of insulin resistance, perhaps the most important. At least in this context, we’ve shown that not to be the case. Before you get Type 2 diabetes, you must become insulin resistant and your insulin producing cells must also fail to compensate. Insulin resistance alone will not give you diabetes.”

Chisholm added, “In our study, we gave intravenous glucose, a specific stimulus to insulin secretion, and showed that insulin secretion was not impaired in Hepatitis C patients compared to our control group. This finding tells us that people with Hepatitis C who develop diabetes probably have susceptible insulin-producing cells, and would probably get it anyway – but much later in life. The extra insulin resistance caused by Hepatitis C apparently brings on diabetes at 35 or 40, instead of 65 or 70. More work now needs to be done into why Hepatitis C causes insulin resistance in muscle. That will give us better insight into the behaviour of the disease.”

The expert mentioned that at this stage, it is helpful for people with Hepatitis C to understand insulin resistance and what it can mean for them. If they have relatives with Type 2 diabetes, they will be genetically prone to developing it themselves and so would be advised to manage their diets very carefully and take plenty of exercise to slow onset.

The study was published in the international journal, Gastroenterology.