Study Links NAFLD to Insulin Resistance

Insulin resistance frequently goes hand-in-hand with Non-Alcoholic Fatty Liver Disease (NAFLD), as well as a host of other hormonal and metabolic issues.
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Now scientists say they have found data linking insulin resistance as a potential direct cause of NAFLD rather than simply a contributing factor.

Insulin resistance, one of a cluster of conditions that make up metabolic syndrome and potentially leading to type 2 diabetes, occurs when the body produces insulin, but can not use it effectively. In many cases, insulin receptors refuse to allow the insulin in due to their having “maxed out” on receiving and reabsorbing this important hormone.

More often than not, insulin resistance occurs when an overweight and under-exercised condition exists. It differs from type 1 diabetes, in which the body either produces an inadequate amount of insulin, or no insulin.

Insulin is necessary to the body in order to “herd” and transport glucose following a meal, but too large a meal, too many carbohydrates per meal or other factors may cause the body to panic and overproduce insulin. When that happens, the overstimulated insulin receptors shut down, leaving both insulin and glucose at too-high levels in the body and potentially causing both immediate and long-term damage.

Now Harvard scientists are saying insulin resistance is not only one factor, but may be the primary one when it comes to NAFLD.

“Insulin resistance appears to be the underlying pathophysiological defect leading to [nonalcoholic fatty liver disease],” said David E. Cohen, MD, PhD, director of Hepatology at Brigham and Women’s Hospital and director of the Harvard-MIT division of health sciences and technology,  at the National Lipid Association Scientific Sessions in New Orleans in May.

Dr. Cohen was keynote speaker at the gathering.

According to researchers, the following were observed (see the full quotes here):

  • In a Dallas Heart Study of 2,200 participants, 31% had liver fat of more than 5.5%, the definition of steatosis. In the NHANES III cohort, 5.5% had NAFLD.
  • Of those with NAFLD, approximately 80% have NAFL and 20% have NASH, but NASH is more common in those with morbid obesity, type 2 diabetes or dyslipidemia.
  • Approximately half of patients with type 2 diabetes have NAFLD, with 87% of those with any form of the condition having NASH. By 2020, NASH will be the leading reason for orthotopic liver transplantation, according to Dr. Cohen.

Novel drug therapies are currently being researched, but a healthy diet, regular cardiovascular exercise and maintaining a healthy weight are still the primary recommendations, according to presenters.

The groundbreaking information was collected and presented at the National Lipid Association Scientific Sessions, which took place May 19-22.

Other topics covered at the meeting included Human genetics and CV Risk Assessment (Nathan O. Stitziel, MD, PhD), Human Genetics Impact on Clinical Practice in Lipidology (Muredach P. Reilly, MBBCH),  and Gene Therapy Marina Cuchel, MD, PhD.

For more information and upcoming symposiums, visit the National Lipid Association site.

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