Fat infiltrates the pancreas
Pancreatic Fat Sign of Diabetes, Obesity
September 25, 2009
by Brendon Nafziger
, DOTmed News Associate Editor
Forget fasting glucose levels: a new way to identify those at risk of developing diabetes could be imaging for fat buildup in the pancreas, according a study published this week in the Journal of Clinical Endocrinology & Metabolism.
Doctors at the University of Texas Southwestern Medical Center in Dallas found that the accumulation of triglyceride fats in the pancreas was linked to diabetes and obesity.
The team, led by Ildiko Lingvay, MD, and Lidia Szczepaniak, PhD, at UT Southwestern, used magnetic resonance spectroscopy (MRS) to image the pancreases of 79 volunteers (33 volunteers were selected to be re-tested a couple of weeks later, just to make sure the results were consistent).
They found that patients with the highest fat buildup, or steatosis, in the pancreas, were those previously diagnosed with type 2 diabetes, or those whose ability to clear sugar from the blood was impaired but who weren't full-blown diabetics yet.
Overweight and obese volunteers -- as measured by a high body mass index -- also had increased pancreatic fat even though blood tests showed they had a normal glycemic response. These volunteers had about six times more pancreatic fat buildup than volunteers with a healthy weight range.
Although obese patients might be expected to have fattier pancreases because they are, in general, fatter, Dr. Lingvay tells DOTmed News that of the non-diabetic obese and diabetic obese in the study, the diabetic ones had significantly more pancreatic fat. "The strongest predictor of pancreatic fat was level of blood sugar two hours after ingesting glucose. It wasn't BMI," she says.
Dr. Lingvay isn't exactly sure why fat infiltrates the pancreas, but she suspects it could happen when the body's usual depot for fat - adipose tissue - gets overloaded by a fat-heavy diet, causing excess fat to circulate in the blood, going "places it has no business being, the heart, the pancreas, the liver," she says.
Dr. Lingvay also speculates that pancreatic fat could be a cause, and not just a symptom, of reduced glycemic response in diabetics and pre-diabetics. Although the triglyceride fats stored in the pancreas are themselves harmless, they are constantly being metabolized, releasing nitric oxide and other toxins that could interfere with the ability of beta cells to produce insulin.
For the next stage in their research, Drs. Lingvay and Szczepaniak are looking to see if reducing pancreatic fat will improve blood sugar levels in diabetics. They want to test if pioglitazone, an FDA-approved drug for treating diabetes that's known to break down fat buildup in the liver, might owe its therapeutic benefits for diabetics to its fat-fighting properties.