Tissue triglycerides, insulin resistance and__ insulin production:
implications for hyperinsulinemia of obesity.
Koyama, Kazunori, Guoxun Chen, Young Lee, Roger H. Unger.
Gifford Laboratories, Center for Diabetes Research, Department of
Internal Medicine, University of Texas Southern Medical Center,
Dallas, TX 75235; and "Department of Veterans Affairs Medical
Center, Dallas, TX 75216
APStracts 4:0143E, 1997.
Obesity is associated with both insulin resistance and
hyperinsulinemia. Initially hyperinsulinemia compensates for the
insulin resistance and thereby maintains normal glucose homeostasis.
Obesity is also associated with increased tissue triglyceride (TG)
content. To determine if both insulin resistance and hyperinsulinemia
might be secondary to increased tissue (TG), we studied correlations
between TG content of skeletal muscle, liver and pancreas and plasma
insulin, plasma [insulin] x [glucose] and _[beta]-cell function_ in 4
rat models with widely varying fat content: obese Zucker Diabetic
Fatty (ZDF) rats, free-feeding lean Wistar rats, Wistar rats
hyperleptinemic with profound tissue lipopenia and rats pairfed to
hyperleptinemics. Correlation coefficients over 0.9 (p<0.05) were
obtained between TG of skeletal muscle, liver and pancreas and plasma
insulin, [insulin] x [glucose] product and [beta]-cell function
gauged by basal, glucose-stimulated and arginine-stimulated insulin
secretion by the isolated perfused pancreas. While these correlations
cannot prove cause and effect, they are consistent with the
hypothesis that the TG content of tissues sets the level of both
insulin resistance and insulin production.
Received 14 March 1997; accepted in final form 19 June 1997.
APS Manuscript Number E115-7-.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 10 July 1997