C Venturi1, G Zoppini, C Zamboni, M Muggeo. 1. Division of Endocrinology and Metabolic Disease, University of Verona Medical School, Verona, Italy.
Abstract
BACKGROUND AND AIM: Hepatic steatosis has recently been associated with insulin resistance and other metabolic abnormalities as a possible feature of the metabolic syndrome, but it is still uncertain how hepatic steatosis and insulin sensitivity are connected. Furthermore, obesity is a well characterized insulin resistant condition that is often associated with hepatic steatosis. The aim of this study was to verify whether hepatic steatosis further worsens insulin sensitivity in obese subjects by comparing the degree of insulin sensitivity in obese subjects with normal glucose tolerance on the basis of the presence or absence of hepatic steatosis. METHODS AND RESULTS: We analyzed 86 obese patients whose alcohol intake was less than 20 g/day and who showed no signs of viral hepatopathy. All of the subjects had normal glucose tolerance as shown by an oral glucose tolerance test. Insulin resistance was estimated using the homeostasis model assessment (HOMA) method and the diagnosis of steatosis was determined by an ultrasound scan of the liver. The subjects were comparable in terms of body mass index (BMI), lipid profile and serum uric acid levels; those with hepatic steatosis were slightly older and tended to have higher systolic blood pressure and fasting glycemia levels. The HOMA values were significantly higher in the group with hepatic steatosis (4.48 +/- 2.22 vs 3.11 +/- 1.47, p=0.002). There was no linear correlation between HOMA and alanine aminotransferase (ALT) levels, but a close linear correlation between HOMA and BMI (r=0.40; p<0.001). The effect of hepatic steatosis on HOMA remained significant after adjusting for age and gender (covariance analysis, p=0.006). When BMI was added to the covariance analysis, hepatic steatosis retained its statistical significance. CONCLUSION: Our data suggest that hepatic steatosis can increase insulin resistance independently of obesity.
BACKGROUND AND AIM: Hepatic steatosis has recently been associated with insulin resistance and other metabolic abnormalities as a possible feature of the metabolic syndrome, but it is still uncertain how hepatic steatosis and insulin sensitivity are connected. Furthermore, obesity is a well characterized insulin resistant condition that is often associated with hepatic steatosis. The aim of this study was to verify whether hepatic steatosis further worsens insulin sensitivity in obese subjects by comparing the degree of insulin sensitivity in obese subjects with normal glucose tolerance on the basis of the presence or absence of hepatic steatosis. METHODS AND RESULTS: We analyzed 86 obesepatients whose alcohol intake was less than 20 g/day and who showed no signs of viral hepatopathy. All of the subjects had normal glucose tolerance as shown by an oral glucose tolerance test. Insulin resistance was estimated using the homeostasis model assessment (HOMA) method and the diagnosis of steatosis was determined by an ultrasound scan of the liver. The subjects were comparable in terms of body mass index (BMI), lipid profile and serum uric acid levels; those with hepatic steatosis were slightly older and tended to have higher systolic blood pressure and fasting glycemia levels. The HOMA values were significantly higher in the group with hepatic steatosis (4.48 +/- 2.22 vs 3.11 +/- 1.47, p=0.002). There was no linear correlation between HOMA and alanine aminotransferase (ALT) levels, but a close linear correlation between HOMA and BMI (r=0.40; p<0.001). The effect of hepatic steatosis on HOMA remained significant after adjusting for age and gender (covariance analysis, p=0.006). When BMI was added to the covariance analysis, hepatic steatosis retained its statistical significance. CONCLUSION: Our data suggest that hepatic steatosis can increase insulin resistance independently of obesity.
Authors: F Santini; M Giannetti; S Mazzeo; P Fierabracci; G Scartabelli; A Marsili; R Valeriano; A Pucci; M Anselmino; V Zampa; P Vitti; A Pinchera Journal: J Endocrinol Invest Date: 2007-02 Impact factor: 4.256
Authors: Rocio Aller; Daniel A de Luis; Luis Fernandez; Fernando Calle; Benito Velayos; Jose Luis Olcoz; Olatz Izaola; Manuel Gonzalez Sagrado; Rosa Conde; Jose Manuel Gonzalez Journal: Dig Dis Sci Date: 2007-10-13 Impact factor: 3.199
Authors: R Aller; D A de Luis; O Izaola; M Gonzalez Sagrado; R Conde; M C Velasco; T Alvarez; D Pacheco; J M González Journal: Dig Dis Sci Date: 2008-11-14 Impact factor: 3.199
Authors: Charlyn G Partridge; Gloria L Fawcett; Bing Wang; Clay F Semenkovich; James M Cheverud Journal: BMC Genomics Date: 2014-02-05 Impact factor: 3.969