CONTEXT: Adipose tissue in obese individuals is characterized by reduced capillary density and reduced oxygenation. OBJECTIVE: Our objective was to test whether hypoxia is associated with reduced antilipolytic effect of insulin. PARTICIPANTS, DESIGN, AND SETTING: Twenty-one lean and obese individuals participated in this cross-sectional study at a university-based clinical research center. INTERVENTION: In all subjects, in situ adipose tissue (AT) oxygenation [AT oxygen partial pressure (ATpO2)] was measured with a Clark electrode, insulin sensitivity as well as basal and insulin-suppressed lipolysis (continuous infusion of (2H5)glycerol) were measured during a euglycemic-hyperinsulinemic clamp, and abdominal sc AT biopsies were collected to assess fat cell size (Coulter counting of osmium-fixed cells), capillary density (by staining of histological sections), and gene expression (by quantitative RT-PCR). MAIN OUTCOME MEASURE: In situ ATpO2 was evaluated. RESULTS: The ability of insulin to suppress lipolysis (percent) was positively correlated with insulin sensitivity (r=0.43; P<0.05), ATpO2 (r=0.44; P<0.05), vascular endothelial growth factor mRNA (r=0.73; P<0.01), and capillary density (r=0.75; P<0.01). CONCLUSION: These results indicate that low capillary density and ATpO2 in AT are potentially upstream causes of AT dysfunction.
CONTEXT: Adipose tissue in obese individuals is characterized by reduced capillary density and reduced oxygenation. OBJECTIVE: Our objective was to test whether hypoxia is associated with reduced antilipolytic effect of insulin. PARTICIPANTS, DESIGN, AND SETTING: Twenty-one lean and obese individuals participated in this cross-sectional study at a university-based clinical research center. INTERVENTION: In all subjects, in situ adipose tissue (AT) oxygenation [AT oxygen partial pressure (ATpO2)] was measured with a Clark electrode, insulin sensitivity as well as basal and insulin-suppressed lipolysis (continuous infusion of (2H5)glycerol) were measured during a euglycemic-hyperinsulinemic clamp, and abdominal sc AT biopsies were collected to assess fat cell size (Coulter counting of osmium-fixed cells), capillary density (by staining of histological sections), and gene expression (by quantitative RT-PCR). MAIN OUTCOME MEASURE: In situ ATpO2 was evaluated. RESULTS: The ability of insulin to suppress lipolysis (percent) was positively correlated with insulin sensitivity (r=0.43; P<0.05), ATpO2 (r=0.44; P<0.05), vascular endothelial growth factor mRNA (r=0.73; P<0.01), and capillary density (r=0.75; P<0.01). CONCLUSION: These results indicate that low capillary density and ATpO2 in AT are potentially upstream causes of AT dysfunction.
Authors: Utpal B Pajvani; Meredith Hawkins; Terry P Combs; Michael W Rajala; Tom Doebber; Joel P Berger; John A Wagner; Margaret Wu; Annemie Knopps; Anny H Xiang; Kristina M Utzschneider; Steven E Kahn; Jerrold M Olefsky; Thomas A Buchanan; Philipp E Scherer Journal: J Biol Chem Date: 2003-12-29 Impact factor: 5.157
Authors: Magdalena Pasarica; Olga R Sereda; Leanne M Redman; Diana C Albarado; David T Hymel; Laura E Roan; Jennifer C Rood; David H Burk; Steven R Smith Journal: Diabetes Date: 2008-12-15 Impact factor: 9.461
Authors: Vincenza Cifarelli; Scott C Beeman; Gordon I Smith; Jun Yoshino; Darya Morozov; Joseph W Beals; Brandon D Kayser; Jeramie D Watrous; Mohit Jain; Bruce W Patterson; Samuel Klein Journal: J Clin Invest Date: 2020-12-01 Impact factor: 14.808
Authors: Doan T M Ngo; Melissa G Farb; Ryosuke Kikuchi; Shakun Karki; Stephanie Tiwari; Sherman J Bigornia; David O Bates; Michael P LaValley; Naomi M Hamburg; Joseph A Vita; Donald T Hess; Kenneth Walsh; Noyan Gokce Journal: Circulation Date: 2014-08-12 Impact factor: 29.690
Authors: Brian S Finlin; Beibei Zhu; Catherine P Starnes; Robert E McGehee; Charlotte A Peterson; Philip A Kern Journal: J Nutr Biochem Date: 2013-03-22 Impact factor: 6.048