High-fat feeding-induced hyperinsulinemia increases cardiac glucose uptake and mitochondrial function despite peripheral insulin resistance. Academic Article uri icon

Overview

abstract

  • In obesity, reduced cardiac glucose uptake and mitochondrial abnormalities are putative causes of cardiac dysfunction. However, high-fat diet (HFD) does not consistently induce cardiac insulin resistance and mitochondrial damage, and recent studies suggest HFD may be cardioprotective. To determine cardiac responses to HFD, we investigated cardiac function, glucose uptake, and mitochondrial respiration in young (3-month-old) and middle-aged (MA) (12-month-old) male Ldlr(-/-) mice fed chow or 3 months HFD to induce obesity, systemic insulin resistance, and hyperinsulinemia. In MA Ldlr(-/-) mice, HFD induced accelerated atherosclerosis and nonalcoholic steatohepatitis, common complications of human obesity. Surprisingly, HFD-fed mice demonstrated increased cardiac glucose uptake, which was most prominent in MA mice, in the absence of cardiac contractile dysfunction or hypertrophy. Moreover, hearts of HFD-fed mice had enhanced mitochondrial oxidation of palmitoyl carnitine, glutamate, and succinate and greater basal insulin signaling compared with those of chow-fed mice, suggesting cardiac insulin sensitivity was maintained, despite systemic insulin resistance. Streptozotocin-induced ablation of insulin production markedly reduced cardiac glucose uptake and mitochondrial dysfunction in HFD-fed, but not in chow-fed, mice. Insulin injection reversed these effects, suggesting that insulin may protect cardiac mitochondria during HFD. These results have implications for cardiac metabolism and preservation of mitochondrial function in obesity.

authors

  • Gupte, Anisha
  • Minze, Laurie J
  • Reyes, Maricela
  • Ren, Yuelan
  • Wang, Xukui
  • Brunner, Gerd
  • Ghosn, Mohamad
  • Cordero-Reyes, Andrea M
  • Ding, Karen
  • Pratico, Domenico
  • Morrisett, Joel
  • Shi, Zheng-Zheng
  • Hamilton, Dale James
  • Lyon, Christopher J
  • Hsueh, Willa A

publication date

  • May 24, 2013

Research

keywords

  • Glucose
  • Hyperinsulinism
  • Insulin Resistance
  • Mitochondria, Heart
  • Myocardium

Identity

PubMed Central ID

  • PMC5398492

Scopus Document Identifier

  • 84880681089

Digital Object Identifier (DOI)

  • 10.1210/en.2012-2272

PubMed ID

  • 23709089

Additional Document Info

volume

  • 154

issue

  • 8