TY - JOUR
T1 - Independent tissue contributors to obesity-associated insulin resistance
AU - Kusters, Yvo H. A. M.
AU - Schalkwijk, Casper G.
AU - Houben, Alfons J. H. M.
AU - Kooi, M. Eline
AU - Lindeboom, Lucas
AU - 't Roodt, Jos Op
AU - Joris, Peter J.
AU - Plat, Jogchum
AU - Mensink, Ronald P.
AU - Barrett, Eugene J.
AU - Stehouwer, Coen D. A.
PY - 2017/7/6
Y1 - 2017/7/6
N2 - BACKGROUND. Induction of insulin resistance is a key pathway through which obesity increases risk of type 2 diabetes, hypertension, dyslipidemia, and cardiovascular events. Although the detrimental effects of obesity on insulin sensitivity are incompletely understood, accumulation of visceral, subcutaneous, and liver fat and impairment of insulin-induced muscle microvascular recruitment (MVR) may be involved. As these phenotypic changes often coincide in obesity, we aimed to unravel whether they independently contribute to insulin resistance and thus constitute separate targets for intervention.METHODS. We measured visceral (VAT) and subcutaneous adipose tissue (SAT) volumes and intrahepatic lipid (IHL) content by MRI, and whole body glucose disposal (WBGD) and MVR (using contrast-enhanced ultrasound) responses to a euglycemic insulin clamp in lean (n = 25) and abdominally obese men (n = 52). Abdominally obese men were randomized to dietary weight loss intervention or habitual diet.RESULTS. Obesity-associated increases in VAT, SAT, and IHL, along with the decrease in MVR, contributed independently to insulin resistance. Moreover, a dietary weight loss intervention reduced insulin resistance, and mediation analyses showed that decreased IHL and insulin-induced MVR, but not decreased VAT or SAT volumes, independently contributed to improved insulin resistance seen with weight loss.CONCLUSION. Quantifying the mutually independent contributions of visceral and subcutaneous adipose tissue, intrahepatic lipid, and insulin-induced muscle microvascular recruitment reveals distinct targets for treating obesity-associated insulin resistance.
AB - BACKGROUND. Induction of insulin resistance is a key pathway through which obesity increases risk of type 2 diabetes, hypertension, dyslipidemia, and cardiovascular events. Although the detrimental effects of obesity on insulin sensitivity are incompletely understood, accumulation of visceral, subcutaneous, and liver fat and impairment of insulin-induced muscle microvascular recruitment (MVR) may be involved. As these phenotypic changes often coincide in obesity, we aimed to unravel whether they independently contribute to insulin resistance and thus constitute separate targets for intervention.METHODS. We measured visceral (VAT) and subcutaneous adipose tissue (SAT) volumes and intrahepatic lipid (IHL) content by MRI, and whole body glucose disposal (WBGD) and MVR (using contrast-enhanced ultrasound) responses to a euglycemic insulin clamp in lean (n = 25) and abdominally obese men (n = 52). Abdominally obese men were randomized to dietary weight loss intervention or habitual diet.RESULTS. Obesity-associated increases in VAT, SAT, and IHL, along with the decrease in MVR, contributed independently to insulin resistance. Moreover, a dietary weight loss intervention reduced insulin resistance, and mediation analyses showed that decreased IHL and insulin-induced MVR, but not decreased VAT or SAT volumes, independently contributed to improved insulin resistance seen with weight loss.CONCLUSION. Quantifying the mutually independent contributions of visceral and subcutaneous adipose tissue, intrahepatic lipid, and insulin-induced muscle microvascular recruitment reveals distinct targets for treating obesity-associated insulin resistance.
KW - FATTY LIVER-DISEASE
KW - CORONARY-HEART-DISEASE
KW - ADIPOSE-TISSUE
KW - VISCERAL FAT
KW - RISK-FACTORS
KW - HYPERTENSION
KW - DYSLIPIDEMIA
KW - SENSITIVITY
KW - DYSFUNCTION
KW - METABOLISM
U2 - 10.1172/jci.insight.89695
DO - 10.1172/jci.insight.89695
M3 - Article
C2 - 28679946
SN - 2379-3708
VL - 2
JO - JCI INSIGHT
JF - JCI INSIGHT
IS - 13
M1 - e89695
ER -