Increased whole‐body adiposity without a concomitant increase in liver fat is not associated with augmented metabolic dysfunction

F Magkos, E Fabbrini, BS Mohammed, BW Patterson… - …, 2010 - Wiley Online Library
F Magkos, E Fabbrini, BS Mohammed, BW Patterson, S Klein
Obesity, 2010Wiley Online Library
Aim of this study was to determine whether an increase in adiposity, without a concomitant
increase in intrahepatic triglyceride (IHTG) content, is associated with a deterioration in
metabolic function. To this end, multiorgan insulin sensitivity, assessed by using a two‐stage
hyperinsulinemic–euglycemic clamp procedure in conjunction with stable isotopically
labeled tracer infusion, and very low‐density lipoprotein (VLDL) kinetics, assessed by using
stable isotopically labeled tracer infusion and mathematical modeling, were determined in …
Aim of this study was to determine whether an increase in adiposity, without a concomitant increase in intrahepatic triglyceride (IHTG) content, is associated with a deterioration in metabolic function. To this end, multiorgan insulin sensitivity, assessed by using a two‐stage hyperinsulinemic–euglycemic clamp procedure in conjunction with stable isotopically labeled tracer infusion, and very low‐density lipoprotein (VLDL) kinetics, assessed by using stable isotopically labeled tracer infusion and mathematical modeling, were determined in 10 subjects with class I obesity (BMI: 31.6 ± 0.3 kg/m2; 37 ± 2% body fat; visceral adipose tissue (VAT): 1,225 ± 144 cm3) and 10 subjects with class III obesity (BMI: 41.5 ± 0.5 kg/m2; 43 ± 2% body fat; VAT: 2,121 ± 378 cm3), matched on age, sex, and IHTG content (14 ± 4 and 14 ± 3%, respectively). No differences between class I and class III obese groups were detected in insulin‐mediated suppression of palmitate (67 ± 3 and 65 ± 3%, respectively; P = 0.635) and glucose (67 ± 3 and 73 ± 5%, respectively; P = 0.348) rates of appearance in plasma, and the insulin‐mediated increase in glucose disposal (218 ± 18 and 193 ± 30%, respectively; P = 0.489). In addition, no differences between class I and class III obese groups were detected in secretion rates of VLDL‐triglyceride (6.5 ± 1.0 and 6.0 ± 1.4 µmol/l·min, respectively; P = 0.787) and VLDL‐apolipoprotein B‐100 (0.40 ± 0.05 and 0.41 ± 0.04 nmol/l·min, respectively; P = 0.866), and plasma clearance rates of VLDL‐triglyceride (31 (16–59) and 29 (18–46) ml/min, respectively; P = 0.888) and VLDL‐apolipoprotein B‐100 (15 (11–19) and 17 (11–25) ml/min, respectively; P = 0.608). We conclude that increased adiposity without a concomitant increase in IHTG content does not cause additional abnormalities in adipose tissue, skeletal muscle, and hepatic insulin sensitivity, or VLDL metabolism.
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