TY - JOUR
T1 - Mitochondrial oxidative phosphorylation is impaired in patients with congenital lipodystrophy
AU - Sleigh, Alison
AU - Stears, Anna
AU - Thackray, Kerrie
AU - Watson, Laura
AU - Gambineri, Alessandra
AU - Nag, Sath
AU - Campi, V. Irene
AU - Schoenmakers, Nadia
AU - Brage, Soren
AU - Carpenter, T. Adrian
AU - Murgatroyd, Peter R.
AU - O'Rahilly, Stephen
AU - Kemp, Graham J.
AU - Savage, David B.
PY - 2012/3
Y1 - 2012/3
N2 - Objective: Lipid accumulation in skeletal muscle and the liver is strongly implicated in the development of insulin resistance and type 2 diabetes, but the mechanisms underpinning fat accrual in these sites remain incompletely understood. Accumulating evidence of muscle mitochondrial dysfunction in insulin-resistant states has fuelled the notion that primary defects in mitochondrial fat oxidation may be a contributory mechanism. The purpose of our study was to determine whether patients with congenital lipodystrophy, a disorder primarily affecting white adipose tissue, manifest impaired mitochondrial oxidative phosphorylation in skeletal muscle. Research Design and Methods: Mitochondrial oxidative phosphorylation was assessed in quadriceps muscle using 31P-magnetic resonance spectroscopy measurements of phosphocreatine recovery kinetics after a standardized exercise bout in nondiabetic patients with congenital lipodystrophy and in age-, gender-, body mass index-, and fitness-matched controls. Results: The phosphocreatine recovery rate constant (k) was significantly lower in patients with congenital lipodystrophy than in healthy controls (P < 0.001). This substantial (∼35%) defect in mitochondrial oxidative phosphorylation was not associated with significant changes in basal or sleeping metabolic rates. Conclusions: Muscle mitochondrial oxidative phosphorylation is impaired in patients with congenital lipodystrophy, a paradigmatic example of primary adipose tissue dysfunction. This finding suggests that changes in mitochondrial oxidative phosphorylation in skeletal muscle could, at least in some circumstances, be a secondary consequence of adipose tissue failure. These data corroborate accumulating evidence that mitochondrial dysfunction can be a consequence of insulinresistant states rather than a primary defect. Nevertheless, impaired mitochondrial fat oxidation is likely to accelerate ectopic fat accumulation and worsen insulin resistance.
AB - Objective: Lipid accumulation in skeletal muscle and the liver is strongly implicated in the development of insulin resistance and type 2 diabetes, but the mechanisms underpinning fat accrual in these sites remain incompletely understood. Accumulating evidence of muscle mitochondrial dysfunction in insulin-resistant states has fuelled the notion that primary defects in mitochondrial fat oxidation may be a contributory mechanism. The purpose of our study was to determine whether patients with congenital lipodystrophy, a disorder primarily affecting white adipose tissue, manifest impaired mitochondrial oxidative phosphorylation in skeletal muscle. Research Design and Methods: Mitochondrial oxidative phosphorylation was assessed in quadriceps muscle using 31P-magnetic resonance spectroscopy measurements of phosphocreatine recovery kinetics after a standardized exercise bout in nondiabetic patients with congenital lipodystrophy and in age-, gender-, body mass index-, and fitness-matched controls. Results: The phosphocreatine recovery rate constant (k) was significantly lower in patients with congenital lipodystrophy than in healthy controls (P < 0.001). This substantial (∼35%) defect in mitochondrial oxidative phosphorylation was not associated with significant changes in basal or sleeping metabolic rates. Conclusions: Muscle mitochondrial oxidative phosphorylation is impaired in patients with congenital lipodystrophy, a paradigmatic example of primary adipose tissue dysfunction. This finding suggests that changes in mitochondrial oxidative phosphorylation in skeletal muscle could, at least in some circumstances, be a secondary consequence of adipose tissue failure. These data corroborate accumulating evidence that mitochondrial dysfunction can be a consequence of insulinresistant states rather than a primary defect. Nevertheless, impaired mitochondrial fat oxidation is likely to accelerate ectopic fat accumulation and worsen insulin resistance.
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U2 - 10.1210/jc.2011-2587
DO - 10.1210/jc.2011-2587
M3 - Article
C2 - 22238385
AN - SCOPUS:84858056414
VL - 97
JO - Journal of Clinical Endocrinology and Metabolism
JF - Journal of Clinical Endocrinology and Metabolism
SN - 0021-972X
IS - 3
ER -