Impaired skeletal muscle glucose uptake by [¹⁸F] fluorodeoxyglucose-positron emission tomography in patients with peripheral artery disease and intermittent claudication

Objective- Reduced limb perfusion from arterial stenosis does not adequately account for intermittent claudication symptoms in peripheral artery disease (PAD). Insulin resistance is associated with PAD and may contribute to claudication by impairing skeletal muscle metabolism. We aimed to determine whether skeletal muscle glucose uptake, assessed by [F]fluorodeoxyglucose positron emission tomography, is reduced in patients with claudication. Methods and results- Thirty-seven subjects with PAD and claudication and 11 healthy controls underwent [F]fluorodeoxyglucose-positron emission tomography imaging of the legs during hyperinsulinemic-euglycemic clamp. Calf glucose uptake was quantified by graphical Patlak analysis, and whole-body insulin sensitivity was assessed as the glucose disposal rate (M) from the insulin clamp. Compared with healthy controls, PAD subjects were insulin resistant (M=3.4 mg/kg per minute [interquartile range, 2.7 to 4.8] versus 5.0 [3.7 to 6.6], P=0.019). Calf muscle glucose uptake was significantly lower in PAD compared with healthy subjects (48.6±2.6 μmol/kg per minute versus 62.9±6.5 μmol/kg per minute, P=0.009) and correlated with systemic insulin sensitivity (r=0.37, P=0.03) in PAD subjects. These abnormalities persisted even after exclusion of PAD subjects with diabetes. Conclusion- Patients with claudication have impaired calf muscle glucose uptake. Future studies are required to assess whether calf muscle insulin resistance contributes to exercise limitation in patients with intermittent claudication.