Reduced Muscle Mass and Muscle Quality in Patients with Intermittent Claudication due to Peripheral Artery Disease

Objective Peripheral arterial disease (PAD) is associated with reduced muscle mass and quality, but the effects of leg ischemia caused by PAD on muscle quality remain poorly understood. The purpose of this study was to evaluate leg muscle mass and muscle quality in patients with intermittent claudication due to PAD using bioelectrical impedance analysis (BIA). Methods One hundred forty-one patients with intermittent claudication due to PAD who visited Tokyo Medical University Hospital from April 2019 to April 2020 were retrospectively analyzed. Leg ischemia was assessed using ankle-brachial index (ABI). The skeletal muscle mass (SMM) assessed leg muscle mass, while the phase angle (PhA) assessed leg muscle quality using BIA. Results A total of 282 legs in 141 patients were included in the analysis. Leg PhA and SMM showed a decreasing trend according to the severity of leg ischemia (borderline/no ischemia: 2.80 ± 0.50 kg/m2, 4.38 ± 0.94°; mild ischemia: 2.83 ± 0.49 kg/m2, 4.33 ± 1.03°; moderate/severe ischemia: 2.50 ± 0.40 kg/m2, 3.89 ± 0. 88°; p<0.001 and p=0.020, respectively). The ABI was moderately correlated with leg SMM (B=0.347, β=0.134, p<0.001) and leg PhA (B=0.577, β=0.111, p=0.013) after adjustment for all significant covariates. Leg PhA was moderately correlated with leg SMM (r = 0.318, p < 0.001). Conclusions Leg ischemia, especially when moderate or severe, has an adverse effect on both muscle mass and quality in the lower extremities and is associated with skeletal muscle myopathy.