The correlation between muscle loss and the severity of vascular stenosis in elderly patients with peripheral artery disease: a retrospective analysis utilizing computed tomography.

backgroundPeripheral artery disease (PAD) is a globally prevalent atherosclerotic disease associated with an increased risk of cardiovascular and cerebrovascular diseases and a poor prognosis. Skeletal muscle loss (sarcopenia) is particularly common in patients with PAD and is closely associated with poor prognosis.

aimsThe aim of this study was to evaluate the area, density and fat infiltration of skeletal muscle in patients with PAD by CT, and to analyze their relationship with the degree of vascular stenosis.

methodsA total of 233 PAD patients who underwent lower extremity CTA in Beijing Hospital were included in this study. Image segmentation was performed using Slice-O-Matic® software, and parameters such as skeletal muscle area, density, and fat infiltration were measured at L3, L4, mid-thigh, and maximum soft tissue cross section of the lower leg. At the same time, the degree of lower extremity arterial stenosis was evaluated by CTA. The lower extremity arterial stenosis severity was graded as 0 (0-30%), 1 (31-50%), 2 (51-70%), 3 (71-99%), or 4 (occlusion).Then the CTA-score was calculated by summing the stenosis scores of the abdominal aorta and the lower limb arteries.

resultsPatients were categorized into high (n = 113) and low (n = 120) CTA score groups. Among males, those in the low score group had higher muscle indices at L3, though not statistically significant. However, thigh and calf muscle areas were significantly larger in low score males (P < 0.001). High score patients had greater intermuscular fat indices. Regression analysis indicated that vascular stenosis accounted for 5% of the variance in muscle mass, with SFA, PoA, and PTA stenosis having the strongest correlations. DISCUSSION: Our study reveals how vascular stenosis affects muscle mass and composition in PAD patients, with the SFA, PoA, and PTA having the greatest impact due to their key role in lower limb blood supply. Severe stenosis leads to muscle mass reduction and increased fat infiltration, possibly due to chronic inflammation and oxidative stress. These findings highlight the need to address muscle health in PAD management, as targeting muscle atrophy and fat infiltration could enhance patient outcomes.

conclusionsPAD severity had a significant effect on the muscles of the lower limbs, especially the stenosis of the SFA, PoA, and PTA. CT evaluation provides a new perspective for understanding muscle loss in patients with PAD.