Background Patients with lower extremity peripheral arterial disease (PAD) and sarcopenia are a population at risk requiring specific and targeted care. The aim of this review is to gather all relevant studies associating sarcopenia and PAD and to identify the underlying pathophysiological mechanisms as well as potential therapeutic strategies to improve skeletal muscle function. Methods A systematic review was carried out following the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). Results Data extraction allowed the evaluation of 140 publications; 87 met the inclusion criteria; of which 79 were included in the final review, reporting sufficient data for epidemiological and diagnostic criteria, mechanical analysis, and therapeutic approaches. Epidemiological analysis and diagnostic criteria were based on 18 studies following 2362 PAD patients [31.39% (SD 7.61) women], aged 72.42 (SD 2.84); sarcopenia was present in 34.63% (SD 12.86) of the patients. Mechanical and pathway analysis were based on five animal studies and 29 clinical reports, showing significantly altered muscle strength and function in 1352 PAD patients [26.49% (SD 17.32) women], aged 67.67 (SD 5.14) years; impaired muscle histology in 192 PAD patients (9.2% (SD 11.22) women), aged 64.3 (SD 0.99) years; +58.63% (SD 25.48) of oxidative stress in 69 PAD patients [16.96% (SD 8.10) women], aged 63.17 (SD 1.43) years; mitochondriopathy in 153 PAD patients [29.39% (SD 28.27) women], aged 63.50 (SD 1.83) years; +15.58% (SD 7.41) of inflammation in 900 PAD patients [40.77% (SD 3.71) women], aged 74.88 (SD 2.76) years; and altered signalling pathways in 51 PAD patients [34.45% (SD 32.23) women], aged 72.25 (SD 5.25) years. Therapeutic approaches analysis was based on seven animal studies and 21 clinical reports. In total, 884 patients followed an exercise therapy, and 18 received an angiogenesis treatment; 30.84% (SD 17.74) were women. Mean ages of patients studied were 66.85 (SD 3.96). Conclusions Sarcopenia and lower extremity PAD have musculoskeletal consequences that directly impair patients' quality of life and prognosis. Although PAD is primarily a vascular disease, all etiological factors of sarcopenia identified so far are present in PAD. Indeed, both sarcopenia and PAD are accompanied by oxidative stress, skeletal muscle mitochondrial impairments, inflammation, inhibition of specific pathways regulating muscle synthesis or protection (i.e. IGF-1, RISK, and SAFE), and activation of molecules associated with muscle degradation. To date, besides revascularization, the best therapeutic strategy includes exercise, but approaches targeting the underlying mechanisms still deserve further studies.

Pulmonary arterial hypertension (PAH) is a rare disease, which leads to the progressive loss and remodeling of the pulmonary vessels, right heart failure, and death. Different clinical presentations can be responsible for such a bad prognosis disease and the underlying mechanisms still need to be further examined. Importantly, skeletal and respiratory muscle abnormalities largely contribute to the decreased quality of life and exercise intolerance observed in patients with PAH. At the systemic level, impaired oxygen supply through reduced cardiac output and respiratory muscle dysfunctions, which potentially result in hypoxemia, is associated with altered muscles vascularization, inflammation, enhanced catabolic pathways, and impaired oxygen use through mitochondrial dysfunctions that are likely participate in PAH-related myopathy. Sharing new insights into the pathological mechanisms of PAH might help stimulate specific research areas, improving the treatment and quality of life of PAH patients. Indeed, many of these muscular impairments are reversible, strongly supporting the development of effective preventive and/or therapeutic approaches, including mitochondrial protection and exercise training.

Background: The post-COVID-19 condition, defined as COVID-19-related signs and symptoms lasting at least 2 months and persisting more than 3 months after infection, appears now as a public health issue in terms of frequency and quality of life alterations. Nevertheless, few data are available concerning long term evolution of malnutrition and sarcopenia, which deserve further attention. Method: Sarcopenia was investigated prospectively, together with weight evolution, at admission and at 3 and 6 months after hospital discharge in 139 COVID-19 patients, using the European Working Group on Sarcopenia in Older People (EWGSOP2) criteria, associating both decreased muscle strength and muscle mass, assessed, respectively, with hand dynamometer and dual-energy X-ray absorptiometry. Results: Of the 139 patients, 22 presented with sarcopenia at 3 months; intensive care units (ICU) length of stay was the sole factor associated with sarcopenia after multivariate analysis. Although the entire group did not demonstrate significant weight change, weight decreased significantly in the sarcopenia group (Five and eight patients, showing, respectively, > 5 or > 10% weight decrease). Interestingly, at 6 months, 16 of the 22 patients recovered from sarcopenia and their weight returned toward baseline values. Conclusions: Sarcopenia and malnutrition are frequently observed in patients hospitalized for COVID-19, even 3 months after infection occurrence, but can largely be reversed at 6 months after discharge. Enhanced patient care is needed in sarcopenic patients, particularly during long stays in an ICU.