Sarcopenia and peripheral arterial disease: a systematic review

Association between grip strength, walking pace and incident peripheral artery disease: A prospective study of 430,886 UK biobank participants

Background and aims

Patients with peripheral artery disease (PAD) presented overall muscle weakness and reduced physical performance. Previous study focused on the impact of muscle weakness on outcomes of established PAD, however the relationship between compromised muscle function and incident PAD remained unclear.

Methods

A prospective study involving 430,886 participants aged 40-69 y from UK biobank was conducted. The main outcome was incident PAD. Grip strength and walking pace were used as indicators for muscle function. Grip strength was measured using a Jamar J00105 hydraulic hand dynamometer, while walking pace was self-reported by the participants. Cox proportional hazard models were employed to investigate the relationship between grip strength, walking pace, and incident PAD.

Results

A total of 430,886 individuals were included in the final analysis. The mean age of the participants were 56.44 years, and 55.3 % were female. Over a median follow-up period of 13.81 years, 5,661 participants developed PAD. Higher grip strength, whether absolute or relative, exhibited a dose-dependent inverse association with incident PAD. Each 1 kg increment in absolute grip strength and each 0.01 kg/kg increase in relative grip strength were associated with reduced PAD risk by 2 % (HR: 0.98; 95 % CI [0.97-0.98]) and 83 % (HR: 0.17; 95 % CI [0.13-0.23]), respectively. Slow walking pace significantly correlated with increased PAD risk, while brisk walking pace was associated with decreased PAD risk.

Conclusion

Absolute grip strength, relative grip strength and walking pace were inversely associated with the risk of incident PAD.

Mesenchymal stromal cell transplantation ameliorates fibrosis and microRNA dysregulation in skeletal muscle ischemia

Peripheral arterial disease (PAD) is associated with lower-extremity muscle wasting. Hallmark features of PAD-associated skeletal muscle pathology include loss of skeletal muscle mass, reduced strength and physical performance, increased inflammation, fibrosis, and adipocyte infiltration. At the molecular level, skeletal muscle ischemia has also been associated with gene and microRNA (miRNA) dysregulation. Mesenchymal stromal cells (MSCs) have been shown to enhance muscle regeneration and improve muscle function in various skeletal muscle injuries. This study aimed to evaluate the effects of intramuscularly delivered human umbilical cord-derived MSCs (hUC-MSCs) on skeletal muscle ischemia. Herein, we report an hUC-MSC-mediated amelioration of ischemia-induced skeletal muscle atrophy and function via enhancement of myofiber regeneration, reduction of tissue inflammation, adipocyte accumulation, and tissue fibrosis. These changes were observed in the absence of cell-mediated enhancement of blood flow recovery as measured by laser Doppler imaging. Furthermore, reduced tissue fibrosis in the hUC-MSC-treated group was associated with upregulation of miR-1, miR-133a, and miR-29b and downregulation of targeted pro-fibrotic genes such as Col1a1 and Fn1. Our results support the use of hUC-MSCs as a novel approach to reduce fibrosis and promote skeletal muscle regeneration after ischemic injury in patients with PAD.

Sarcopenia Influences Clinical Outcome in Hospitalized Patients with Peripheral Artery Disease Aged 75 Years and Older

BACKGROUND

Sarcopenia represents a relevant comorbidity in patients with peripheral artery disease (PAD). However, only few studies exist assessing the clinical burden of sarcopenia in PAD.

METHODS

All hospitalizations of patients aged ≥75 years who were admitted due to PAD within 2005-2020 in Germany were included in the study and stratified for sarcopenia. Temporal trends and the impact of sarcopenia on treatment procedures as well as adverse in-hospital events were investigated.

RESULTS

Overall, 1,166,848 hospitalization cases of patients admitted due to PAD (median age 81.0 [78.0-85.0] years; 49.5% female sex) were included, of which 2,109 (0.2%) were coded with sarcopenia. Prevalence of sarcopenia in these patients increased during the observational period from 0.05% in 2005 to 0.34% in 2020 (β 2.61 [95%CI 2.42-2.80], P < 0.001). Sarcopenic PAD patients were more often female (52.1% vs. 49.5%, P = 0.015), obese (6.6% vs. 5.5%, P = 0.021), and revealed higher prevalences of comorbidities (Charlson comorbidity index, 7.00 [6.00-9.00] vs. 6.00 [5.00-7.00], P < 0.001). Sarcopenia was associated with reduced usage of reperfusion treatments (endovascular intervention: odds ratio (OR) 0.409 [95%CI 0.358-0.466], P < 0.001; surgical revascularization: OR 0.705 [95%CI 0.617-0.805], P < 0.001) but higher conduction of amputation (OR 1.365 [95%CI 1.231-1.514], P < 0.001) and higher rates of major adverse cardiovascular and cerebrovascular events (MACCE) (OR 1.313 [95%CI 1.141-1.512], P < 0.001) and in-hospital death (OR 1.229 [95%CI 1.052-1.436], P = 0.009).

CONCLUSIONS

Sarcopenia is an under-recognized condition in PAD patients of high clinical relevance causing a crucial disease burden. Awareness of the ailment needs to be increased in daily clinical practice to identify sarcopenia and improve the clinical outcome of this vulnerable patient group.

A Systematic Review on the Role of Neutrophil to Lymphocyte Ratio in Limb Ischemia

OBJECTIVES

Limb ischemia is a severe vascular condition that can lead to critical complications, endangering both limbs and lives. The goal of this research was to explore the role of Neutrophil to lymphocyte ratio (NLR) in limb ischemia.

METHODS

From inception to June 8, 2022, PubMed/MEDLINE, ISI Web of Science, and Scopus were searched for papers comparing NLR in limb ischemia to healthy individuals.

RESULTS

Finally, a total of 23 studies were included in the review. There was a direct link between NLR and critical limb ischemia (CLI) development in peripheral arterial disease (PAD) patients. Elevated NLR levels predict a higher risk of CLI among PAD patients. Also, it was concluded that NLR is a dependable predictor of survival in patients with limb ischemia, and higher NLR readings are linked to decreased survival rates. Moreover, the risk of amputation is related to the level of NLR in CLI patients. However, based on the data, NLR is not a reliable indicator of sarcopenia in CLI patients. More research is needed to determine the relationship between NLR and response to treatment in CLI patients. Also, we recommend investigating the effect of each treatment on NLR level in these patients.

CONCLUSIONS

Our results provide evidence that NLR level is associated with risk of amputation and mortality in patients with limb ischemia. It is a promising biomarker that can be easily incorporated into clinical practice to assist in the prediction and prevention of CLI.

Association of serum intact parathyroid hormone levels with sarcopenia in patients undergoing peritoneal dialysis

Objective

Sarcopenia is highly prevalent in patients undergoing peritoneal dialysis (PD), contributing to adverse clinical outcomes. Animal models suggest that parathyroid hormone (PTH) induces muscle wasting through adipose tissue browning. However, the relationship between PTH dysregulation and sarcopenia in the PD population remains unclear. Thus, we aimed to explore the association between serum intact PTH levels and sarcopenia in PD patients.

Methods

We conducted a cross-sectional analysis using data from the Tzu-Chi PD cohort, comprising 186 PD patients with a mean age of 57.5 ± 14.1 years. Basic information, comorbidities, serum intact PTH levels, and other biochemical data were retrieved. Atherosclerotic cardiovascular disease (ASCVD) includes any history of coronary artery disease, myocardial infarction, peripheral arterial disease, and stroke. All patients were evaluated for appendicular skeletal muscle mass (ASM) using the Body Composition Monitor (BCM), handgrip strength, and 6-m usual gait speed. Sarcopenia was defined based on the consensus of the Asian Working Group for Sarcopenia 2019. Relative over-hydration (OH) was also assessed using BCM.

Results

The overall prevalence of sarcopenia was 38.2%. Across three groups of intact PTH levels (<150 pg/mL, 150-300 pg/mL, and >300 pg/mL), the prevalence rates of sarcopenia were 29.7, 36.4, and 46.2%, respectively (p for trend = 0.044). In the unadjusted model, age, ASCVD, subjective global assessment score, body mass index, relative OH, serum albumin, creatinine, phosphorus, and log-transformed intact PTH levels were significantly associated with sarcopenia. After full adjustment for all above factors, age (odds ratio [OR] = 1.04, 95% confidence interval [CI] = 1.00-1.08), ASCVD (OR = 4.12, 95% CI = 1.34-12.65), BMI (OR = 0.51, 95% CI = 0.41-0.64), relative OH (OR = 1.04, 95% CI = 1.00-1.07), log-transformed intact PTH levels (OR = 3.72, 95% CI = 1.51-9.14) were independently associated sarcopenia among PD patients.

Conclusion

Among PD patients, elevated serum intact PTH levels are independently associated with sarcopenia. Further longitudinal studies are warranted to confirm their causal relationship.

Genetically proxied appendicular lean mass and stroke risk: A two-step mendelian randomization study

BACKGROUND AND PURPOSE

Prior observational studies have suggested a strong correlation between sarcopenia and stroke, but the causal link between them remains uncertain. This study aims to investigate the associations between genetically predicted sarcopenia-related traits and stroke using a two-step Mendelian randomization (MR) approach.

METHODS

Genome-wide association study (GWAS) summary data for sarcopenia-related traits were acquired from the UK Biobank. Genetic associations for ischemic stroke (IS) and its subtypes were selected from the MEGASTROKE consortium comprising European ancestry participants. GWAS summary data for cerebral hemorrhage were obtained from the FinnGen consortium, including intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH). MR estimates were calculated using the inverse-variance weighted (IVW) method. The robustness of results was assessed for heterogeneity and pleiotropy of individual single nucleotide polymorphisms (SNPs).

RESULTS

Higher appendicular lean mass (ALM) exhibited a potential causal association with a reduced incidence of large artery atherosclerosis (LAA) (odds ratio [OR] = 0.81, 95% confidence interval [CI]:0.71-0.93; P = 0.003) and small vessel disease (SVD) (OR = 0.83, 95% CI:0.74-0.94; P = 0.002). The associations of ALM with IS and ICH were compromised after adjusting for body fat and physical activity with multivariable MR. Two-step MR mediation analysis explored 33 candidate mediators, among which hypertension and SBP accounted for more than 10% of the mediation proportion in the relationship between ALM and stroke and its subtypes.

CONCLUSION

Our research findings indicate that lower ALM is associated with a increased risk of stroke . It is necessary to explore the specific protective mechanisms of higher ALM for preventing stroke occurrence.

Vascular Impairment, Muscle Atrophy, and Cognitive Decline: Critical Age-Related Conditions

The triad of vascular impairment, muscle atrophy, and cognitive decline represents critical age-related conditions that significantly impact health. Vascular impairment disrupts blood flow, precipitating the muscle mass reduction seen in sarcopenia and the decline in neuronal function characteristic of neurodegeneration. Our limited understanding of the intricate relationships within this triad hinders accurate diagnosis and effective treatment strategies. This review analyzes the interrelated mechanisms that contribute to these conditions, with a specific focus on oxidative stress, chronic inflammation, and impaired nutrient delivery. The aim is to understand the common pathways involved and to suggest comprehensive therapeutic approaches. Vascular dysfunctions hinder the circulation of blood and the transportation of nutrients, resulting in sarcopenia characterized by muscle atrophy and weakness. Vascular dysfunction and sarcopenia have a negative impact on physical function and quality of life. Neurodegenerative diseases exhibit comparable pathophysiological mechanisms that affect cognitive and motor functions. Preventive and therapeutic approaches encompass lifestyle adjustments, addressing oxidative stress, inflammation, and integrated therapies that focus on improving vascular and muscular well-being. Better understanding of these links can refine therapeutic strategies and yield better patient outcomes. This study emphasizes the complex interplay between vascular dysfunction, muscle degeneration, and cognitive decline, highlighting the necessity for multidisciplinary treatment approaches. Advances in this domain promise improved diagnostic accuracy, more effective therapeutic options, and enhanced preventive measures, all contributing to a higher quality of life for the elderly population.

Six-month combined aerobic and resistance exercise program enhances 6-minute walk test and physical fitness in people with peripheral arterial disease: A pilot study

BACKGROUND

Exercise therapy is a recognized non-pharmacological intervention for peripheral arterial disease (PAD); however, the effects of combined exercise remain under investigation. This study aimed to compare the effects of a 6-month combined supervised exercise program (SUP) with a usual care (UC) approach on walking ability, physical fitness, and peripheral blood flow in people with PAD and claudication.

METHODS

Twenty-three male participants (Age=64.1 ± 6.2years and ABI=0.58±0.07) with PAD and claudication were assigned to either the SUP group (n = 10), engaging in structured supervised treadmill walking combined with three resistance exercises, three times a week, or the UC group (n = 13), receiving advice to walk. The primary outcome measure was walking ability, with assessments conducted at baseline (M0), after 3 months (M3), and 6 months (M6).

RESULTS

After the 6-month intervention, the SUP group exhibited significant improvements in absolute claudication time (ACT, p = 0.045), maximal walking time (MWT, p = 0.045), maximal walking distance (MWD, p = 0.027), and pause duration (p = 0.045) during the 6-minute walk test (6MWT), when compared to the UC group. Over time, a significant increase in walking speed during the 6MWT (Speed6MWT, p = 0.001) and walking speed without claudication (SpeedNoC, p < 0.001) was found, although no significant differences were found between the groups. The SUP group increased by 0.8 km/h in both Speed6MWT and SpeedNoC, while the UC group increased by 0.3 km/h and 0.6 km/h, respectively. Despite claudication consistently occurring at the same time, the SUP group demonstrated an improved tolerance to pain or a better understanding of pain, enabling them to walk longer distances at higher speeds. A positive effect of SUP was found for chair sit-and-reach test (p = 0.023), percentage of fat mass (p = 0.048), fat-free mass (p = 0.040), and total body water (p = 0.026), suggesting potential benefits attributed to the resistance strength exercises.

CONCLUSION

A 6-month combined treadmill and resistance exercise program improved walking ability, walking speed, lower body and lower back flexibility, and body composition in people with PAD and claudication.

Home-based Circuit Training and Community Walking for Intermittent Claudication

BACKGROUND

Supervised exercise training is recommended for people with peripheral artery disease (PAD), yet it remains underutilized. Home-based exercise programs (HBEPs) are a potential alternative. The aim of this study was to assess the feasibility of conducting a full scale trial of a 12-week HBEP for people living with symptomatic PAD.

METHODS

In a randomized feasibility trial, patients with intermittent claudication were allocated to either an HBEP or a nonexercise control. The HBEP group was given a Fitbit to use during a 12-week exercise program comprising of personalized step goals and a resistance-based circuit to be undertaken at home twice weekly. The primary outcome was feasibility, assessed via eligibility, recruitment, attrition, tolerability, and adherence. Acceptability was assessed via semistructured interviews. Secondary analysis was undertaken to determine the feasibility of collecting clinical outcome data.

RESULTS

188 people were screened, 133 were eligible (70.7%), 30 were recruited (22.6%) and one withdrew (3.33%). Mean adherence to the daily step goal was 53.5% (range = 29.8-90.5%), and 58.6% of prescribed circuits were completed of which 56.4% were at the desired intensity. Six adverse events were recorded, 3 of which were related to study involvement. No significant differences were observed in exploratory outcomes. Small clinically important differences were seen in walking speed and pain-free treadmill walking distance which should be confirmed or refuted in a larger trial.

CONCLUSIONS

The HBEP was feasible and well tolerated, with successful recruitment and minimal attrition. The intervention was acceptable, with walking seen as more enjoyable than circuit exercise. The WALKSTRONG program may be suitable for those who will not, or cannot, take part in supervised exercise outside of the home.

The Association Between Completion of Supervised Exercise Therapy and Long-Term Outcomes in Patients with Intermittent Claudication, Concomitant Sarcopenia, and Cardiometabolic Multimorbidity

INTRODUCTION

The combination of intermittent claudication (IC), cardiometabolic multimorbidity (CMM), and sarcopenia is associated with worse outcomes than IC alone. This study aimed to identify whether the completion of supervised exercise therapy (SET) attenuates these adverse outcomes in patients with combined IC, sarcopenia, and CMM.

METHODS

This registry review included consecutive IC patients with concomitant CMM and sarcopenia, who were referred for SET from 2014 to 2017. CMM was defined as 2 or more comorbidities (diabetes, heart disease, stroke, or chronic kidney disease). Sarcopenia was assessed using the L3-skeletal muscle index (L3SMI) from computed tomography (CT) scans in the preceding 18 months. The outcomes of interest were progression to chronic limb-threatening ischemia (CLTI), major adverse cardiovascular events (MACE), and major adverse limb events (MALE). Survival and Cox regression analyses were performed.

RESULTS

Eighty-two patients with a combination of IC, CMM, and sarcopenia were included. Of these, 56 declined or prematurely discontinued SET and 26 completed SET. Baseline characteristics and L3SMI did not significantly differ between groups. Completion of SET was associated with slower progression to CLTI (HR: 0.23; 95% CI: 0.07-0.69; P = 0.02) and a reduced risk of MALE (HR: 0.21; 95% CI: 0.057-0.775; P = 0.02). However, there was no reduction in the risk of MACE (HR: 0.88; 95%CI: 0.423-1.629; P = 0.73). Models demonstrated good predictive accuracy (Harrell's C-index >0.6).

CONCLUSIONS

Completion of SET was associated with significant improvements in adverse limb outcomes in patients with IC, concomitant sarcopenia, and CMM.

The Association Between Triglyceride-Glucose Index and Its Combination with Obesity Indicators and Lower Extremity Peripheral Artery Disease in Patients with Type 2 Diabetes Mellitus: A Cross-Sectional Study

Background

Lower extremity peripheral artery disease (LEAD) is a significant chronic complication of type 2 diabetes mellitus (T2DM) that significantly contributes to disability and mortality. The subtle presentation of LEAD symptoms often leads to underrecognition and misdiagnosis. Therefore, identifying simple and effective evaluation indicators is essential for the early detection and management of LEAD. Insulin resistance is closely associated with diabetes and its complications. However, the specific relationship between insulin resistance-measured by the triglyceride-glucose (TyG) index-and obesity indicators in relation to LEAD remains unclear.

Objective

This study aims to investigate the association between the TyG index and its combination with obesity indicators in participants with T2DM and LEAD.

Methods

We performed a univariate analysis on 3176 T2DM patients to identify risk factors for LEAD. Patients were then divided into quartiles based on the TyG index combined with various obesity indicators. The chi-square test was used to compare the prevalence of LEAD across these groups. Logistic regression analysis was conducted to examine the association between the TyG index, in combination with different obesity indicators, and the occurrence of LEAD. Finally, we assessed the predictive ability of the TyG index combined with obesity indicators for LEAD by comparing the area under the ROC curve (AUC).

Results

The study included 3176 T2DM patients (1691 males and 1485 females) with a mean age of 56.16±10.60 years. Among them, 106 individuals had LEAD. The prevalence of LEAD varied significantly across quartiles of the TyG index, TyG-WC, and TyG-WHR (Q4 > Q3 > Q2 > Q1; P < 0.05). Multiple logistic regression analysis showed that the TyG index, TyG-WC, and TyG-WHR were positively associated with the risk of LEAD in T2DM patients. ROC curve analysis identified the best cutoff values for predicting LEAD: 9.8059 for the TyG index (sensitivity: 49.1%, specificity: 67.9%, AUC: 0.583), 808.8397 for TyG-WC (sensitivity: 70.8%, specificity: 47.8%, AUC: 0.603), and 8.8543 for TyG-WHR (sensitivity: 75.5%, specificity: 44.6%, AUC: 0.607).

Conclusion

In T2DM patients, the TyG index, TyG-WHR, and TyG-WC are positively associated with the occurrence of LEAD. TyG-WHR and TyG-WC exhibit a stronger correlation with LEAD compared to the TyG index alone, indicating their superior diagnostic value.

Association between macro- and microvascular damage and sarcopenia index in individuals with type 2 diabetes mellitus

Sarcopenia was recently reported to be relevant to an increased macro-and microvascular disease risk. Sarcopenia index (SI) has been identified as a surrogate marker for sarcopenia. The aim of the present study was to investigate the association between macro- and microvascular disease and SI in patients with type 2 diabetes mellitus (T2DM). A total of 783 patients with T2DM were enrolled in this cross-sectional study. The SI was calculated by (serum creatinine [mg/dL]/cystatin C [mg/L]) × 100. The subjects were divided into three groups according to SI tertiles: T1 (41.27-81.37), T2 (81.38- 99.55), and T3 (99.56-192.31). Parameters of macro- and microvascular complications, including diabetic retinopathy (DR), micro- and macroalbuminuria (MAU), diabetic peripheral neuropathy (DPN), and lower extremity peripheral artery disease (LEAD) were evaluated. Multivariate logistic regression analysis revealed that when taking the top tertile of SI as a reference, an increasing trend of the prevalence of DR, MAU, DPN, and LEAD were presented (all P for trend  < 0.05), where the OR (95% CI) for DR prevalence was 1.967 (1.252-3.090) in T2, 2.195 (1.278-3.769) in T1, for MAU was 1.805 (1.149-2.837) in T2, 2.537 (1.490-4.320) in T1, for DPN was 2.244 (1.485-3.391) in T2, 3.172 (1.884-5.341) in T1, and for LEAD was 2.017 (1.002-4.057) in T2, 2.405 (1.107-5.225) in T1 (all P < 0.05). Patients with lower SI were more inclined to have an increased risk of macro- and microvascular damage in T2DM population, which may be related to sarcopenia.

Association of endothelial dysfunction and peripheral arterial disease with sarcopenia in chronic kidney disease

BACKGROUND

Endothelial dysfunction and peripheral arterial disease (PAD), which disturb skeletal muscle microperfusion, are highly prevalent in patients with chronic kidney disease (CKD). We evaluated the association of endothelial dysfunction and PAD with sarcopenia in patients with non-dialysis CKD.

METHODS

This cross-sectional study included 420 patients with stages 3-5 non-dialysis CKD aged 69.0 ± 11.8 years. Skeletal muscle index (skeletal muscle mass/height2), handgrip strength, 6-m gait speed and strength of hip flexion and knee extension were measured. Sarcopenia was defined according to the Asian Working Group for Sarcopenia 2019. Endothelial dysfunction and PAD were assessed using the vascular reactivity index (VRI) and ankle-brachial index (ABI), respectively. A VRI < 1.0 was classified as poor endothelial function, and an ABI < 0.9 was defined as PAD. Additionally, endothelial and inflammatory biomarkers, including intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), asymmetric dimethylarginine, endothelin-1 (ET-1) and interleukin-6, were measured in a subgroup of 262 patients.

RESULTS

Among the participants, 103 (24.5%) were classified as having sarcopenia. Compared with patients without sarcopenia, those with sarcopenia had significantly lower ABI (1.04 ± 0.16 vs. 1.08 ± 0.15, P = 0.028 for the right ABI; 1.01 ± 0.16 vs. 1.06 ± 0.16, P = 0.002 for the left ABI) and VRI (0.83 ± 0.57 vs. 1.08 ± 0.56, P < 0.001) and had higher serum levels of ICAM-1 (P < 0.001), VCAM-1 (P = 0.003) and ET-1 (P = 0.037). Multivariate logistic regression revealed that, beyond age and body mass index, the average ABI (odds ratio [OR]: 0.81/0.1 increase; 95% confidence interval [CI]: 0.67-0.98; P = 0.032) and VRI (OR: 0.93/0.1 increase; 95% CI: 0.88-0.98; P = 0.010) were independently associated with sarcopenia. Among the endothelial biomarkers measured, ICAM-1 (OR: 2.47/1-SD increase; 95% CI: 1.62-3.75) and VCAM-1 (OR: 1.91/1-SD increase; 95% CI: 1.27-2.87) were independent predictors of sarcopenia. Group stratification based on the cut-offs of VRI and ABI showed that those with both poor VRI and ABI had the greatest risk for sarcopenia (OR: 4.22; 95% CI: 1.69-10.49), compared with those with normal VRI and ABI.

CONCLUSIONS

Endothelial dysfunction and PAD are independently associated with sarcopenia in patients with stages 3-5 CKD, suggesting the dominant role of vascular dysfunction in sarcopenia.

Inflammatory Cells in Adipose Tissue and Skeletal Muscle of Patients with Peripheral Arterial Disease or Chronic Venous Disease: A Prospective, Observational, and Histological Study

The main goal of this study was to assess whether the presence of peripheral arterial disease (PAD) correlates with increased inflammatory cell infiltration. An observational, single-centre, and prospective study was conducted from January 2018 to July 2022. Clinical characteristics and anthropometric measures were registered. Consecutive PAD patients with surgical indications for a common femoral artery approach and patients with varicose veins with an indication for surgical ligation of the saphenofemoral junction were included. In both groups, samples of sartorius skeletal muscle, subcutaneous adipose tissue (SAT), and perivascular adipose tissue (PVAT) were collected from the femoral region. We analysed the characteristics of adipocytes and the presence of haemorrhage and inflammatory cells in the samples of PVAT and SAT via haematoxylin-eosin staining. We found that patients with PAD had significantly more inflammatory cells in PVAT [16 (43.24%) vs. 0 (0%) p = 0.008]. Analysing SAT histology, we observed that patients with PAD had significantly more CD45+ leucocytes upon immunohistochemical staining [32 (72.73%) vs. 3 (27.27%) p = 0.005]. Upon analysing skeletal muscle histology with haematoxylin-eosin staining, we evaluated skeletal fibre preservation, as well as the presence of trauma, haemorrhage, and inflammatory cells. We registered a significantly higher number of inflammatory cells in patients with PAD [well-preserved skeletal fibres: PAD = 26 (63.41%) vs. varicose veins = 3 (37.50%) p = 0.173; trauma: PAD = 4 (9.76%) vs. varicose veins = 2 (25.00%) p = 0.229; haemorrhage: PAD = 6 (14.63%) vs. varicose veins = 0 (0%) p = 0.248; inflammatory cells: PAD = 18 (43.90%) vs. varicose veins = 0 (0%) p = 0.018]. Patients with PAD had a higher number of inflammatory cells in skeletal muscle and adipose tissue (PVAT and SAT) when compared with those with varicose veins, emphasizing the role of inflammation in this group of patients.

Sarcopenia in peripheral arterial disease: Establishing and validating a predictive nomogram based on clinical and computed tomography angiography indicators

Purpose

To establish, validate, and clinically evaluate a nomogram for predicting the risk of sarcopenia in patients with peripheral arterial disease (PAD) based on clinical and lower extremity computed tomography angiography (LE-CTA) imaging characteristics.

Methods

Clinical data and CTA imaging features from 281 PAD patients treated between January 1, 2019, and May 1, 2023, at two hospitals were retrospectively analyzed using binary logistic regression to identify the independent risk factors for sarcopenia. These identified risk factors were used to develop a predictive nomogram. The nomogram's effectiveness was assessed through various metrics, including the receiver operating characteristic (ROC) curve, area under the curve (AUC), concordance index (C-index), Hosmer-Lemeshow (HL) test, and calibration curve. Its clinical utility was demonstrated using decision curve analysis (DCA).

Results

Several key independent risk factors for sarcopenia in PAD patients were identified, namely age, body mass index (BMI), history of coronary heart disease (CHD), and white blood cell (WBC) count, as well as the severity of luminal stenosis (P < 0.05). The discriminative ability of the nomogram was supported by the C-index and an AUC of 0.810 (95% confidence interval: 0.757-0.862). A robust concordance between predicted and observed outcomes was reflected by the calibration curve. The HL test further affirmed the model's calibration with a P-value of 0.40. The DCA curve validated the nomogram's favorable clinical utility. Lastly, the model underwent internal validation.

Conclusions

A simple nomogram based on five independent factors, namely age, BMI, history of CHD, WBC count, and the severity of luminal stenosis, was developed to assist clinicians in estimating sarcopenia risk among PAD patients. This tool boasts impressive predictive capabilities and broad utility, significantly aiding clinicians in identifying high-risk individuals and enhancing the prognosis of PAD patients.

Exercise therapy for chronic symptomatic peripheral artery disease

All guidelines worldwide strongly recommend exercise as a pillar of the management of patients affected by lower extremity peripheral artery disease (PAD). Exercise therapy in this setting presents different modalities, and a structured programme provides optimal results. This clinical consensus paper is intended for clinicians to promote and assist for the set-up of comprehensive exercise programmes to best advice in patients with symptomatic chronic PAD. Different exercise training protocols specific for patients with PAD are presented. Data on patient assessment and outcome measures are narratively described based on the current best evidence. The document ends by highlighting disparities in access to supervised exercise programmes across Europe and the series of gaps for evidence requiring further research.

Targeting Mitochondrial Dynamics during Lower-Limb Ischemia Reperfusion in Young and Old Mice: Effect of Mitochondrial Fission Inhibitor-1 (mDivi-1)

Peripheral arterial disease (PAD) strikes more than 200 million people worldwide and has a severe prognosis by potentially leading to limb amputation and/or death, particularly in older patients. Skeletal muscle mitochondrial dysfunctions and oxidative stress play major roles in this disease in relation with ischemia-reperfusion (IR) cycles. Mitochondrial dynamics through impairment of fission-fusion balance may contribute to skeletal muscle pathophysiology, but no data were reported in the setting of lower-limb IR despite the need for new therapeutic options. We, therefore, investigated the potential protective effect of mitochondrial division inhibitor-1 (mDivi-1; 50 mg/kg) in young (23 weeks) and old (83 weeks) mice submitted to two-hour ischemia followed by two-hour reperfusion on systemic lactate, muscle mitochondrial respiration and calcium retention capacity, and on transcripts specific for oxidative stress and mitochondrial dynamics. At the systemic levels, an IR-related increase in circulating lactate was still major despite mDivi-1 use (+305.9% p < 0.0001, and +269.4% p < 0.0001 in young and old mice, respectively). Further, IR-induced skeletal muscle mitochondrial dysfunctions (more severely impaired mitochondrial respiration in old mice (OXPHOS CI state, -68.2% p < 0.0001 and -84.9% p < 0.0001 in 23- and 83-week mice) and reduced calcium retention capacity (-46.1% p < 0.001 and -48.2% p = 0.09, respectively) were not corrected by mDivi-1 preconditioning, whatever the age. Further, mDivi-1 treatment did not oppose superoxide anion production (+71.4% p < 0.0001 and +37.5% p < 0.05, respectively). At the transcript level, markers of antioxidant enzymes (SOD 1, SOD 2, catalase, and GPx) and fission markers (Drp1, Fis) remained unchanged or tended to be decreased in the ischemic leg. Fusion markers such as mitofusin 1 or 2 decreased significantly after IR in both groups. In conclusion, aging enhanced the deleterious effects or IR on muscle mitochondrial respiration, and in this setting of lower-limb IR, mDivi-1 failed to protect the skeletal muscle both in young and old mice.

Exercise therapy for chronic symptomatic peripheral artery disease

All guidelines worldwide strongly recommend exercise as a pillar in the management of patients affected by lower extremity peripheral artery disease (PAD). Exercise therapy in this setting presents different modalities, and a structured programme provides optimal results. This clinical consensus paper is intended to promote and assist the set up of comprehensive exercise programmes and best advice for patients with symptomatic chronic PAD. Different exercise training protocols specific for patients with PAD are presented. Data on patient assessment and outcome measures are described based on the current best evidence. The document ends by highlighting supervised exercise programme access disparities across Europe and the evidence gaps requiring further research.

Exploring Possible Links: Thigh Muscle Mass, Apolipoproteins, and Glucose Metabolism in Peripheral Artery Disease-Insights from a Pilot Sub-Study following Endovascular Treatment

Peripheral artery disease (PAD) compromises walking and physical activity, which results in further loss of skeletal muscle. The cross-sectional area of the thigh muscle has been shown to be correlated with systemic skeletal muscle volume. In our previous pilot study, we observed an increase in thigh muscle mass following endovascular treatment (EVT) in patients with proximal vascular lesions affecting the aortoiliac and femoropopliteal arteries. Considering the potential interactions between skeletal muscle, lipid profile, and glucose metabolism, we aimed to investigate the relationship between thigh muscle mass and apolipoproteins as well as glucose metabolism in PAD patients undergoing EVT. This study is a prespecified sub-study conducted as part of a pilot study. We prospectively enrolled 22 symptomatic patients with peripheral artery disease (PAD) and above-the-knee lesions, specifically involving the blood vessels supplying the thigh muscle. The mid-thigh muscle area was measured with computed tomography before and 6 months after undergoing EVT. Concurrently, we measured levels of apolipoproteins A1 (Apo A1) and B (Apo B), fasting blood glucose, 2 h post-load blood glucose (using a 75 g oral glucose tolerance test), and glycated hemoglobin A1c (HbA1c). Changes in thigh muscle area (delta muscle area: 2.5 ± 8.1 cm2) did not show significant correlations with changes in Apo A1, Apo B, fasting glucose, 2 h post-oral glucose tolerance test blood glucose, HbA1c, or Rutherford classification. However, among patients who experienced an increase in thigh muscle area following EVT (delta muscle area: 8.41 ± 5.93 cm2), there was a significant increase in Apo A1 (pre: 121.8 ± 15.1 mg/dL, 6 months: 136.5 ± 19.5 mg/dL, p < 0.001), while Apo B remained unchanged (pre: 76.4 ± 19.2 mg/dL, 6 months: 80.5 ± 4.9 mg/dL). Additionally, post-oral glucose tolerance test 2 h blood glucose levels showed a decrease (pre: 189.7 ± 67.5 mg/dL, 6 months: 170.6 ± 69.7 mg/dL, p = 0.075). Patients who exhibited an increase in thigh muscle area demonstrated more favorable metabolic changes compared to those with a decrease in thigh muscle area (delta muscle area: -4.67 ± 2.41 cm2). This pilot sub-study provides insights into the effects of EVT on thigh muscle, apolipoproteins, and glucose metabolism in patients with PAD and above-the-knee lesions. Further studies are warranted to validate these findings and establish their clinical significance. The trial was registered on the University Hospital Medical Information Network Clinical Trials Registry (UMIN000047534).

Winners do what they fear: exercise and peripheral arterial disease-an umbrella review

AIMS

This systematic review aims to evaluate and summarize findings from published meta-analyses on the effects of regular exercise in patients with peripheral arterial disease (PAD). The review will assess the impact of exercise on functional parameters, health-related quality of life, haemodynamic parameters, physical activity levels, adverse events, and mortality.

METHODS AND RESULTS

A systematic search was performed in PubMed, Web of Science, Scopus, and Cochrane Library databases (up to May 2023) to identify meta-analyses including randomized controlled trials that examined the effects of regular exercise in patients with PAD. Sixteen studies, with a total of 198 meta-analyses, were identified. Results revealed with strong evidence that patients with PAD who exercised improved functional and health-related quality of life parameters. Specifically, supervised aerobic exercise (i.e. walking to moderate-maximum claudication pain) improves maximum walking distance [mean difference (MD): 177.94 m, 95% confidence interval (CI) 142.29-213.60; P < 0.00001; I2: 65%], pain-free walking distance (fixed MD: 68.78 m, 95% CI 54.35-83.21; P < 0.00001; I2: 67%), self-reported walking ability [i.e. distance score (MD: 9.22 points, 95% CI 5.74-12.70; P < 0.00001; I2: 0%), speed score (MD: 8.71 points, 95% CI 5.64-11.77; P < 0.00001, I2: 0%), stair-climbing score (MD: 8.02 points, 95% CI 4.84-11.21; P < 0.00001, I2: 0%), and combined score (MD: 8.76 points, 95% CI 2.78-14.74; P < 0.0001, I2: 0%)], aerobic capacity (fixed MD: 0.62 mL/kg/min, 95% CI 0.47-0.77, P < 0.00001, I2: 64%), and pain score (MD: 7.65, 95% CI 3.15-12.15; P = 0.0009; I2: 0%), while resistance exercise improves lower limb strength (standardized mean difference: 0.71, 95% CI 0.29-1.13, P = 0.0009; I2: 0%]. Regarding other outcomes, such as haemodynamic parameters, no significant evidence was found, while physical activity levels, adverse events, and mortality require further investigation.

CONCLUSION

Synthesis of the currently available meta-analyses suggests that regular exercise may be beneficial for a broad range of functional tasks improving health-related quality of life in patients with PAD. Supervised aerobic exercise is the best type of exercise to improve walking-related outcomes and pain, while resistance exercise is more effective to improve lower limb strength.

Sarcopenia is associated with lower step count in patients with peripheral artery disease following endovascular treatment

INTRODUCTION

Patients with peripheral artery disease (PAD) often complain of reduced physical activity (PA) despite improvements in intermittent claudication after successful endovascular treatment (EVT). Sarcopenia resulting from chronic ischemia can affect post-EVT PA levels.

OBJECTIVE

This study aims to assess the association between sarcopenia and post-EVT PA levels.

METHODS

One hundred five patients with PAD were consecutively enrolled in this study. PA was assessed using the post-EVT step count and the pre-EVT International Physical Activity Questionnaire. Sarcopenia was diagnosed based on the Asia Working Group for Sarcopenia and defined as low muscle mass and strength, and/or slow walking speed. The patients were categorized into three groups: 1) patients with sarcopenia (Sarcopenia Group); 2) patients with only low muscle mass or strength, and/or slow walking speed (Suspected-Sarcopenia Group); and 3) patients who did not fulfill all the sarcopenia criteria (No-Sarcopenia Group).

RESULTS

Proportions of patients in the Sarcopenia, Suspected-Sarcopenia, and No-Sarcopenia Groups were 31.4, 38.1, and 30.5%, respectively. After controlling for potential confounders, the Sarcopenia Group demonstrated significantly lower step counts than the Suspected-Sarcopenia Group (p = .016) and No-Sarcopenia Group (p = .009).

CONCLUSIONS

Our findings indicate that patients with PAD and sarcopenia require rehabilitation strategies to enhance physical performance.

Exercise Therapy for Chronic Symptomatic Peripheral Artery Disease: A Clinical Consensus Document of the European Society of Cardiology Working Group on Aorta and Peripheral Vascular Diseases in Collaboration With the European Society of Vascular Medicine and the European Society for Vascular Surgery

All guidelines worldwide strongly recommend exercise as a pillar in the management of patients affected by lower extremity peripheral artery disease (PAD). Exercise therapy in this setting presents different modalities, and a structured programme provides optimal results. This clinical consensus paper is intended to promote and assist the set up of comprehensive exercise programmes and best advice for patients with symptomatic chronic PAD. Different exercise training protocols specific for patients with PAD are presented. Data on patient assessment and outcome measures are described based on the current best evidence. The document ends by highlighting supervised exercise programme access disparities across Europe and the evidence gaps requiring further research.

Hybrid ultrasound and single wavelength optoacoustic imaging reveals muscle degeneration in peripheral artery disease

Peripheral arterial disease (PAD) leads to chronic vascular occlusion and results in end organ damage in critically perfused limbs. There are currently no clinical methods available to determine the muscular damage induced by chronic mal-perfusion. This monocentric prospective cross-sectional study investigated n = 193 adults, healthy to severe PAD, in order to quantify the degree of calf muscle degeneration caused by PAD using a non-invasive hybrid ultrasound and single wavelength optoacoustic imaging (US/SWL-OAI) approach. While US provides morphologic information, SWL-OAI visualizes the absorption of pulsed laser light and the resulting sound waves from molecules undergoing thermoelastic expansion. US/SWL-OAI was compared to multispectral data, clinical disease severity, angiographic findings, phantom experiments, and histological examinations from calf muscle biopsies. We were able to show that synergistic use of US/SWL-OAI is most likely to map clinical degeneration of the muscle and progressive PAD.

Utility of bioelectrical phase angle for cardiovascular risk assessment among individuals with and without diabetes mellitus

PURPOSE

Low values of bioimpedance-derived phase angle (PA) have been associated with various adverse outcomes. We investigated the association of PA with cardiovascular markers in individuals with and without diabetes mellitus (DM).

METHODS

PA was measured in 452 adults (without DM n = 153, T1DM n = 67, T2DM n = 232). Carotid intima-media thickness (IMT), renal resistive index (RRI), ankle-brachial index (ABI) and carotid-femoral Pulse Wave Velocity (cfPWV) were estimated. Furthermore, the levels of high-sensitive Troponin-T [hsTnT], N-terminal brain natriuretic peptide [NT-pro-BNP]) were measured.

RESULTS

PA values were lower in DM independently of age, gender, and BMI (estimated marginal means 6.21, 5.83, 5.95 for controls, T1DM, T2DM p < .05), a finding which persisted after propensity score matching. PA correlated negatively with IMT (r = -0.181), RRI (r = -0.374), cfPWV (r = -0.358), hsTnT (r = -0.238) and NT-pro-BNP (r = -0.318) (all p < .001). In multivariable analysis, the associations with RRI, cfPWV, hsTnT and NT-pro-BNP remained unchanged. PA values 6.0-6.5° for males and 5.2-5.8° for females were predictive of commonly used cutoffs. The combination of ΑCC/AHA ASCVD Score with PA outperformed either factor in predicting cfPWV, RRI for males and hsTnT, BNP for both genders.

CONCLUSIONS

PA exhibits independent correlations with various parameters pertinent to cardiovascular risk and may be useful for cardiovascular assessment.

Exercise and Ischemia-Activated Pathways in Limb Muscle Angiogenesis and Vascular Regeneration

Exercise has a profound effect on cardiovascular disease, particularly through vascular remodeling and regeneration. Peripheral artery disease (PAD) is one such cardiovascular condition that benefits from regular exercise or rehabilitative physical therapy in terms of slowing the progression of disease and delaying amputations. Various rodent pre-clinical studies using models of PAD and exercise have shed light on molecular pathways of vascular regeneration. Here, I review key exercise-activated signaling pathways (nuclear receptors, kinases, and hypoxia inducible factors) in the skeletal muscle that drive paracrine regenerative angiogenesis. The rationale for highlighting the skeletal muscle is that it is the largest organ recruited during exercise. During exercise, skeletal muscle releases several myokines, including angiogenic factors and cytokines that drive tissue vascular regeneration via activation of endothelial cells, as well as by recruiting immune and endothelial progenitor cells. Some of these core exercise-activated pathways can be extrapolated to vascular regeneration in other organs. I also highlight future areas of exercise research (including metabolomics, single cell transcriptomics, and extracellular vesicle biology) to advance our understanding of how exercise induces vascular regeneration at the molecular level, and propose the idea of "exercise-mimicking" therapeutics for vascular recovery.

Skeletal muscle regeneration failure in ischemic-damaged limbs is associated with pro-inflammatory macrophages and premature differentiation of satellite cells

BACKGROUND

Chronic limb-threatening ischemia (CLTI), a severe manifestation of peripheral arterial disease (PAD), is associated with a 1-year limb amputation rate of approximately 15-20% and substantial mortality. A key feature of CLTI is the compromised regenerative ability of skeletal muscle; however, the mechanisms responsible for this impairment are not yet fully understood. In this study, we aim to delineate pathological changes at both the cellular and transcriptomic levels, as well as in cell-cell signaling pathways, associated with compromised muscle regeneration in limb ischemia in both human tissue samples and murine models of CLTI.

METHODS

We performed single-cell transcriptome analysis of ischemic and non-ischemic muscle from the same CLTI patients and from a murine model of CLTI. In both datasets, we analyzed gene expression changes in macrophage and muscle satellite cell (MuSC) populations as well as differential cell-cell signaling interactions and differentiation trajectories.

RESULTS

Single-cell transcriptomic profiling and immunofluorescence analysis of CLTI patient skeletal muscle demonstrated that ischemic-damaged tissue displays a pro-inflammatory macrophage signature. Comparable results were observed in a murine CLTI model. Moreover, integrated analyses of both human and murine datasets revealed premature differentiation of MuSCs to be a key feature of failed muscle regeneration in the ischemic limb. Furthermore, in silico inferences of intercellular communication and in vitro assays highlight the importance of macrophage-MuSC signaling in ischemia induced muscle injuries.

CONCLUSIONS

Collectively, our research provides the first single-cell transcriptome atlases of skeletal muscle from CLTI patients and a murine CLTI model, emphasizing the crucial role of macrophages and inflammation in regulating muscle regeneration in CLTI through interactions with MuSCs.

Myogenesis Effects of RGX365 to Improve Skeletal Muscle Atrophy

Age-related skeletal muscle atrophy and weakness not only reduce the quality of life of those afflicted, but also worsen the prognosis of underlying diseases. We evaluated the effect of RGX365, a protopanaxatriol-type rare ginsenoside mixture, on improving skeletal muscle atrophy. We investigated the myogenic effect of RGX365 on mouse myoblast cells (C2C12) and dexamethasone (10 µM)-induced atrophy of differentiated C2C12. RGX365-treated myotube diameters and myosin heavy chain (MyHC) expression levels were analyzed using immunofluorescence. We evaluated the myogenic effects of RGX365 in aging sarcopenic mice. RGX365 increased myoblast differentiation and MyHC expression, and attenuated the muscle atrophy-inducing F-box (Atrogin-1) and muscle RING finger 1 (MuRF1) expression. Notably, one month of oral administration of RGX365 to 23-month-old sarcopenic mice improved muscle fiber size and the expression of skeletal muscle regeneration-associated molecules. In conclusion, rare ginsenosides, agonists of steroid receptors, can ameliorate skeletal muscle atrophy during long-term administration.

Six-month effects of supervised exercise on walking ability and health-related factors in peripheral arterial disease: a pilot study

BACKGROUND

In peripheral arterial disease (PAD) patients with intermittent claudication (IC), the combination of aerobic and resistance exercises could counteract muscle loss and attenuate disease progression. This study analyzed the effects of six months of a combined exercise program on walking ability, lower limb body composition, cardiovascular risk factors, and Ankle-Brachial Index (ABI).

METHODS

Twenty-three patients (age 63.2±1.5 years and ABI 0.58±0.07) with PAD and IC were allocated to a control group (CG) or a supervised exercise group (SUP). Ten patients underwent six months of treadmill walking combined with resistance exercises, three times a week. The CG (N.=13) received a recommendation for walking. All patients were measured at baseline (M0), after three months (M3), and six months (M6).

RESULTS

During constant treadmill protocol, the claudication onset time/distance (COT/COD), absolute claudication time/distance (ACT/ACD), and number of pauses of overall patients significantly improved at M3 and M6. Between groups were found significant differences in COT and COD at M6 (P=0.005 and P=0.007, respectively); and in ACT and ACD at M3 (P=0.003 for both) and at M6 (P=0.005 and P=0.005, respectively), with major improvements in the SUP. Over the six months, a significant group effect was found in fat-free mass (P=0.041) and predicted muscle mass (P=0.039) of the lower ABI leg, with greater improvements in the SUP.

CONCLUSIONS

A supervised exercise program that combines aerobic and resistance training improves PAD symptoms and has additional benefits for patients. Patients in the program showed improvements in walking ability, lower-limb body composition, perceived exertion, and heart rate during treadmill walking.

Association of AST/ALT (De Ritis) ratio with sarcopenia in a Chinese population of community-dwelling elderly

Background

The aspartate aminotransferase/alanine aminotransferase (AST/ALT) ratio, also known as De Ritis ratio, has been reportedly associated with malnutrition which plays a crucial role in sarcopenia. The aim of this study was to examine the relationship between AST/ALT ratio and sarcopenia in the Chinese community-dwelling elderly.

Methods

A cross-sectional study with 2751 participants (1343 men and 1408 women) aged ≥60 years was performed. Appendicular skeletal muscle mass index (ASMI), grip strength, and gait speed were measured to diagnose sarcopenia according to the latest Asian Working Group for Sarcopenia (AWGS) consensus. The association of AST/ALT ratio with sarcopenia was examined using logistic regression analysis.

Results

The prevalence of sarcopenia in the present study was 4.4%. AST/ALT ratio was higher in the sarcopenia group than in the non-sarcopenia group (1.30 ± 0.33 vs. 1.16 ± 0.62, P = 0.010). AST/ALT ratio was negatively correlated with the components of sarcopenia, including ASMI, grip strength, and gait speed. Logistic regression analysis indicated that high AST/ALT ratio (>1.20) was associated with increased risk of sarcopenia even after adjustment for potential confounders (adjusted OR = 2.33, 95%CI = 1.48-3.68, P < 0.001). Stratification analyses indicated that the association of high AST/ALT ratio with high risk of sarcopenia was more significant in males and the elderly with ≥70 years.

Conclusions

Our findings demonstrate that high AST/ALT ratio is associated with increased risk of sarcopenia in a Chinese population of community-dwelling elderly.

Time-course evolution of functional performance during a 3-month supervised exercise training program in patients with symptomatic peripheral artery disease

INTRODUCTION

Functional performance is impaired in patients with peripheral artery disease (PAD). The effects of a supervised exercise training (SET) program on functional performance have yet to be clearly determined. The aim was to investigate the time-course evolution of functional performance during a 3-month SET program.

METHODS

Patients with chronic symptomatic PAD participating in a 3-month SET program were investigated. Six-minute walking distance (6MWD), the stair climbing test (SCT), and the Short Physical Performance Battery (SPPB) were assessed before SET, after the first and second months of SET, and following the SET program. The ankle- and toe-brachial indices were measured before and after the SET program.

RESULTS

Ninety patients with PAD (age 65.4 ± 10.2 years) were analyzed. The 6MWD significantly improved after the first (+7%, p ⩽ 0.001) and second months (+13%, p ⩽ 0.001) and following SET (+14%, p ⩽ 0.001) compared to before the SET program. The 6MWD significantly improved after the 2nd month (+6%, p ⩽ 0.001) and following SET (+7%, p ⩽ 0.001) compared to after the first month of the SET program. The SPPB score and SCT performance significantly improved after the first (SPPB score: +9%, p ⩽ 0.001; SCT: +17%, p ⩽ 0.001) and second months (SPPB score: +11%, p ⩽ 0.001; SCT: +24%, p ⩽ 0.001) and following SET (SPPB score: +12%, p ⩽ 0.001; SCT: +25%, p ⩽ 0.001) compared to before the SET program. No significant differences were observed following SET compared to the second month of the SET program. Vascular parameters did not change significantly.

CONCLUSIONS

A 3-month SET program improves several components of functional performance, and adaptations mainly occur during the 1st and 2nd months of the SET program.

Diet-induced obesity augments ischemic myopathy and functional decline in a murine model of peripheral artery disease

Peripheral artery disease (PAD) causes an ischemic myopathy contributing to patient disability and mortality. Most preclinical models to date use young, healthy rodents with limited translatability to human disease. Although PAD incidence increases with age, and obesity is a common comorbidity, the pathophysiologic association between these risk factors and PAD myopathy is unknown. Using our murine model of PAD, we sought to elucidate the combined effect of age, diet-induced obesity and chronic hindlimb ischemia (HLI) on (1) mobility, (2) muscle contractility, and markers of muscle (3) mitochondrial content and function, (4) oxidative stress and inflammation, (5) proteolysis, and (6) cytoskeletal damage and fibrosis. Following 16-weeks of high-fat, high-sucrose, or low-fat, low-sucrose feeding, HLI was induced in 18-month-old C57BL/6J mice via the surgical ligation of the left femoral artery at 2 locations. Animals were euthanized 4-weeks post-ligation. Results indicate mice with and without obesity shared certain myopathic changes in response to chronic HLI, including impaired muscle contractility, altered mitochondrial electron transport chain complex content and function, and compromised antioxidant defense mechanisms. However, the extent of mitochondrial dysfunction and oxidative stress was significantly greater in obese ischemic muscle compared to non-obese ischemic muscle. Moreover, functional impediments, such as delayed post-surgical recovery of limb function and reduced 6-minute walking distance, as well as accelerated intramuscular protein breakdown, inflammation, cytoskeletal damage, and fibrosis were only evident in mice with obesity. As these features are consistent with human PAD myopathy, our model could be a valuable tool to test new therapeutics.

Negative association between triglyceride glucose index and BMI-adjusted skeletal muscle mass index in hypertensive adults

BACKGROUND

The triglyceride glucose (TyG) index, an indicator of insulin resistance, is often associated with adverse outcomes in various cardiovascular diseases, while hypertension is associated with an increased risk of cardiovascular diseases. As the loss of muscle mass in people with hypertension is poorly understood, the current study aimed to explore the relationship between TyG index and muscle mass in hypertensive population.

METHODS

We analyzed data from hypertensive adult participants in the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2018. The TyG index and body mass index (BMI)-adjusted skeletal muscle mass index (SMI) were calculated and the relationship between the two was evaluated using multivariable linear regression and restricted cubic spline (RCS) regression models.

RESULTS

A total of 1633 participants in the dataset were included for the final analysis. In the multivariable regression analysis, the adjusted β of SMI with a 95% confidence interval (CI) for the highest TyG index quartile was - 5.27 (- 9.79 to - 0.75), compared with the lowest quartile. A negative linear relationship between TyG index and SMI was plotted by RCS regression (nonlinear P = 0.128). Stratified models of non-smoking women of different ages also demonstrated that SMI decreased as TyG index increased (all P for trend < 0.05).

CONCLUSION

This linear and negative correlation between TyG index and SMI in hypertensive patients suggests that insulin resistance adversely affects muscle mass.

A Narrative Review of Non-Pharmacological Strategies for Managing Sarcopenia in Older Adults with Cardiovascular and Metabolic Diseases

This narrative review examines the mechanisms underlying the development of cardiovascular disease (CVD) and metabolic diseases (MDs), along with their association with sarcopenia. Furthermore, non-pharmacological interventions to address sarcopenia in patients with these conditions are suggested. The significance of combined training in managing metabolic disease and secondary sarcopenia in type II diabetes mellitus is emphasized. Additionally, the potential benefits of resistance and aerobic training are explored. This review emphasises the role of nutrition in addressing sarcopenia in patients with CVD or MDs, focusing on strategies such as optimising protein intake, promoting plant-based protein sources, incorporating antioxidant-rich foods and omega-3 fatty acids and ensuring sufficient vitamin D levels. Moreover, the potential benefits of targeting gut microbiota through probiotics and prebiotic fibres in sarcopenic individuals are considered. Multidisciplinary approaches that integrate behavioural science are explored to enhance the uptake and sustainability of behaviour-based sarcopenia interventions. Future research should prioritise high-quality randomized controlled trials to refine exercise and nutritional interventions and investigate the incorporation of behavioural science into routine practices. Ultimately, a comprehensive and multifaceted approach is essential to improve health outcomes, well-being and quality of life in older adults with sarcopenia and coexisting cardiovascular and metabolic diseases.

IGF-1 Therapy Improves Muscle Size and Function in Experimental Peripheral Arterial Disease

Lower-extremity peripheral arterial disease (PAD) has increased in prevalence, yet therapeutic development has remained stagnant. Skeletal muscle health and function has been strongly linked to quality of life and medical outcomes in patients with PAD. Using a rodent model of PAD, this study demonstrates that treatment of the ischemic limb with insulin-like growth factor (IGF)-1 significantly increases muscle size and strength without improving limb hemodynamics. Interestingly, the effect size of IGF1 therapy was larger in female mice than in male mice, highlighting the need to carefully examine sex-dependent effects in experimental PAD therapies.

Transcriptomic and Proteomic of Gastrocnemius Muscle in Peripheral Artery Disease

BACKGROUND

Few effective therapies exist to improve lower extremity muscle pathology and mobility loss due to peripheral artery disease (PAD), in part because mechanisms associated with functional impairment remain unclear.

METHODS

To better understand mechanisms of muscle impairment in PAD, we performed in-depth transcriptomic and proteomic analyses on gastrocnemius muscle biopsies from 31 PAD participants (mean age, 69.9 years) and 29 age- and sex-matched non-PAD controls (mean age, 70.0 years) free of diabetes or limb-threatening ischemia.

RESULTS

Transcriptomic and proteomic analyses suggested activation of hypoxia-compensatory mechanisms in PAD muscle, including inflammation, fibrosis, apoptosis, angiogenesis, unfolded protein response, and nerve and muscle repair. Stoichiometric proportions of mitochondrial respiratory proteins were aberrant in PAD compared to non-PAD, suggesting that respiratory proteins not in complete functional units are not removed by mitophagy, likely contributing to abnormal mitochondrial activity. Supporting this hypothesis, greater mitochondrial respiratory protein abundance was significantly associated with greater complex II and complex IV respiratory activity in non-PAD but not in PAD. Rate-limiting glycolytic enzymes, such as hexokinase and pyruvate kinase, were less abundant in muscle of people with PAD compared with non-PAD participants, suggesting diminished glucose metabolism.

CONCLUSIONS

In PAD muscle, hypoxia induces accumulation of mitochondria respiratory proteins, reduced activity of rate-limiting glycolytic enzymes, and an enhanced integrated stress response that modulates protein translation. These mechanisms may serve as targets for disease modification.

Sarcopenia and Cardiovascular Diseases

Sarcopenia is the loss of muscle strength, mass, and function, which is often exacerbated by chronic comorbidities including cardiovascular diseases, chronic kidney disease, and cancer. Sarcopenia is associated with faster progression of cardiovascular diseases and higher risk of mortality, falls, and reduced quality of life, particularly among older adults. Although the pathophysiologic mechanisms are complex, the broad underlying cause of sarcopenia includes an imbalance between anabolic and catabolic muscle homeostasis with or without neuronal degeneration. The intrinsic molecular mechanisms of aging, chronic illness, malnutrition, and immobility are associated with the development of sarcopenia. Screening and testing for sarcopenia may be particularly important among those with chronic disease states. Early recognition of sarcopenia is important because it can provide an opportunity for interventions to reverse or delay the progression of muscle disorder, which may ultimately impact cardiovascular outcomes. Relying on body mass index is not useful for screening because many patients will have sarcopenic obesity, a particularly important phenotype among older cardiac patients. In this review, we aimed to: (1) provide a definition of sarcopenia within the context of muscle wasting disorders; (2) summarize the associations between sarcopenia and different cardiovascular diseases; (3) highlight an approach for a diagnostic evaluation; (4) discuss management strategies for sarcopenia; and (5) outline key gaps in knowledge with implications for the future of the field.

Pro-inflammatory macrophages impair skeletal muscle regeneration in ischemic-damaged limbs by inducing precocious differentiation of satellite cells

Chronic limb-threatening ischemia (CLTI), representing the end-stage of peripheral arterial disease (PAD), is associated with a one-year limb amputation rate of ∼15-20% and significant mortality. A key characteristic of CLTI is the failure of the innate regenerative capacity of skeletal muscle, though the underlying mechanisms remain unclear. Here, single-cell transcriptome analysis of ischemic and non-ischemic muscle from the same CLTI patients demonstrated that ischemic-damaged tissue is enriched with pro-inflammatory macrophages. Comparable results were also observed in a murine CLTI model. Importantly, integrated analyses of both human and murine data revealed premature differentiation of muscle satellite cells (MuSCs) in damaged tissue and indications of defects in intercellular signaling communication between MuSCs and their inflammatory niche. Collectively, our research provides the first single-cell transcriptome atlases of skeletal muscle from CLTI patients and murine models, emphasizing the crucial role of macrophages and inflammation in regulating muscle regeneration in CLTI through interactions with MuSCs.

Peripheral arterial disease: A small and large vessel problem

Peripheral arterial disease (PAD) is one clinical manifestation of systemic atherosclerosis and is very common. Despite its prevalence, PAD remains underdiagnosed, undertreated, and understudied. The most common symptom in patients with PAD is intermittent claudication (IC), or pain in the lower extremities with walking or exertion, which is relieved after a short period of rest. Many patients with confirmed PAD are asymptomatic or have symptoms other than IC. Regardless of symptoms, patients with PAD have poor cardiovascular outcomes. PAD has largely been viewed a disease of large vessel atherosclerosis but what is becoming clear is that arterial plaques and occlusions are only one piece of the puzzle. Recent work has shown that abnormalities in the microvasculature contribute to the outcome of patients with PAD. From the perspective of the leg, limitation in blood flow is not the only problem as patients have a myriad of other problems, including muscle fibrosis, neuropathic changes, changes in the cellular respiration machinery and dysfunction of the small vessels that perfuse skeletal muscle and the supporting structures. Supervised exercise training remains one of the most effective tool to treat patients with PAD, however, the mechanisms behind its effectiveness are still being elucidated and use of structured exercise programs is not widespread. Medical therapy to treat systemic atherosclerosis is underutilized in patients with PAD. Invasive therapies are used only when patients with PAD have reached an advanced stage. While invasive strategies are effective in some patients with PAD, these strategies are costly, carry risk, and many patients are not amenable to invasive therapy. Appreciating the complex pathophysiology of PAD will hopefully spur new research and development of effective therapies for PAD.

Influence of lower limb ischemia on skeletal muscle mass depletion in patients with peripheral artery disease

OBJECTIVES

The aim of the study was to determine the change in skeletal muscle mass over time by bioelectrical impedance analysis (BIA) in patients with peripheral artery disease (PAD).

METHODS

Patients with symptomatic PAD visiting Tokyo Medical University Hospital between January 2018 and October 2020 were retrospectively analyzed. PAD was diagnosed based on ankle brachial pressure index (ABI) < 0.9 with either leg, and confirmed by duplex scan and/or computed tomography angiography as needed. Patients undergoing endovascular treatment, surgery, or supervised exercise therapy were excluded before and during the study period. Skeletal muscle mass of the extremities was measured using bioelectrical impedance analysis. The sum of skeletal muscle masses in the arms and legs was calculated as skeletal muscle mass index (SMI). Patients were scheduled to undergo BIA at an interval of 1 year.

RESULTS

Of 119 patients, 72 patients were included in the study. All patients were ambulatory and had symptoms of intermittent claudication (Fontaine's satge II). SMI significantly decreased from 6.98 ± 1.30 at baseline to 6.83 ± 1.29 at one-year follow-up. Individual skeletal muscle mass of the ischemic leg was significantly reduced after 1 year, but not in the non-ischemic leg. A decrease in SMI (defined as SMI ≥ 0.1 kg/m² per year) was independently associated with low ABI. The optimal cut-off value of ABI for the decrease in SMI was 0.72.

CONCLUSION

These results suggest that lower limb ischemia due to PAD, especially if ABI is <0.72 or less, may result in a decrease in skeletal muscle mass that affects health and physical function.

Development and Validation of a Multiparametric Semiquantitative Scoring System for the Histopathological Assessment of Ischaemia Severity in Skeletal Muscle

Skeletal muscle is one of the most abundant and dynamic tissues of the body, with a strong regenerative capacity. Muscle injuries can occur as a result of a variety of events, including tissue ischaemia. Lower limb ischaemia occurs when there is an insufficient nutrient and oxygen supply, often caused by stenosis of the arteries due to atherosclerosis. The aim of this study was to develop and validate a multiparametric scoring tool for assessing ischaemia severity in skeletal muscle in a commonly used preclinical animal model. Tissue ischaemia was surgically induced in mice by ligation and excision of the femoral artery. Calf muscles were carefully dissected, prepared for histological analysis, and scored for inflammation, fibrosis, necrosis, adipocyte infiltration, and muscle fibre degeneration/regeneration. Kendall’s coefficient of concordance (W) showed a very good agreement between the appraisers when scoring each individual histological feature: inflammation (W = 0.92, $p\le 0.001$ ), fibrosis (W = 0.94, $p\le 0.001$ ), necrosis (W = 0.77, $p\le 0.001$ ), adipocyte infiltration (W = 0.91, $p\le 0.001$ ), and fibre degeneration/regeneration (W = 0.86, $p\le 0.001$ ). Intrarater agreement was also excellent (W = 0.94 or more, $p\le 0.001$ ). There was a statistically significant negative association between the level of muscle ischaemia damage and the calf muscle weight and skeletal muscle fibre diameter. Here, we have developed and validated a new multiparametric, semiquantitative scoring system for assessing skeletal muscle damage due to ischaemia, with excellent inter- and intrarater reproducibility. This scoring system can be used for assessing treatment efficacy in preclinical models of hind limb ischaemia.

Epidemiology of sarcopenia: Prevalence, risk factors, and consequences

Sarcopenia is a geriatric condition featured by a progressive loss of muscle mass and function and associated with various adverse health outcomes. In this review, we aimed to summarize the epidemiological features of sarcopenia as well as consequences and risk factors of the disease. We performed a systematic review of meta-analysis on sarcopenia to collect data. The prevalence of sarcopenia varied between studies and depending on definition used. Sarcopenia was estimated to influence 10 %-16 % of the elderly worldwide. The prevalence of sarcopenia was higher among patients compared to general populations. The prevalence of sarcopenia ranged from 18 % in diabetic patients to 66 % in patients with unresectable esophageal cancer. Sarcopenia is associated with a high risk of a wide range of adverse health outcomes, including poor overall and disease-progression free survival rate, postoperative complications, and longer hospitalization in patients with different medical situations as well as falls and fracture, metabolic disorders, cognitive impairment, and mortality in general populations. Physical inactivity, malnutrition, smoking, extreme sleep duration, and diabetes were associated with an increased risk of sarcopenia. However, these associations were mainly based on non-cohort observational studies and need confirmation. High-quality cohort, omics, and Mendelian randomization studies are needed to deeply understand the etiological basis of sarcopenia.

Low muscle mass determined by psoas muscle area does not correlate with dual-energy x-ray absorptiometry or total lumbar muscle mass scores: A prospective cohort study of patients undergoing vascular surgery

Background/Objective: Low muscle mass and sarcopenia have been explored as risk factors for poor outcomes following vascular surgery. The findings have been variable. The use of a diverse range of techniques to identify low muscle mass is a confounder in establishing the true relationship between low muscle mass, sarcopenia and outcomes. Our aim was to establish if different scoring methods identified the same patients as sarcopenic. We also explored which method best predicted outcomes. Method: 70 patients undergoing vascular surgery were prospectively assessed for sarcopenia using dual-energy x-ray absorptiometry (DEXA) scan, grip strength and gait speed. These patients underwent abdominal CT imaging as routine care. The muscle mass of each patient was determined using DEXA and by both psoas muscle and total skeletal muscle area on CT, normalised for patient height (PMI and CT-SMI, respectively). Low muscle mass was defined by published age- and sex-specific cut-offs. Grip strength data was combined with muscle mass to define sarcopenic patients. One- and 3-year mortality and time to readmission was recorded. Conclusion and Results: 10-22% of patients had low muscle mass and 4-10% of patients were sarcopenic, depending on the method employed. PMI did not correlate with DEXA or CT-SMI for low muscle mass, but CT-SMI correlated with DEXA (p = 0.0007). For sarcopenia, CT-SMI and DEXA scoring correlated (p = 0.002); PMI correlated with CT-SMI (p = 0.0006) but not DEXA. Low muscle mass by PMI predicted 1-year mortality (p = 0.02, X2 = 5.34, Effect size = 1.04) but the applicability of this finding is limited by the diverse pathologies explored. No other method predicted 1- or 3-year mortality or readmissions in this heterogenous cohort. The psoas area did not correlate with muscle mass defined by DEXA or total lumbar skeletal muscle area. Low psoas muscle index may be an independent marker of poor outcome, unrelated to generalised sarcopenia, and this warrants investigation in specific pathologies. A lower total number of patients were sarcopenic than had been expected, emphasising the need to use population-based pre-defined cut-offs.

Sarcopenia is a risk factor for major adverse cardiac events after surgical revascularization for critical limb ischemia

OBJECTIVES

We examined the effect of sarcopenia on early surgical outcomes in patients with critical limb ischemia (CLI) in terms of major adverse cardiac events (MACE) and major adverse limb events (MALE), as well as the value of inflammatory markers of neutrophil-to-lymphocyte (NLR) and platelet-to-lymphocyte ratios (PLR) as indicators of sarcopenia in CLI patients.

METHODS

This was an observational retrospective single-center study. Patients who required surgical revascularization for CLI between October 2015 and December 2020 were identified. Psoas muscle areas were calculated from computed tomography images for psoas muscle index (PMI) calculations. Sarcopenia was defined as PMI < 5.5 cm²/m² for men and PMI < 4.0 cm²/m² for women. Risk factors for 30-day major adverse cardiac events (MACE) and major adverse limb events (MALE) were analyzed. NLR and PLR were compared between sarcopenic and non-sarcopenic patients.

RESULTS

The mean age of 217 study patients was 61.5 ± 10.9, and 16 (7.4%) patients were female. 82 (37.8%) patients were sarcopenic. Patients with sarcopenia were older (65.1 ± 9.3 vs 59.4 ± 11.2, p < .001) and history of myocardial infarction was more frequent (23.2% vs 12.6%, p = 0.042) among sarcopenic patients. Sarcopenic patients more frequently encountered MACE (9.8% vs 0.7%, p = 0.002), but not MALE. Sarcopenia increased early postoperative MACE in our cohort with an odds ratio of 11.925. NLR was not different between the two groups, while PLR was higher (127.16 vs 104.06, p = 0.010) among sarcopenic patients. The platelet-to-lymphocyte ratio of 125.11 had a sensitivity of 53.7% and a specificity of 68.1% for differentiating sarcopenia.

CONCLUSIONS

Sarcopenia was associated with more frequent 30-day MACE and perioperative mortality after revascularization for CLI. 30-day MALE was not increased in patients with sarcopenia. The use of PLR as a simple marker of sarcopenia is limited by its low sensitivity and specificity.

Insights into Pathogenesis, Nutritional and Drug Approach in Sarcopenia: A Systematic Review

Sarcopenia is a multifactorial condition related to the loss of muscle mass and strength due to aging, eating habits, physical inactivity, or even caused by another disease. Affected individuals have a higher risk of falls and may be associated with heart disease, respiratory diseases, cognitive impairment, and consequently an increased risk of hospitalization, in addition to causing an economic impact due to the high cost of care during the stay in hospitals. The standardization of appropriate treatment for patients with sarcopenia that could help reduce pathology-related morbidity is necessary. For these reasons, this study aimed to perform a systematic review of the role of nutrition and drugs that could ameliorate the health and quality of life of sarcopenic patients and PRISMA guidelines were followed. Lifestyle interventions have shown a profound impact on sarcopenia treatment but using supplements and different drugs can also impact skeletal muscle maintenance. Creatine, leucine, branched-chain amino acids, omega 3, and vitamin D can show benefits. Although with controversial results, medications such as Metformin, GLP-1, losartan, statin, growth hormone, and dipeptidyl peptidase 4 inhibitors have also been considered and can alter the sarcopenic's metabolic parameters, protect against cardiovascular diseases and outcomes, while protecting muscles.

Combined Effect of Dynapenia and Abdominal Obesity on the Prevalence of Peripheral Artery Disease in Older Adults Over 75 Years Old in China

The objective is to examine the separate and joint effects of dynapenia and abdominal obesity on the prevalence of peripheral artery disease (PAD) in older adults of different ages (60-74 and over 75 years old). This study comprised 1293 community-dwelling Chinese participants recruited from Shanghai, China, who were aged at least 60 years (753 women; mean age: 72.0 ± 5.9 years). Dynapenia was defined as low-grip strength (<28.0 kg for males and <18.0 kg for females) but normal skeletal muscle index (≥7.0 kg/m² for males and ≥5.7 kg/m² for females). Abdominal obesity was determined according to waist circumference (≥90 cm for males and ≥85 cm for females), and PAD was diagnosed by an ankle-brachial index  ≤ 0.9. Binary logistic regression models were performed to determine associations between dynapenia, abdominal obesity, and the combination of dynapenia and abdominal obesity and PAD. According to dynapenia and abdominal obesity status stratified by age (60-74 or over 75), the patients were divided into 4 groups: normal, dynapenia alone, abdominal obesity alone, and co-occurring groups. A logistic regression showed that the co-occurring groups (odds ratio = 4.63, 95% confidence interval = 1.41-15.21) had a higher prevalence of PAD than the normal group after adjusting for the covariates in older adults over 75 years of age. The combination of dynapenia and abdominal obesity increase the prevalence of PAD in older adults over 75 years. The present findings have important implications for the early identification of older adults with PAD and appropriate interventions should be implemented.

Lower-extremity muscle wasting in patients with peripheral arterial disease: quantitative measurement and evaluation with CT

OBJECTIVES

Lower-extremity peripheral arterial disease (PAD) results in limb ischemia and is strongly associated with sarcopenia. This study aimed to retrospectively evaluate the association between the quantity of muscle mass in the lower extremities and the severity of vascular stenosis in PAD patients.

METHODS

Between January 2018 and August 2021, 128 patients with PAD and 53 individuals without PAD, diagnosed by computed tomography, were enrolled. The severity of stenosis of lower-extremity arteries was measured using a grading system. The muscle and fat mass areas were calculated in the abdomen at the L3 or L4 level, mid-thigh, and lower leg. Multivariable logistic regression was conducted to clarify the risk associated with low muscle mass. The difference in muscle mass between PAD and non-PAD patients was evaluated by using propensity score matching.

RESULTS

A strong positive correlation between the abdomen muscle area and leg muscle area was observed. The muscle area and muscle index of the leg were lower in PAD patients. These changes occurred earlier than in the abdomen muscle area. The group with more severe artery stenosis had more muscle wasting in the lower extremities. Greater age, female, lower BMI, and PAD were associated with low muscle mass. After propensity score matching, the leg muscle area was still lower in PAD patients.

CONCLUSIONS

There is a direct association between PAD and regional muscle wasting. This occurs earlier regionally in the lower extremities than in central muscles. Early diagnosis of PAD might prevent progressive muscle loss, improving disease outcome and quality of life.

KEY POINTS

• Peripheral arterial disease is strongly associated with sarcopenia. • Muscle wasting in the lower extremities is earlier and more prominent than that in the abdomen. • More severe arterial stenoses are associated with higher muscle wasting in the lower extremities.

Discrimination between possible sarcopenia and metabolic syndrome using the arterial pulse spectrum and machine-learning analysis

Sarcopenia is defined as decreased skeletal muscle mass and function, and is an important cause of frailty in the elderly, also being associated with vascular lesions and poor microcirculation. The present study aimed to combine noninvasive pulse measurements, frequency-domain analysis, and machine learning (ML) analysis (1) to determine the effects on the pulse waveform induced by sarcopenia and (2) to develop discriminating models for patients with possible sarcopenia. Radial blood pressure waveform (BPW) signals were measured noninvasively for 1 min in 133 subjects who visited Tri-Service General Hospital for geriatric health checkups. They were assigned to a robust group and a possible-sarcopenia group that combined dynapenia, presarcopenia, and sarcopenia. Two classification methods were used: ML analysis and a self-developed scoring system that used 40 harmonic pulse indices as features: amplitude proportions and their coefficients of variation, and phase angles and their standard deviations. Significant differences were found in several spectral indices of the BPW between possible-sarcopenia and robust subjects. Threefold cross-validation results indicated excellent discrimination performance, with AUC equaling 0.77 when using LDA and 0.83 when using our scoring system. The present noninvasive and easy-to-use measurement and analysis method for detecting sarcopenia-induced changes in the arterial pulse transmission condition could aid the discrimination of possible sarcopenia.

Sarcopenia and cardiovascular disease in patients with and without kidney disease: what do we know?

Cardiovascular disease (CVD) incidence is high in patients with chronic kidney disease (CKD) and is the most frequent cause of mortality in this population. Advanced age, hypertension, uremic toxins, endothelial dysfunction, atherosclerosis, hyperhomocysteinemia, oxidative stress, and inflammation are among the leading causes of increased CVD in advanced stages of CKD. Although defined as a decrease in muscle strength associated with aging, sarcopenia is also prevalent in CKD patients. Sarcopenia causes physical disability, low quality of life, and mortality. Regular exercise and nutritional supplementation may slow the progression of sarcopenia. Recent studies have shown that sarcopenia increases the risk of CVD and mortality in people with or without kidney disease. This review discusses the relationship between sarcopenia and CVD in light of the current literature.

Ultrasound-assessed diaphragm dysfunction predicts clinical outcomes in hemodialysis patients

Skeletal muscle atrophy is prevalent and remarkably increases the risk of cardiovascular (CV) events and mortality in hemodialysis (HD) patients. However, whether diaphragm dysfunction predicts clinical outcomes in HD patients is unknown. This was a prospective cohort study of 103 HD patients. After assessment of diaphragm function by ultrasonography and collection of other baseline data, a 36-month follow-up was then initiated. Participants were divided into diaphragm dysfunction (DD+) group and normal diaphragm function (DD−) group, according to cutoff value of thickening ratio (i.e. the change ratio of diaphragm thickness) at force respiration. The primary endpoint was the first nonfatal CV event or all-cause mortality. A secondary endpoint was less serious CV events (LSCEs, a composite of heart failure readmission, cardiac arrhythmia or myocardial ischemia needed pharmacological intervention in hospital). 98 patients were eligible to analysis and 57 (58.16%) were men. 28 of 44 patients(63.64%) in DD+ group and 23 of 54 patients (42.59%) in DD− group had at least one nonfatal CV event or death (p = 0.038). Compared to DD− group, DD+ group had significantly higher incidence of LSCEs (21 vs.14, p = 0.025) and shorter survival time (22.02 ± 12.98 months vs. 26.74 ± 12.59 months, p = 0.046). Kaplan–Meier analysis revealed significantly higher risks of primary endpoint (p = 0.039), and LSCEs (p = 0.040) in DD+ group. Multivariate hazard analysis showed that DD+ group had significantly higher risk of primary endpoint [hazard ratio (HR) 1.59; 95% confident interval (CI) 1.54–1.63], and LSCEs (HR 1.47; 95%CI 1.40–1.55). Ultrasound-assessed diaphragm dysfunction predicts clinical outcomes in HD patients.

Trial registration: This study was registered with Chinese Clinical Trials Registry (www.chictr.org.cn) as ChiCTR1800016500 on Jun 05, 2018.