Identification of possible cigarette smoke constituents responsible for muscle catabolism

Dynamics for High-Sensitivity Detection of Free Radicals in Primary Bronchial Epithelial Cells upon Stimulation with Cigarette Smoke Extract

Chronic obstructive pulmonary disease (COPD), the third leading cause of death worldwide, is caused by chronic exposure to toxic particles and gases, such as cigarette smoke. Free radicals, which are produced during a stress response to toxic particles, play a crucial role in disease progression. Measuring these radicals is difficult since the complex mixture of chemicals within cigarette smoke interferes with radical detection. We used a new quantum sensing technique called relaxometry to measure free radicals with nanoscale resolution on cells from COPD patients and healthy controls exposed to cigarette smoke extract (CSE) or control medium. Epithelial cells from COPD patients display a higher free radical load than those from healthy donors and are more vulnerable to CSE. We show that epithelial cells of COPD patients are more susceptible to the damaging effects of cigarette smoke, leading to increased release of free radicals.

Effects of cigarette smoking associated with sarcopenia in persons 60 years and older: a cross-sectional study in Zhejiang province

PURPOSE

Smoking is a risk factor for sarcopenia. Nevertheless, few studies analyzed the independent effects of various smoking dimensions (duration, intensity, cumulative dose) on sarcopenia risk. This is a cross-sectional study based on an older population in Zhejiang Province to determine which smoking dimensions are mainly important for sarcopenia risk and to explore the dose-response relationship between them.

METHODS

Our study included 783 patients with sarcopenia and 4918 non-sarcopenic individuals. Logistic regression and restricted cubic with logistic regression (for nonlinear dose effects) were used to obtain odds ratios (ORs) and 95% confidence intervals as well as restricted cubic splines (RCS) curves.

RESULTS

Compared with never-smokers, current smokers had an increased risk of sarcopenia (OR = 1.786; 95% CI 1.387-2.301) after adjusting for confounders such as age, sex, education, alcohol consumption, disease history, etc. There was no significant association between smoking intensity and sarcopenia after more than 20 cigarettes per day (OR = 1.484; 95% CI 0.886-2.487), whereas the risk of sarcopenia increased significantly with increasing duration of smoking after more than 40 years (OR = 1.733; 95% CI 1.214-2.473). Meanwhile, there was a significant non-linear dose-response relationship between smoking duration or intensity and the risk of sarcopenia. However, the risk of sarcopenia increased linearly with the number of pack-years of smoking, which is not a significant nonlinear dose-response relationship.

CONCLUSIONS

This study indicated the association between smoking and sarcopenia. Both smoking duration and cumulative dose were significantly and positively associated with sarcopenia. These findings reflect the important role of the number of years of smoking in increasing the risk of sarcopenia and provide scientific evidence that different smoking dimensions may influence the risk of the sarcopenia.

A simple framework to distinguish 'individualistic' from a 'uniform rate' of ageing within or between study populations

Ageing is accompanied by a progressive decline in physiological functions. It is often argued that the rate of ageing differs between people and is 'highly individualistic'. This view is not unequivocally shared, and others have argued that the rate of ageing is rather 'uniform'. Distinguishing conclusively between these views requires longitudinal data, but these are difficult to obtain as they require decades of data collection from individuals. Here, a simple framework is proposed to assess in cross-sectional data whether in a given population the rate is 'highly individualistic' or rather 'uniform'. It is illustrated that an age-related decrease in the standard deviation (SD) of a certain parameter combined with a non-changing coefficient of variation (COVAR) reflects a 'uniform' rate of ageing, whilst an increase or decrease in COVAR with or without a concomitant increase in SD reflects a 'highly individualistic' rate of ageing. This framework is applied to some published data, focussing on muscle strength, power and physical function for the sake of illustration, and it is suggested that most studies do in fact show a 'highly individualistic' rate of ageing, perhaps apart from a 'uniform' rate of ageing in master athletes.

Cigarette smoking inhibits myoblast regeneration by promoting proteasomal degradation of NPAT protein and hindering cell cycle progression

Cigarette smoking (CS) causes skeletal muscle dysfunction, leading to sarcopenia and worse prognosis of patients with diverse systemic diseases. Here, we found that CS exposure prevented C2C12 myoblasts proliferation in a dose-dependent manner. Immunoblotting assays verified that CS exposure promoted the expression of cell cycle suppressor protein p21. Furthermore, CS exposure significantly inhibited replication-dependent (RD) histone transcription and caused S phase arrest in the cell cycle during C2C12 proliferation. Mechanistically, CS deregulated the expression levels of Nuclear Protein Ataxia-Telangiectasia Locus (NPAT/p220). Notably, the proteasome inhibitor MG132 was able to reverse the expression of NPAT in myoblasts, implying that the degradation of CS-mediated NPAT is proteasome-dependent. Overexpression of NPAT also rescued the defective proliferation phenotype induced by CS in C2C12 myoblasts. Taken together, we suggest that CS exposure induces NPAT degradation in C2C12 myoblasts and impairs myogenic proliferation through NPAT associated proteasomal-dependent mechanisms. As an application of the proteasome inhibitor MG132 or overexpression of NPAT could reverse the impaired proliferation of myoblasts induced by CS, the recovery of myoblast proliferation may be potential strategies to treat CS-related skeletal muscle dysfunction.

Resistance training prevents damage to the mitochondrial function of the skeletal muscle of rats exposed to secondary cigarette smoke

AIM

To analyze the consumption of oxygen and to quantify the mitochondrial respiratory chain proteins (OXPHOS) in the gastrocnemius muscle of rats exposed to cigarette smoke and/or RT practitioners.

MAIN METHODS

Wistar rats were divided into groups: Control (C), Smoker (S), Exercise (E) and Exercise Smoker (ES). Groups F and ES were exposed to the smoke of 4 cigarettes for 30 min, 2× a day, 5× a week, for 16 weeks. Groups E and ES performed four climbs with progressive load, 1× per day, 5× per week, for 16 weeks. The gastrocnemius muscle was collected for analysis of OXPHOS content and oxygen consumption. Groups S (vs. C) and ES (vs. C and E) showed lower body weight gain when observing the evolution curve.

KEY FINDINGS

The S rats showed a reduction in the NDUFB8 proteins of complex 1, SDHB of complex 2, MTC01 of complex 4 and ATP5A of complex 5 (ATP Synthase) compared to Group C. Additionally, S rats also showed increased consumption of O2 in Basal, Leak, Complex I and I/II combined measures compared to the other groups, suggesting that the activity of the mitochondria of these animals increased in terms of coupling and uncoupling parameters.

SIGNIFICANCE

Our data suggest that exposure to cigarette smoke for 16 weeks is capable of causing impairment of mitochondrial function with reduced expression of respiratory chain proteins in skeletal muscle. However, the RT was effective in preventing impairment of mitochondrial function in the skeletal muscle of rats exposed to secondary cigarette smoke.

The Impact of Tobacco Cigarettes, Vaping Products and Tobacco Heating Products on Oxidative Stress

Cells constantly produce oxidizing species because of their metabolic activity, which is counteracted by the continuous production of antioxidant species to maintain the homeostasis of the redox balance. A deviation from the metabolic steady state leads to a condition of oxidative stress. The source of oxidative species can be endogenous or exogenous. A major exogenous source of these species is tobacco smoking. Oxidative damage can be induced in cells by chemical species contained in smoke through the generation of pro-inflammatory compounds and the modulation of intracellular pro-inflammatory pathways, resulting in a pathological condition. Cessation of smoking reduces the morbidity and mortality associated with cigarette use. Next-generation products (NGPs), as alternatives to combustible cigarettes, such as electronic cigarettes (e-cig) and tobacco heating products (THPs), have been proposed as a harm reduction strategy to reduce the deleterious impacts of cigarette smoking. In this review, we examine the impact of tobacco smoke and MRPs on oxidative stress in different pathologies, including respiratory and cardiovascular diseases and tumors. The impact of tobacco cigarette smoke on oxidative stress signaling in human health is well established, whereas the safety profile of MRPs seems to be higher than tobacco cigarettes, but further, well-conceived, studies are needed to better understand the oxidative effects of these products with long-term exposure.

Upper Extremity Function following Transradial Percutaneous Coronary Intervention: Results of the ARCUS Trial

Objectives. To determine the incidence of upper extremity dysfunction (UED), after a transradial percutaneous coronary intervention (TR-PCI). Background. Transradial approach (TRA) is the preferred approach for coronary interventions. However, upper extremity complications may be underreported. Methods. The ARCUS was designed as a prospective cohort study, including 502 consecutive patients admitted for PCI. Patients treated with transfemoral PCI (TF-PCI) acted as a control group. A composite score of physical examinations and questionnaires was used for determining UED. Clinical outcomes were monitored during six months of follow-up, with its primary endpoint at two weeks. Results. A total of 440 TR-PCI and 62 control patients were included. Complete case analysis (n = 330) at 2 weeks of follow-up showed that UED in the TR-PCI group was significantly higher than that in the TF-PCI group: 32.7% versus 13.9%, respectively ( $p=0.04$ ). The three impaired variables most contributing to UED were impaired elbow extension, wrist flexion, and extension. Multivariate logistic regression showed that smokers were almost three times more likely to develop UED. Conclusions. This study demonstrates that UED seems to occur two times more in TR-PCI than in TF-PCI at 2 weeks of follow-up. However, no significant long-term difference or difference between the intervention arm and the contralateral arm was found at all timepoints.

Association between serum 25-hydroxyvitamin d and myeloperoxidase: A cross-sectional study of a general population in China

Background

Several studies have found a strong association between cardiovascular diseases and myeloperoxidase (MPO) as a marker of oxidative stress. Although the anti-inflammatory effects of vitamin D in adults have been validated, evidence about the relationship between MPO and 25(OH)D is lacking. This study aimed to investigate the relationship between MPO and 25(OH)D in the general Chinese population.

Methods

From November 2018 to August 2019, a total of 6414 subjects were enrolled in a tertiary referral hospital in China, which included 3,122 women and 3,292 men. The dependent and independent variables were MPO and 25(OH)D, respectively. The confounders included age, sex, body mass index, waist-hip ratio, smoking status, alcohol drinking status, calcium, and parathyroid hormone concentration.

Results

In the fully adjusted model, we found that MPO decreased by 0.12 (95% CI −0.16, −0.08), ng/mL for each unit (1 nmol/L) increase in 25(OH)D. When 25(OH) D was divided into quartiles, compared with Q1 (< 41.4 nmol/L), the adjusted beta coefficients (β) of MPO in Q2–Q4 were −2.29 (95% CI, −4.31 to −0.27), −4.76 (95% CI, −6.83 to −2.69), and −6.07 (95% CI, −8.23 to −3.92), respectively (P for the trend < 0.0001). When 25(OH) D was divided according to clinical severity, compared with the severely deficient (< 30 nmol/L) s≥ 30, < 50 nmol/L) and sufficient groups (≥ 50 nmol/L) were −2.59 (95% CI, −5.87 to 0.69) and −5.87 (95% CI, −9.17 to −2.57), respectively (P for the trend < 0.0001).

Conclusion

After adjusting for age, sex, BMI, waist-hip ratio, smoking status, alcohol status, calcium, and PTH, circulating 25(OH)D was negatively associated with MPO.

The 8th Wonder of the Cancer World: Esophageal Cancer and Inflammation

Esophageal cancer is a devastating malignancy which can be detected at an early stage but is more often diagnosed as an advanced process. It affects both men and women and inflicts the young and the elderly. There are multiple underlying factors involved in the pathogenesis of this cancer including inflammation. The interplay of these factors promotes inflammation through various mechanisms including the recruitment of pro-inflammatory cells, mediators such as cytokines, reactive oxygen species, and interleukins, among others. The presentation can vary widely with one of the most notable symptoms being dysphagia. Diagnosis is based on clinical symptomatology, imaging and endoscopy with biopsy. Once the diagnosis has been established, treatment and prognosis are based on the stage of the disease. This review outlines esophageal cancer and its link to inflammation in relation to pathogenesis, along with clinical features, diagnosis and treatment.

Effects of cigarette smoking on the association between respiratory muscle strength and skeletal muscle mass in middle-aged and older adults: the Wakayama Study

PURPOSE

This study aimed to examine whether cumulative smoking exposure affects the association between peak expiratory flow rate (PEFR) and skeletal muscle mass in middle-aged and older adults.

METHODS

The study participants comprised 832 community-dwelling individuals aged 50-89 years (mean age: 69 years) without chronic obstructive pulmonary disease. Bioelectrical impedance analysis was performed to estimate the skeletal muscle mass of each participant. PEFR was assessed using an electronic spirometer. Cumulative smoking exposure was expressed in pack years, that is a product of the average number of packs of cigarettes smoked per day and smoking duration in years.

RESULTS

The whole-body skeletal muscle mass progressively reduced with decreasing PEFR levels in both males and females. In the multiple regression analysis, PEFR was found to be significantly associated with skeletal muscle mass, independent of the potential confounding factors. When participants were stratified based on the cumulative smoking exposure, the association between low PEFR and reduced skeletal muscle mass persisted in individuals with non-smoking and light-to-moderate smoking exposure (< 30 pack-years). However, this association was not clearly observed in individuals with heavy smoking exposure (≥ 30 pack-years).

CONCLUSION

The findings of this study support the notion that PEFR declines with a reduction in systemic skeletal muscle mass due to aging. However, chronic cigarette smoking induces respiratory dysfunction exceeding the expected values by age, and thus a low PEFR level may not be used as a marker of reduced muscle mass in older adults exposed to heavy smoking.

The immediate effect of thoracolumbar manipulation and diaphragmatic release on inspiratory muscle strength in healthy smokers: A randomized clinical trial

BACKGROUND

Diaphragmatic release technique and thoracolumbar manipulation have been found effective in restoring normal diaphragmatic movement in healthy and diseased populations. Smoking has deleterious effects on human systems, including the musculoskeletal system.

OBJECTIVE

The current study aimed to investigate the immediate effects of diaphragmatic release technique and thoracolumbar manipulation on diaphragm muscle strength in healthy smokers.

METHODS

A double-blinded randomized clinical trial was conducted on 30 asymptomatic healthy smokers randomly assigned into two groups [intervention group (IG) and sham group (SG)] with 15 participants each. The IG received thoracolumbar manipulation and diaphragmatic release techniques, while the SG received no active treatment. The outcome measure was sniff nasal inspiratory pressure (SNIP).

RESULTS

The IG showed a significant increase in the SNIP with a mean difference of 20.13 cmH2O (95% CI: 13.62-26.64; P< 0.001), while the SG had a reduction in the SNIP value -3.27 cmH2O (95% CI: -0.65 to -5.89; P= 0.02). Diaphragmatic release technique and thoracolumbar manipulation significantly improved SNIP values immediately after the intervention, with a between-group difference of 31.07 cmH2O (95% CI: 15.26-46.87; P< 0.001).

CONCLUSIONS

Diaphragmatic release technique and thoracolumbar manipulation increased the diaphragm strength in healthy adult smokers, suggesting its potential utility in the management of participants with reduced respiratory muscle strength.

Conversion of Fused Hip to Total Hip Arthroplasty: Long-Term Clinical and Radiological Outcomes

BACKGROUND

Despite promising results at the mid-term followup, several aspects of conversion of the fused hip to total hip arthroplasty (THA) remain controversial. The aim of this study was to evaluate clinical and radiological outcomes with a minimum 5-year followup in patients who underwent conversion of the fused hip to THA.

METHODS

Fifty-seven patients (59 hips) were evaluated. The Harris Hip Score (HHS), range of motion (ROM), and the Visual Analogue Scale (VAS) were used to assess hip function and low back pain. Subjective satisfaction with surgery and the presence of the Trendelenburg sign was also evaluated. Radiological assessment was performed pre- and postoperatively to evaluate loosening and heterotopic ossification (HO).

RESULTS

After a mean followup of 13.0 ± 6.2 years, HHS and VAS significantly improved from 46.0 ± 16.7 to 80.8 ± 18.8 and from 4.4 ± 1.5 to 2.1 ± 1.4 (both P < .001), respectively. Twenty-three patients (40.4%) had a positive Trendelenburg sign, and HOs were found in 29 cases (49.1%). An overall 29.8% complication rate was noted. Smoking habits and rheumatoid arthritis were predictive of Trendelenburg sign (P = .046 and P = .038, respectively). Implant survival rate as the end point was 98.7 ± 1.3% at 5 years, 92.4 ± 3.3% at 10 years, 82.1 ± 5.7% at 15 years, and 73.4 ± 8.0% at 20 and 25 years. A worse cumulative implant survival rate was noted in patients who underwent previous hip surgery, defined as any hip operation before fusion (P = .005).

CONCLUSION

Conversion of the fused hip to hip arthroplasty provides high levels of hip functionality and satisfaction with surgery at long-term followup. An implant survival rate higher than 70% can be expected 25 years postoperatively.

[Association of Cigarette Smoking with Muscle Mass Reduction and Low Muscle Strength in Community-Dwelling Elderly Men]

OBJECTIVES

Recently, attention has been paid to the impact of cigarette smoking on skeletal muscles, as its underlying pathophysiological mechanism has been gradually elucidated. In this study, we aimed to examine whether cigarette smoking is associated with muscle mass reduction and low muscle strength in elderly men.

METHODS

The study participants comprised 417 community-dwelling elderly men (aged 73±6 years) without severe glucose intolerance, chronic kidney disease, or liver disease. Bioelectrical impedance analysis was performed to estimate appendicular skeletal muscle mass (ASM), which was normalized for height (ASM index, kg/m²). Handgrip strength (HGS) was measured using a Smedley grip dynamometer. Cumulative smoking exposure level during a lifetime was expressed in pack-years, which is a product of the average number of packs of cigarettes smoked per day and smoking duration in years.

RESULTS

When the participants were stratified on the basis of cumulative smoking exposure (<10 pack-years, 10-39 pack-years, ≥40 pack-years), the ASM index and HGS progressively decreased with increasing exposure level (P for trend <0.01). In multiple regression analysis, heavy smoking (defined as ≥40 pack-years) was found to be a significant determinant of the ASM index and HGS, independent of potential confounding factors. Among former smokers, the subgroup that quit smoking for ≥20 years had a significantly higher ASM index and HGS than the subgroup that quit smoking for <10 years. The duration of smoking cessation was significantly associated with the ASM index and HGS, even after adjusting for cumulative smoking exposure.

CONCLUSIONS

These findings suggest that cigarette smoking contributes to the loss of muscle mass and function in elderly men and that smoking cessation could reverse the impact of cigarette smoking on skeletal muscles.

Physical Exercise-Mediated Changes in Redox Profile Contribute to Muscle Remodeling After Passive Hand-Rolled Cornhusk Cigarette Smoke Exposure

Consumption of non-traditional cigarettes has increased considerably worldwide, and they can induce skeletal muscle dysfunction. Physical exercise has been demonstrated to be important for prevention and treatment of smoking-related diseases. Therfore, the aim of this study was to investigate the effects of combined physical exercise (aerobic plus resistance exercise) on muscle histoarchitecture and oxidative stress in the animals exposed chronically to smoke from hand-rolled cornhusk cigarette (HRCC). Male Swiss mice were exposed to ambient air or passively to the smoke of 12 cigarettes over three daily sessions (four cigarettes per session) for 30 consecutive days with or without combined physical training. 48 h after the last training session, total leukocyte count was measured in bronchoalveolar lavage fluid (BALF), and the quadriceps were removed for histological/immunohistochemical analysis and measurement of oxidative stress parameters. The effects of HRCC on the number of leukocytes in BALF, muscle fiber diameter, central nuclei, and nuclear factor kappa B (NF-κB) were reverted after combined physical training. In addition, increased myogenic factor 5, tumor necrosis factor alpha (TNFα), reduced transforming growth factor beta (TGF-β), and nitrate levels were observed after physical training. However, the reduction in superoxide dismutase and glutathione/glutathione oxidized ratio induced by HRCC was not affected by the training program. These results suggest the important changes in the skeletal muscle brought about by HRCC-induced alteration in the muscle redox profile. In addition, combined physical exercise contributes to remodeling without disrupting muscle morphology.

Cigarette Smoking Is Associated With Lower Quadriceps Cross-sectional Area and Attenuation in Older Adults

INTRODUCTION

In addition to well-established links with cardiovascular and respiratory diseases, cigarette smoking may affect skeletal muscle; however, associations with quadriceps atrophy, density, and function are unknown. This study explored the associations of current and former smoking with quadriceps muscle area and attenuation as well as muscle force (assessed as knee extension peak torque) and rate of torque development-a measure of muscle power in older adults.

METHODS

Data from 4469 older adults, aged 66-95 years at baseline in the Age, Gene/Environment Susceptibility-Reykjavik Study with measurements of thigh computed tomography, isometric knee extension testing, self-reported smoking history, and potential covariates were analyzed.

RESULTS

Sex differences were observed in these data; therefore, our final analyses are stratified by sex. In men, both former smokers and current smokers had lower muscle area (with β= -0.10, 95% confidence interval [CI] = -0.17 to -0.03 and β = -0.19, 95% CI = -0.33 to -0.05, respectively) and lower muscle attenuation (ie, higher fat infiltration, β = -0.08, 95% CI = -0.16 to -0.01 and β = -0.17, 95% CI = -0.34 to -0.01, respectively) when compared with never smokers. Smoking status was not associated with male peak torque or rate of torque development. In women, current smoking was associated with lower muscle attenuation (β = -0.24, 95% CI = -0.34 to -0.13) compared to never smoking. Among female smokers (current and former), muscle attenuation and peak torque were lower with increasing pack-years.

CONCLUSIONS

Results suggest that cigarette smoking is related to multiple muscle properties at older age and that these relationships may be different among men and women.

IMPLICATIONS

This article presents novel data, as it examined for the first time the relationship between smoking and computed tomography-derived quadriceps muscle size (cross-sectional area) and attenuation. This study suggests that current cigarette smoking is related to higher muscle fat infiltration, which may have significant health implications for the older population, because of its known association with poor physical function, falls, and hip fractures.

What are the factors associated with sarcopenia-related variables in adult women with severe obesity?

BACKGROUND

Understanding the association between sarcopenia-related variables and several risk factors may help to implement interventions aimed at preventing its occurrence by reducing or controlling the identified risk factors. Although changes in body composition occur in both sexes, in women, muscle loss is accentuated due to decreased estrogen levels following menopause. This study aims to determine the factors associated with sarcopenia-related parameters in middle-aged women identified with class II/III obesity (body mass index [BMI] ≥ 35 kg/m2).

METHODS

The study included 104 women with severe obesity (40.23 ± 8.49 years) with an average body fat percentage of 52.45 ± 4.14%. Sarcopenia was assessed using total appendicular skeletal muscle mass (ASMM), appendicular skeletal muscle mass index (ASMMI), and appendicular skeletal muscle mass adjusted by BMI (ASMM/BMI) as evaluated using dual energy X-ray absorptiometry (DXA). Hand grip strength (HGS) and HGS adjusted by BMI (HGS/BMI) were evaluated using dynamometry. Functional performance was assessed using the walking speed test (WS). The explanatory variables were age, lifestyle, comorbidities, food consumption, and metabolic parameters. A multivariate linear regression was performed.

RESULTS

Factors associated with sarcopenia-related variables in 104 severely obese women with a mean BMI of 43.85 kg/m2 were as follows: ASMMI negatively correlated with serum levels of tetraiodothyronine (T4) and tobacco use; ASMM/BMI negatively correlated with age, serum T4 levels, and diabetes; ASMM negatively correlated with T4 serum levels and diabetes; HGS negatively correlated with age and hypercholesterolemia, and positively correlated with low-density lipoprotein cholesterol (LDL-c); HGS/BMI negatively correlated with age and hypercholesterolemia and positively correlated with LDL-c; and WS negatively correlated with hypothyroidism and diabetes.

CONCLUSION

In severely obese women, muscle mass and function were inversely associated with age, smoking status, endocrine parameters, hypercholesterolemia, and comorbidities such as diabetes. Thus, the results of this investigation are relevant in supporting the development of clinical interventions to aid in the prevention of sarcopenia in adult women with severe obesity.

Cigarette Smoking Exacerbates Skeletal Muscle Injury without Compromising Its Regenerative Capacity

Skeletal muscle dysfunction in patients with chronic obstructive pulmonary disease negatively impacts quality of life and survival. Cigarette smoking (CS) is the major risk factor for chronic obstructive pulmonary disease and skeletal muscle dysfunction; however, how CS affects skeletal muscle function remains enigmatic. To examine the impact of CS on skeletal muscle inflammation and regeneration, male BALB/c mice were exposed to CS for 8 weeks before muscle injury was induced by barium chloride injection, and were maintained on the CS protocol for up to 21 days after injury. Barium chloride injection resulted in architectural damage to the tibialis anterior muscle, resulting in a decrease contractile function, which was worsened by CS exposure. CS exposure caused muscle atrophy (reduction in gross weight and myofiber cross-sectional area) and altered fiber type composition (31% reduction of oxidative fibers). Both contractile function and loss in myofiber cross-sectional area by CS exposure gradually recovered over time. Satellite cells are muscle stem cells that confer skeletal muscle the plasticity to adapt to changing demands. CS exposure blunted Pax7⁺ centralized nuclei within satellite cells and thus prevented the activation of these muscle stem cells. Finally, CS triggered muscle inflammation; in particular, there was an exacerbated recruitment of F4/80⁺ monocytic cells to the site of injury along with enhanced proinflammatory cytokine expression. In conclusion, CS exposure amplified the local inflammatory response at the site of skeletal muscle injury, and this was associated with impaired satellite cell activation, leading to a worsened muscle injury and contractile function without detectable impacts on the recovery outcomes.

Salidroside mitigates skeletal muscle atrophy in rats with cigarette smoke-induced COPD by up-regulating myogenin and down-regulating myostatin expression

OBJECTIVES

The present study aimed at investigating the therapeutic effect of Salidroside on skeletal muscle atrophy in a rat model of cigarette smoking-induced chronic obstructive pulmonary disease (COPD) and its potential mechanisms.

METHODS

Male Wistar rats were randomized, and treated intraperitoneally (IP) with vehicle (injectable water) or a low, medium or high dose of Salidroside, followed by exposure to cigarette smoking daily for 16 weeks. A healthy control received vehicle injection and air exposure. Their lung function, body weights and gastrocnemius (GN) weights, grip strength and cross-section area (CSA) of individual muscular fibers in the GN were measured. The levels of TNF-α, IL-6, malondialdehyde (MDA), superoxide dismutase (SOD), glutathione (GSH) in serum and GN tissues as well as myostatin and myogenin expression in GN tissues were measured.

RESULTS

In comparison with that in the healthy control, long-term cigarette smoking induced emphysema, significantly impaired lung function, reduced body and GN weights and CSA values in rats, accompanied by significantly increased levels of TNF-α, IL-6 and MDA, but decreased levels of SOD and GSH in serum and GN tissues. Furthermore, cigarette smoking significantly up-regulated myostatin expression, but down-regulated myogenin expression in GN tissues. Salidroside treatment decreased emphysema, significantly ameliorated lung function, increased antioxidant, but reduced MDA, IL-6 and TNF-α levels in serum and GN tissues of rats, accompanied by decreased myostain, but increased myogenin expression in GN tissues.

CONCLUSION

Salidroside mitigates the long-term cigarette smoking-induced emphysema and skeletal muscle atrophy in rats by inhibiting oxidative stress and inflammatory responses and regulating muscle-specific transcription factor expression.

Association between Cigarette Smoking and Sarcopenia according to Obesity in the Middle-Aged and Elderly Korean Population: The Korea National Health and Nutrition Examination Survey (2008-2011)

Background

The definition of sarcopenia focuses on muscle mass and function. Sarcopenic obesity is the relative excess of fat tissue with decreased muscle mass. We examined the association between cigarette smoking and sarcopenia according to obesity in middle-aged and elderly Koreans.

Methods

We conducted a cross-sectional study of 9,385 subjects (age ≥50 years) based on data from the fourth and fifth Korea National Health and Nutrition Examination Surveys (2008–2011). Smoking groups were categorized by smoking status and the number of cigarettes smoked daily. Sarcopenia was defined as weight-adjusted appendicular skeletal muscle mass of 2 standard deviations below the sex-specific mean for young adults. Obesity was defined as fat mass ≥30% for men and ≥40% for women. Subjects were categorized into three groups: sarcopenic obese (SO), sarcopenic non-obese (SNO), and normal. Multiple logistic regression analysis was performed to assess the association between smoking and SNO and SO.

Results

Among men, current smokers were more associated with SNO than never-smokers (adjusted odds ratio [OR], 3.34; 95% confidence interval [CI], 1.09–10.26). However, there was no significant association between smoking status and SNO in women or SO in either sex. Among current smokers, moderate smokers (11–20 cigarettes/d) were more likely to be SNO (adjusted OR, 5.81; 95% CI, 1.12–30.31) and heavy smokers (>20 cigarettes/d) were more likely to be SO (adjusted OR, 9.53; 95% CI, 1.65–55.01) than light smokers (<11 cigarettes/d).

Conclusion

In men, smoking was positively associated with SNO, and heavy smokers were more likely to be SO than light smokers.

Injury Occurrence and Return to Dance in Professional Ballet: Prospective Analysis of Specific Correlates

Professional ballet is a highly challenging art, but studies have rarely examined factors associated with injury status in ballet professionals. This study aimed to prospectively examine gender-specific correlates of injury occurrence and time-off from injury in professional ballet dancers over a one-year period. The participants were 99 professional ballet dancers (41 males and 58 females). Variables included: (i) predictors: sociodemographic data (age, educational status), ballet-related factors (i.e., experience in ballet, ballet status), cigarette smoking, alcohol drinking, and consumption of illicit drugs; and (ii) outcomes: injury occurrence and time-off from injury. Participants were questioned on predictors at the beginning of the season, while data on outcomes were collected continuously once per month over the study period. Dancers reported total of 196 injuries (1.9 injuries (95% CI: 1.6–2.3) per dancer in average), corresponding to 1.4 injuries per 1000 dance-hours (95% CI: 1.1–1.7). In females, cigarette smoking was a predictor of injury occurrence in females (OR: 4.33, 95% CI: 1.05–17.85). Alcohol drinking was a risk factor for absence from dance in females (OR: 1.29, 95% CI: 1.01–4.21) and males (OR: 1.21, 95% CI: 1.05–3.41). Less experienced dancers were more absent from dance as a result of injury than their more experienced peers (Mann-Whitney Z: 2.02, p < 0.04). Ballet dancers and their managers should be aware of the findings of this study to make informed decisions on their behavior (dancers) or to initiate specific programs aimed at the prevention of substance use and misuse in this profession (managers).

Ideal cardiovascular health associated with fatty liver: Results from a multi-ethnic survey

BACKGROUND AND AIMS

Little is known about the role of liver enzymes as predictors of non-liver-related morbidity and mortality. The ideal cardiovascular health (CVH) score proposed by the American Heart Association (AHA) can be used to predict mortality and morbidity. We investigated the association of the CVH score with liver enzymes and the risk of non-alcoholic fatty liver disease (NAFLD) among US adults.

METHODS

By using the National Health and Nutrition Examination Survey database (cross-sectional), the CVH score was calculated as meeting ideal levels of the following components: 4 behaviors (smoking, body mass index, physical activity and diet adherence) and 3 factors (total cholesterol, blood pressure and fasting glucose).

RESULTS

Individuals with a higher CVH score ("better CVH") had a more favorable profile of liver biomarkers. Adjusted (for age, gender, race, poverty to income ratio, education, marital status and alcohol intake) linear regression indicated significant and negative associations between liver biomarkers and CVH score: (β = -0.069, p < 0.001) for alanine aminotransferase, (β = -0.095, p < 0.001), aspartate aminotransferase, (β = -0.067, p < 0.001), alkaline phosphatase and (β = -0.125, p < 0.001) and fatty liver index. In the logistic regression, with the same confounders, individuals with a higher CVH score had 12% less likelihood of NAFLD compared with those with a lower score. Furthermore, each CVH metric separately was inversely linked to the risk of NAFLD.

CONCLUSIONS

For the first time among US adults, our findings shed light on the role CVH on liver biomarkers.

Association of betel nut chewing with exercise performance in a military male cohort: the CHIEF study

INTRODUCTION

Betel nut chewing may cause obesity, neurohormonal activation and inflammation, possibly impairing exercise performances.

METHODS

We examined the cross-sectional association in 4388 military male adults aged 18-50 years from the cardiorespiratory fitness in armed forces study in Taiwan between 2013 and 2014. The status of betel nut chewing was classified as current and former/never based on each participant's response to a questionnaire. Physical fitness was evaluated by three basic exercise tests including 3000 m running, 2 min sit-ups and 2 min push-ups. Multiple logistic regression for the best 10% and the worst 10% performers in each exercise, and linear regression were used to determine the relationship.

RESULTS

There were 564 current chewers and 3824 non-current chewers for the analysis. The linear regression shows that current betel nut chewing was positively correlated with 3000 m running duration (r=0.37, p=0.042) after adjusting for age, service specialty, body mass index, exercise frequency and alcohol intake. In addition, the logistic regression shows that as compared with non-current chewers, current chewers had lower odds of being the top 10% performers in 2 min push-ups and higher odds of being the bottom 10% performers in 2 min sit-ups (ORs and 95% CIs: 0.71 (0.50 to 0.99) and 1.32 (1.00 to 1.75), respectively). However, the associations between betel nut chewing and physical fitness were all insignificant after further adjusting for current smoking.

CONCLUSIONS

Our findings suggest that the impairment of physical fitness associated with betel nut chewing of military young men might be mainly mediated or moderated by the coexisted cigarette smoking.

Skeletal Muscle Pathophysiology: The Emerging Role of Spermine Oxidase and Spermidine

Skeletal muscle comprises approximately 40% of the total body mass. Preserving muscle health and function is essential for the entire body in order to counteract chronic diseases such as type II diabetes, cardiovascular diseases, and cancer. Prolonged physical inactivity, particularly among the elderly, causes muscle atrophy, a pathological state with adverse outcomes such as poor quality of life, physical disability, and high mortality. In murine skeletal muscle C2C12 cells, increased expression of the spermine oxidase (SMOX) enzyme has been found during cell differentiation. Notably, SMOX overexpression increases muscle fiber size, while SMOX reduction was enough to induce muscle atrophy in multiple murine models. Of note, the SMOX reaction product spermidine appears to be involved in skeletal muscle atrophy/hypertrophy. It is effective in reactivating autophagy, ameliorating the myopathic defects of collagen VI-null mice. Moreover, spermidine treatment, if combined with exercise, can affect D-gal-induced aging-related skeletal muscle atrophy. This review hypothesizes a role for SMOX during skeletal muscle differentiation and outlines its role and that of spermidine in muscle atrophy. The identification of new molecular pathways involved in the maintenance of skeletal muscle health could be beneficial in developing novel therapeutic lead compounds to treat muscle atrophy.

Independent and combined effect of bilirubin and smoking on the progression of chronic kidney disease

Objective

Whether serum bilirubin and cigarette smoking affect the risk of renal function decline remains inconclusive. We aimed to test the independent and combined effects of bilirubin and cigarette smoking on the progression of chronic kidney disease (CKD) in hypertensive adults.

Methods

The study population consisted of 12,633 patients in the renal sub-study of the China Stroke Primary Prevention Trial. The primary outcome was progression of CKD, defined as a decrease in estimated glomerular filtration rate (eGFR) of ≥30% and to a level of <60 mL/min/1.73 m² if baseline eGFR was ≥60 mL/min/1.73 m², or a decrease in eGFR of ≥50% if baseline eGFR was <60 mL/min/1.73 m², or end-stage renal disease. The secondary outcomes included 1) rapid decline in renal function and 2) annual rate of eGFR decline.

Results

The median follow-up duration was 4.4 years. Cigarette smoking had no significant effect on the progression of CKD (odds ratio [OR]: 1.11, 95% confidence interval [95% CI]: 0.78-1.57). However, a significantly lower risk of the primary event (OR: 0.72, 95% CI: 0.55-0.95) was found in participants in tertile 3 compared to those in tertiles 1-2 for total bilirubin (TBiL) levels. More importantly, there was an interaction between TBiL and smoking status on the primary outcome (P for interaction =0.013). Among ever smokers, TBiL levels had no significant effect on the primary outcome. However, among never smokers, higher TBiL levels were significantly associated with a lower risk of the primary outcome (tertile 3 vs 1-2; OR: 0.53, 95% CI: 0.36-0.78). Similar trends were observed for direct bilirubin and secondary outcomes.

Conclusion

Among hypertensive patients, bilirubin was inversely associated with the progression of CKD in never smokers, but not in ever smokers.

Ideal cardiovascular health predicts lower risk of abnormal liver enzymes levels in the Chilean National Health Survey (2009-2010)

High levels of gamma glutamyltransferase (gamma-GT) and alanine aminotransferase (ALT), as well as fatty liver index (FLI) has been associated with higher cardiovascular disease risk factors in adults. The aim of this study was to examine the relationship between gamma-GT, ALT, and fatty liver index FLI levels across a gradient number of ideal cardiovascular health metrics in a representative sample of adults from the Chilean National Health Survey 2009-2010. Data from 1,023 men and 1,449 women (≥ 15 years) from the Chilean Health Survey 2009-2010 were analyzed. Ideal cardiovascular health was defined as meeting ideal levels of the following components: four behaviours (smoking, body mass index, physical activity and diet adherence) and three factors (total cholesterol, blood pressure and fasting glucose). Adults were grouped into three categories according to their number of ideal cardiovascular health metrics: ideal (5-7 metrics), intermediate (3-4 metrics), and poor (0-2 metrics). Blood levels of gamma-GT and ALT were measured and the FLI was calculated. A higher number of ideal cardiovascular health index metric was associated with lower gamma-GT, ALT and FLI (p from trend analysis <0.001). Also, adults meeting at least 3-4 metrics were predicted less likely to have prevalence of abnormal levels of gamma-GT and FLI (p<0.001) compared to adults who met only 0-2 metrics. These findings reinforce the usefulness of the ideal cardiovascular health metrics proposed by the American Heart Association as a tool to identify target subjects and promote cardiovascular health in South-American adults.

Handgrip Strength and Ideal Cardiovascular Health among Colombian Children and Adolescents

OBJECTIVE

To evaluate the association between handgrip strength and ideal cardiovascular health (CVH) in Colombian children and adolescents.

STUDY DESIGN

During the 2014-2015 school years, we examined a cross-sectional component of the FUPRECOL (Association for Muscular Strength with Early Manifestation of Cardiovascular Disease Risk Factors among Colombian Children and Adolescents) study. Participants included 1199 (n = 627 boys) youths from Bogota (Colombia). Handgrip strength was measured with a standard adjustable hand held dynamometer and expressed relative to body mass (handgrip/body mass) and as absolute values in kilograms. Ideal CVH, as defined by the American Heart Association, was determined as meeting ideal levels of the following components: 4 behaviors (smoking status, body mass index, cardiorespiratory fitness, and diet) and 3 factors (total cholesterol, blood pressure, and glucose).

RESULTS

Higher levels of handgrip strength (both absolute and relative values) were associated with a higher frequency of ideal CVH metrics in both sexes (P for trend ≤ .001). Also, higher levels of handgrip strength were associated with a greater number of ideal health behaviors (P for trend < .001 in both boys and girls), and with a higher number of ideal health factors in boys (P for trend < .001). Finally, levels of handgrip strength were similar between ideal versus nonideal glucose or total cholesterol groups in girls.

CONCLUSIONS

Handgrip strength was strongly associated with ideal CVH in Colombian children and adolescents, and thus supports the relevance of early targeted interventions to promote strength adaptation and preservation as part of primordial prevention.

The role of E3 ubiquitin-ligases MuRF-1 and MAFbx in loss of skeletal muscle mass

The ubiquitin-proteasome system (UPS) is the main regulatory mechanism of protein degradation in skeletal muscle. The ubiquitin-ligase enzymes (E3s) have a central role in determining the selectivity and specificity of the UPS. Since their identification in 2001, the muscle specific E3s, muscle RING finger-1 (MuRF-1) and muscle atrophy F-box (MAFbx), have been shown to be implicated in the regulation of skeletal muscle atrophy in various pathological and physiological conditions. This review aims to explore the involvement of MuRF-1 and MAFbx in catabolism of skeletal muscle during various pathologies, such as cancer cachexia, sarcopenia of aging, chronic kidney disease (CKD), diabetes, and chronic obstructive pulmonary disease (COPD). In addition, the effects of various lifestyle and modifiable factors (e.g. nutrition, exercise, cigarette smoking, and alcohol) on MuRF-1 and MAFbx regulation will be discussed. Finally, evidence of potential strategies to protect against skeletal muscle wasting through inhibition of MuRF-1 and MAFbx expression will be explored.

Paraoxsonase2 (PON2) and oxidative stress involvement in pomegranate juice protection against cigarette smoke-induced macrophage cholesterol accumulation

Exposure to cigarette smoke (CS) promotes various stages of atherosclerosis development. Macrophages are the predominant cells in early atherogenesis, and the polyphenolic-rich pomegranate juice (PJ) is known for its protective role against macrophage atherogenicity. The aim of the current study was to examine the atherogenic effects of CS on macrophages, and to evaluate the protective effects of PJ against CS-induced macrophage atherogenicity. Murine J774A.1 macrophages were treated with CS-exposed medium in the absence or presence of PJ. Parameters of lipid peroxidation in CS-exposed medium were measured by the lipid peroxides and thiobarbituric acid reactive substances (TBARS) assays. Atherogenicity of macrophages incubated with increasing concentrations of CS-exposed medium was assessed by cytotoxicity, oxidative stress determined by generation of reactive oxygen species (ROS) using DCFH-DA, activity of the cellular anti-oxidant paraoxonase2 (PON2), macrophage accumulation of cholesterol and triglycerides, as well as through high density lipoprotein (HDL)-mediated cholesterol efflux from the cells. CS exposure resulted in significant and dose-dependent increases in lipid peroxides and TBARS medium levels (up to 3 and 8-fold, respectively). Incubation of macrophages with CS-exposed medium resulted in dose-dependent increases in macrophage damage/injury (up to 6-fold), intracellular ROS levels (up to 31%), PON2 activity (up to 2-fold), and macrophage cholesterol content (up to 24%). The latter might be explained by reduced HDL-mediated cholesterol efflux from CS-exposed macrophages (by 21%). PJ protected macrophages from CS-induced increases in intracellular ROS levels and cholesterol accumulation, as well as the attenuated efflux of cholesterol. These data indicate that CS stimulates macrophage oxidation and activates PON2 as a possible compensatory response to the oxidative burden. CS impairs HDL-mediated cholesterol efflux from macrophages leading to cellular accumulation of cholesterol. The atherogenic and oxidative effects of CS are attenuated by PJ, a polyphenolic-rich anti-oxidant.

Sarcopenia-related features and factors associated with lower muscle strength and physical performance in older Chinese: a cross sectional study

BACKGROUND

The associations of sarcopenia with adverse health status have highlighted the importance of sarcopenia research and intervention. This study was designed to analyze the characteristics of aging-related differences in appendicular skeletal muscle mass (ASM), handgrip strength (HS), gait speed (GS) and their associated factors in older Chinese, in order to generate guidance for sarcopenia intervention in this population.

METHODS

Population-based cross-sectional study. The criteria proposed by Asian Working Group for Sarcopenia were used to define low ASM, HS, and GS. The time required for five repeated chair stands (RCS) was also measured to evaluate physical performance. The differences of continuous variables were compared using one-way ANOVA tests and the Pearson correlation was used to analyze the relationship of each measurement adjusted by gender and age. Stepwise logistic regression was used to determine associated factors of low HS and low physical performance.

RESULTS

The data were analyzed in a total of 218 younger adults (aged 20-59, 76 males, 142 females) and 461 older adults (≥60 year, 207 males and 254 females). There were significant differences among age groups for HS, GS, and RCS while females were found to have significantly lower HS and GS values. ASM was significantly correlated with HS but not with other measures. Correlations among HS and GS, RCS were influenced by age differences. In the older group, unstructured daily routine (OR = 2.77) was associated with the risk of low GS, while physical exercise (OR = 0.27), and engaging in hobbies (OR = 0.11) were associated with faster GS. Co-morbidity (OR = 1.99) was associated with the risk of reduced performance of RCS, while engaging in hobbies was associated with faster RCS performance (OR = 0.35).

CONCLUSIONS

Muscle strength and physical performance varied with aging in older Chinese. Measures of GS, HS, and RCS provide a readily available and effective method for assessing the risk of functional mobility decline. Maintaining a healthy life style and physical activity throughout life is beneficial for older people to improve their physical performance, especially in the early stages of aging.

Frequency of sarcopenia and associated factors among hospitalized elderly patients

Background

Sarcopenia is an important public health problem that affects mainly elders, and has negative consequences, such as disability and even death. Due to the lack of studies evaluating sarcopenia in elderly persons hospitalized in Brazil, the aim of the present study was to describe the frequency of sarcopenia and associated factors among elders in a hospital in the city of Salvador - Brazil.

Methods

This cross-sectional study included 110 hospitalized elderly patients in a multi-specialty hospital in Salvador-BA, Brazil. Inclusion criteria: were elders aged ≥60 years between the first and fifth day of hospitalization; who were able to walk without external assistance; with medical permission to walk, and who did not take vasoactive and inotropic drugs. The diagnosis of sarcopenia was determined by combining the reduction in skeletal muscle mass with muscle weakness (women, <20 kg; men, <30 kg) and/or poor physical performance (gait speed ≤0.8 m/s). To obtain reduced skeletal muscle mass, the skeletal muscle mass index ≤6.37 kg/m² for women and ≤8.90 kg/m² for men was used. Cognitive function, Charlson index, admission profile (clinical and surgical), smoking, falls suffered in the last year and physical inactivity prior to admission were also evaluated. The frequency of sarcopenia was described in percentages with their respective confidence intervals and logistic regression was performed for multivariate analysis of factors associated with sarcopenia.

Results

Among the 110 patients included, the frequency of sarcopenia was 21.8%, with 10.0% being of the severe type. There was a predominance of clinical profile (59.1%), such as heart disease (20.0%), pneumonia (13.6%) and skin infections (9.1%), with a Charlson index of 5.4 ± 1.8. The factors associated with sarcopenia were age (OR = 1.14; 95% CI = 1.06 to 1.23), clinical profile on admission (OR = 5.15; 95% CI = 1.16–22.9) and smoking (OR = 7.8; 95% CI = 1.53–39.9).

Conclusions

The frequency of sarcopenia in elderly hospitalized patients was high (1 in 5 elderly) and anthropometric equation can be a viable and inexpensive alternative to screening and programming intervention in this population.

Smoking cessation-related weight gain--beneficial effects on muscle mass, strength and bone health

AIMS

To examine the effects of smoking cessation on body composition and muscle strength in comparison with continued smoking.

DESIGN AND SETTING

Twelve-month longitudinal study of adult smokers conducted in Haifa, Israel.

PARTICIPANTS

Eighty-one smokers recruited from a smoking cessation programme combining group counselling and varenicline treatment.

MEASUREMENTS

Measurements were taken at the beginning of the programme and after 12 months. Body composition was assessed by dual-energy X-ray absorptiometry. Muscle strength was measured by handgrip dynamometry and predicted one-repetition maximum tests. Dietary intake and physical activity levels were estimated using questionnaires. Smoking status was determined by urine cotinine. The effect of smoking cessation was assessed using univariate and multivariable linear regression analyses.

FINDINGS

Forty-one participants (age 44 ± 12 years) completed all baseline and follow-up measurements (76% continued smokers; 24% quitters). All measures of body composition and muscle strength were increased among quitters when compared with continued smokers. Adjusted differences [95% confidence interval (CI)] between quitters and smokers were: body weight 4.43 kg (1.56-7.31 kg); lean mass 1.26 kg (0.24-2.28 kg); fat mass 3.15 kg (0.91-5.39 kg); bone mineral content 48.76 g (12.06-85.54 g); bone mineral density 0.024 g/cm(2) (0.004-0.043 g/cm(2) ); handgrip strength 3.6 kg (1.12-6.08 kg); predicted one-repetition maximum of chest press 7.85 kg (1.93-13.76 kg); and predicted one-repetition maximum of leg press 17.02 kg (7.29-26.75 kg).

CONCLUSIONS

Smoking cessation is associated with weight gain mainly through accumulating extra fat, but is also associated with increased muscle mass, muscle strength and bone density.

The environmental pollutant cadmium induces homeostasis alteration in muscle cells in vitro

BACKGROUND

Cadmium (Cd) is a heavy metal widely distributed throughout the environment as a result of contamination from a variety of sources. It exerts toxic effects in many tissues but scarce data are present as yet on potential effects on skeletal muscle tissue.

AIM

To evaluate the potential alteration induced by Cd in skeletal muscle cells.

MATERIALS AND METHODS

C2C12 skeletal muscle cells were treated with Cd at different times of cellular differentiation and gene expression was evaluated.

RESULTS

Exposure to Cd decreased significantly p21 mRNA expression and strongly up-regulated cyclin D1 mRNA expression in committed cells and in differentiated myotubes. Moreover, myogenin, fast MyHC-IIb and slow MyHC-I mRNAs expression were also significantly decreased both in committed cells and in myotubes. Moreover, Cd exposure induced a strong increase of Pax3, Pax7 and Myf5 mRNAs expression and stimulated an up-regulation of IL6 and TNF-α proinflammatory cytokines.

CONCLUSION

These data lead to hypothesize that environmental Cd exposure might trigger an injury-like event in muscle tissue, possibly by an estrogen receptor-mediated mechanism.

Pathophysiology of tobacco smoke exposure: recent insights from comparative and redox proteomics

First-hand and second-hand tobacco smoke are causally linked to a huge number of deaths and are responsible for a broad spectrum of pathologies such as cancer, cardiovascular, respiratory, and eye diseases as well as adverse effects on female reproductive function. Cigarette smoke is a complex mixture of thousands of different chemical species, which exert their negative effects on macromolecules and biochemical pathways, both directly and indirectly. Many compounds can act as oxidants, pro-inflammatory agents, carcinogens, or a combination of these. The redox behavior of cigarette smoke has many implications for smoke related diseases. Reactive oxygen and nitrogen species (both radicals and non-radicals), reactive carbonyl compounds, and other species may induce oxidative damage in almost all the biological macromolecules, compromising their structure and/or function. Different quantitative and redox proteomic approaches have been applied in vitro and in vivo to evaluate, respectively, changes in protein expression and specific oxidative protein modifications induced by exposure to cigarette smoke and are overviewed in this review. Many gel-based and gel-free proteomic techniques have already been used successfully to obtain clues about smoke effects on different proteins in cell cultures, animal models, and humans. The further implementation with other sensitive screening techniques could be useful to integrate the comprehension of cigarette smoke effects on human health. In particular, the redox proteomic approach may also help identify biomarkers of exposure to tobacco smoke useful for preventing these effects or potentially predictive of the onset and/or progression of smoking-induced diseases as well as potential targets for therapeutic strategies.

Musculoskeletal disorders in chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) is a lung disease characterized by airway obstruction and inflammation but also accompanied by several extrapulmonary consequences, such as skeletal muscle weakness and osteoporosis. Skeletal muscle weakness is of major concern, since it leads to poor functional capacity, impaired health status, increased healthcare utilization, and even mortality, independently of lung function. Osteoporosis leads to fractures and is associated with increased mortality, functional decline, loss of quality of life, and need for institutionalization. Therefore, the presence of the combination of these comorbidities will have a negative impact on daily life in patients with COPD. In this review, we will focus on these two comorbidities, their prevalence in COPD, combined risk factors, and pathogenesis. We will try to prove the clustering of these comorbidities and discuss possible preventive or therapeutic strategies.

Peroxynitrite induces degradation of myosin heavy chain via p38 MAPK and muscle-specific E3 ubiquitin ligases in C2 skeletal myotubes

Oxidative stress and inflammation play an important role in the catabolism of skeletal muscles. Recently, cigarette smoke (CS) was shown to stimulate muscle catabolism by activation of p38 MAPK and up-regulation of the muscle-specific E3 ubiquitin ligases (E3s) atrogin-1 and MuRF1 which are over-expressed during muscle atrophy. Peroxynitrite (ONOO-), an oxidative ingredient of CS, also produced during oxidative stress and inflammation, was previously shown to induce ubiquitination and degradation of muscle proteins. To investigate the involvement of p38 MAPK and the muscle-specific E3s in ONOO--induced muscle catabolism, C2 myotubes, differentiated from a myoblast cell line, were exposed to ONOO- (25 μM) in a time-dependent manner. Following exposure, degradation of myosin heavy chain (MyHC) and actin, activation of p38 MAPK, and levels of atrogin-1 and MuRF1 were studied by Western blotting. Peak phosphorylation of p38 MAPK was observed at 1 h of ONOO- exposure. ONOO- caused a significant increase in the levels of atrogin-1 and MuRF1. In accordance, a significant decrease in MyHC levels was observed in a time-dependent manner. These findings support previous studies in which the catabolic effects of ONOO- were shown. In addition, ONOO- was demonstrated to induce degradation of muscle proteins by activation of p38 MAPK and up-regulation of the muscle-specific E3s atrogin-1 and MuRF1.

The effects of acetaldehyde and acrolein on muscle catabolism in C2 myotubes

The toxic aldehydes acetaldehyde and acrolein were previously suggested to damage skeletal muscle. Several conditions in which exposure to acetaldehyde and acrolein is increased were associated with muscle wasting and dysfunction. These include alcoholic myopathy, renal failure, oxidative stress, and inflammation. A main exogenous source of both acetaldehyde and acrolein is cigarette smoking, which was previously associated with increased muscle catabolism. Recently, we have shown that exposure of skeletal myotubes to cigarette smoke stimulated muscle catabolism via increased oxidative stress, activation of p38 MAPK, and upregulation of muscle-specific E3 ubiquitin ligases. In this study, we aimed to investigate the effects of acetaldehyde and acrolein on catabolism of skeletal muscle. Skeletal myotubes differentiated from the C2 myoblast cell line were exposed to acetaldehyde or acrolein and their effects on signaling pathways related to muscle catabolism were studied. Exposure of myotubes to acetaldehyde did not promote muscle catabolism. However, exposure to acrolein caused increased generation of free radicals, activation of p38 MAPK, upregulation of the muscle-specific E3 ligases atrogin-1 and MuRF1, degradation of myosin heavy chain, and atrophy of myotubes. Inhibition of p38 MAPK by SB203580 abolished acrolein-induced muscle catabolism. Our findings demonstrate that acrolein but not acetaldehyde activates a signaling cascade resulting in muscle catabolism in skeletal myotubes. Although within the limitations of an in vitro study, these findings indicate that acrolein may promote muscle wasting in conditions of increased exposure to this aldehyde.

Cigarette smoking and musculoskeletal disorders

Cigarette smoking has deleterious effects on the musculo-skeletal system. The loss of bone mineral content and increased incidence of fractures are the best known negative consequences. The pathogenesis is complex, due to direct toxic effects on osteoblasts/osteoclasts activity of nicotine, and indirect actions on sex and adrenocortical hormones, vitamin D, intestinal calcium absorption, vessels and oxygen supply. Smoking may favour the onset or aggravate the progression of rheumatoid arthritis and back pain. Negative influences have been observed on muscle and on tendons. Moreover, smoking habit is associated to a number of short term post-operative complications and higher resource consumption. Smoking cessation is highly advisable with positive effects on the bone metabolism on the long term. More positive and immediate results can be obtained in patients submitted to orthopedic surgery: the healing process is improved, the frequency of complications is reduced, and the length of hospital stay is shortened.

Exposure to secondhand smoke promotes sympathetic activity and cardiac muscle cachexia

Recent trials demonstrated that a single brief exposure to secondhand smoke (SHS) generates acute adverse health effects. We evaluated the acute (immediately after exposure) and short-term (0.5, 1, 2, 3 and 4 h after exposure) effects of SHS on cardiac autonomic control and myocardial integrity. Nineteen adult healthy never-smokers underwent a 1 h exposure to SHS at bar/restaurant levels and a 1 h control exposure. Heart rate variability (HRV), serum cotinine, and six cardiac protein markers were assessed before, during, and up to four hours following each exposure. SHS reduced the standard deviation of normal-to-normal intervals and increased cotinine levels, creatine kinase (CK)-MB, and myoglobin (p < 0.05). We conclude that acute exposure to SHS suppresses HRV and augments CK-MB and myoglobin. The SHS-induced elevations in CK-MB and myoglobin may reflect a generalized lytic state, especially of the cardiac muscle, which is apparent for at least 2 h following the SHS exposure.

Cigarette smoking and inflammation revisited

Despite the significant health risks resulting from tobacco use, the prevalence of smokers worldwide remains high. Cigarette smoking is one of the major sources of toxic chemical exposure to humans and is the greatest cause of preventable illnesses and premature death. The adverse consequences of smoking in various pathologies are mediated by its effects on the immune-inflammatory system. In this review, we aim to explore the effects of cigarette smoking on the inflammatory response and molecular mechanisms with emphasis on the nuclear factor kappa B (NF-kB) pathway. The effects of smoking on various inflammatory pathologies will be discussed, focusing on oral diseases, airway inflammation, chronic obstructive pulmonary disease (COPD) and inflammatory bowel diseases (IBD).

Lifestyle and sarcopenia-etiology, prevention, and treatment

The term sarcopenia describes the loss of skeletal muscle mass, strength, and function in old age. As the world population continues to grow older, more attention is given to the phenomena of sarcopenia and the search for strategies of prevention and treatment. The progression of sarcopenia is affected by age-related physiological and systemic changes in the body, including alterations in skeletal muscle tissue, hormonal changes, increased inflammatory activities, and oxidative stress. Sarcopenia progression is also affected by lifestyle factors which are far more controllable. These factors include various aspects of nutrition, physical activity, exercise, alcohol intake, and tobacco use. Raising the public awareness regarding the impact of these factors, as causes of sarcopenia and potential strategies of prevention and treatment, is of great importance. In this review we aim to describe various lifestyle factors that affect the etiology, prevention, and treatment of sarcopenia.