Hypogonadism, quadriceps weakness, and exercise intolerance in chronic obstructive pulmonary disease

Association between hypogonadism and severity of chronic obstructive pulmonary disease: A cross-sectional study

INTRODUCTION AND OBJECTIVES

Chronic obstructive pulmonary disease (COPD) frequently coexists with other comorbidities, including hypogonadism. However, the association between COPD severity and hypogonadism remains controversial. This study aimed to evaluate this association and compare the clinical characteristics of hypogonadal and eugonadal COPD patients.

MATERIALS AND METHODS

A cross-sectional study including men with stable COPD was performed. Hypogonadism was diagnosed based on the presence of symptoms, according to the Androgen Deficiency in Aging Males questionnaire, and a total testosterone deficit (<300ng/dL). COPD severity was classified according to the Spanish COPD guideline risk classification. A multivariate logistic regression analysis was performed in order to evaluate the relationship between COPD severity and hypogonadism.

RESULTS

134 subjects were recruited. The prevalence of hypogonadism was higher in severe COPD than in mild COPD, with a prevalence ratio of 1.8 (p=0.007). An increased odds of hypogonadism was observed in severe COPD subjects (OR 2.60, 95% CI 1.23-5.48, p=0.012) independent of age, body mass index, cardiovascular disease, and chronic renal failure. Hypogonadal COPD patients exhibited lower percentage levels of FVC and FEV1 and a higher degree of dyspnea than compared to eugonadal COPD patients.

CONCLUSION

Patients with severe COPD had a higher prevalence of hypogonadism compared to those with mild COPD. Additionally, severe COPD was identified as an independent risk factor for hypogonadism. These findings suggest that hypogonadism should be evaluated in patients with COPD, particularly in those with severe disease.

Prevalence of hypogonadism in men with and without chronic obstructive pulmonary disease: A cross-sectional study

BACKGROUND

Hypogonadism is a common finding of chronic obstructive pulmonary disease (COPD). However, the prevalence of hypogonadism in COPD varies among studies. The aim of this study was to determine and compare the prevalence of hypogonadism in men with and without COPD.

METHODS

We conducted a cross-sectional study with 134 patients with stable COPD and 70 age-matched men with non-COPD. Hypogonadism was defined by the presence of symptoms according to the Androgen Deficiency in Aging Males questionnaire, along with total testosterone deficiency (<300ng/dL).

RESULTS

Patients had a mean age of 68 years (SD, 6), a body mass index of 28kg/m2 (SD, 6), and 17% were current smokers. The prevalence of hypogonadism was 41.8% in COPD men (N=56, 95%CI, 33-51) and 10.0% in non-COPD men (N=7, 95%CI, 4-20), with a prevalence ratio of 4.2 (95%CI, 2.0-8.7, p<0.001). The prevalence of low total testosterone concentrations (<300ng/dL) were significantly higher in COPD patients vs the control group (47.0% vs 15.7%, p=<0.001). In the COPD group, 89.3% of patients had hypogonadotropic hypogonadism and 10.7%, hypergonadotropic hypogonadism. The prevalence of hypogonadism was higher in severe vs non-severe COPD patients (55.8% vs 35.2%; p=0.024).

CONCLUSIONS

The prevalence of hypogonadism was high and greater in COPD vs non-COPD men. This study suggests that COPD patients should be screened for hypogonadism.

Combined Exercise Training and Nutritional Interventions or Pharmacological Treatments to Improve Exercise Capacity and Body Composition in Chronic Obstructive Pulmonary Disease: A Narrative Review

Chronic obstructive pulmonary disease (COPD) is a chronic respiratory disease that is associated with significant morbidity, mortality, and healthcare costs. The burden of respiratory symptoms and airflow limitation can translate to reduced physical activity, in turn contributing to poor exercise capacity, muscle dysfunction, and body composition abnormalities. These extrapulmonary features of the disease are targeted during pulmonary rehabilitation, which provides patients with tailored therapies to improve the physical and emotional status. Patients with COPD can be divided into metabolic phenotypes, including cachectic, sarcopenic, normal weight, obese, and sarcopenic with hidden obesity. To date, there have been many studies performed investigating the individual effects of exercise training programs as well as nutritional and pharmacological treatments to improve exercise capacity and body composition in patients with COPD. However, little research is available investigating the combined effect of exercise training with nutritional or pharmacological treatments on these outcomes. Therefore, this review focuses on exploring the potential additional beneficial effects of combinations of exercise training and nutritional or pharmacological treatments to target exercise capacity and body composition in patients with COPD with different metabolic phenotypes.

A computational musculoskeletal arm model for assessing muscle dysfunction in chronic obstructive pulmonary disease

Computational models have been used extensively to assess diseases and disabilities effects on musculoskeletal system dysfunction. In the current study, we developed a two degree-of-freedom subject-specific second-order task-specific arm model for characterizing upper-extremity function (UEF) to assess muscle dysfunction due to chronic obstructive pulmonary disease (COPD). Older adults (65 years or older) with and without COPD and healthy young control participants (18 to 30 years) were recruited. First, we evaluated the musculoskeletal arm model using electromyography (EMG) data. Second, we compared the computational musculoskeletal arm model parameters along with EMG-based time lag and kinematics parameters (such as elbow angular velocity) between participants. The developed model showed strong cross-correlation with EMG data for biceps (0.905, 0.915) and moderate cross-correlation for triceps (0.717, 0.672) within both fast and normal pace tasks among older adults with COPD. We also showed that parameters obtained from the musculoskeletal model were significantly different between COPD and healthy participants. On average, higher effect sizes were achieved for parameters obtained from the musculoskeletal model, especially for co-contraction measures (effect size = 1.650 ± 0.606, p < 0.001), which was the only parameter that showed significant differences between all pairwise comparisons across the three groups. These findings suggest that studying the muscle performance and co-contraction, may provide better information regarding neuromuscular deficiencies compared to kinematics data. The presented model has potential for assessing functional capacity and studying longitudinal outcomes in COPD.

The Association between Inflammation, Testosterone and SHBG in men: A cross-sectional Multi-Ethnic Study of Atherosclerosis

CONTEXT

Earlier studies have investigated the role of obesity-related inflammation and endogenous sex hormones in men. The role of interleukin-6 (IL-6) and C-reactive protein (CRP) with testosterone and sex hormone binding globulin (SHBG) levels in men is still debated.

OBJECTIVE

To investigate the independent association between levels of high sensitivity CRP (hsCRP) and IL-6 with endogenous sex hormones in men.

DESIGN

Cross-sectional observational study using data from the Multi-Ethnic Study of Atherosclerosis.

PATIENTS OR OTHER PARTICIPANTS

A community-based sample of 3212 men aged 45-84 years was included. After exclusions, 3041 men remained for the analyses.

MAIN OUTCOME MEASURE(S)

Serum concentrations of testosterone, SHBG, hsCRP, IL-6, and sTNFR were measured from the baseline exam. Multivariable linear regressions were used to examine the association of inflammatory markers with sex hormones.

RESULTS

An inverse association was found between levels of hsCRP and levels of testosterone and SHBG, even after adjustment for confounders and IL-6 (Total Testosterone; B = -0.14, Bioavailable Testosterone; B = -0.06, and SHBG; B = -0.66). Similar results were found for IL-6, although a positive association was found for SHBG (B = 0.95). Notably, an inverse association was found for IL-6 with bioavailable testosterone in African Americans and Hispanic Americans aged 45-54 years. No associations were found for sTNFR and endogenous sex hormones.

CONCLUSION

Our results indicate that inflammatory markers have independent associations with levels of testosterone (total and bioavailable) and furthermore, appear to associate differently with SHBG levels.

Circulating testosterone levels and health outcomes in chronic obstructive pulmonary disease: results from ECLIPSE and ERICA

The relationship of circulating testosterone levels with health outcomes in people with chronic obstructive pulmonary disease (COPD) is unknown.

AIM

To determine whether serum testosterone levels predict hospitalised acute exacerbations of COPD (H-AECOPD), cardiovascular disease outcome, and mortality in people with COPD.

METHODS

Separate analyses were carried out on two observational, multicentre COPD cohorts, Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points (ECLIPSE) and Evaluation of the Role of Inflammation in Chronic Airways Disease (ERICA), both of which had serum testosterone measured using a validated liquid chromatography assay at the same laboratory. Data from 1296 male participants in ECLIPSE and 386 male, 239 female participants in ERICA were analysed. All analyses were sex-specific. Multivariate logistic regression was used to determine associations with H-AECOPD during follow-up (3 years ECLIPSE, 4.5 years ERICA), a composite endpoint of cardiovascular hospitalisation and cardiovascular death, and all-cause mortality.

RESULTS

Mean (SD) testosterone levels were consistent across cohorts; 459 (197) and 455 (200) ng/dL for males in ECLIPSE and ERICA, respectively, and in ERICA females: 28 (56) ng/dL. Testosterone was not associated with H-AECOPD (ECLIPSE: OR: 0.76, p=0.329, ERICA males: OR (95% CI): 1.06 (0.73 to 1.56), p=0.779, ERICA females: OR: 0.77 (0.52 to 1.12), p=0.178) or cardiovascular hospitalisation and death. Testosterone was associated with all-cause mortality in Global Initiative for Obstructive Lung Disease (GOLD) stage 2 male patients only, in ECLIPSE (OR: 0.25, p=0.007) and ERICA (OR: (95% CI): 0.56 (0.32 to 0.95), p=0.030).

CONCLUSIONS

Testosterone levels do not relate to H-AECOPD or cardiovascular outcome in COPD, but are associated with all-cause mortality in GOLD stage 2 COPD male patients, although the clinical significance of this finding is uncertain.

Association of testosterone therapy with disease progression in older males with COVID-19

Importance

Low testosterone levels in males have been linked with increase in proinflammatory cytokines—a primary culprit in COVID‐19 disease progression—and with adverse COVID‐19 outcomes. To date, however, no published studies have assessed the effect of testosterone therapy on COVID‐19 outcomes in older men.

Objective

To examine whether testosterone therapy reduced disease progression in older men diagnosed with COVID‐19.

Design, setting, and participants

Nested within a national cohort of older (aged ≥50 years) male patients diagnosed with COVID‐19 between January 1, 2020 and July 1, 2021 from the Optum electronic health record COVID‐19 database, two matched case–control studies of COVID‐19 outcomes were conducted. Cases—defined, respectively, as persons who (a) were hospitalized ≤30 days after COVID‐19 diagnosis (n = 33,380), and (b) were admitted to the intensive care unit or received mechanical ventilation during their COVID‐19 hospitalization (n = 10,273)—were matched 1:1 with controls based on demographic and clinical factors.

Exposures

Testosterone therapy was defined based on receipt of prescription at ≤60, ≤90, or ≤120 days before COVID‐19 diagnosis.

Main outcomes and measures

Adjusted odds ratios (ORs) for the risk of hospitalization within 30 days of COVID‐19 diagnosis and intensive care unit admission/mechanical ventilation during COVID‐19 hospitalization.

Results

The use of testosterone therapy was not associated with decreased odds of hospitalization (≤60 days: OR = 0.92, 95% confidence interval [CI] = 0.70–1.20; ≤90 days: OR = 0.87, 95% CI = 0.68–1.13; ≤120 days: OR = 0.97, 95% CI = 0.72–1.32) or intensive care unit admission/mechanical ventilation (≤60 days: OR = 0.67, 95% CI = 0.37–1.23; ≤90 days: OR = 0.63, 95% CI = 0.36–0.11; ≤120 days: OR = 0.58, 95% CI = 0.29–1.19).

Conclusions and relevance

This study showed that testosterone therapy was not associated with decreased risks of COVID‐19 adverse outcomes. These findings may provide clinically relevant information regarding testosterone treatment in older men with COVID‐19 and other respiratory viral infections with similar pathogenesis.

Androgen Deficiency In Men With Chronic Obstructive Pulmonary Disease

Hypogonadism is a clinical condition comprising symptoms and laboratory evidence of testosterone deficiency and low androgen receptor sensitivity. The importance of hypogonadism in clinical practice is often underestimated. Androgen deficiency habitually occurs in various conditions causing abnormal functioning of many organs and systems, as well as impairing the quality of life in patients. Androgen deficiency often occurs with various somatic diseases. Chronic obstructive pulmonary disease (COPD) is one of the most important medical and social problems of modern medicine, in which severe systemic (including hormonal) disorders occur. This review presents data on androgen deficiency in men with COPD and its potential impact on the patients. We have analyzed literary sources in the eLIBRARY and PubMed databases.

Does branched-chain amino acid supplementation improve pulmonary rehabilitation effect in COPD?

BACKGROUND

Muscle wasting is frequent in chronic obstructive lung disease (COPD) and associated with low branched-chain amino acids (BCAA). We hypothesized that BCAA supplementation could potentiate the effect of a pulmonary rehabilitation program (PRP) by inducing muscular change.

MATERIALS AND METHODS

Sixty COPD patients (GOLD 2-3) were involved in an ambulatory 4-week PRP either with BCAA oral daily supplementation or placebo daily supplementation in a randomized double-blind design. Maximal exercise test including quadriceps oxygenation measurements, functional exercise test, muscle strength, lung function tests, body composition, dyspnea and quality of life were assessed before and after PRP.

RESULTS

Fifty-four patients (64.9 ± 8.3 years) completed the protocol. In both groups, maximal exercise capacity, functional and muscle performances, quality of life and dyspnea were improved after 4-week PRP (p ≤ 0.01). Changes in muscle oxygenation during the maximal exercise and recovery period were not modified after 4-week PRP in BCAA group. Contrarily, in the placebo group the muscle oxygenation kinetic of recovery was slowed down after PRP.

CONCLUSION

This study demonstrated that a 4-week PRP with BCAA supplementation is not more beneficial than PRP alone for patients. A longer duration of supplementation or a more precise targeting of patients would need to be investigated to validate an effect on muscle recovery and to demonstrate other beneficial effects.

Effects of Environmental and Pathological Hypoxia on Male Fertility

Male infertility is a widespread health problem affecting approximately 6%-8% of the male population, and hypoxia may be a causative factor. In mammals, two types of hypoxia are known, including environmental and pathological hypoxia. Studies looking at the effects of hypoxia on male infertility have linked both types of hypoxia to poor sperm quality and pregnancy outcomes. Hypoxia damages testicular seminiferous tubule directly, leading to the disorder of seminiferous epithelium and shedding of spermatogenic cells. Hypoxia can also disrupt the balance between oxidative phosphorylation and glycolysis of spermatogenic cells, resulting in impaired self-renewal and differentiation of spermatogonia, and failure of meiosis. In addition, hypoxia disrupts the secretion of reproductive hormones, causing spermatogenic arrest and erectile dysfunction. The possible mechanisms involved in hypoxia on male reproductive toxicity mainly include excessive ROS mediated oxidative stress, HIF-1α mediated germ cell apoptosis and proliferation inhibition, systematic inflammation and epigenetic changes. In this review, we discuss the correlations between hypoxia and male infertility based on epidemiological, clinical and animal studies and enumerate the hypoxic factors causing male infertility in detail. Demonstration of the causal association between hypoxia and male infertility will provide more options for the treatment of male infertility.

The relationship of serum testosterone levels with the clinical course and prognosis of COVID-19 disease in male patients: A prospective study

Background

A potential role of testosterone among sex hormones has been hypothesized in identifying sex‐related differences in the clinical consequences of severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2) infection. Due to the high global prevalence of hypogonadism, the relationship between hypogonadism and SARS‐CoV‐2 infection outcomes deserves an in‐depth study.

Objective

The present study aimed to investigate the relationship of serum testosterone with other laboratory parameters on the prognosis of coronavirus disease‐19 (COVID‐19) in male patients with COVID‐19 diagnosis.

Materials and methods

This prospective cohort study included 358 male patients diagnosed with COVID‐19 and 92 COVID‐19 negative patients admitted to the urology outpatient clinics as a control group. The COVID‐19 patients were divided into groups according to prognosis (mild‐moderate and severe group), lung involvement in chest computed tomography (<50% and >50%), intensive care unit needs, and survival.

Results

The measured serum total testosterone level of the COVID‐19 patients group was found to be significantly lower than that of the control group (median, 140 ng/dl; range, 0.21–328, 322 ng/dl; range, median, 125–674, p < 0.001, respectively). The serum TT levels were statistically significantly lower in severe COVID‐19 patients compared to mild‐moderate COVID‐19 patients (median, 85.1 ng/dl; range, 0.21–532, median, 315 ng/dl; range, 0.88–486, p < 0.001, respectively), in COVID‐19 patients in need of intensive care compared to COVID‐19 patients who did not need intensive care (median, 64.0 ng/dl; range, 0.21–337, median, 286 ng/dl; range, 0.88–532 p < 0.001, respectively), and in COVID‐19 patients who died compared to survivors (median, 82.9 ng/dl; range, 2.63–165, median, 166 ng/dl; range, 0.21–532, p < 0.001, respectively).

Discussion and conclusion

Our data are compatible with low TT levels playing a role on the pathogenesis of the disease in Covid‐19 patients with poor prognosis and a mortal course and may guide clinicians in determining the clinical course of the disease.

Sex Hormones and Lung Inflammation

Inflammation is a characteristic marker in numerous lung disorders. Several immune cells, such as macrophages, dendritic cells, eosinophils, as well as T and B lymphocytes, synthetize and release cytokines involved in the inflammatory process. Gender differences in the incidence and severity of inflammatory lung ailments including asthma, chronic obstructive pulmonary disease (COPD), pulmonary fibrosis (PF), lung cancer (LC), and infectious related illnesses have been reported. Moreover, the effects of sex hormones on both androgens and estrogens, such as testosterone (TES) and 17β-estradiol (E2), driving characteristic inflammatory patterns in those lung inflammatory diseases have been investigated. In general, androgens seem to display anti-inflammatory actions, whereas estrogens produce pro-inflammatory effects. For instance, androgens regulate negatively inflammation in asthma by targeting type 2 innate lymphoid cells (ILC2s) and T-helper (Th)-2 cells to attenuate interleukin (IL)-17A-mediated responses and leukotriene (LT) biosynthesis pathway. Estrogens may promote neutrophilic inflammation in subjects with asthma and COPD. Moreover, the activation of estrogen receptors might induce tumorigenesis. In this chapter, we summarize the most recent advances in the functional roles and associated signaling pathways of inflammatory cellular responses in asthma, COPD, PF, LC, and newly occurring COVID-19 disease. We also meticulously deliberate the influence of sex steroids on the development and progress of these common and severe lung diseases.

Shorter androgen receptor polyQ alleles protect against life-threatening COVID-19 disease in European males

Background

While SARS-CoV-2 similarly infects men and women, COVID-19 outcome is less favorable in men. Variability in COVID-19 severity may be explained by differences in the host genome.

Methods

We compared poly-amino acids variability from WES data in severely affected COVID-19 patients versus SARS-CoV-2 PCR-positive oligo-asymptomatic subjects.

Findings

Shorter polyQ alleles (≤22) in the androgen receptor (AR) conferred protection against severe outcome in COVID-19 in the first tested cohort (both males and females) of 638 Italian subjects. The association between long polyQ alleles (≥23) and severe clinical outcome (p = 0.024) was also validated in an independent cohort of Spanish men <60 years of age (p = 0.014). Testosterone was higher in subjects with AR long-polyQ, possibly indicating receptor resistance (p = 0.042 Mann-Whitney U test). Inappropriately low serum testosterone level among carriers of the long-polyQ alleles (p = 0.0004 Mann-Whitney U test) predicted the need for intensive care in COVID-19 infected men. In agreement with the known anti-inflammatory action of testosterone, patients with long-polyQ and age ≥60 years had increased levels of CRP (p = 0.018, not accounting for multiple testing).

Interpretation

We identify the first genetic polymorphism that appears to predispose some men to develop more severe disease. Failure of the endocrine feedback to overcome AR signaling defects by increasing testosterone levels during the infection leads to the polyQ tract becoming dominant to serum testosterone levels for the clinical outcome. These results may contribute to designing reliable clinical and public health measures and provide a rationale to test testosterone as adjuvant therapy in men with COVID-19 expressing long AR polyQ repeats.

Funding

MIUR project “Dipartimenti di Eccellenza 2018-2020” to Department of Medical Biotechnologies University of Siena, Italy (Italian D.L. n.18 March 17, 2020) and “Bando Ricerca COVID-19 Toscana” project to Azienda Ospedaliero-Universitaria Senese. Private donors for COVID-19 research and charity funds from Intesa San Paolo.

Testosterone attenuates pulmonary epithelial inflammation in male rats of COPD model through preventing NRF1-derived NF-κB signaling

Testosterone deficiency is common in male patients with chronic obstructive pulmonary disease (COPD) and may correlate with the deterioration of COPD. Clinical research suggests that testosterone replacement therapy may slow the COPD progression, but the specific biological pathway remains unclear. In this study, we explored the effect of testosterone on pulmonary inflammation in male COPD rats. The animals were co-treated with lipopolysaccharide (LPS) and cigarette to induce COPD. In COPD rats, nuclear respiratory factor 1 (NRF1) and NF-κB p65 were upregulated. In cigarette smoke extract (CSE)-, LPS-, or the combination of CSE and LPS-treated L132 cells, NRF1 and p65 were also upregulated. Silencing NRF1 resulted in the downregulation of p65. ChIP‒seq, ChIP‒qPCR, and luciferase results showed that NRF1 transcriptionally regulated p65. Both male and female COPD rats showed an upregulated NRF1 level and similar pulmonary morphology. But NRF1 was further upregulated in male castrated rats. Further supplementing testosterone in castrated male rats significantly reduced NRF1, pulmonary lesions, and inflammation. Supplementation of testosterone also reduced the phosphorylation of p65 and IKKβ induced by LPS or CSE in L132 cells. Our results suggest that testosterone plays a protective role in pulmonary epithelial inflammation of COPD through inhibition of NRF1-derived NF-κB signaling and the phosphorylation of p65.

[Testosterone and chronic obstructive pulmonary disease]

INTRODUCTION

Testosterone level has been shown to be associated with respiratory function and loss of lean body mass in patients with chronic obstructive pulmonary disease (COPD). The aim of this study was to assess the relationship between testosterone level and functional respiratory parameters during COPD.

METHODS

We conducted a cross-sectional study that included 95 male patients with stable COPD. Functional tests (body plethysmography, six-minute walk test (6MWT), arterial blood gas) were performed in all patients and serum levels of testosterone, prolactin, FSH, LH and C-reactive protein were determined. Lean body mass was measured using bioelectric impedance.

RESULTS

The average age was 63.78±8.90years. COPD was classified as stage 3 in 38% of cases and stage 4 in 11% of cases, group C in 10% of cases and group D in 18% of cases. The average testosterone was 20.87±8.60nmol/L. A significant positive correlation was found between FEV1 (P=0.005), FVC (P=0.005), FEV1/FVC ratio (P=0.001), lean mass index (P=0.021), and testosterone. However, testosterone was not correlated with 6MWT or blood gas parameters. Similarly, it was not correlated with FSH, LH, prolactin and C-reactive protein.

CONCLUSION

This study found that serum testosterone level was associated with lung function and lean mass during COPD. Further investigations are required to better evaluate the relationship between COPD and serum testosterone levels and the effect of androgen substitution in lung function.

Androgen and Androgen Receptors as Regulators of Monocyte and Macrophage Biology in the Healthy and Diseased Lung

Androgens, the predominant male sex hormones, drive the development and maintenance of male characteristics by binding to androgen receptor (AR). As androgens are systemically distributed throughout the whole organism, they affect many tissues and cell types in addition to those in male sexual organs. It is now clear that the immune system is a target of androgen action. In the lungs, many immune cells express ARs and are responsive to androgens. In this review, we describe the effects of androgens and ARs on lung myeloid immune cells-monocytes and macrophages-as they relate to health and disease. In particular, we highlight the effect of androgens on lung diseases, such as asthma, chronic obstructive pulmonary disease and lung fibrosis. We also discuss the therapeutic use of androgens and how circulating androgens correlate with lung disease. In addition to human studies, we also discuss how mouse models have helped to uncover the effect of androgens on monocytes and macrophages in lung disease. Although the role of estrogen and other female hormones has been broadly analyzed in the literature, we focus on the new perspectives of androgens as modulators of the immune system that target myeloid cells during lung inflammation.

Aging and the Male Reproductive System

This narrative review presents an overview of current knowledge on fertility and reproductive hormone changes in aging men, the factors driving and modulating these changes, their clinical consequences, and the benefits and risks of testosterone (T) therapy. Aging is accompanied by moderate decline of gamete quality and fertility. Population mean levels show a mild total T decline, an SHBG increase, a steeper free T decline, and a moderate LH increase with important contribution of comorbidities (e.g., obesity) to these changes. Sexual symptoms and lower hematocrit are associated with low T and are partly responsive to T therapy. The relationship of serum T with body composition and metabolic health is bidirectional; limited beneficial effects of T therapy on body composition have only marginal effects on metabolic health and physical function. Skeletal changes are associated primarily with estradiol and SHBG. Cognitive decline is not consistently linked to low T and is not improved by T therapy. Although limited evidence links moderate androgen decline with depressive symptoms, T therapy has small beneficial effects on mood, depressive symptoms, and vitality in elderly patients with low T. Suboptimal T (and/or DHT) has been associated with increased risk of stroke, but not of ischemic heart disease, whereas an association with mortality probably reflects that low T is a marker of poor health. Globally, neither severity of clinical consequences attributable to low T nor the nature and magnitude of beneficial treatment effects justify the concept of some broadly applied "T replacement therapy" in older men with low T. Moreover, long-term safety of T therapy is not established.

Pathobiological mechanisms underlying metabolic syndrome (MetS) in chronic obstructive pulmonary disease (COPD): clinical significance and therapeutic strategies

Chronic obstructive pulmonary disease (COPD) is a major incurable global health burden and is currently the 4th largest cause of death in the world. Importantly, much of the disease burden and health care utilisation in COPD is associated with the management of its comorbidities (e.g. skeletal muscle wasting, ischemic heart disease, cognitive dysfunction) and infective viral and bacterial acute exacerbations (AECOPD). Current pharmacological treatments for COPD are relatively ineffective and the development of effective therapies has been severely hampered by the lack of understanding of the mechanisms and mediators underlying COPD. Since comorbidities have a tremendous impact on the prognosis and severity of COPD, the 2015 American Thoracic Society/European Respiratory Society (ATS/ERS) Research Statement on COPD urgently called for studies to elucidate the pathobiological mechanisms linking COPD to its comorbidities. It is now emerging that up to 50% of COPD patients have metabolic syndrome (MetS) as a comorbidity. It is currently not clear whether metabolic syndrome is an independent co-existing condition or a direct consequence of the progressive lung pathology in COPD patients. As MetS has important clinical implications on COPD outcomes, identification of disease mechanisms linking COPD to MetS is the key to effective therapy. In this comprehensive review, we discuss the potential mechanisms linking MetS to COPD and hence plausible therapeutic strategies to treat this debilitating comorbidity of COPD.

Testosterone replacement therapy and hospitalization rates in men with COPD

Testosterone deficiency is common in men with chronic obstructive pulmonary disease (COPD) and may exacerbate their condition. Research suggests that testosterone replacement therapy (TRT) may have a beneficial effect on respiratory outcomes in men with COPD. To date, however, no large-scale nationally representative studies have examined this association. The objective of the study was to assess whether TRT reduced the risk of respiratory hospitalizations in middle-aged and older men with COPD. We conducted two retrospective cohort studies. First, using the Clinformatics Data Mart—a database of one of the largest commercially insured populations in the United States—we examined 450 men, aged 40–63 years, with COPD who initiated TRT between 2005 and 2014. Second, using the national 5% Medicare database, we examined 253 men, aged ≥66 years, with COPD who initiated TRT between 2008 and 2013. We used difference-in-differences (DID) statistical modeling to compare pre- versus post-respiratory hospitalization rates in TRT users versus matched TRT nonusers over a parallel time period. DID analyses showed that TRT users had a greater relative decrease in respiratory hospitalizations compared with nonusers. Specifically, middle-aged TRT users had a 4.2% greater decrease in respiratory hospitalizations compared with nonusers (−2.4 decrease vs. 1.8 increase; p = 0.03); and older TRT users had a 9.1% greater decrease in respiratory hospitalizations compared with nonusers (−0.8 decrease vs. 8.3 increase; p = 0.04). These findings suggest that TRT may slow disease progression in patients with COPD. Future studies should examine this association in larger cohorts of patients, with particular attention to specific biological pathways.

Effects of aging and comorbidities on nutritional status and muscle dysfunction in patients with COPD

Chronic obstructive pulmonary disease (COPD) is a prevalent, complex and debilitating disease which imposes a formidable burden on patients and the healthcare system. The recognition that COPD is a multifaceted disease is not new, and increasing evidence have outlined the importance of its extra-pulmonary manifestations and its relation to other comorbid conditions in the clinical course of the disease and its societal cost. The relationship between aging, COPD and its comorbidities on skeletal muscle function and nutritional status is complex, multidirectional and incompletely understood. Despite this, the current body of knowledge allows the identification of various, seemingly partially independent factors related both to the normal aging process and to the independent deleterious effects of chronic diseases on muscle function and body composition. There is a dire need of studies evaluating the relative contribution of each of these factors, and their potential synergistic effects in patients with COPD and advanced age/comorbid conditions, in order to delineate the best course of therapeutic action in this increasingly prevalent population.

Larger Testicular Volume Is Independently Associated with Favorable Indices of Lung Function

BACKGROUND

Men with chronic obstructive pulmonary disease, have reduced endogenous testosterone levels, but the relationship between pulmonary function and endogenous testosterone levels, is inconsistent. Testicular volume is a known indicator of endogenous testosterone levels, male fertility, and male potency. In the present study, the authors investigated the relationship, between testicular volume and lung function.

METHODS

One hundred and eighty-one South Korean men age 40-70, hospitalized for urological surgery, were retrospectively enrolled, irrespective of the presence of respiratory disease. Study subjects underwent pulmonary function testing, prior to procedures, and testicular volumes were measured by orchidometry. Testosterone levels of patients in blood samples collected between 7 AM and 11 AM, were measured by a direct chemiluminescent immunoassay.

RESULTS

The 181 study subjects were divided into two groups, by testicular volume (≥35 mL vs. <35 mL), the larger testes group, had better lung functions (forced vital capacity [FVC]: 3.87±0.65 L vs. 3.66±0.65 L, p=0.037; forced expiratory volume in 1 second [FEV₁]: 2.92±0.57 L vs. 2.65±0.61 L, p=0.002; FVC % predicted: 98.2±15.2% vs. 93.8±13.1%, p=0.040; FEV₁ % predicted: 105.4±19.5% vs. 95.9±21.2%, p=0.002). In addition, the proportion of patients with a FEV₁/FVC of <70%, was lower in the larger testes group. Univariate analysis conducted using linear regression models, revealed that testicular volume was correlated with FVC (r=0.162, p=0.029), FEV₁ (r=0.218, p=0.003), FEV₁/FVC (r=0.149, p=0.046), and FEV₁ % predicted (r=0.178, p=0.017), and multivariate analysis using linear regression models, revealed that testicular volume was a significant predictive factor for FEV₁ % predicted (β=0.159, p=0.041).

CONCLUSION

Larger testicular volume was independently associated, with favorable indices of lung function. These results suggest that androgens, may contribute to better lung function.

Anemia in Chronic obstructive pulmonary disease: Prevalence, pathogenesis, and potential impact

Chronic obstructive pulmonary disease (COPD) is a common preventable and treatable lifestyle-related disease with high global prevalence. COPD is associated with significant morbidity and mortality worldwide. Comorbidities are important events in the natural history of the disease and have a negative effect on the morbidity and mortality of COPD patients. Cardiac diseases, lung cancer, osteoporosis, and depression are common comorbidities reported for COPD. Recently, anemia has been recognized as a frequent comorbidity in COPD patients. The prevalence of anemia in patients with COPD varies from 7.5% to 33%. Anemia of chronic disease (ACD) is probably the most common type of anemia associated with COPD. ACD is driven by COPD-mediated systemic inflammation. Anemia in COPD is associated with greater healthcare resource utilization, impaired quality of life, decreased survival, and a greater likelihood of hospitalization. We need large prospective studies to discern the association between anemia and COPD.

Chronic obstructive pulmonary disease and the metabolic syndrome: Consequences of a dual threat

The metabolic syndrome is found to be more frequent in chronic obstructive pulmonary disease (COPD). The presence of inflammatory markers in circulation, sputum, and broncho-alveolar fluid suggest systemic inflammation is one of the potential mechanisms responsible for both COPD and metabolic syndrome. Physical inactivity, skeletal muscle dysfunction, hypogonadism, and steroid use are also important causes of the metabolic syndrome in COPD. Obesity and insulin resistance is found to be more common in mild to moderate stages (I and II) of COPD. Patients with COPD and the metabolic syndrome have increase risk of morbidity and mortality due to cardiovascular disease. This review describes in details the various components of metabolic syndrome and its impact on long outcomes in COPD patients.

An official American Thoracic Society/European Respiratory Society statement: update on limb muscle dysfunction in chronic obstructive pulmonary disease

BACKGROUND

Limb muscle dysfunction is prevalent in chronic obstructive pulmonary disease (COPD) and it has important clinical implications, such as reduced exercise tolerance, quality of life, and even survival. Since the previous American Thoracic Society/European Respiratory Society (ATS/ERS) statement on limb muscle dysfunction, important progress has been made on the characterization of this problem and on our understanding of its pathophysiology and clinical implications.

PURPOSE

The purpose of this document is to update the 1999 ATS/ERS statement on limb muscle dysfunction in COPD.

METHODS

An interdisciplinary committee of experts from the ATS and ERS Pulmonary Rehabilitation and Clinical Problems assemblies determined that the scope of this document should be limited to limb muscles. Committee members conducted focused reviews of the literature on several topics. A librarian also performed a literature search. An ATS methodologist provided advice to the committee, ensuring that the methodological approach was consistent with ATS standards.

RESULTS

We identified important advances in our understanding of the extent and nature of the structural alterations in limb muscles in patients with COPD. Since the last update, landmark studies were published on the mechanisms of development of limb muscle dysfunction in COPD and on the treatment of this condition. We now have a better understanding of the clinical implications of limb muscle dysfunction. Although exercise training is the most potent intervention to address this condition, other therapies, such as neuromuscular electrical stimulation, are emerging. Assessment of limb muscle function can identify patients who are at increased risk of poor clinical outcomes, such as exercise intolerance and premature mortality.

CONCLUSIONS

Limb muscle dysfunction is a key systemic consequence of COPD. However, there are still important gaps in our knowledge about the mechanisms of development of this problem. Strategies for early detection and specific treatments for this condition are also needed.

Effect of rehabilitation program on endocrinological parameters in patients with COPD and in healthy subjects

BACKGROUND

Skeletal muscle wasting commonly occurs in patients with chronic obstructive pulmonary disease (COPD) and has been associated with the presence of systemic inflammation and endocrinological disturbance. The aim of this study is to analyze the effect of rehabilitation program on the balance of anabolic versus catabolic hormone in patients with COPD and in healthy subjects.

METHODS

Nineteen patients with COPD and 16 age-matched healthy subjects undertooked exercise training 3 days/week for 8 weeks. Before and after the training program the concentration of growth hormone (GH), Insulin-Like Growth Factor-1 (IGF-1), Insulin-like Growth Factor-Binding Protein 3 (IGF-BP3), testosterone and cortisol in serum were determined. The exercise measurements included a 6-Minute Walking Test (6MWT).

RESULTS

After 8 weeks, there was no significant change in lung function in patients with COPD and healthy subjects. Growth hormone, Insulin-like Growth Factor-1 and Insulin-like Growth Factor-Binding Protein 3 increased significantly after rehabilitation training (p < 0.01). The rehabilitation program improves the testosterone/cortisol ratio (T/C ratio) in both groups. There is a significant improvement in the 6-Minute Walking distance (6MWD) in both groups (p < 0.01). Dyspnea and heart rate at rest and at the peak of the 6-Minute Walking Test (6MWT) decreased significantly after training program (p < 0.01).

CONCLUSION

Pulmonary rehabilitation induces an improvement of the anabolic process and reduces proteine distruction by the modifications in endocrinological factors regulating skeletal muscle in patients with COPD.

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.

Structural alterations of skeletal muscle in copd

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a respiratory disease associated with a systemic inflammatory response. Peripheral muscle dysfunction has been well characterized in individuals with COPD and results from a complex interaction between systemic and local factors.

OBJECTIVE

In this narrative review, we will describe muscle wasting in people with COPD, the associated structural changes, muscle regenerative capacity and possible mechanisms for muscle wasting. We will also discuss how structural changes relate to impaired muscle function and mobility in people with COPD. Key Observations: Approximately 30-40% of individuals with COPD experience muscle mass depletion. Furthermore, muscle atrophy is a predictor of physical function and mortality in this population. Associated structural changes include a decreased proportion and size of type-I fibers, reduced oxidative capacity and mitochondrial density mainly in the quadriceps. Observations related to impaired muscle regenerative capacity in individuals with COPD include a lower proportion of central nuclei in the presence or absence of muscle atrophy and decreased maximal telomere length, which has been correlated with reduced muscle cross-sectional area. Potential mechanisms for muscle wasting in COPD may include excessive production of reactive oxygen species (ROS), altered amino acid metabolism and lower expression of peroxisome proliferator-activated receptors-gamma-coactivator 1-alpha mRNA. Despite a moderate relationship between muscle atrophy and function, impairments in oxidative metabolism only seems weakly related to muscle function.

CONCLUSION

This review article demonstrates the cellular modifications in the peripheral muscle of people with COPD and describes the evidence of its relationship to muscle function. Future research will focus on rehabilitation strategies to improve muscle wasting and maximize function.

Pulmonary rehabilitation: the reference therapy for undernourished patients with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) combines the deleterious effects of chronic hypoxia, chronic inflammation, insulin-resistance, increased energy expenditure, muscle wasting, and exercise deconditioning. As for other chronic disorders, loss of fat-free mass decreased survival. The preservation of muscle mass and function, through the protection of the mitochondrial oxidative metabolism, is an important challenge in the management of COPD patients. As the prevalence of the disease is increasing and the medical advances make COPD patients live longer, the prevalence of COPD-associated nutritional disorders is expected to increase in future decades. Androgenopenia is observed in 40% of COPD patients. Due to the stimulating effects of androgens on muscle anabolism, androgenopenia favors loss of muscle mass. Studies have shown that androgen substitution could improve muscle mass in COPD patients, but alone, was insufficient to improve lung function. Two multicentric randomized clinical trials have shown that the association of androgen therapy with physical exercise and oral nutritional supplements containing omega-3 polyinsaturated fatty acids, during at least three months, is associated with an improved clinical outcome and survival. These approaches are optimized in the field of pulmonary rehabilitation which is the reference therapy of COPD-associated undernutrition.

Characterization of the male ApcMin/+ mouse as a hypogonadism model related to cancer cachexia

Cancer cachexia, the unintentional loss of lean body mass, is associated with decreased quality of life and poor patient survival. Hypogonadism, involving a reduction in circulating testosterone, is associated with the cachectic condition. At this time there is a very limited understanding of the role of hypogonadism in cancer cachexia progression. This gap in our knowledge is related to a lack of functional hypogonadal models associated with cancer cachexia. The Apc^Min/+ mouse is an established colorectal cancer model that develops an IL-6 dependent cachexia which is physiologically related to human disease due to the gradual progression of tumor development and cachexia. The purpose of this study was to assess the utility of the Apc^Min/+ mouse for the examination of hypogonadism during cancer cachexia and to investigate if IL-6 has a role in this process. We report that Apc^Min/+ mice that are weight stable have comparable testosterone levels and gonad size compared to wild type mice. Cachectic Apc^Min/+ mice exhibit a reduction in circulating testosterone and gonad size, which has a significant association with the degree of muscle mass and functional strength loss. Circulating testosterone levels were also significantly associated with the suppression of myofibrillar protein synthesis. Skeletal muscle and testes androgen receptor expression were decreased with severe cachexia. Although testes STAT3 phosphorylation increased with severe cachexia, systemic IL-6 over-expression for 2 weeks was not sufficient to reduce either testes weight or circulating testosterone. Inhibition of systemic IL-6 signaling by an IL-6 receptor antibody to Apc^Min/+ mice that had already initiated weight loss was sufficient to attenuate a reduction in testes size and circulating testosterone. In summary, the Apc^Min/+ mouse becomes hypogonadal with the progression of cachexia severity and elevated circulating IL-6 levels may have a role in the development of hypogonadism during cancer cachexia.

An official American Thoracic Society/European Respiratory Society statement: key concepts and advances in pulmonary rehabilitation

BACKGROUND

Pulmonary rehabilitation is recognized as a core component of the management of individuals with chronic respiratory disease. Since the 2006 American Thoracic Society (ATS)/European Respiratory Society (ERS) Statement on Pulmonary Rehabilitation, there has been considerable growth in our knowledge of its efficacy and scope.

PURPOSE

The purpose of this Statement is to update the 2006 document, including a new definition of pulmonary rehabilitation and highlighting key concepts and major advances in the field.

METHODS

A multidisciplinary committee of experts representing the ATS Pulmonary Rehabilitation Assembly and the ERS Scientific Group 01.02, "Rehabilitation and Chronic Care," determined the overall scope of this update through group consensus. Focused literature reviews in key topic areas were conducted by committee members with relevant clinical and scientific expertise. The final content of this Statement was agreed on by all members.

RESULTS

An updated definition of pulmonary rehabilitation is proposed. New data are presented on the science and application of pulmonary rehabilitation, including its effectiveness in acutely ill individuals with chronic obstructive pulmonary disease, and in individuals with other chronic respiratory diseases. The important role of pulmonary rehabilitation in chronic disease management is highlighted. In addition, the role of health behavior change in optimizing and maintaining benefits is discussed.

CONCLUSIONS

The considerable growth in the science and application of pulmonary rehabilitation since 2006 adds further support for its efficacy in a wide range of individuals with chronic respiratory disease.

Distribution of bone mineral content is associated with body weight and exercise capacity in patients with chronic obstructive pulmonary disease

BACKGROUND

Although low bone mineral density is highly prevalent in patients with chronic obstructive pulmonary disease (COPD), the distribution of the reduced bone mass has not been fully elucidated.

OBJECTIVES

To determine regional bone mass loss in patients with COPD and investigate whether the change in distribution may be associated with body weight loss and functional capacity.

METHODS

Body mass index (BMI) was assessed, and height squared indices were derived for the bone mineral content index (BMCI) of the arms, legs and trunk by dual-energy X-ray absorptiometry in 45 male patients with COPD and 12 age- and sex-matched control subjects. Pulmonary function tests were performed, and maximal oxygen uptake (VO2max) was measured.

RESULTS

The BMCI was lower in the total bone, legs and trunk of patients with COPD than in control subjects, although the BMCI in the arms was similar between the groups. BMI correlated significantly with the BMCI in all 3 segments. Bone mineral content (BMC) in the trunk, expressed as a percentage of total BMC (BMC trunk/total BMC), correlated significantly with BMI. The BMCI in the trunk was closely related with VO2max but not with airflow limitation.

CONCLUSIONS

There was a regional difference in BMC reduction, but a predominant reduction of bone mass in the trunk was not associated with the severity of airflow limitation but rather with body weight loss and exercise intolerance. These data suggest that body weight loss and exercise intolerance are important risk factors for vertebral fracture in patients with COPD.

Endogenous testosterone level and testosterone supplementation therapy in chronic obstructive pulmonary disease (COPD): a systematic review and meta-analysis

OBJECTIVE

Low testosterone level may be a reversible risk factor for functional disability and deterioration in patients with chronic obstructive pulmonary disease (COPD). We sought to systematically assess the endogenous testosterone levels and effect of testosterone therapy on exercise capacity and health-related quality of life (HRQoL) outcomes in COPD patients, as well as to inform guidelines and practice.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

We searched PubMed, Scopus, Cochrane Library, CINAHL, Health Source Nursing and PsychINFO and the reference lists of retrieved articles published before May 2012.

INCLUSION CRITERIA

Observational studies on endogenous testosterone levels in people with chronic lung disease compared with controls, or randomised controlled trials (RCTs) on testosterone therapy for exercise capacity and/or HRQoL outcomes in COPD patients were eligible.

DATA EXTRACTION AND ANALYSIS

Data on the mean difference in endogenous total testosterone (TT) values, and the mean difference in exercise capacity and HRQoL values were extracted and pooled using random effects meta-analysis.

RESULTS

Nine observational studies in 2918 men with COPD reported consistently lower levels of TT compared with controls (weighted mean difference was -3.21 nmol/L (95% CI -5.18 to -1.23)). Six RCTs in 287 participants yielded five studies on peak muscle strength and peak cardiorespiratory fitness outcomes (peak oxygen uptake (VO2) and workload) and three studies on HRQoL outcomes. Testosterone therapies significantly improved peak muscle strength (standardised mean difference (SMD) was 0.31 (95% CI 0.05 to 0.56)) and peak workload (SMD was 0.27 (95% CI 0.01 to 0.52)) compared with control conditions (all but one used placebo), but not peak VO2 (SMD was 0.21 (95% CI -0.15 to 0.56)) or HRQoL (SMD was -0.03 (95% CI -0.32 to 0.25)).

CONCLUSIONS

Men with COPD have clinically relevant lower than normal TT levels. Insufficient evidence from short-term studies in predominately male COPD patients suggests that testosterone therapy improves exercise capacity outcomes, namely peak muscle strength and peak workload.

Efficacy and safety of long-acting intramuscular testosterone undecanoate in aging men: a randomised controlled study

OBJECTIVE

To evaluate the efficacy and safety of long-acting i.m. testosterone undecanoate (TU) in Malaysian men with testosterone deficiency (TD).

PATIENTS AND METHODS

A total of 120 men, aged 40-70 years, with TD (serum total testosterone [TT] ≤ 12 nmol/L) were randomised to receive either i.m. TU (1000 mg) or placebo. In all, 58 and 56 men in the placebo and treatment arm, respectively, completed the study. Participants were seen six times in the 48-week period and the following data were collected: physical examination results, haemoglobin, haematocrit, TT, lipid profile, fasting blood glucose, sex hormone-binding globulin, liver function test, prostate- specific antigen (PSA) and adverse events.

RESULTS

The mean (sd) age of the participants was 53.4 (7.6) years. A significant increase in serum TT (P < 0.001), PSA (P = 0.010), haematocrit (P < 0.001), haemoglobin (P < 0.001) and total bilirubin (P = 0.001) were seen in the treatment arm over the 48-week period. Two men in the placebo arm and one man in the treatment arm developed myocardial infarction. Common adverse events observed in the treatment arm included itching/swelling/pain at the site of injection, flushing and acne. Overall, TU injections were well tolerated.

CONCLUSIONS

TU significantly increases serum testosterone in men with TD. PSA, haemoglobin and haematocrit were significantly elevated but were within clinically safe limits. There was no significant adverse reaction that led to the cessation of treatment.

Testosterone regulation of Akt/mTORC1/FoxO3a signaling in skeletal muscle

Low endogenous testosterone production, known as hypogonadism is commonly associated with conditions inducing muscle wasting. Akt signaling can control skeletal muscle mass through mTOR regulation of protein synthesis and FoxO regulation of protein degradation, and this pathway has been previously identified as a target of androgen signaling. However, the testosterone sensitivity of Akt/mTOR signaling requires further understanding in order to grasp the significance of varied testosterone levels seen with wasting disease on muscle protein turnover regulation. Therefore, the purpose of this study is to determine the effect of androgen availability on muscle Akt/mTORC1/FoxO3a regulation in skeletal muscle and cultured C(2)C(12) myotubes. C57BL/6 mice were either castrated for 42 days or castrated and treated with the nandrolone decanoate (ND) (6 mg/kg bw/wk). Testosterone loss (TL) significantly decreased volitional grip strength, body weight, and gastrocnemius (GAS) muscle mass, and ND reversed these changes. Related to muscle mass regulation, TL decreased muscle IGF-1 mRNA, the rate of myofibrillar protein synthesis, Akt phosphorylation, and the phosphorylation of Akt targets, GSK3β, PRAS40 and FoxO3a. TL induced expression of FoxO transcriptional targets, MuRF1, atrogin1 and REDD1. Muscle AMPK and raptor phosphorylation, mTOR inhibitors, were not altered by low testosterone. ND restored IGF-1 expression and Akt/mTORC1 signaling while repressing expression of FoxO transcriptional targets. Testosterone (T) sensitivity of Akt/mTORC1 signaling was examined in C(2)C(12) myotubes, and mTOR phosphorylation was induced independent of Akt activation at low T concentrations, while a higher T concentration was required to activate Akt signaling. Interestingly, low concentration T was sufficient to amplify myotube mTOR and Akt signaling after 24 h of T withdrawal, demonstrating the potential in cultured myotubes for a T initiated positive feedback mechanism to amplify Akt/mTOR signaling. In summary, androgen withdrawal decreases muscle myofibrillar protein synthesis through Akt/mTORC1 signaling, which is independent of AMPK activation, and readily reversible by anabolic steroid administration. Acute Akt activation in C(2)C(12) myotubes is sensitive to a high concentration of testosterone, and low concentrations of testosterone can activate mTOR signaling independent of Akt.

Chronic obstructive pulmonary disease and comorbidities

Results of epidemiological studies have shown that chronic obstructive pulmonary disease (COPD) is frequently associated with comorbidities, the most serious and prevalent being cardiovascular disease, lung cancer, osteoporosis, muscle weakness, and cachexia. Mechanistically, environmental risk factors such as smoking, unhealthy diet, exacerbations, and physical inactivity or inherent factors such as genetic background and ageing contribute to this association. No convincing evidence has been provided to suggest that treatment of COPD would reduce comorbidities, although some indirect indications are available. Clear evidence that treatment of comorbidities improves COPD is also lacking, although observational studies would suggest such an effect for statins, β blockers, and angiotensin-converting enzyme blockers and receptor antagonists. Large-scale prospective studies are needed. Reduction of common risk factors seems to be the most powerful approach to reduce comorbidities. Whether reduction of so-called spill-over of local inflammation from the lungs or systemic inflammation with inhaled or systemic anti-inflammatory drugs, respectively, would also reduce COPD-related comorbidities is doubtful.

Chronic obstructive pulmonary disease and glucose metabolism: a bitter sweet symphony

Chronic obstructive pulmonary disease, metabolic syndrome and diabetes mellitus are common and underdiagnosed medical conditions. It was predicted that chronic obstructive pulmonary disease will be the third leading cause of death worldwide by 2020. The healthcare burden of this disease is even greater if we consider the significant impact of chronic obstructive pulmonary disease on the cardiovascular morbidity and mortality. Chronic obstructive pulmonary disease may be considered as a novel risk factor for new onset type 2 diabetes mellitus via multiple pathophysiological alterations such as: inflammation and oxidative stress, insulin resistance, weight gain and alterations in metabolism of adipokines. On the other hand, diabetes may act as an independent factor, negatively affecting pulmonary structure and function. Diabetes is associated with an increased risk of pulmonary infections, disease exacerbations and worsened COPD outcomes. On the top of that, coexistent OSA may increase the risk for type 2 DM in some individuals. The current scientific data necessitate a greater outlook on chronic obstructive pulmonary disease and chronic obstructive pulmonary disease may be viewed as a risk factor for the new onset type 2 diabetes mellitus. Conversely, both types of diabetes mellitus should be viewed as strong contributing factors for the development of obstructive lung disease. Such approach can potentially improve the outcomes and medical control for both conditions, and, thus, decrease the healthcare burden of these major medical problems.

Genetic predictors of fatigue in prostate cancer patients treated with androgen deprivation therapy: preliminary findings

BACKGROUND

Fatigue is a common and distressing side effect of androgen deprivation therapy (ADT) for prostate cancer. The goal of the current study was to examine the relationship between changes in fatigue following initiation of ADT and single nucleotide polymorphisms (SNPs) in three pro-inflammatory cytokine genes: interleukin-1 beta (IL1B), interleukin-6 (IL6), and tumor necrosis factor alpha (TNFA).

METHODS

As part of a larger study, men with prostate cancer (n = 53) were recruited prior to initiation of ADT. Fatigue was assessed at recruitment and 6 months after initiation of ADT. DNA was extracted from blood drawn at baseline.

RESULTS

Patients with the IL6-174 (rs1800795) G/C or C/C genotype displayed greater increases in fatigue intrusiveness, frequency, and duration than the G/G genotype (p values ≤ 0.05), although inclusion of age, race, and baseline depressive symptomatology in the model attenuated these relationships (p values ≤ 0.09). Patients with the TNFA-308 (rs1800629) G/A genotype showed greater increases in fatigue severity than the G/G genotype (p = 0.02). IL1B-511 (rs16944) genotype did not significantly predict changes in fatigue (p values >0.46). Patients with higher numbers of variants displayed greater increases in fatigue duration and interference (p values ≤ 0.02) than patients with lower numbers of variants.

CONCLUSIONS

Prostate cancer patients treated with ADT who carry variant alleles of the IL6 and TNFA genes are susceptible to heightened fatigue. These preliminary data lend support for the role of genetic variation in the development of cancer-related fatigue secondary to ADT. Findings are relevant to attempts to develop personalized approaches to cancer treatment.

The influence of abdominal visceral fat on inflammatory pathways and mortality risk in obstructive lung disease

BACKGROUND

Low-grade systemic inflammation, particularly elevated IL-6, predicts mortality in chronic obstructive pulmonary disease (COPD). Although altered body composition, especially increased visceral fat (VF) mass, could be a significant contributor to low-grade systemic inflammation, this remains unexplored in COPD.

OBJECTIVE

The objective was to investigate COPD-specific effects on VF and plasma adipocytokines and their predictive value for mortality.

DESIGN

Within the Health, Aging, and Body Composition (Health ABC) Study, an observational study in community-dwelling older persons, we used propensity scores to match n = 729 persons with normal lung function to n = 243 persons with obstructive lung disease (OLD; defined as the ratio of forced expiratory volume in 1 s to forced vital capacity < lower limit of normal). Matching was based on age, sex, race, clinic site, BMI, and smoking status. Within this well-balanced match, we compared computed tomography-acquired visceral fat area (VFA) and plasma adipocytokines, analyzed independent associations of VFA and OLD status on plasma adipocytokines, and studied their predictive value for 9.4-y mortality.

RESULTS

Whereas whole-body fat mass was comparable between groups, persons with OLD had increased VFA and higher plasma IL-6, adiponectin, and plasminogen activator inhibitor 1 (PAI-1). Both OLD status and VFA were independently positively associated with IL-6. Adiponectin was positively associated with OLD status but negatively associated with VFA. PAI-1 was no longer associated with OLD status after VFA was accounted for. Participants with OLD had increased risk of all-cause, respiratory, and cardiovascular mortality, of which IL-6 was identified as an independent predictor.

CONCLUSION

Our data suggest that excessive abdominal visceral fat contributes to increased plasma IL-6, which, in turn, is strongly associated with all-cause and cause-specific mortality in older persons with OLD.

Association of bone mineral density with airway obstruction and emphysema

BACKGROUND

Airway obstruction and the extent of emphysema are reported to be responsible for reduced bone mineral density (BMD). Corresponding to different phenotypes of a pulmonary disease, different severity in extra pulmonary features may exist. We compared BMDs of subjects with or without airway obstruction and/or emphysema and investigated the relationships among BMD, the severity of airway obstruction, and the extent of emphysema.

METHODS

Using a university hospital database, we reviewed patients over 40 years old who performed spirometry, computed tomography of chest, and measurement of BMD of the lumbar (L) spine. According to the presence or absence of airway obstruction and/or emphysema, four groups were classified.

RESULTS

Among a total of 59 subjects, 33 (56%) had osteoporosis. The prevalence of osteoporosis in subjects with no airway obstruction and no emphysema, those with only emphysema, those with only airway obstruction, and those with both airway obstruction and emphysema were 42%, 57%, 64%, and 73%, respectively (p=0.047 by linear-by-linear association). The mean T-scores of BMD of L1 (p=0.032) and L1-4 spines were different among the four groups (p=0.034). Although the T-score of L1 BMD negatively correlated with the extent of emphysema (r=-0.275, p=0.035) and positively with each of body mass index (BMI) (r=0.520, p<0.001), forced expiratory volume in one second (FEV(1)) (r=0.330, p=0.011), FEV(1)/forced vital capacity (r=0.409, p=0.001), and forced expiratory flow at 25~75% of FVC (FEF(25-75%)) (r=0.438, p=0.0001), respectively, multiple linear regression analysis indicated that BMI (p<0.001) and FEF(25-75%) were predictive of BMD (p=0.012).

CONCLUSION

Low BMI and airway obstruction were strongly associated with reduced bone density rather than the extent of emphysema.

Hypogonadism in chronic obstructive pulmonary disease: incidence and effects

PURPOSE OF REVIEW

This review summarizes the literature on hypogonadism in men with chronic obstructive pulmonary disease (COPD).

RECENT FINDINGS

COPD is a systemic disease with effects beyond the lungs. Many prior studies have shown that middle-aged and elderly COPD patients may develop hypogonadism. Prevalence of hypogonadism in men with COPD can range from 22 to 69% and has been associated with several other systemic manifestations including osteoporosis, depression, and muscle weakness. Recent studies have revealed conflicting results with regards to these previous perceptions. The discrepancies in the findings can be mainly attributed to small sample size, differences in patient selection, and inconsistent findings. Testosterone replacement therapy may result in modest improvements in fat-free mass and limb muscle strength but its therapeutic efficacy in COPD patients still remains controversial.

SUMMARY

The relationship between hypogonadism and COPD still remains poorly understood. The current literature is at best circumstantial.

Does radiographic emphysema correlate with low bone mineral density?

PURPOSE OF REVIEW

Several large epidemiologic studies have shown an association between chronic obstructive pulmonary disease (COPD) and osteoporosis. Recent studies have further implied an emphysema-specific association with low bone mineral density independent of obstruction severity.

RECENT FINDINGS

This review will outline the studies demonstrating an independent association between radiographic emphysema and decreased bone mineral density and will discuss potential disease mechanisms, including systemic inflammation and immune-mediated factors, linking these disease processes.

SUMMARY

Radiographic emphysema should be considered an independent risk factor in studies examining the mechanisms underlying COPD-related bone loss. Future research focused on the relationship between emphysema and low bone mineral density could provide mechanistic insight and result in the development of targeted therapies designed to halt progression of both disease processes.