Predictive parameters of accelerated muscle loss in men-MINOS study

Decline in muscle strength and physical function after fracture in men - the prospective STRAMBO study

Studies on muscle strength and physical function after fracture are focused on short follow-ups and adjacent anatomical region. We compared loss of muscle strength and physical function in men after fracture with normal ageing-related decline. In 823 men aged 60-87, measurements of grip strength and clinical tests (chair stands, balance) were performed every 4 years for 12 years. In 155 men with incident fracture, we compared the status after vs. before the fracture. In men without fracture (controls), we compared the status on the first follow-up (4 years) vs. baseline. In men with fracture, grip strength decreased more than in the controls (41%, 0.28SD, P < .01). Men with fracture had higher risk of incident deterioration on the five chair-stand test vs. the controls (OR = 2.45, P < .001). They had higher risk of incident inability to stand for 10s with closed eyes vs. the controls (OR = 4.80, P < .01). They also had higher risk of deterioration on the tandem walk than the controls: forwards (OR = 2.04, P < .01), backwards (OR = 2.25, P < .005). The rapid physical decline was not limited to the region of the fracture site. In men who had incident non-upper limb fractures, grip strength decreased more (32%, P < .05) vs. the controls. In men who had incident non-lower limb fractures, the risk of decline in the tests of the lower limbs was higher vs. controls (chair stands, OR = 2.73, P < .001). The risk of decline was higher in men with clinical fractures which occurred >1 year before the next visit vs. controls (tandem walk forwards, OR = 2.98, P < .005). Overall, in older men, fractures were associated with greater loss of muscle strength and physical function vs. normal ageing. This accelerated decline was also found in the anatomical regions remote from the fracture site. Thus, programs to decrease or reverse the post-fracture decline could have beneficial effects on subsequent fracture risk.

Association of depression with incident sarcopenia and modified effect from healthy lifestyle: The first longitudinal evidence from the CHARLS

BACKGROUND

The prospective association of depression with incident sarcopenia remains unknown, as does whether such an association is modified by a healthy lifestyle. Thus, the goal of this study was to determine whether depression is independently related to the risk of developing sarcopenia and to detect the effect of a healthy lifestyle on its modification.

METHODS

The prospective study included 9486 participants from the China Health and Retirement Longitudinal Study who were followed from 2011 to 2015. We calculated a lifestyle score based on body mass index, drinking, smoking, social activities, and sleeping time. Cox proportional hazards regression models with hazard ratios (HRs) and 95 % confidence intervals were used to estimate the effect of depression on the risk of sarcopenia and the modification effect of lifestyle (CIs).

RESULTS

During a mean of 3.53 years of follow-up, 1373 individuals developed sarcopenia. After adjusting for confounding factors, depression was significantly associated with a higher risk of incident sarcopenia (HR = 1.34; 95 % CI: 1.19, 1.50). In addition, we observed that individuals adhering to a healthy lifestyle had an 18 % lower risk of sarcopenia onset, compared with individuals with an unhealthy lifestyle.

LIMITATIONS

We couldn't completely rule out potential residual bias due to its observational design. Second, ascertainment of the history of diseases in CHARLS was based on self-reported information, which may introduce recall bias or misclassification.

CONCLUSIONS

Depression was associated with a higher risk of sarcopenia in Chinese adults, and such a risk may be alleviated by adhering to a healthy lifestyle.

Resistance Exercise Counteracts the Impact of Androgen Deprivation Therapy on Muscle Characteristics in Cancer Patients

CONTEXT

Androgen deprivation therapy (ADT) forms the cornerstone in prostate cancer (PCa) treatment. However, ADT also lowers skeletal muscle mass.

OBJECTIVE

To identify the impact of ADT with and without resistance exercise training on muscle fiber characteristics in PCa patients.

METHODS

Twenty-one PCa patients (72 ± 6 years) starting ADT were included. Tissue samples from the vastus lateralis muscle were assessed at baseline and after 20 weeks of usual care (n = 11) or resistance exercise training (n = 10). Type I and II muscle fiber distribution, fiber size, and myonuclear and capillary contents were determined by immunohistochemistry.

RESULTS

Significant decreases in type I (from 7401 ± 1183 to 6489 ± 1293 μm2, P < .05) and type II (from 6225 ± 1503 to 5014 ± 714 μm2, P < .05) muscle fiber size were observed in the usual care group. In addition, type I and type II individual capillary-to-fiber ratio (C/Fi) declined (-12% ± 12% and -20% ± 21%, respectively, P < .05). In contrast, significant increases in type I (from 6700 ± 1464 to 7772 ± 1319 μm2, P < .05) and type II (from 5248 ± 892 to 6302 ± 1385 μm2, P < .05) muscle fiber size were observed in the training group, accompanied by an increase in type I and type II muscle fiber myonuclear contents (+24% ± 33% and +21% ± 23%, respectively, P < .05) and type I C/Fi (+18% ± 14%, P < .05).

CONCLUSION

The onset of ADT is followed by a decline in both type I and type II muscle fiber size and capillarization in PCa patients. Resistance exercise training offsets the negative impact of ADT and increases type I and II muscle fiber size and type I muscle fiber capillarization in these patients.

Fourier-Transform Infrared Spectroscopy as a Screening Tool for Osteosarcopenia in Community-Dwelling Older Women

Osteosarcopenia is a complex geriatric syndrome characterized by the presence of both sarcopenia and osteopenia/osteoporosis. This condition increases rates of disability, falls, fractures, mortality, and mobility impairments in older adults. The purpose of this study was to analyze the Fourier-transform infrared (FTIR) spectroscopy diagnostic power for osteosarcopenia in community-dwelling older women (n = 64; 32 osteosarcopenic and 32 non-osteosarcopenia). FTIR is a fast and reproducible technique highly sensitive to biological tissues, and a mathematical model was created using multivariate classification techniques that denoted the graphic spectra of the molecular groups. Genetic algorithm and support vector machine regression (GA-SVM) was the most feasible model, achieving 80.0% of accuracy. GA-SVM identified 15 wave numbers responsible for class differentiation, in which several amino acids (responsible for the proper activation of the mammalian target of rapamycin) and hydroxyapatite (an inorganic bone component) were observed. Imaging tests and low availability of instruments that allow the observation of osteosarcopenia involve high health costs for patients and restrictive indications. Therefore, FTIR can be used to diagnose osteosarcopenia due to its efficiency and low cost and to enable early detection in geriatric services, contributing to advances in science and technology that are potential "conventional" methods in the future.

A pas de deux of osteoporosis and sarcopenia: osteosarcopenia

The musculoskeletal conditions osteoporosis and sarcopenia are highly prevalent in older adults. Osteoporosis is characterized by low bone mass and microarchitectural deterioration of bone, whereas sarcopenia is identified by the loss of muscle strength, function and mass. Osteoporosis represents a major health problem contributing to millions of fractures worldwide on an annual basis, whereas sarcopenia is associated with a range of adverse physical and metabolic outcomes. They both affect physical and social function, confidence and quality of life as well as contributing to high health-care costs worldwide. Osteosarcopenia is the term given when both conditions occur concomitantly and it has been suggested that interactions between these two conditions may accelerate individual disease progression as co-existence of osteoporosis and sarcopenia is associated with higher morbidity from falls, fracture, disability as well as mortality. In this review, we will outline the epidemiology, pathogenesis and clinical consequences of osteosarcopenia and discuss available management strategies.

Bone Microarchitecture Decline and Risk of Fall and Fracture in Men With Poor Physical Performance-The STRAMBO Study

CONTEXT

High fracture risk in individuals with low muscle strength is attributed to high risk of falls.

OBJECTIVE

This work aims to study the association of muscle mass and physical performance with bone microarchitecture decline and risk of fall and nonvertebral fracture in men.

METHODS

A prospective, 8-year follow-up of a cohort was conducted among the general population. A total of 821 volunteer men aged 60 and older participated. Hip areal bone mineral density (aBMD) and appendicular lean mass (ALM) were assessed at baseline by dual x-ray absorptiometry. Lower-limb relative ALM (RALM-LL) is ALM-LL/(leg length)2. The physical performance score reflects the ability to perform chair stands and static and dynamic balance. Bone microarchitecture was assessed by high-resolution peripheral quantitative computed tomography (HR-pQCT) at baseline and after 4 and 8 years. Statistical analyses were adjusted for shared risk factors. Outcome measurements included the rate of change in the HR-pQCT indices, incident falls, and fractures.

RESULTS

Cortical bone loss and estimated bone strength decline were faster in men with low vs normal RALM-LL (failure load: -0.74 ± 0.09 vs -0.43 ± 0.10%/year; P < .005). Differences were similar between men with poor and those with normal physical performance (failure load: -1.12 ± 0.09 vs -0.40 ± 0.05%/year; P < .001). Differences were similar between men having poor performance and low RALM-LL and men having normal RALM-LL and performance (failure load: -1.40 ± 0.17 vs -0.47 ± 0.03%/year; P < .001). Men with poor physical performance had a higher risk of fall (hazard ratio [HR] = 3.52; 95% CI, 1.57-7.90, P < .05) and fracture (HR = 2.68; 95% CI, 1.08-6.66, P < .05).

CONCLUSION

Rapid decline of bone microarchitecture and estimated strength in men with poor physical performance and low RALM-LL may contribute to higher fracture risk.

Osteosarcopenia: where osteoporosis and sarcopenia collide

The coexistence of osteoporosis and sarcopenia has been recently considered in some groups as a syndrome termed 'osteosarcopenia'. Osteoporosis describes low bone mass and deterioration of the micro-architecture of the bone, whereas sarcopenia is the loss of muscle mass, strength and function. With an ageing population the prevalence of both conditions is likely to increase substantially over the coming decades and is associated with significant personal and societal burden. The sequelae for an individual suffering from both conditions together include a greater risk of falls, fractures, institutionalization and mortality. The aetiology of 'osteosarcopenia' is multifactorial with several factors linking muscle and bone function, including genetics, age, inflammation and obesity. Several biochemical pathways have been identified that are facilitating the development of several promising therapeutic agents, which target both muscle and bone. In the current review we outline the epidemiology, pathogenesis and clinical consequences of 'osteosarcopenia' and explore current and potential future management strategies.

Rapid Progression of Aortic Calcification in Older Men with Low Appendicular Lean Mass and Poor Physical Function

OBJECTIVES

Assessment of the progression of abdominal aortic calcification (AAC) may be a surrogate marker of the impact of physical function on cardiovascular risk. Our aim was to assess the risk of rapid AAC progression in older men with low relative appendicular lean mass (RALM) and poor physical function.

DESIGN

Prospective cohort study.

SETTING

Community-dwelling older men.

PARTICIPANTS

621 men aged 50-85 followed prospectively (baseline, 3 and 7.5 years).

MEASUREMENTS

Body composition was assessed by DXA. Poor physical function was defined as incapacity to perform ≥1 of 5 clinical tests (balance, muscle strength). AAC was assessed using Kauppila's semiquantitative score. Reclassification improvement was assessed by comparing the areas under the curve (AUC) using DeLong's method.

RESULTS

Rapid AAC progression (>0.6 point/year) was found in 168 men (27.1%). After adjustment for confounders including baseline AAC, the risk of rapid AAC progression increased with lower RALM (OR=1.42/SD, 95%CI: 1.09-1.86, p<0.01) and was higher in the lowest (<7.5kg/m2) vs. highest (>8.6kg/m2) quartile (OR=2.15, 95%CI: 1.17-3.95, p<0.01). Poor physical performance was associated with rapid AAC progression (OR=2.76, 95%CI: 1.48-5.91, p<0.005). Low RALM (<7.84kg/m2 defined using Youden's index) and poor physical function contributed to the risk of rapid AAC progression jointly. Men who had low RALM and poor physical function had higher risk of rapid AAC progression vs. men without these traits (OR=4.66, 95%CI: 1.72-12.62, p<0.05). RALM and physical function improved the identification of men with rapid AAC progression (DAUC=0.026, 95%CI: 0.005-0.046, p<0.05) after adjustment for confounders including baseline AAC score.

CONCLUSIONS

Low RALM and poor physical function are associated with higher risk of rapid AAC progression and possibly represent another measure of cardiovascular risk.

Neighborhood environment and muscle mass and function among rural older adults: a 3-year longitudinal study

BACKGROUND

Sarcopenia, resulting from loss of muscle mass and function, is highly prevalent in the ageing societies and is associated with risk of falls, frailty, loss of independence, and mortality. It is important to identify environmental risk factors, so that evidence-based interventions to prevent sarcopenia can be implemented at the population level. This study aimed to examine the potential effect of several objectively measured neighborhood environmental factors on longitudinal change of muscle mass and function among older adults living in rural Japanese towns where the population is ageing.

METHODS

This study was based on data from the Shimane CoHRE Study conducted by the Center for Community-based Healthcare Research and Education (CoHRE) at Shimane University in 3 rural towns in the Shimane Prefecture, Japan. Subjects older than 60 years, who participated in an annual health examination in 2016 and any follow-up years until 2019, i.e., 4 possible time points in total, were included (n = 2526). The skeletal muscle mass index (SMI) and grip strength were assessed objectively for each year as a measure of muscle mass and function, respectively. Neighborhood environmental factors, i.e., hilliness, bus stop density, intersection density, residential density, and distance to a community center were measured by geographic information systems (GIS). Linear mixed models were applied to examine the potential effect of each neighborhood environmental factor on the change of SMI and grip strength over time.

RESULTS

Males living far from community centers had a less pronounced decline in SMI compared to those living close to community centers. Females living in areas with higher residential density had a less pronounced decline in grip strength compared to those living in areas with lower residential density.

CONCLUSIONS

Neighborhood environmental factors had limited effects on change of SMI and grip strength among rural older adults within the 3 years follow up. Further long-term follow up studies are necessary by also taking into account other modifiable neighborhood environmental factors.

Human T-cell lymphotropic virus type-1 infection associated with sarcopenia: community-based cross-sectional study in Goto, Japan

Sarcopenia is characterized by a progressive skeletal muscle disorder that involves the loss of muscle mass and low muscle strength, which contributes to increased adverse outcomes. Few studies have investigated the association between chronic infection and sarcopenia. This study aimed to examine the association between human T-cell lymphotropic virus type-1 (HTLV-1) and sarcopenia. We conducted a cross-sectional study and enrolled 2,811 participants aged ≥ 40 years from a prospective cohort study in Japanese community dwellers during 2017-2019. Sarcopenia was defined as low appendicular skeletal muscle mass and low handgrip strength. The association between HTLV-1 seropositivity and sarcopenia was assessed using multivariable logistic regression. Odds ratio (OR) and 95% confidence interval (CI) of sarcopenia were analysed using HTLV-1 seropositivity. We adjusted for age, sex, body mass index, physical activity, systolic blood pressure, glycated haemoglobin, low-density lipoprotein cholesterol, and smoking and drinking status. Of 2,811 participants, 484 (17.2%) HTLV-1 infected participants were detected. HTLV-1 infection was significantly associated with sarcopenia (adjusted OR 1.46, 95% CI 1.03-2.07, P = 0.034). HTLV-1 was associated with sarcopenia among community-dwelling adults. Active surveillance and early detection of asymptomatic HTLV-1 infection might be beneficial to reinforce countermeasures to inhibit the progress of HTLV infection-associated sarcopenia.

Factors Associated with Sarcopenia and 7-Year Mortality in Very Old Patients with Hip Fracture Admitted to Rehabilitation Units: A Pragmatic Study

Background: Admitted bedridden older patients are at risk of the development of sarcopenia during hospital stay (incident sarcopenia). The objective of this study was to assess the factors associated with sarcopenia (incident and chronic) and its impact on mortality in older people with hip fracture. Methods: A multicenter, pragmatic, prospective observational study was designed. Older subjects with hip fracture admitted to two rehabilitation units were included. Sarcopenia was assessed at admission and at discharge according to the revised EWGSOP (European Working Group on Sarcopenia in Older People) consensus definition. The mortality was evaluated after 7 years of follow-up. Results: A total of 187 subjects (73.8% women) age 85.2 ± 6.3 years were included. Risk factors associated to incident and chronic sarcopenia were undernutrition (body mass index—BMI and Mini Nutritional Assessment−Short Form—MNA-SF), hand-grip strength and skeletal muscle index. During follow-up 114 patients died (60.5% sarcopenic vs. 39.5% non-sarcopenic, p = 0.001). Cox regression analyses showed that factors associated to increased risk of mortality were sarcopenia (HR: 1.67, 95% CI 1.11–2.51) and low hand-grip strength (HR: 1.76, 95% CI 1.08–2.88). Conclusions: Older patients with undernutrition have a higher risk of developing sarcopenia during hospital stay, and sarcopenic patients have almost two times more risk of mortality than non-sarcopenic patients during follow-up after hip fracture.

The Association between Body Composition using Dual energy X-ray Absorptiometry and Type-2 Diabetes: A Systematic Review and Meta-Analysis of Observational studies

The association between objective measures of body composition (BC) with type 2 diabetes (T2DM) is inconclusive. We conducted a systematic review and meta-analysis to examine the association between several body composition (BC) indices assessed using dual energy X-ray absorptiometry (DXA), and T2DM. Using PRISMA guidelines, we searched for observational studies investigating BC measures, including total body fat mass (BFM), visceral fat mass (VFM), subcutaneous fat mass (SFM), and fat free mass (FFM); and T2DM. Of 670 titles initially identified, 20 were included. High VFM was consistently associated with T2DM. For every kg increase in VFM, the odds of having T2DM increased by two-fold for males (OR 2.28 [95% CI 1.42 to 3.65], p = 0.001) and more than 4-fold for females (OR 4.24 [1.64 to 11.02], p = 0.003). The presence of T2DM was associated with 2-fold higher odds of low FFM (OR 2.38 [1.44 to 3.95]). We found evidence that greater VFM is a risk factor for prevalent and incident T2DM. While the presence of T2DM is associated with reduced FFM; the relationship between FFM and BFM with T2DM remains unclear. Reducing VFM and increasing FFM through lifestyle changes may reduce the risk of T2DM and mitigate its deleterious effect on BC, respectively.

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.

Urinary Sex Steroid and Glucocorticoid Hormones Are Associated With Muscle Mass and Strength in Healthy Adults

CONTEXT

Sex steroid hormones exhibit anabolic effects whereas a deficiency engenders sarcopenia. Moreover, supraphysiological levels of glucocorticoids promote skeletal muscle atrophy, whereas physiologic levels of glucocorticoids may improve muscle performance.

OBJECTIVE

To study the relationship between both groups of steroid hormones at a physiological range with skeletal muscle mass and function in the general population.

DESIGN

Cross-sectional analysis of the associations between urinary excreted androgens, estrogens, glucocorticoids, and steroid hormone metabolite ratios with lean mass and handgrip strength in a population-based cohort.

SETTING

Three centers in Switzerland including 1128 participants.

MEASURES

Urinary steroid hormone metabolite excretion by gas chromatography-mass spectrometry, lean mass by bioimpedance analysis, and isometric handgrip strength by dynamometry.

RESULTS

For lean mass a strong positive association was found with 11β-OH-androsterone and with most glucocorticoids. Androsterone showed a positive association in middle-aged and older adults. Estriol showed a positive association only in men. For handgrip strength, strong positive associations with androgens were found in middle-aged and older adults, whereas positive associations were found with cortisol metabolites in young to middle-aged adults.

CONCLUSIONS

Sex steroids and glucocorticoids are strongly positively associated with skeletal muscle mass and strength in the upper limbs. The associations with muscle strength appear to be independent of muscle mass. Steroid hormones exert age-specific anabolic effects on lean mass and handgrip strength. Deficits in physical performance of aged muscles may be attenuated by androgens, whereas glucocorticoids in a physiological range increase skeletal muscle mass at all ages, as well as muscle strength in particular in younger adults.

Preventive Effects of Low Parathyroid Hormone Levels on Hip Fracture in Patients with Vitamin D Deficiency

Background

The objective of the current study is to determine the role of serum parathyroid hormone (PTH) on hip fracture development by retrospectively analyzing the relationship between vitamin D and PTH levels and hip fracture prevalence.

Methods

Among 288 patients over 50 years of age, 113 patients with hip fracture and 111 controls without fracture were analyzed after excluding patients with conditions affecting bone metabolism. Bone mineral density and serum biochemical markers were measured, while demographic data were obtained. Patients were divided into 4 groups according to serum 25-hydroxy-vitamin D (25-[OH]D) and PTH levels: LowD+LowP (low 25[OH]D and PTH); LowD+HighP, (low 25[OH]D and high PTH); HighD+LowP (high 25[OH]D and low PTH); and HighD+HighP, patients with (high 25[OH]D and PTH). Measured values and percentages of patients with hip fracture in each group were then determined and compared.

Results

The number of patients included in the LowD+LowP, LowD+HighP, HighD+LowP, and HighD+HighP groups was 116, 17, 87, and 4, while the percentages of patients with hip fracture in the same groups were 60.3%, 88.2%, 27.6%, and 100%, respectively. The percentage of hip fracture was significantly lower in the LowD+LowP than the LowD+HighP group (P=0.049).

Conclusions

Patients with low serum 25(OH)D and PTH levels showed lower hip fracture prevalence, indicating the potential protective role of low PTH levels on bone health in patients with vitamin D deficiency. Therefore, clinicians should pay more attention to the possibility of fractures in patients with vitamin D deficiency who present with high PTH levels.

Smoking and Diabetes as Predictive Factors of Accelerated Loss of Muscle Mass in Middle-Aged and Older Women: A Six-Year Retrospective Cohort Study

Background: Preservation of muscle mass during aging reduces the risk of frailty and age-related chronic diseases. We investigated the lifestyle, psychological factors, and common cardiometabolic diseases associated with accelerated muscle loss in middle-aged and older women. Materials and Methods: A total of 881 women aged 40 years and older who underwent regular health checkup at a tertiary care hospital in Korea in 2010-2011 and underwent a 6-year follow-up were included in this study. Lifestyle and health statuses were evaluated through a standardized questionnaire and laboratory testing. Muscle mass was estimated using bioelectrical impedance analysis. Results: The accelerated loss group showing appendicular skeletal muscle mass (ASM) loss >3% for 6 years represented 24.4% (n = 215) of the total participants. Current smoking women presented a higher odds ratio (OR) for accelerated loss of ASM than nonsmoking individuals after adjusting for age, body mass index, exercise, caloric intake, alcohol consumption, menopausal state, and diabetes mellitus (DM) (OR 3.53, confidence interval [95% CI] 1.28-9.74, p = 0.015). Women with DM showed a higher OR than non-DM individuals after adjusting for the aforementioned variables and smoking status (OR 2.92, 95% CI 1.39-6.14, p = 0.005). Conclusion: Current smoking and DM are predictors for accelerated muscle mass loss in middle-aged and older women. Smokers and DM patients need to monitor muscle mass changes and apply preventive intervention steps. Smoking cessation and good glycemic control are required not only for reducing cardiovascular risk but also for improving muscle health.

Dietary wild bitter gourd displays selective androgen receptor modulator like activity and improves the muscle decline of orchidectomized mice

Loss of skeletal muscle mass and strength is often associated with disability and poor quality of life. Selective Androgen Receptor Modulators (SARMs) are under development as potential treatment. This study aims at examining the potential of wild bitter gourd (BG) as a SARM and its effects on the muscle decline induced by orchiectomy. In the cell-based androgen receptor (AR) transactivation assay, the BGP extract showed weak agonistic and antagonistic activities, resembling those of some SARMs. Male C57BL/6J mice were sham-operated (Sham group) or castrated (Cast groups) and fed a modified AIN-93G high sucrose diet supplemented without (Cast group) or with 5% lyophilized BG powder (Cast + BGP) or with testosterone propionate (7 mg TP per kg diet, Cast + TP) for 23 weeks. In contrast to the Cast + TP group, the BGP supplementation did not affect the serum testosterone concentration, and prostate and seminal vesicle mass. Both TP and BGP supplementation increased the weight of androgen responsive muscles, bulbocavernosus (BC) and levator ani (LA) (p < 0.05). The grip strength and the performance on a rotarod of the Cast + BGP group were comparable to those of the Cast + TP group (p > 0.05). The number of succinate dehydrogenase (SDH)-positive fibers of the Cast + BGP group was not significantly different from that of the Sham and Cast + TP groups (p > 0.05). The BGP supplementation up-regulated the Pgc1α, Ucp2 or Ucp3 gene expressions in skeletal muscles of castrated mice (p < 0.05). BGP showed some characteristics of the SARM and might improve skeletal muscle function through the up-regulation of mitochondrial biogenic genes and oxidative capacity, and ameliorated the castration-induced decline of skeletal muscle function in mice.

Role of androgens for urethral homeostasis

Background

We observed that patients with hypogonadism are at higher risk to experience artificial urinary sphincter cuff erosion. Sphincter erosions have been found to be associated with urethral atrophy or compromised urethras subsequent to events limiting its blood supply. We therefore analyzed possible mechanisms how a decrease in testosterone serum levels can result decreased urethral blood flow.

Methods

In a cohort of >1,200 urethroplasties, tissue specimens obtained during surgeries were analyzed for expression of androgen receptor (AR), AR-responsive TIE-2 associated with angiogenesis, and the endothelial cell marker CD31 for determination of vessel counts were analyzed immunohistochemically. A total of 11 patients were included in whom both tissue and serum testosterone levels within 2 years of the urethroplasty was available. Low serum testosterone level defined as <280 ng/dL. Image J software was used to analyze expression profiles.

Results

Mean serum testosterone level was significant lower in hypogonadal patients (179.4 ng/dL) compared to eugonadal patients (375.0 ng/dL, P=0.003). Urethral tissue of hypogonadal patients showed decreased AR expression [1.11% high power field (HPF)] compared to eugonadal patients (1.62%, P=0.016), decreased TIE-2 expression (1.84% HPF vs. 3.08%, P=0.006), and also decreased vessel counts (44.47 vessels/HPF vs. 98.33, P=0.004). There was a direct correlation of AR and TIE-2 expression levels with serum testosterone levels (rho 0.685, P=0.029, and rho 0.773, P=0.005, respectively). Of note, we did not detect a difference in age, prior radiation, coronary artery disease or hypertension among hypo- or eugonadal patient. However, higher body mass index was associated with low serum testosterone levels.

Conclusions

Hypogonadal status is associated with decreased expression of AR and TIE-2 and also reduced vessel count in urethral tissue. We believe that the resulting decreased urethral vascularity subsequent to a hypogonadal state may be an important risk factor for complications of urethral surgery.

Nonandrogenic Anabolic Hormones Predict Risk of Frailty: European Male Ageing Study Prospective Data

CONTEXT

Low levels of nonandrogenic anabolic hormones have been linked with frailty, but evidence is conflicting and prospective data are largely lacking.

OBJECTIVE

To determine associations between nonandrogenic anabolic hormones and prospective changes in frailty status.

DESIGN/SETTING

A 4.3-year prospective observational study of community-dwelling men participating in the European Male Ageing Study.

PARTICIPANTS

Men (n = 3369) aged 40 to 79 years from eight European centers.

MAIN OUTCOME MEASURES

Frailty status was determined using frailty phenotype (FP; n = 2114) and frailty index (FI; n = 2444).

ANALYSIS

Regression models assessed relationships between baseline levels of insulinlike growth factor 1 (IGF-1), its binding protein 3 (IGFBP-3), dehydroepiandrosterone sulfate (DHEA-S), 25-hydroxyvitamin D (25OHD), and parathyroid hormone (PTH), with changes in frailty status (worsening or improving frailty).

RESULTS

The risk of worsening FP and FI decreased with 1 standard deviation higher IGF-1, IGFBP-3, and 25OHD in models adjusted for age, body mass index, center, and baseline frailty [IGF-1: odds ratio (OR) for worsening FP, 0.82 (0.73, 0.93), percentage change in FI, -3.7% (-6.0, -1.5); IGFBP-3: 0.84 (0.75, 0.95), -4.2% (-6.4, -2.0); 25OHD: 0.84 (0.75, 0.95); -4.4%, (-6.7, -2.0)]. Relationships between IGF-1 and FI were attenuated after adjusting for IGFBP-3. Higher DHEA-S was associated with a lower risk of worsening FP only in men >70 years old [OR, 0.57 (0.35, 0.92)]. PTH was unrelated to change in frailty status.

CONCLUSIONS

These longitudinal data confirm the associations between nonandrogenic anabolic hormones and the changes in frailty status. Interventional studies are needed to establish causality and determine therapeutic implications.

Epidemiology of sarcopenia and insight into possible therapeutic targets

Musculoskeletal ageing is a major public health concern owing to demographic shifts in the population. Sarcopenia, generally defined as the age-related loss of muscle mass and function, is associated with considerable risk of falls, loss of independence in older adults and hospitalization with poorer health outcomes. This condition is therefore associated with increased morbidity and health care costs. As with bone mass, muscle mass and strength increase during late adolescence and early adulthood, but begin to decline substantially from ∼50 years of age. Sarcopenia is characterized by many features, which include loss of muscle mass, altered muscle composition, infiltration with fat and fibrous tissue and alterations in innervation. A better understanding of these factors might help us to develop strategies that target these effects. To date, however, methodological challenges and controversies regarding how best to define the condition, in addition to uncertainty about what outcome measures to consider, have delayed research into possible therapeutic options. Most pharmacological agents investigated to date are hormonal, although new developments have seen the emergence of agents that target myostatin signalling to increase muscle mass. In this review we consider the current approaching for defining sarcopenia and discuss its epidemiology, pathogenesis, and potential therapeutic opportunities.

Assessing the Risk of Sarcopenia in the Elderly: The Mini Sarcopenia Risk Assessment (MSRA) Questionnaire

OBJECTIVES

to validate the MSRA questionnaire proposed as prescreening tool for sarcopenia, in a population of community-dwelling elderly subjects.

DESIGN

observational study.

SETTING

community dwelling elderly subjects.

PARTICIPANTS

274 community dwelling elderly subjects, 177 women and 97 men, aged 66-78 years.

MEASUREMENTS

Based on EWGSOP diagnostic criteria subjects were classified as sarcopenic and non-sarcopenic. The Mini Sarcopenia Risk Assessment (MSRA) questionnaire, is composed of seven questions and investigates anamnestic and nutritional characteristics related to risk of sarcopenia onset (age, protein and dairy products consumption, number of meals per day, physical activity level, number of hospitalizations and weight loss in the last year).

RESULTS

33.5% of the study population, were classified as sarcopenic. With the 7-item MSRA score, subjects with a score of 30 or less, had a 4-fold greater risk of being sarcopenic than subjects with a score higher than 30 (OR:4.20;95% CI:2.26-8.06); area under the ROC curve was 0.786 (95% CI:0.725-0.847). In a logistic regression, considering as dependent variable the probability of being sarcopenic, and as independent variables the 7 items of the questionnaire, two items (number of meals and milk and dairy products consumption) showed non-significant diagnostic power. A 5-item score was then derived and the area under the ROC curve was 0.789 (95% IC:0.728-0.851). Taking into account the cost of false positive and false negative costs and the prevalence of sarcopenia, the "optimal" threshold of the original MSRA score (based on 7 items) is 30, with a sensitivity of 0.804 and a specificity of 0.505, while the "optimal" threshold of the MSRA score based on 5 items, is 45, with a sensitivity of 0.804 and a specificity of 0.604.

CONCLUSION

this preliminary study shows that the MSRA questionnaire is predictive of sarcopenia and can be suggested as prescreening instrument to detect this condition. The use of a short form of the MSRA questionnaire improves the capacity to identify sarcopenic subjects.

The association between physiologic testosterone levels, lean mass, and fat mass in a nationally representative sample of men in the United States

Testosterone deficiency leads to increased muscle loss with aging and increased fat mass. Supraphysiologic levels cause an increase in muscle mass and decrease in fat mass. The difference in lean and fat mass across physiologic levels of testosterone has been under examined in men.

OBJECTIVE

Examine the association between physiologic testosterone levels with lean and fat mass.

METHODS

Data from the 1999-2000 NHANES were used (n=252 men; 18-85yrs). Testosterone and SHBG values were obtained by a morning blood sample. Body composition was measured by DXA. Multivariable linear regression was used to compute unadjusted, minimally adjusted, and extended models of relative upper- and lower-body lean and fat mass.

RESULTS

In the extended model, men with total testosterone levels in the highest 25% (4th quartile) had more lower-body lean mass (LBLM) (β=22.1(%), 95%CI: 9.0, 35.3, p=0.003) and upper-body lean mass (UBLM) (β=5.6(%), 95%CI: 0.1, 11.2, p=0.046), and less lower-body fat mass (LBFM) (β=-9.9(%), 95%CI: -17.7, -2.1, p=0.016) and upper-body fat mass (UBFM) (β=-6.1(%), 95%CI: -10.1, -2.1, p=0.005) than those in the 1st quartile. Men in the 3rd quartile had more LBLM (β=14.2, 95%CI: 5.3, 23.1, p=0.004), UBLM (β=5.6, 95%CI: 2.0, 9.2, p=0.004), and less LBFM (β=-9.7(%), 95%CI: -16.7, -2.7, p=0.010) and UBFM (β=-4.7(%), 95%CI: -8.3, -1.2, p=0.012) than those in the 1st quartile.

CONCLUSION

These findings suggest that, at physiologic levels, an association exists between higher levels of testosterone and favorable lean and fat measures.

Aging of the endocrine system and its potential impact on sarcopenia

Sarcopenia, occurring as a primary consequence of aging, is a progressive generalized decline of skeletal muscle mass, strength and function. The pathophysiology of sarcopenia is complex and multifactorial. One major cause of muscle mass and strength loss with aging appears to be the alteration in hormonal networks involved in the inflammatory processes, muscle regeneration and protein synthesis. This review describes the recent findings concerning the role of the aging on the endocrine system in the development of sarcopenia. We also report the benefits and safety of hormone replacement therapy in elderly subjects and discuss future perspectives in the therapy and prevention of skeletal muscle aging.

Muscle-bone interactions: From experimental models to the clinic? A critical update

Bone is a biomechanical tissue shaped by forces from muscles and gravitation. Simultaneous bone and muscle decay and dysfunction (osteosarcopenia or sarco-osteoporosis) is seen in ageing, numerous clinical situations including after stroke or paralysis, in neuromuscular dystrophies, glucocorticoid excess, or in association with vitamin D, growth hormone/insulin like growth factor or sex steroid deficiency, as well as in spaceflight. Physical exercise may be beneficial in these situations, but further work is still needed to translate acceptable and effective biomechanical interventions like vibration therapy from animal models to humans. Novel antiresorptive and anabolic therapies are emerging for osteoporosis as well as drugs for sarcopenia, cancer cachexia or muscle wasting disorders, including antibodies against myostatin or activin receptor type IIA and IIB (e.g. bimagrumab). Ideally, increasing muscle mass would increase muscle strength and restore bone loss from disuse. However, the classical view that muscle is unidirectionally dominant over bone via mechanical loading is overly simplistic. Indeed, recent studies indicate a role for neuronal regulation of not only muscle but also bone metabolism, bone signaling pathways like receptor activator of nuclear factor kappa-B ligand (RANKL) implicated in muscle biology, myokines affecting bone and possible bone-to-muscle communication. Moreover, pharmacological strategies inducing isolated myocyte hypertrophy may not translate into increased muscle power because tendons, connective tissue, neurons and energy metabolism need to adapt as well. We aim here to critically review key musculoskeletal molecular pathways involved in mechanoregulation and their effect on the bone-muscle unit as a whole, as well as preclinical and emerging clinical evidence regarding the effects of sarcopenia therapies on osteoporosis and vice versa.

Frailty and sarcopenia as the basis for the phenotypic manifestation of chronic diseases in older adults

Frailty is a functional status that precedes disability and is characterized by decreased functional reserve and increased vulnerability. In addition to disability, the frailty phenotype predicts falls, institutionalization, hospitalization and mortality. Frailty is the consequence of the interaction between the aging process and some chronic diseases and conditions that compromise functional systems and finally produce sarcopenia. Many of the clinical manifestations of frailty are explained by sarcopenia which is closely related to poor physical performance. Reduced regenerative capacity, malperfusion, oxidative stress, mitochondrial dysfunction and inflammation compose the sarcopenic skeletal muscle alterations associated to the frailty phenotype. Inflammation appears as a common determinant for chronic diseases, sarcopenia and frailty. The strategies to prevent the frailty phenotype include an adequate amount of physical activity and exercise as well as pharmacological interventions such as myostatin inhibitors and specific androgen receptor modulators. Cell response to stress pathways such as Nrf2, sirtuins and klotho could be considered as future therapeutic interventions for the management of frailty phenotype and aging-related chronic diseases.

Determinants of Muscle and Bone Aging

Loss of bone and muscle with advancing age represent a huge threat to loss of independence in later life. Osteoporosis represents a major public health problem through its association with fragility fractures, primarily of the hip, spine and distal forearm. Sarcopenia, the age related loss of muscle mass and function, may add to fracture risk by increasing falls risk. In the context of muscle aging, it is important to remember that it is not just a decline in muscle mass which contributes to the deterioration of muscle function. Other factors underpinning muscle quality come into play, including muscle composition, aerobic capacity and metabolism, fatty infiltration, insulin resistance, fibrosis and neural activation. Genetic, developmental, endocrine and lifestyle factors, such as physical activity, smoking and poor diet have dual effects on both muscle and bone mass in later life and these will be reviewed here. Recent work has highlighted a possible role for the early environment. Inflammaging is an exciting emerging research field that is likely to prove relevant to future work, including interventions designed to retard to reverse bone and muscle loss with age.

Endocrine determinants of incident sarcopenia in middle-aged and elderly European men

BACKGROUND

In men, the long-term consequences of low serum levels of sex steroids, vitamin D metabolites, and insulin-like growth factor 1 (IGF-1) on the evolution of muscle mass, muscle strength, or physical performance are unclear. Moreover, there are no data about the relationship between these hormones and incident sarcopenia defined as low muscle mass and function. The aim of this study was to determine whether the baseline levels of sex hormones, vitamin D metabolites, and IGF-1 predict changes in muscle mass, muscle strength, physical performance, and incident sarcopenia.

METHODS

In 518 men aged 40-79 years, recruited for participation in the European Male Ageing Study, total, free, and bioavailable testosterone (T), oestradiol (E), sex hormone-binding globulin, IGF-1, 25-hydroxyvitamin D (25OHD), 1,25-dihydroxyvitamin D (1,25(OH)2D), and parathyroid hormone were assessed at baseline. Appendicular lean mass (aLM), gait speed, and grip strength were measured at baseline and after a mean follow-up of 4.3 years. Sarcopenia was defined by the definition of Baumgartner (relative aLM ≤7.26 kg/m(2)), the International Working Group on Sarcopenia (IWGS), and the European Working Group on Sarcopenia in Older People (EWGSOP).

RESULTS

aLM significantly decreased from age 50 years, while gait speed and grip strength significantly decreased from age 70 years. The incidence of sarcopenia by the definitions of Baumgartner, IWGS, and EWGSOP was 8.1%, 3.0%, and 1.6%, respectively. After adjustment for age, centre, body mass index, smoking, and number of comorbidities at baseline, baseline levels of T and vitamin D metabolites were not associated with change in aLM, gait speed, and/or grip strength, while a high baseline level of total E2 was associated with a greater decrease in aLM. In men aged ≥70 years, low IGF-1 was associated with a greater decrease in gait speed. Baseline endocrine variables were not independently associated with an increased risk of incident sarcopenia by any definition.

CONCLUSIONS

Low levels of T and 25OHD do not predict loss of muscle mass, gait speed, or grip strength in middle-aged and elderly community-dwelling European men. Low IGF-1 predicts change in gait speed in men aged ≥70 years.

Sex steroid actions in male bone

Sex steroids are chief regulators of gender differences in the skeleton, and male gender is one of the strongest protective factors against osteoporotic fractures. This advantage in bone strength relies mainly on greater cortical bone expansion during pubertal peak bone mass acquisition and superior skeletal maintenance during aging. During both these phases, estrogens acting via estrogen receptor-α in osteoblast lineage cells are crucial for male cortical and trabecular bone, as evident from conditional genetic mouse models, epidemiological studies, rare genetic conditions, genome-wide meta-analyses, and recent interventional trials. Genetic mouse models have also demonstrated a direct role for androgens independent of aromatization on trabecular bone via the androgen receptor in osteoblasts and osteocytes, although the target cell for their key effects on periosteal bone formation remains elusive. Low serum estradiol predicts incident fractures, but the highest risk occurs in men with additionally low T and high SHBG. Still, the possible clinical utility of serum sex steroids for fracture prediction is unknown. It is likely that sex steroid actions on male bone metabolism rely also on extraskeletal mechanisms and cross talk with other signaling pathways. We propose that estrogens influence fracture risk in aging men via direct effects on bone, whereas androgens exert an additional antifracture effect mainly via extraskeletal parameters such as muscle mass and propensity to fall. Given the demographic trends of increased longevity and consequent rise of osteoporosis, an increased understanding of how sex steroids influence male bone health remains a high research priority.