Benefits of estrogen replacement for skeletal muscle mass and function in post-menopausal females: evidence from human and animal studies

Evaluating the effects of hormone therapy termination on skeletal muscle and physical independence in postmenopausal women

OBJECTIVE

In women, the age-related decline in skeletal muscle structure and function is accelerated after menopause, which implicates the role of decreased circulating estrogen levels. Indeed, boosting estrogen, by means of postmenopausal hormone therapy (HT), generally proves beneficial to skeletal muscle. The evidence regarding whether these benefits persist even after cessation of HT is limited, nor is it clear how physical behavior (PB) impacts on benefits. Hence, this exploratory study focused on the interplay between HT administration/cessation, PB and in vivo skeletal muscle structure and function.

METHODS

Fifty healthy women (≥60 y) were included; 19 had an HT administration history (≥9 mo, with now ~8-y hiatus in treatment) and 31 no such history. On seven continuous days, PB data were collected using triaxial accelerometry and analyzed using compositional data analysis. Gastrocnemius medialis muscle volume, architecture, and function were determined using ultrasonography, electromyography, dual x-ray absorptiometry, and dynamometry. Current serum estradiol levels were measured using ELISA.

RESULTS

Only fascicle length and duration of HT administration were positively associated. With respect to PB levels, we found a pattern suggesting greater vitality (higher physical activity and lower sedentarism) in previous HT users, compared with nonusers, despite the two groups currently no longer exhibiting significantly different levels of circulating estradiol.

CONCLUSIONS

After an 8-year hiatus in treatment, HT provides limited advantages in gastrocnemius medialis muscle properties. Interestingly, it perhaps enhances vitality despite prolonged cessation, which in the longer term would facilitate greater physical independence, especially considering the association of sedentary behavior with greater frailty.

Prevalence of sarcopenic obesity in the older non-hospitalized population: a systematic review and meta-analysis

BACKGROUND

Sarcopenic obesity emerges as a risk factor for adverse clinical outcomes in non-hospitalized older adults, including physical disabilities, metabolic diseases, and even mortality. In this systematic review and meta-analysis, we investigated the overall SO prevalence in non-hospitalized adults aged ≥ 65 years and assessed the sociodemographic, clinicobiological, and lifestyle factors related to SO.

METHODS

We searched the PubMed, Embase, Cochrane Library, and Web of Science databases for studies reporting the prevalence of SO from database inception to October 2023. Two researchers independently screened the literature, evaluated the study quality, and extracted the data. Both fixed- and random-effects models were used in the meta-analysis to estimate the pooled SO prevalence and perform subgroup analyses. Publication and sensitivity bias analyses were performed to test the robustness of the associations.

RESULTS

Among 46 studies eligible for review and a total of 71,757 non-hospitalized older adults, the combined prevalence of SO was 14% (95% CI:11-17%, I2 = 99.5%, P < 0.01). Subgroup analysis according to lifestyle factors demonstrated that the SO prevalence was 17% (95% CI: 8-29%, I2 = 99.5%, P < 0.01) in older adults without exercise habits. Regarding clinicobiological factors, older adults with a history of falls (15% [95% CI: 10-22%, I2 = 82%, P < 0.01]), two or more chronic diseases (19% [95% CI: 10-29%, I2 = 97%, P < 0.01]), functional impairment (33% [95% CI: 29-37%, I2 = 0%, P = 0.95]), cognitive impairment (35% [95% CI: 9-65%, I2 = 83%, P = 0.02]), osteoporosis (20% [95% CI: 8-35%, I2 = 96%, P < 0.01]), high fasting glucose level (17% [95% CI: 1-49%, I2 = 98%, P < 0.01]), or the use of antipsychotics (13% [95% CI: 2-28%, I2 = 0%, P = 0.32]) exhibited a higher SO prevalence.

CONCLUSION

SO prevalence is high among non-hospitalized older adults, especially those with functional and cognitive impairments. Thus, SO is a potential problem for the aging population; implementation of planned interventions in the community is needed to reduce the prevalence and adverse outcomes of SO.

Effects of chemically induced ovarian failure on single muscle fiber contractility in a mouse model of menopause

OBJECTIVE

Menopause is associated with impaired skeletal muscle contractile function. The temporal and mechanistic bases of this dysfunction are unknown. Using a mouse model of menopause, we identified how gradual ovarian failure affects single muscle fiber contractility.

STUDY DESIGN

Ovarian failure was chemically induced over 120 days, representing the perimenopausal transition. Mice were sacrificed and soleus and extensor digitorum longus muscles were dissected and chemically permeabilized for single fiber mechanical testing.

MAIN OUTCOME MEASURES

Muscle fiber contractility was assessed via force, rate of force redevelopment, instantaneous stiffness, and calcium sensitivity.

RESULTS

Peak force and cross-sectional area of the soleus were, respectively, ~33 % and ~24 % greater following ovarian failure compared with controls (p < 0.05) with no differences in force produced by the extensor digitorum longus across groups (p > 0.05). Upon normalizing force to cross-sectional area there were no differences across groups (p > 0.05). Following ovarian failure, rate of force redevelopment of single fibers from the soleus was ~33 % faster compared with controls. There was no shift in the midpoint of the force‑calcium curve between groups or muscles (p > 0.05). However, following ovarian failure, Type I fibers from the soleus had a higher calcium sensitivity between pCa values of 4.5 and 6.2 compared with controls (p < 0.05), with no differences for Type II fibers or the extensor digitorum longus (p > 0.05).

CONCLUSIONS

In our model of menopause, alterations to muscle contractility were less evident than in ovariectomized models. This divergence across models highlights the importance of better approximating the natural trajectory of menopause during and after the transitional phase of ovarian failure on neuromuscular function.

Effect of Resistance Exercise on Body Composition and Functional Capacity in Older Women with Sarcopenic Obesity-A Systematic Review with Narrative Synthesis

BACKGROUND

Resistance exercise has shown effectiveness in reducing various risk factors related to sarcopenic obesity (SO) compared to other types of exercise, e.g., aerobic exercise.

OBJECTIVE

This systematic review evaluates the effect of resistance exercise on body composition, muscular strength, and functional capacity among older women with sarcopenic obesity aged ≥ 60 years.

METHODS

This systematic review is registered on PROSPERO (registration No. CRD42023394603) and follows the PRISMA guidelines. The following electronic databases were used to search the literature: Pedro, Cochrane Central Register of Controlled Trials, Embase, PubMed, and Web of Science. We included only RCTs that investigated the effect of resistance exercise on body composition and functional capacity. Two independent reviewers conducted the process of study selection and data extraction.

RESULTS

The search strategy retrieved 687 results. One hundred and twenty-six records were deleted as duplicates. Consequently, 534 studies were excluded after the title/abstract assessment. After further detailed evaluation of twenty-seven full texts, seven RCTs were included; all the RCTs examined the isolated effect of resistance exercise in women with sarcopenic obesity. The included studies comprised 306 participants, with an average age of 64 to 72 years. We noticed a trend of improvement in the included studies among the intervention groups compared to the control groups among the different outcomes. The study protocol was inconsistent for the intervention settings, duration, and outcomes. Including a modest number of trials made it impossible to perform data meta-analysis.

CONCLUSIONS

Heterogeneity among studies regarding training protocols and the outcome measures reported limited robust conclusions. Still, resistance exercise intervention can improve body composition and functional capacity among elderly women with sarcopenic obesity.

Molecular and clinical effects of aromatase inhibitor therapy on skeletal muscle function in early-stage breast cancer

We evaluated biochemical changes in skeletal muscle of women with breast cancer initiating aromatase inhibitors (AI), including oxidation of ryanodine receptor RyR1 and loss of stabilizing protein calstabin1, and detailed measures of muscle function. Fifteen postmenopausal women with stage I-III breast cancer planning to initiate AI enrolled. Quadriceps muscle biopsy, dual-energy x-ray absorptiometry, isokinetic dynamometry, Short Physical Performance Battery, grip strength, 6-min walk, patient-reported outcomes, and serologic measures of bone turnover were assessed before and after 6 months of AI. Post-AI exposure, oxidation of RyR1 significantly increased (0.23 ± 0.37 vs. 0.88 ± 0.80, p < 0.001) and RyR1-bound calstabin1 significantly decreased (1.69 ± 1.53 vs. 0.74 ± 0.85, p < 0.001), consistent with dysfunctional calcium channels in skeletal muscle. Grip strength significantly decreased at 6 months. No significant differences were seen in isokinetic dynamometry measures of muscle contractility, fatigue resistance, or muscle recovery post-AI exposure. However, there was significant correlation between oxidation of RyR1 with muscle power (r = 0.60, p = 0.02) and muscle fatigue (r = 0.57, p = 0.03). Estrogen deprivation therapy for breast cancer resulted in maladaptive changes in skeletal muscle, consistent with the biochemical signature of dysfunctional RyR1 calcium channels. Future studies will evaluate longer trajectories of muscle function change and include other high bone turnover states, such as bone metastases.

Sarcopenia and Diabetes: A Detrimental Liaison of Advancing Age

Sarcopenia is an age-related clinical complaint characterized by the progressive deterioration of skeletal muscle mass and strength over time. Type 2 diabetes (T2D) is associated with faster and more relevant skeletal muscle impairment. Both conditions influence each other, leading to negative consequences on glycemic control, cardiovascular risk, general health status, risk of falls, frailty, overall quality of life, and mortality. PubMed/Medline, Scopus, Web of Science, and Google Scholar were searched for research articles, scientific reports, observational studies, clinical trials, narrative and systematic reviews, and meta-analyses to review the evidence on the pathophysiology of di-abetes-induced sarcopenia, its relevance in terms of glucose control and diabetes-related outcomes, and diagnostic and therapeutic challenges. The review comprehensively addresses key elements for the clinical definition and diagnostic criteria of sarcopenia, the pathophysiological correlation be-tween T2D, sarcopenia, and related outcomes, a critical review of the role of antihyperglycemic treatment on skeletal muscle health, and perspectives on the role of specific treatment targeting myokine signaling pathways involved in glucose control and the regulation of skeletal muscle metabolism and trophism. Prompt diagnosis and adequate management, including lifestyle inter-vention, health diet programs, micronutrient supplementation, physical exercise, and pharmaco-logical treatment, are needed to prevent or delay skeletal muscle deterioration in T2D.

Mechanisms of Ovarian Cancer-Associated Cachexia

Cancer-associated cachexia occurs in 50% to 80% of cancer patients and is responsible for 20% to 30% of cancer-related deaths. Cachexia limits survival and treatment outcomes, and is a major contributor to morbidity and mortality during cancer. Ovarian cancer is one of the leading causes of cancer-related deaths in women, and recent studies have begun to highlight the prevalence and clinical impact of cachexia in this population. Here, we review the existing understanding of cachexia pathophysiology and summarize relevant studies assessing ovarian cancer-associated cachexia in clinical and preclinical studies. In clinical studies, there is increased evidence that reduced skeletal muscle mass and quality associate with worse outcomes in subjects with ovarian cancer. Mouse models of ovarian cancer display cachexia, often characterized by muscle and fat wasting alongside inflammation, although they remain underexplored relative to other cachexia-associated cancer types. Certain soluble factors have been identified and successfully targeted in these models, providing novel therapeutic targets for mitigating cachexia during ovarian cancer. However, given the relatively low number of studies, the translational relevance of these findings is yet to be determined and requires more research. Overall, our current understanding of ovarian cancer-associated cachexia is insufficient and this review highlights the need for future research specifically aimed at exploring mechanisms of ovarian cancer-associated cachexia by using unbiased approaches and animal models representative of the clinical landscape of ovarian cancer.

Early menopause and premature ovarian insufficiency may increase the risk of sarcopenia: A systematic review and meta-analysis

PURPOSE

Menopausal transition, resulting from a decline in estrogen concentrations, may compromise musculoskeletal health. However, it is unclear if early menopause (defined as age at menopause <45 years) and premature ovarian insufficiency (defined as age at menopause <40 years) are associated with increased risk of sarcopenia. The aim of this systematic review and meta-analysis was to synthesize studies evaluating the association between age at menopause and risk of sarcopenia.

METHODS

A comprehensive search was conducted in PubMed, CENTRAL and Scopus, up to 31 December 2022. Data were expressed as standardized mean difference with 95 % confidence intervals. The I² index was employed to evaluate heterogeneity.

RESULTS

Six studies were included in the qualitative and quantitative analysis, with a total of 18,291 post-menopausal women. Compared with women of normal age at menopause (>45 years), women with early menopause demonstrated lower muscle mass, assessed by appendicular skeletal muscle mass/body mass index [standardized mean difference (SMD) -0.14, 95 % confidence interval (CI) -0.20 to -0.07, p < 0.001; I² 0%]. However, no differences in muscle strength, assessed by handgrip strength (SMD -0.15, 95 % CI -0.31 to 0.01, p = 0.071; I² 72%), and muscle performance, assessed by gait speed (SMD -0.11, 95 % CI -0.29 to 0.05, p = 0.18; I² 79%), were found. Women with premature ovarian insufficiency had lower handgrip strength (SMD -0.3, 95 % CI -0.58 to -0.01, p = 0.04; I² 74.6 %) and gait speed (SMD -0.13, 95 % CI -0.23 to -0.04, p = 0.004; I² 0%) compared with women of normal age at menopause.

CONCLUSION

Early menopause is associated with reduced muscle mass and premature ovarian insufficiency with reduced muscle strength and performance compared with normal age at menopause.

Sarcopenia and osteosarcopenia among patients undergoing hemodialysis

Background

Sarcopenia and osteoporosis are closely interconnected and associated with adverse health outcomes. Osteosarcopenia is the concurrent presence of the two conditions and has rarely been reported in hemodialysis patients. Whether hemodialysis patients with osteosarcopenia are at greater risk of mortality than those with either condition alone remains unknown. The aim of this study was to explore the prevalence of sarcopenia and its association with osteoporosis and to determine its impact on survival risk in hemodialysis patients.

Methods

A total of 209 adults undergoing hemodialysis were enrolled from the dialysis center in the West China Hospital of Sichuan University, and our study was registered at the Chinese Clinical Trial Register (number: ChiCTR2100043932). Muscle mass, handgrip strength, bone mineral density (BMD), and biochemical parameters were assessed. All deaths were recorded during a follow-up of 35.15 ± 15.37 months.

Results

Seventy-eight patients were diagnosed with sarcopenia, with a prevalence of 37.3%. After adjustment for potential confounders, age (OR=1.094, P <0.001), female sex (OR= 3.44, P =0.005), diabetes (OR=3.756, P =0.008), CRP (OR=1.09, P =0.015), serum magnesium (OR=0.755, p=0.042) and BMI (OR=0.701, P <0.001) were independently associated with sarcopenia. Among the 209 patients, 103 patients completed the BMD assessment. The prevalence of osteosarcopenia was 22.3%, while 20.4% of participants had sarcopenia alone and 12.6% had osteoporosis alone. The proportions of patients who died were 13.0% for nonsarcopenia&nonosteoporosis, 15.4% for osteoporosis alone, 47.6% for sarcopenia alone, and 52.2% for osteosarcopenia. Cox regression analysis showed that osteosarcopenia was independently associated with all-cause mortality (HR=3.74, 95% CI: 1.172-11.938), while osteoporosis alone and sarcopenia alone were not.

Conclusion

Patients undergoing hemodialysis had a high incidence of sarcopenia and osteosarcopenia, muscle mass and strength showed a significant association with BMD, and osteosarcopenia might have a powerful impact on mortality in those patients.

Clinical trial registration

http://www.chictr.org.cn/, identifier ChiCTR2100043932.

Sex-specific associations of single metal and metal mixture with handgrip strength: a cross-sectional study among Chinese adults

Metallic elements are ubiquitous in the natural environment and always collaborate to affect human health. The relationship of handgrip strength, a marker of functional ability or disability, with metal co-exposure remains vague. In this study, we aimed to investigate the effect of metal co-exposure on sex-specific handgrip strength. A total of 3594 participants (2296 men and 1298 women) aged 21 to 79 years recruited from Tongji Hospital were included in the present study. Urinary concentrations of 21 metals were measured by inductively coupled plasma mass spectrometer (ICP-MS). We used linear regression, restricted cubic spline (RCS) model, and weighted quantile sum (WQS) regression to evaluate the association of single metal as well as metal mixture with handgrip strength. After adjusting for important confounding factors, the results of linear regression showed that vanadium (V), zinc (Zn), arsenic (As), rubidium (Rb), cadmium (Cd), thallium (Tl), and uranium (U) were adversely associated with handgrip strength in men. The results of RCS showed a non-linear association between selenium (Se), silver (Ag), and nickel (Ni) with handgrip strength in women. The results of WQS regression revealed that metal co-exposure was inversely related to handgrip strength for men (β = -0.65, 95% CI: -0.98, -0.32). Cd was the critical metal in men (weighted 0.33). In conclusion, co-exposure to a higher level of metals is associated with lower handgrip strength, especially among men, and Cd may contribute most to the conjunct risk.

Sharing Circulating Micro-RNAs between Osteoporosis and Sarcopenia: A Systematic Review

Background: Osteosarcopenia, a combination of osteopenia/osteoporosis and sarcopenia, is a common condition among older adults. While numerous studies and meta-analyses have been conducted on osteoporosis biomarkers, biomarker utility in osteosarcopenia still lacks evidence. Here, we carried out a systematic review to explore and analyze the potential clinical of circulating microRNAs (miRs) shared between osteoporosis/osteopenia and sarcopenia. Methods: We performed a systematic review on PubMed, Scopus, and Embase for differentially expressed miRs (p-value < 0.05) in (i) osteoporosis and (ii) sarcopenia. Following screening for title and abstract and deduplication, 83 studies on osteoporosis and 11 on sarcopenia were identified for full-text screening. Full-text screening identified 54 studies on osteoporosis, 4 on sarcopenia, and 1 on both osteoporosis and sarcopenia. Results: A total of 69 miRs were identified for osteoporosis and 14 for sarcopenia. There were 9 shared miRs, with evidence of dysregulation (up- or down-regulation), in both osteoporosis and sarcopenia: miR-23a-3p, miR-29a, miR-93, miR-133a and b, miR-155, miR-206, miR-208, miR-222, and miR-328, with functions and targets implicated in the pathogenesis of osteosarcopenia. However, there was little agreement in the results across studies and insufficient data for miRs in sarcopenia, and only three miRs, miR-155, miR-206, and miR-328, showed the same direction of dysregulation (down-regulation) in both osteoporosis and sarcopenia. Additionally, for most identified miRs there has been no replication by more than one study, and this is particularly true for all miRs analyzed in sarcopenia. The study quality was typically rated intermediate/high risk of bias. The large heterogeneity of the studies made it impossible to perform a meta-analysis. Conclusions: The findings of this review are particularly novel, as miRs have not yet been explored in the context of osteosarcopenia. The dysregulation of miRs identified in this review may provide important clues to better understand the pathogenesis of osteosarcopenia, while also laying the foundations for further studies to lead to effective screening, monitoring, or treatment strategies.

Gender-Specific Prevalence and Risk Factors of Sarcopenic Obesity in the Korean Elderly Population: A Nationwide Cross-Sectional Study

Sarcopenic obesity (SO) is characterized by the combination of sarcopenia and obesity. This study evaluates the gender-specific prevalence of SO and examines the identified gender-specific risk factors in a community-dwelling elderly population aged 75-84 years. A total of 813 subjects participated in the study via the Korea National Health and Nutrition Examination Survey. The SO prevalence in males and females was 15.46% (95%CI: 11.36-20.70) and 13.59% (95%CI: 10.59-17.28), respectively. The clinical sex-specific risk factors for males were low height, high weight, body mass index, waist circumference, skeletal muscle index, fasting glucose, and triglycerides. The clinical risk factors for females were low height, high weight, body mass index, waist circumference, skeletal muscle index, smoking status, fasting glucose, total cholesterol, and systolic blood pressure. These results are essential to assist healthcare professionals and primary care clinicians with early detection, diagnosis, and intervention for potential SO patients by acknowledging the sex-based prevalence and risk factors.

The bone-muscle connection in breast cancer: implications and therapeutic strategies to preserve musculoskeletal health

Breast cancer and its therapies frequently result in significant musculoskeletal morbidity. Skeletal complications include bone metastases, pain, bone loss, osteoporosis, and fracture. In addition, muscle loss or weakness occurring in both the metastatic and curative setting is becoming increasingly recognized as systemic complications of disease and treatment, impacting quality of life, responsiveness to therapy, and survival. While the anatomical relationship between bone and muscle is well established, emerging research has led to new insights into the biochemical and molecular crosstalk between the skeletal and muscular systems. Here, we review the importance of both skeletal and muscular health in breast cancer, the significance of crosstalk between bone and muscle, and the influence of mechanical signals on this relationship. Therapeutic exploitation of signaling between bone and muscle has great potential to prevent the full spectrum of musculoskeletal complications across the continuum of breast cancer.

Sex Differences of Sarcopenia in an Elderly Asian Population: The Prevalence and Risk Factors

The loss of muscle mass is widespread in age-related health phenomena in the elderly population. This study examined the prevalence of sarcopenia in a community-dwelling elderly population according to gender. The study also identified gender-specific risk factors in older people aged 75-84 years old. One thousand two hundred and ninety-three participants aged between 75 and 84 years from the National Health and Nutrition Examination Surveys in Korea were investigated. The prevalence of sarcopenia in males and females in the weighted-value sample was 41.2% (95%CI: 35.8-46.8) and 37.2% (32.7-41.9), respectively. Gender-specific clinical risk factors in males were height, weight, body mass index, waist circumference, skeletal muscle mass index, fasting glucose, and triglyceride levels. Height, weight, body mass index, waist circumference, skeletal muscle mass index, and total cholesterols were clinical risk factors for females. These outcomes would be crucial to primary care clinicians and health care professionals when patients require a referral for early detection and treatment. Health care professionals and clinicians can quickly identify potential sarcopenic patients by acknowledging the gender-specific prevalence and risk factors.

Association between lower parity and low muscle mass in postmenopausal women: data from KNHANES (2010-2011)

OBJECTIVE

This study aimed to investigate whether parity is associated with the prevalence of low muscle mass in postmenopausal women.

METHODS

This study was performed using data from the 2010-2011 Korean National Health and Nutrition Examination Survey, which included 1,338 postmenopausal women aged 46 to 70 years. The association between parity and low muscle mass was analyzed after adjusting parity, multiparity, age, body mass index, diabetes mellitus, education level, and Homeostatic Model Assessment of Insulin Resistance and using weighted multiple logistic regression analysis. Modifiable risk factors were evaluated in a susceptible population. Low muscle mass was defined as an appendicular skeletal muscle mass index below 2 SDs with a cutoff value of 5.45 kg/m 2 .

RESULTS

The low muscle mass group ( n = 343) had lower parity, lower body mass index, more frequent previous history of diabetes mellitus, higher Homeostatic Model Assessment of Insulin Resistance, and higher education level compared with the non-low muscle mass group ( n = 995). After adjusting for the confounding factors, parity with three births or more was associated with a significantly lower odds of postmenopausal low muscle mass than nulliparity (model 1: odds ratio, 0.32; 95% confidence interval, 0.12-0.87; P = 0.03; model 2: odds ratio, 0.27; 95% confidence interval, 0.11-0.67; P < 0.05). In the subgroup analysis of the lower parity group, moderate aerobic activity was associated with a lower low muscle mass prevalence.

CONCLUSIONS

A lower parity is associated with increasing the odds of low muscle mass in postmenopausal Korean women. Moderate aerobic activity may be effective in lowering the odds of low muscle mass in postmenopausal women with lower parity.

Pharmacologic Enhancement of Rotator Cuff Repair: A Narrative Review

INTRODUCTION

As rotator cuff repairs (RCRs) are among the most common procedures in upper extremity orthopedics, healing augmentation using pharmacologic enhancement of the repaired rotator cuff muscle is of particular interest.

OBJECTIVE

The purpose of this study is to review the current understanding of Matrix Metalloproteinases (MMPs), Doxycycline, Testosterone, Estrogen, Growth hormone/ IGF-1, Vitamin D, and Vitamin C as a means to mitigate deleterious effects and propagate factors that support healing following RCR.

METHODS

A review of English language articles in PubMed and Medline was conducted in December of 2020. All articles describing the current understanding of the aforementioned therapies were reviewed. Studies were excluded if they were non-English or reported incomplete results.

RESULTS

Matrix metalloproteinases (MMP's) are fundamental to the healing process after rotator cuff tears through a delicate balance of various proteases that can be modulated by doxycycline through inhibition. While testosterone has shown to induce replication and differentiation of the tendon stem-cells, estrogen agonists have been shown to decrease inflammation and muscle atrophy. Though growth hormone being associated with elevated collagen synthesis and decreased anoxic damage when present, clinical studies have shown inconclusive and adverse effects on rotator cuff healing. Patients with Vitamin D deficiency have shown to have increased fatty infiltration in rotator cuff muscle while Vitamin C functions as an antioxidant that increases collagen and fibroblast proliferation.

CONCLUSION

As manipulation of pharmacologic factors shows potential for enhancing healing following RCRs, future studies are needed to establish a viable augmentation strategy to improve patient outcomes.

Prevalence and Determinants of Sarcopenic Obesity in Older Adults: Secondary Data Analysis of the Longitudinal Ageing Study in India (LASI) Wave 1 Survey (2017-18)

INTRODUCTION

Sarcopenic obesity (SO) represents the confluence of two epidemics-an aging population and an increasing rate of obesity. The two diseases may act synergistically, and SO may significantly affect morbidity and mortality. However, the burden is not defined to drive the policy changes. Hence the present study was done to estimate the prevalence and predictors of SO in India.

METHODS

We did a secondary data analysis of the 72,250 older adults who participated in the first wave of the Longitudinal Aging Study in India (2017-18). Possible sarcopenia was defined as per the guidelines by the Asian Working Group for Sarcopenia (AWGS) criteria. The modified criterion of overweight and obesity for Asian adults was used to categorize obesity. Presence of both sarcopenia and obesity depicted SO. Weighted analysis was done to estimate the prevalence of SO, and multinomial bivariate logistics regression was used to identify the predictors of SO.

RESULTS

The overall prevalence of obesity, sarcopenia, and SO was 27.1%, 41.9%, and 8.7%, respectively. The mean age, weight, body mass index (BMI), and blood pressure of adults with SO were significantly higher compared to others. Higher age, urban residence, west and south regions of India, consumption of tobacco or alcohol, no physical activity, and presence of diabetes contribute to SO.

CONCLUSION

The burden of SO seems to be less but amounts to a massive number in an aging country. We stress increased screening of the geriatric age group and advocate increased physical activity and dietary modifications to realize the concept of healthy aging.

Sarcopenia in Menopausal Women: Current Perspectives

Menopause is associated with hormonal changes, which could accelerate or lead to sarcopenia. Functional impairment and physical disability are the major consequences of sarcopenia. In order to hamper these negative health outcomes, it appears necessary to prevent and even treat sarcopenia, through healthy lifestyle changes including diet and regular physical activity or through hormonal replacement therapy when appropriate. Therefore, the purpose of this narrative review will be 1) to present the prevalence of sarcopenia in postmenopausal women; 2) to address the risk factors related to sarcopenia in this specific population; and 3) to discuss how to manage sarcopenia among postmenopausal women.

Lowering of lysophosphatidylcholines in ovariectomized rats by Curcuma comosa

Decline of ovarian function in menopausal women increases metabolic disease risk. Curcuma comosa extract and its major compound, (3R)-1,7-diphenyl-(4E,6E)-4,6-heptadien-3-ol (DPHD), improved estrogen-deficient ovariectomized (OVX) rat metabolic disturbances. However, information on their effects on metabolites is limited. Here, we investigated the impacts of C. comosa ethanol extract and DPHD on 12-week-old OVX rat metabolic disturbances, emphasizing the less hydrophobic metabolites. Metabolomics analysis of OVX rat serum showed a marked increase compared to sham-operated rat (SHAM) in levels of lysophosphatidylcholines (lysoPCs), particularly lysoPC (18:0) and lysoPC (16:0), and of arachidonic acid (AA), metabolites associated with inflammation. OVX rat elevated lysoPCs and AA levels reverted to SHAM levels following treatments with C. comosa ethanol extract and DPHD. Overall, our studies demonstrate the effect of C. comosa extract in ameliorating the metabolic disturbances caused by ovariectomy, and the elevated levels of bioactive lipid metabolites, lysoPCs and AA, may serve as potential biomarkers of menopausal metabolic disturbances.

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.

The Intricate Web of Fatigue in Women

The modern woman has taken her rightful place in society as a worker, a caregiver, a mother, and a world citizen. However, along with the privileges of these roles comes the great cost of stress and resultant exhaustion and fatigue. Psychosocial, physical, cultural, and disease-related realms of stress act as strands of a web that serve to bind and hinder women with chronic stress. New areas of research, such as exercise intervention, improved social programs (e.g., childcare), and supplementation are constantly evaluated for effectiveness alongside traditional remedies such as exercise. This review will highlight some of the key issues regarding stress in women and explore reports of new treatment modalities in light of the specific requirements of the modern woman.

The Therapeutic Intervention of Sex Steroid Hormones for Sarcopenia

Sarcopenia, characterized by the excessive loss of skeletal muscle mass, strength, and function, is associated with the overall poor muscle performance status of the elderly, and occurs more frequently in those with chronic diseases. The causes of sarcopenia are multifactorial due to the inherent relationship between muscles and molecular mechanisms, such as mitochondrial function, inflammatory pathways, and circulating hormones. Age-related changes in sex steroid hormone concentrations, including testosterone, estrogen, progesterone, and their precursors and derivatives, are an important aspect of the pathogenesis of sarcopenia. In this review, we provide an understanding of the treatment of sarcopenia through the regulation of sex steroid hormones. The potential benefits and future research emphasis of each sex steroid hormone therapeutic intervention (testosterone, SARMs, estrogen, SERMs, DHEA, and progesterone) for sarcopenia are discussed. Enhanced understanding of the role of sex steroid hormones in the treatment for sarcopenia could lead to the development of hormone therapeutic approaches in combination with specific exercise and nutrition regimens.

Evaluation of Nutrients Intake for a Group of Jordanian Older Adults with Sarcopenia Syndrome in Amman: An Explorative and Pilot Study

Aim

Sarcopenia is an age-related syndrome that is characterized by a progressive loss of muscle mass, strength, and function. This study was performed in order to evaluate nutrients intake and physical activity level and to investigate the effect of sarcopenia syndrome on food intake for a group of Jordanian older adults with sarcopenia syndrome in Amman. Methodology. The study sample consisted of 25 nonsarcopenic people and 25 sarcopenic patients aged over 60 years old with a male to female ratio of 1 : 1. A special questionnaire was used to collect demographic data, health data, data about syndrome characteristics, nutritional assessment, and physical activity level. A 24-hour recall was also used to collect food intake data. Body weight, height, and skinfold thicknesses were measured.

Results

The mean of the sarcopenic patients' age was 77.5 ± 6.9 years, and the mean of the weight was significantly lower in sarcopenic patients than the nonsarcopenic people. In this study, all macronutrients and micronutrients from dietary intake information were analyzed. Vitamin intake (water- and fat-soluble), as well as minerals (major and trace), amino acids, and essential fatty acids, was assessed. The mean intake of energy and carbohydrates, fat, and dietary fiber was lower than their recommendations, while the mean intake of protein was within the range of its recommendations in the sarcopenia group. The mean of the intake of omega 3 and omega 6 was below their recommendations.

Conclusion

It could be concluded that sarcopenic older patients in Jordan have similar characteristics with patients studied worldwide with regard to age of patients, female to male ratio, and main symptoms. Sarcopenic older patients in Jordan generally have lower weight and BF% than nonsarcopenic adults and have inadequate dietary intake compared to their recommendations and compared to nonsarcopenic older adults. Therefore, the diet of sarcopenic patients needs modification and follow-up. The level of physical activity and daily living activities for sarcopenic older patients is lower than that of nonsarcopenic older adults.

Discovery Genome-Wide Association Study of Body Composition in 4,386 Adults From the UK Biobank's Pilot Imaging Enhancement Study

Body composition (fat, skeletal muscle and bone mass) is an important determinant of overall health and risk of endocrine disorders such as type 2 diabetes and osteoporosis. Although diet and physical activity are strongly implicated, body composition is also heritable. We conducted a discovery genome-wide association study on 31 phenotypes from the three-compartment body composition model (fat, lean and bone mass) in a set of 4 386 individuals (n = 2 109 males, n = 2 294 females) from the UK Biobank pilot imaging enhancement program that underwent a dual energy X-ray absorptiometry (DXA) scan for assessment of body composition and genetic screening. From 6 137 607 imputed single nucleotide polymorphisms (SNPs) we identified 17 body composition loci (P<5.0 x 10-8). GWAS from the combined dataset identified four statistically significant SNPs (rs7592270, rs145972737, rs13212044, rs77772562). In sex-stratified GWAS, 10 male specific SNPs across all traits were identified and five female specific SNPs. Of the 17 SNPs, six were in or close to a gene where there was a plausible functional connection. Three SNPs (rs7592270, rs77772562 and rs7552312) were correlated with obesity phenotypes, one SNP (rs2236705) with lean phenotypes and two with bone mass phenotypes (rs112098641 and rs113380185). These results highlight candidate genes and biological pathways related to body composition, including glucose metabolism and estrogen regulation, that are of interest to replicate in future studies.

The association between hormone therapy and sarcopenia in postmenopausal women: the Korea National Health and Nutrition Examination Survey, 2008-2011

Objective:

Menopausal transition contributes to sarcopenia, but the effects of hormone therapy (HT) on sarcopenia in postmenopausal women have not been determined. This study assessed the effect of HT on sarcopenia in postmenopausal women.

Methods:

The present study included 4,254 postmenopausal women who participated in the Korea National Health and Nutritional Examination Surveys from 2008 to 2011. Appendicular skeletal muscle mass divided by weight (ASM/Wt) and the prevalence of sarcopenia were analyzed in groups of women stratified by duration of HT use.

Results:

ASM/Wt was higher and the prevalence of sarcopenia was lower in participants with a history of prolonged (≥13 mo) HT use than in participants with a shorter duration of HT use or no HT use. After adjusting for multiple confounding factors, prolonged use of HT remained significantly associated with estimated mean ASM/Wt and the prevalence of sarcopenia (odds ratio: 0.60; 95% confidence interval: 0.41-0.88; P = 0.01). In addition, the prevalence of sarcopenia was linearly associated with history of hypertension, duration of hypertension, physical activity, and duration of HT use. Subgroup analysis showed that the association between duration of HT use and the prevalence of sarcopenia was maintained in younger (<65 y old) and leaner (body mass index <25 kg/m²) postmenopausal women.

Conclusions:

The present study showed that the prolonged use of HT was associated with high muscle mass and a low prevalence of sarcopenia in postmenopausal women.

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.

Musculoskeletal Health in Premature Ovarian Insufficiency. Part One: Muscle

Accelerated bone loss and muscle decline coexist in women with premature ovarian insufficiency (POI), but there are significant gaps in our understanding of musculoskeletal health in POI. This article is the first of a two-part review which describes estrogen signaling in muscle and its role in musculoskeletal health and disease. Current evidence regarding the utility of available diagnostic tests and therapeutic options is also discussed. A literature review from January 2000 to March 2020 was conducted to identify relevant studies. Women with POI experience significant deterioration in musculoskeletal health due to the loss of protective effects of estrogen. In addition to bone loss, muscle decay and dysfunction is now increasingly recognized. Nevertheless, there is a paucity of validated tools to assess muscle parameters. There is a growing need to acknowledge bone-muscle codependence to design new therapies which target both muscle and bone, resulting in improved physical performance and reduced morbidity and mortality. More high-quality research and international collaborations are needed to address the deficiencies in our understanding and management of musculoskeletal health in women with POI.

Rastreamento do risco de sarcopenia em adultos com 50 anos ou mais hospitalizados

Resumo Objetivo Rastrear o risco de sarcopenia em indivíduos hospitalizados por meio dos instrumentos SARC-F e SARC-Calf e verificar a associação entre o risco de sarcopenia com as variáveis sociodemográficas, clínicas e as variáveis que compõem o fenótipo de sarcopenia. Métodos Trata-se de um estudo transversal. Características sociodemográficas, clínicas e todas as variáveis que compõem o fenótipo de sarcopenia (força de prensão palmar, massa muscular e velocidade de marcha) foram investigadas. Para o rastreamento e diagnóstico da sarcopenia adotou-se o algoritmo e critérios propostos pelo European Working Group on Sarcopenia in Older People (EWGSOP2). Resultados Participaram 90 indivíduos. A maioria encontrava-se sem sinais sugestivos de sarcopenia, tanto pelo SARC-F (58,9%) quanto pelo SARC-Calf (68,9%), com força de preensão palmar (FPP) (28,59±9,21;26,74±10,60) e índice de massa muscular esquelética apendicular (IMMEA) (9,31±1,78;9,58±1,62) normais e com baixa velocidade de marcha (VM) (0,69±0,26; 0,68±0,44), respectivamente. O SARC-F apresentou associação significativa com as variáveis sexo (p=0,032), FPP (p<0,001), VM (p=0,001) e sarcopenia (p<0,001). Quando da adição da circunferência da panturrilha (CP), foi encontrado associação com as variáveis grupo etário (p=0,029), atividade laboral (p=0,008), FPP (p<0,001), IMMEA (p=0,033), VM (p=0,019) e sarcopenia (p<0,001). Conclusão O risco de sarcopenia foi observado em aproximadamente um terço dos pacientes avaliados. Sugere-se o uso rotineiro nos hospitais da ferramenta de rastreamento de sarcopenia SARC-Calf, uma vez que apresentou associação com os três fatores preditivos da sarcopenia, além de ser um instrumento de aplicação ágil, baixo custo e não invasivo. A investigação do diagnóstico da sarcopenia deve ser encorajada na prática clínica.

Role of hormones in sarcopenia

Aging involves numerous changes in body composition that include a decrease in skeletal muscle mass. The gradual reduction in muscle mass is associated with a simultaneous decrease in muscle strength, which leads to reduced mobility, fragility and loss of independence. This process called sarcopenia is secondary to several factors such as sedentary lifestyle, inadequate nutrition, chronic inflammatory state and neurological alterations. However, the endocrine changes associated with aging seem to be of special importance in the development of sarcopenia. On one hand, advancing age is associated with a decreased secretion of the main hormones that stimulate skeletal muscle mass and function (growth hormone, insulin-like growth factor 1 (IGFI), testosterone and estradiol). On the other hand, the alteration of the IGF-I signaling along with decreased insulin sensitivity also have an important impact on myogenesis. Other hormones that decline with aging such as the adrenal-derived dehydroepiandrosterone, thyroid hormones and vitamin D seem to also be involved in sarcopenia. Adipokines released by adipose tissue show important changes during aging and can affect muscle physiology and metabolism. In addition, catabolic hormones such as cortisol and angiotensin II can accelerate aged-induced muscle atrophy, as they are involved in muscle wasting and their levels increase with age. The role played by all of these hormones and the possible use of some of them as therapeutic tools for treating sarcopenia will be discussed.

Prevalence and risk factors of primary sarcopenia in community-dwelling outpatient elderly: a cross-sectional study

No previous study has investigated the prevalence and risk factors for primary sarcopenia in outpatient setting. This study aims to evaluate the prevalence and factors associated with primary sarcopenia in outpatient elderly. Additionally, we compared the severity of sarcopenia based on the 2014 and 2019 Asian Working Group for Sarcopenia (AWGS) criteria. This cross-sectional study was performed in 330 subjects aged over 60 years in an outpatient setting. The muscle strength, muscle performance and muscle mass were assessed using the handheld dynamometer, 6-m gait speed, and bioelectrical impedance analysis, respectively. The prevalence of sarcopenia was 10% as per the 2014 and 2019 AWGS criteria. The development of sarcopenia was positively correlated with the age with an odds ratio (OR) of 6.87 [95% confidence interval (CI) 1.63–28.88] in the middle-old group (70–79 years), and 13.71 (95%CI 3.66–51.41; p = 0.009) in the very old group (≥ 80 years). Prefrailty and low physical activity were significantly associated with sarcopenia with an OR of 4.75 (95%CI 1.90—11.89) in prefrailty, 15.35 (95%CI 1.69–139.47) in the middle activity group, and 17.99 (95%CI 1.95–165.73) in the lowest activity group. In conclusion, primary sarcopenia was found in one-tenth of outpatient elderly. Age, prefrailty, and low activity were independent factors associated with sarcopenia.

Association of skeletal muscle mass, kidney disease and mortality in older men and women: the cardiovascular health study

Low muscle mass (sarcopenia) is a prevalent and major concern in the aging population as well as in patients with chronic kidney disease (CKD). We hypothesized that sarcopenia is an independent predictor of incident and progressive CKD and increased mortality in older men and women (≥65 years) from the Cardiovascular Health Study. Sarcopenia was defined by bioimpedance-estimated skeletal muscle mass index (SMI) as a continuous variable and categorically (normal, class I, and class II). Cox regression hazard ratios (HRs) estimated the risk of incident and prevalent CKD and mortality in individuals with and without CKD. Low SMI was associated with increased prevalence of CKD in men (p<0.001), but lower prevalence of CKD in women (p=0.03). Low muscle mass was not associated with incident CKD or rapid CKD progression (>3 ml/minute/1.73m²/year decline in eGFR) in men, but was associated with lower risk of incident CKD in women ([adjusted RR=0.69, 95% (0.51,0.94)]. Low muscle mass (class II) was independently associated with higher mortality only in men [(adjusted HR=1.26, 95% (1.05,1.50)]. Neither definition of sarcopenia was associated with mortality in men or women with CKD. Further studies are needed to understand the mechanisms by which sarcopenia contributes to higher mortality in aging men.

Effects of Dietary or Supplementary Micronutrients on Sex Hormones and IGF-1 in Middle and Older Age: A Systematic Review and Meta-Analysis

Observational research suggests that micronutrients may be protective for sarcopenia, a key health issue during ageing, potentially via effects on hormone synthesis and metabolism. We aimed to carry out a systematic review of RCTs investigating effects of increasing dietary or supplemental micronutrient intake on sex hormones and IGF-1 in individuals aged 45 years or older. We searched MEDLINE, EMBASE and Cochrane databases for RCTs reporting the effects of different micronutrients (vitamins A, C, D, or E; carotenoids; iron; copper; zinc; magnesium; selenium; and potassium) on sex hormones or IGF-1. Of the 26 RCTs identified, nine examined effects of vitamin D, nine of multi-nutrients, four of carotenoids, two of selenium, one of zinc, and one of vitamin E. For IGF-1 increasing vitamin D (MD: −0.53 nmol/L, 95% CI: −1.58, 0.52), multi-nutrients (MD: 0.60 nmol/L, 95% CI −1.12 to 2.33) and carotenoids (MD −1.32 nmol/L; 95% CI −2.76 to 0.11) had no significant effect on circulating concentrations. No significant effects on sex hormones of other micronutrients were found, but data were very limited. All trials had significant methodological limitations making effects of micronutrient supplementation on sex hormones unclear. Further high quality RCTs with physiological doses of micronutrients in people with low baseline intakes or circulating concentrations, using robust methodology, are required to assess effects of supplementation adequately.

Sex differences in the prevalence and adverse outcomes of sarcopenia and sarcopenic obesity in community dwelling elderly in East China using the AWGS criteria

BACKGROUND

Sarcopenia and sarcopenic obesity (SO) have a greater impact on the elderly. This study aimed to explore whether there were sex differences in the prevalence and adverse outcomes of sarcopenia and SO in community-dwelling elderly individuals in East China.

METHODS

This was a cross-sectional study that enrolled 213 males and 418 females aged > 65 years. Demographic characteristics, body composition, hand grip, gait speed, and indices of glucose and lipid metabolism were collected. Sarcopenia and SO were diagnosed using the Asian Working Group for Sarcopenia criteria.

RESULTS

(1) The prevalence of sarcopenia was 19.2% in males and 8.6% in females. The prevalence of SO was 7.0% in males and 2.4% in females. (2) In males, the odds ratios (ORs) of osteoporosis and dyslipidemia in the SO group were 4.21-fold and 4.15-fold higher than those in the normal group, respectively. In females, the ORs of osteoporosis and hyperglycemia in the SO group were 1.12-fold and 4.21-fold higher than those in the normal group.

CONCLUSIONS

Males were more likely to be sarcopenic and to have SO than females using the AWGS criteria. Females with SO were more likely to have higher blood glucose, whereas males with SO were more likely to have osteoporosis and dyslipidemia.

17β-estradiol alters mRNA co-expression after murine muscle injury and mild hypobaria

Here, we assessed the effects of 17β-estradiol exposure on mRNA co-expression patterns of muscle tissue during recovery in a closed muscle crush injury and hypobaria exposure murine model. Eighteen ovariectomized placebo-treated and 18 ovariectomized 17β-estradiol-treated female mice underwent closed muscle crush injury and hypobaric simulated flight. The mice recovered for 32, 96, or 192 h, and then were euthanized. Their harvested injured lateral gastrocnemius muscles underwent microarray analysis. We used weighted gene co-expression network analysis to construct a co-expression network for the control mice, and then applied the same network to the estrogen-treated mice. We compared the relationships between co-expression in gene modules over time between the two experimental groups. Enriched functional cluster analyses of significant co-expression network modules document a variety of different pathways of interest. Some of the functional cluster enrichments within several of the significantly correlated modules are related to the formation and function of microtubules. Our findings demonstrate that following a closed muscle crush injury in a murine model, the presence of 17β-estradiol alters mRNA co-expression patterns over time. It appears that estrogen promotes the expression of mRNA related to microtubule activity within the cytoskeleton of myofibers and in movement of organelles and receptors. Further study is needed, but the enrichment of these microtubule-related pathways may be integral in the muscle tissue regeneration process, and thus suggests that the presence of estrogen may promote muscle recovery through the work of the microtubules.

Impact statement

This study uses a murine model to address the clinical situation of transporting soldiers or civilians who have sustained skeletal muscle trauma by air. Our findings show that crush-injured muscle tissue of ovariectomized, 17β-estradiol-treated mice exposed to mild hypobaric hypoxia exhibited mRNA co-expression patterns among pathways associated with microtubule-dependent processes. Palmitoylation and other pathways necessary for movement of estrogen receptors to the cell membrane were also differentially enriched in the estrogen-treated mice. These first findings reframe the discussion regarding estrogen effects during muscle recovery from an inflammation-oriented inquiry to that of a structural, cytoskeletal inquiry and support additional research to understand the non-inflammation-related influences of estrogen during muscle recovery. Also, these results may suggest a role for estrogen or estrogen-like substances to treat muscle trauma.

Association Between Hormone Therapy and Muscle Mass in Postmenopausal Women: A Systematic Review and Meta-analysis

IMPORTANCE

Hormone therapy (HT) has been suggested for protection against age-related muscle weakness in women. However, the potential for HT-associated health risks necessitates a better understanding of the direction and magnitude of the association between HT and health outcomes, such as lean body mass (LBM).

OBJECTIVE

To determine whether HT was associated with reduced LBM loss compared with not receiving HT among postmenopausal women aged 50 years and older.

DATA SOURCES

MEDLINE, Embase, AgeLine, CINAHL, and SportDiscus (searched from inception until April 25, 2018).

STUDY SELECTION

For this systematic review and meta-analysis, randomized clinical trials including postmenopausal women undergoing HT and control groups of women not receiving HT were selected by 2 reviewers. Studies were included if LBM or fat-free mass were measured as an outcome. Studies with participants from hospitals, long-term care facilities, or with specific diseases were excluded.

DATA EXTRACTION AND SYNTHESIS

Information regarding study characteristics and outcome measures were extracted by 1 reviewer and verified by another. Risk of bias was evaluated. Quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach. Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were used to abstract data and assess data quality/validity. Data were pooled using a fixed-effects model.

MAIN OUTCOMES AND MEASURES

The primary study outcome was the overall absolute change in LBM (measured in kilograms), captured by dual-energy x-ray absorptiometry, dual-photon absorptiometry, or bioelectrical impedance analysis imaging.

RESULTS

Of 8961 studies that met selection criteria, 12 were included, with a total of 4474 recruited participants. Of the participants, mean (SD) age was 59.0 (6.1) years. Data on ethnicity were collected by 2 of the studies. Of the 22 HT intervention arms, 15 used estrogen-progesterone combination HT and 7 used estrogen-only HT. Control participants were women who received no HT at all or who received placebo. The median follow-up duration was 2 years (range, 6 months to 6 years). Seven treatment arms showed a loss of LBM, and 14 were protective. Overall, HT users lost 0.06 kg (95% CI, -0.05 to 0.18) less LBM compared with control participants, but the difference was not statistically significant (P = .26). The results were unchanged when stratified based on treatment type and dosage, duration of follow-up, time since menopause, study quality, and type of LBM measurement, with HT users losing between 0.06 kg more to 0.20 kg less LBM compared with control participants for all strata. The quality of evidence based on GRADE was low.

CONCLUSIONS AND RELEVANCE

This systematic review and meta-analysis did not show a significant beneficial or detrimental association of HT with muscle mass. Although muscle retention in aging women is of crucial importance, these findings suggest that interventions other than HT should be explored.

Resistance exercise-induced hormonal response promotes satellite cell proliferation in untrained men but not in women

The purpose of this work was to determine the effect of resistance exercise (RE)-induced hormonal changes on the satellite cell (SC) myogenic state in response to muscle damage. Untrained men (n = 10, 22 ± 3 yr) and women (n = 9, 21 ± 4 yr) completed 2 sessions of 80 unilateral maximal eccentric knee extensions followed by either an upper body RE protocol (EX) or a 20-min rest (CON). Muscle samples were collected and analyzed for protein content of Pax7, MyoD, myogenin, cyclin D1, and p21 before (PRE), 12 h, and 24 h after the session was completed. Serum testosterone, growth hormone, cortisol, and myoglobin concentrations were analyzed at PRE, post-damage, immediately after (IP), and 15, 30, and 60 min after the session was completed. Testosterone was significantly (P < 0.05) higher immediately after the session in EX vs. CON for men. A significant time  × sex × condition interaction was found for MyoD with an increase in EX (men) and CON (women) at 12 h. A significant time × condition interaction was found for Pax7, with a decrease in EX and increase in CON at 24 h. A significant time effect was found for myogenin, p21, and cyclin D1. Myogenin and p21 were increased at 12 and 24 h, and cyclin D1 was increased at 12 h. These results suggest that the acute RE-induced hormonal response can be important for men to promote SC proliferation after muscle damage but had no effect in women. Markers of SC differentiation appeared unaffected by the hormonal response but increased in response to muscle damage.

Cognitive Decline, Body Mass Index, and Waist Circumference in Community-Dwelling Elderly Participants

OBJECTIVE

The aim of this study was to explore the association of body mass index (BMI), waist circumference (WC), and BMI and WC changes over time with cognitive decline in a nationally representative sample.

METHODS

A total of 5239 participants (≥65 years) were followed for 3 years as part of the National Health and Aging Trends Study. Cox proportional hazard regression was applied to model the risk of cognitive decline.

RESULTS

BMI, after adjusting for WC and main confounders, was associated with reduced risk of cognitive decline (hazard ratio [HR] 0.97 for each unit BMI increase, 0.95-0.99). After stratifying by gender and age, this effect remained significant among females and young elders ≤80 years. A BMI decrease and WC increase >10% over the study period were associated with increased risk of cognitive decline (HR 1.98, 1.16-3.38; HR 1.30, 1.04-1.62, respectively).

CONCLUSION

In the elderly individuals, lean mass, as measured by BMI adjusted for WC, was associated with reduced risk of cognitive decline. Loss of lean mass and gain of fat mass, as measured by WC adjusted for BMI, were associated with elevated risk of cognitive decline.

Increased fat deposition in injured skeletal muscle is regulated by sex-specific hormones

Sex differences in skeletal muscle regeneration are controversial; comparisons of regenerative events between sexes have not been rigorously defined in severe injury models. We comprehensively quantified inflammation and muscle regeneration between sexes and manipulated sex-specific hormones to determine effects on regeneration. Cardiotoxin injury was induced in intact, castrated and ovariectomized female and male mice; ovariectomized mice were replaced with low- or high-dose 17-β estradiol (E(2)) or progesterone (P4). Extent of injury was comparable between intact mice, but females were more efficient in removal of necrotic debris, despite similar tissue levels of inflammatory cells and chemokines. Myofiber size during regeneration was equivalent between intact mice and after castration or ovariectomy (OVX) but was decreased (P < 0.001) in ovariectomized mice with high-dose E(2) replacement. Intermuscular adipocytes were absent in uninjured muscle, whereas adipocyte area was increased among regenerated myofibers in all groups. Interestingly, intermuscular fat was greater (P = 0.03) in intact females at day 14 compared with intact males. Furthermore, castration increased (P = 0.01) and OVX decreased adipocyte accumulation. After OVX, E(2), but not P4, replacement decreased (P ≤ 0.03) fat accumulation. In conclusion, sex-dependent differences in regeneration consisted of more efficient removal of necrosis and increased fat deposition in females with similar injury, inflammation, and regenerated myofiber size; high-dose E(2) decreased myofiber size and fat deposition. Adipocyte accumulation in regenerating muscle was influenced by sex-specific hormones. Recovery following muscle injury was different between males and females, and sex-specific hormones contributed to these differences, suggesting that sex-specific treatments could be beneficial after injury.