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

Thigh muscle composition changes in knee osteoarthritis patients during weight loss: Sex-specific analysis using data from osteoarthritis initiative

OBJECTIVES

Sex of patients with knee osteoarthritis (KOA) may impact changes in thigh muscle composition during weight loss, the most well-known disease-modifying intervention. We investigated longitudinal sex-based changes in thigh muscle quality during weight loss in participants with KOA.

METHODS

Using Osteoarthritis Initiative (OAI) cohort data, we included females and males with baseline radiographic KOA who experienced > 5 % reduction in Body Mass Index (BMI) over four years. Using a previously validated deep-learning algorithm, we measured Magnetic Resonance Imaging (MRI)-derived biomarkers of thigh muscles at baseline and year-4. Outcomes were the intra- and inter-muscular adipose tissue (Intra-MAT and Inter-MAT) and contractile percentage of thigh muscles between females and males. The analysis adjusted for potential confounders, such as demographics, risk factors, BMI change, physical activity, diet, and KOA status.

RESULTS

A retrospective selection of available thigh MRIs from KOA participants who also had a 4-year weight loss (>5 % of BMI) yielded a sample comprising 313 thighs (192 females and 121 males). Female and male participants exhibited a comparable degree of weight loss (females: -9.72 ± 4.38, males: -8.83 ± 3.64, P-value=0.060). However, the changes in thigh muscle quality were less beneficial for females compared to males, as shown by a less degree of longitudinal decrease in Intra-MAT (change difference,95 %CI: 783.44 mm2/4-year, 505.70 to 1061.19, P-value<0.001) and longitudinal increase in contractile percentage (change difference,95 %CI: -3.9 %/4-year, -6.5 to -1.4, P-value=0.019).

CONCLUSIONS

In participants with KOA and 4-year weight loss, the longitudinal changes in thigh muscle quality were overall beneficial but to a less degree in females compared to males. Further research is warranted to investigate the underlying mechanisms and develop sex-specific interventions to optimize muscle quality during weight loss.

The influence of body composition on the response to dynamic stimulation of the endocrine pituitary-testis axis

BACKGROUND

Testosterone treatment is generally not recommended in men with obesity induced low serum testosterone. However, distinguishing this condition from overt testosterone deficiency in men with obesity where treatment should be initiated is a diagnostic challenge and tools to differentiate these conditions are scarce but could be of important clinical relevance.

OBJECTIVES

To investigate the association between body composition and dynamic responses of the pituitary-testis axis in men.

METHODS

Single-center cross-sectional study including 112 healthy men. Participants went through a full biochemical assessment of the pituitary-testis axis, and dynamic stimulatory tests of luteinizing hormone (LH) secretion (gonadotropin-releasing hormone (GnRH)-test) and testosterone secretion (choriogonadotropin (hCG)-test). A subset (N = 78) further had a DXA-scan performed.

RESULTS

A higher body mass index (BMI) was associated with lower basal serum LH (BU = -0.44, 95% CI: -0.88--0.01, p = 0.04). The GnRH-stimulated LH increase was not significantly associated with BMI (BU = -0.10, 95% CI: -0.72-0.51, p = 0.74). Furthermore, a high BMI was associated with low basal testosterone (BU -0.02, 95% CI: -0.03--0.02, p < 0.001), and free testosterone (BU -15.0, 95% CI: -19.9--10.0, p < 0.001) and men with overweight and obesity had significantly lower testosterone (9%, p = 0.003 and 24%, p < 0.001) and free testosterone (25%, p = 0.006 and 50%, p < 0.001) concentrations compared to men with normal weight. The HCG-stimulated testosterone increase was significantly less dependent on BMI compared to the influence of BMI on basal testosterone concentrations (p = 0.04 for the interaction).

CONCLUSIONS

Dynamic sex hormone responses following pituitary-testis axis stimulation were less dependent on BMI, compared to the influence of BMI on basal hormone concentrations and could potentially assist clinical decision making in patients with obesity suspected of testosterone deficiency.

Sex differences in human performance

Sex as a biological variable is an underappreciated aspect of biomedical research, with its importance emerging in more recent years. This review assesses the current understanding of sex differences in human physical performance. Males outperform females in many physical capacities because they are faster, stronger and more powerful, particularly after male puberty. This review highlights key sex differences in physiological and anatomical systems (generally conferred via sex steroids and puberty) that contribute to these sex differences in human physical performance. Specifically, we address the effects of the primary sex steroids that affect human physical development, discuss insight gained from an observational study of 'real-world data' and elite athletes, and highlight the key physiological mechanisms that contribute to sex differences in several aspects of physical performance. Physiological mechanisms discussed include those for the varying magnitude of the sex differences in performance involving: (1) absolute muscular strength and power; (2) fatigability of limb muscles as a measure of relative performance; and (3) maximal aerobic power and endurance. The profound sex-based differences in human performance involving strength, power, speed and endurance, and that are largely attributable to the direct and indirect effects of sex-steroid hormones, sex chromosomes and epigenetics, provide a scientific rationale and framework for policy decisions on sex-based categories in sports during puberty and adulthood. Finally, we highlight the sex bias and problem in human performance research of insufficient studies and information on females across many areas of biology and physiology, creating knowledge gaps and opportunities for high-impact studies.

Management of male obesity-related secondary hypogonadism: A clinical update

The global obesity pandemic has resulted in a rise in the prevalence of male obesity-related secondary hypogonadism (MOSH) with emerging evidence on the role of testosterone therapy. We aim to provide an updated and practical approach towards its management. We did a comprehensive literature search across MEDLINE (via PubMed), Scopus, and Google Scholar databases using the keywords "MOSH" OR "Obesity-related hypogonadism" OR "Testosterone replacement therapy" OR "Selective estrogen receptor modulator" OR "SERM" OR "Guidelines on male hypogonadism" as well as a manual search of references within the articles. A narrative review based on available evidence, recommendations and their practical implications was done. Although weight loss is the ideal therapeutic strategy for patients with MOSH, achievement of significant weight reduction is usually difficult with lifestyle changes alone in real-world practice. Therefore, androgen administration is often necessary in the management of hypogonadism in patients with MOSH which also improves many other comorbidities related to obesity. However, there is conflicting evidence for the appropriate use of testosterone replacement therapy (TRT), and it can also be associated with complications. This evidence-based review updates the available evidence including the very recently published results of the TRAVERSE trial and provides comprehensive clinical practice pearls for the management of patients with MOSH. Before starting testosterone replacement in functional hypogonadism of obesity, it would be desirable to initiate lifestyle modification to ensure weight reduction. TRT should be coupled with the management of other comorbidities related to obesity in MOSH patients. Balancing the risks and benefits of TRT should be considered in every patient before and during long-term management.

Prevalence and factors associated with sarcopenia among older adults in a post-acute hospital in Singapore

BACKGROUND

Sarcopenia is common in older adults worldwide, but its prevalence varies widely owing to differences in diagnostic criteria, population sampled, and care setting. We aimed to determine the prevalence and factors associated with sarcopenia in patients aged 65 and above admitted to a post-acute hospital in Singapore.

METHODS

This was a cross-sectional study of 400 patients recruited from a community hospital in Singapore. Data including socio-demographics, physical activity, nutritional status, cognition, clinical and functional status, as well as anthropometric measurements were collected. Sarcopenia was defined using the Asian Working Group for Sarcopenia 2019 criteria [AWGS2019].

RESULTS

Of the 383 patients with complete datasets, overall prevalence of sarcopenia was 54% while prevalence of severe sarcopenia was 38.9%. Participants with increased age, male gender and a low physical activity level were more likely to be sarcopenic, while those with higher hip circumference and higher BMI of ≥27.5m/kg2 were less likely to be sarcopenic. Other than the above-mentioned variables, cognitive impairment was also associated with severe sarcopenia.

CONCLUSIONS

More than 1 in 2 older adults admitted to a post-acute hospital in Singapore are sarcopenic. There is an urgent need to address this important clinical syndrome burden and to identify patients at risk of sarcopenia in post-acute settings in Singapore for early intervention.

The role of estrogen in female skeletal muscle aging: A systematic review

Aging is associated with a loss of skeletal muscle mass and function that negatively impacts the independence and quality of life of older individuals. Females demonstrate a distinct pattern of muscle aging compared to males, potentially due to menopause, when the production of endogenous sex hormones declines. This systematic review aims to investigate the current knowledge about the role of estrogen in female skeletal muscle aging. A systematic search of MEDLINE Complete, Global Health, Embase, PubMed, SPORTDiscus, and CINHAL was conducted. Studies were considered eligible if they compared a state of estrogen deficiency (e.g. postmenopausal females) or supplementation (e.g. estrogen therapy) to normal estrogen conditions (e.g. premenopausal females or no supplementation). Outcome variables of interest included measures of skeletal muscle mass, function, damage/repair, and energy metabolism. Quality assessment was completed with the relevant Johanna Briggs critical appraisal tool, and data were synthesized in a narrative manner. Thirty-two studies were included in the review. Compared to premenopausal women, postmenopausal women had reduced muscle mass and strength, but the effect of menopause on markers of muscle damage and expression of the genes involved in metabolic signaling pathways remains unclear. Some studies suggest a beneficial effect of estrogen therapy on muscle size and strength, but evidence is largely conflicting and inconclusive, potentially due to large variations in the reporting and status of exposure and outcomes. The findings from this review point toward a potential negative effect of estrogen deficiency on aging skeletal muscle, but further mechanistic evidence is needed to clarify its role.

Pathophysiology of sarcopenia: Genetic factors and their interplay with environmental factors

Sarcopenia is a geriatric disorder characterized by a progressive decline in muscle mass and function. This disorder has been associated with a range of adverse health outcomes, including fractures, functional deterioration, and increased mortality. The pathophysiology of sarcopenia is highly complex and multifactorial, involving both genetic and environmental factors as key contributors. This review consolidates current knowledge on the genetic factors influencing the pathogenesis of sarcopenia, particularly focusing on the altered gene expression of structural and metabolic proteins, growth factors, hormones, and inflammatory cytokines. While the influence of environmental factors such as physical inactivity, chronic diseases, smoking, alcohol consumption, and sleep disturbances on sarcopenia is relatively well understood, there is a dearth of studies examining their mechanistic roles. Therefore, this review emphasizes the interplay between genetic and environmental factors, elucidating their cumulative role in exacerbating the progression of sarcopenia beyond their individual effects. The unique contribution of this review lies in synthesizing the latest evidence on the genetic factors and their interaction with environmental factors, aiming to inform the development of novel therapeutic or preventive interventions for sarcopenia.

Difference of the association between low muscle mass and physical inactivity by sex resulting from the choice of the diagnostic criterion for low muscle mass in elderly Koreans

AIM

We investigated the difference in the relationship between physical activity and low muscle mass resulting from the choice of diagnostic criterion for low muscle mass.

METHODS

Our study was cross-sectional, using data from the 2008-2011 National Health and Nutrition Examination Survey. Muscle mass was measured by dual-energy X-ray absorptiometry. Low muscle mass was defined as height-adjusted and weight-adjusted low muscle mass. Odds ratios (ORs) and 95% confidence intervals (CIs) of low muscle mass in relation to physical inactivity were analyzed using multivariate logistic regression analysis.

RESULTS

Our study included 3977 older people (1698 men and 2279 women). The prevalence of height-adjusted and weight-adjusted low muscle mass was 4.1% and 11.8%, respectively, in the physically inactive group, and 3.9% and 7.9%, respectively, in the physically active group. The prevalence of weight-adjusted low muscle mass increased by 48% in the physically inactive group in the fully adjusted model (OR, 1.48; 95% CI, 1.13-1.95) and increased by 61% in men and 50% in women (men: OR, 1.61; 95% CI, 1.12-2.31 and women: OR, 1.50; 95% CI, 1.20-2.20) compared with the physically active group. The risk of height-adjusted low muscle mass in men tended to be higher in the physically inactive group than in the physically active group. However, this trend was not observed among women.

CONCLUSIONS

Physical inactivity was associated with an increased prevalence of low muscle mass in weight-adjusted measures among elderly adults in Korea. Height-adjusted low muscle mass in women is less useful as an indicator of the relationship between low muscle mass and physical inactivity. Geriatr Gerontol Int 2023; 23: 71-77.

Physiological and molecular sex differences in human skeletal muscle in response to exercise training

Sex differences in exercise physiology, such as substrate metabolism and skeletal muscle fatigability, stem from inherent biological factors, including endogenous hormones and genetics. Studies investigating exercise physiology frequently include only males or do not take sex differences into consideration. Although there is still an underrepresentation of female participants in exercise research, existing studies have identified sex differences in physiological and molecular responses to exercise training. The observed sex differences in exercise physiology are underpinned by the sex chromosome complement, sex hormones and, on a molecular level, the epigenome and transcriptome. Future research in the field should aim to include both sexes, control for menstrual cycle factors, conduct large-scale and ethnically diverse studies, conduct meta-analyses to consolidate findings from various studies, leverage unique cohorts (such as post-menopausal, transgender, and those with sex chromosome abnormalities), as well as integrate tissue and cell-specific -omics data. This knowledge is essential for developing deeper insight into sex-specific physiological responses to exercise training, thus directing future exercise physiology studies and practical application.

Association between serum total testosterone levels and metabolic syndrome among adult women in the United States, NHANES 2011-2016

OBJECTIVE

To investigate the association between serum total testosterone (TT) levels and metabolic syndrome (MetS) or its components among adult women.

METHODS

2,678 women from NHANES 2011-2016 were included in this cross-sectional study. MetS was determined according to the National Cholesterol Education Program Adult Treatment Panel III guidelines. The association between serum TT levels and MetS was evaluated by two logistics regression models and the adjusted restricted cubic spline (RCS). Stratified analysis and sensitive analysis were also conducted.

RESULTS

Continuous TT levels were negatively associated with the occurrence of MetS, and the ORs associated with per SD increase in ln TT were 0.70 (95%CI: 0.58-0.85) in 2011-2014 and 0.56 (95%CI: 0.39-0.79) in 2015-2016 in Model A. High TT group were less likely to have MetS (OR=0.60, 95%CI: 0.45-0.80 in 2011-2014 and OR=0.50, 95%CI: 0.32-0.78 in 2015-2016) when compared to the low TT group. When TT levels were divided into quartiles, TT levels were negatively correlated with the incidence of MetS (p for trend < 0.001). Similar trend was observed in Model B. Multivariate-adjusted logistic regression with RCS exhibited that TT had a L-shaped dose-response association with MetS or its components. Interaction analyses revealed that women who were less than 50 years old (OR=0.37, 95%CI: 0.22, 0.63), with depression (OR=0.50, 95%CI: 0.29, 0.87) or being smokers (OR=0.37, 95%CI: 0.23, 0.54) showed lower ORs than those who were over 50 years old (OR=0.66, 95%CI: 0.40, 1.09), without depression (OR=0.59, 95%CI: 0.41, 0.85) or non-smokers (OR=0.59, 95%CI: 0.39, 0.89) when measure the association between ln TT and the occurrence of MetS.

CONCLUSIONS

Our study indicated that TT levels are negatively correlated with the occurrence of MetS, with interaction effects of age, smoke behaviors, and depressive status.

Changes in Sex Steroids and Enteric Peptides After Sleeve Gastrectomy in Youth in Relation to Changes in Bone Parameters

CONTEXT

Sleeve gastrectomy (SG) improves metabolic endpoints but is associated with impaired bone outcomes.

OBJECTIVE

To determine mechanisms contributing to impaired bone health in youth following SG.

METHODS

12-month longitudinal observational study in a multidisciplinary tertiary-care hospital, including 64 youth 13-25 years old with moderate-to-severe obesity (51 females); 30 underwent SG and 34 were nonsurgical (NS) controls. SG was undertaken after a combined decision-making process between treatment team and patient. The main outcome measures were fasting blood for enteric peptides, sex steroids, sclerostin, and bone turnover markers (N-terminal propeptide of type 1 procollagen [P1NP] and C-terminal cross-linking telopeptide [CTX]); dual-energy X-ray absorptiometry measures of areal bone mineral density (aBMD) and body composition; high resolution peripheral quantitative computed tomography; measures of volumetric BMD (vBMD); microfinite element analysis of strength estimates (distal radius and tibia).

RESULTS

SG had greater reductions in body mass index (BMI) z-scores, serum estrone, and the free androgen index (FAI) (P ≤ .046), and greater increases in sclerostin, P1NP, and CTX (P ≤ .010) than NS controls. Fasting ghrelin decreased in SG vs NS (P < .0001); fasting peptide YY did not change. Most changes were driven by female SG participants. Among females (the majority of study participants), after controlling for baseline age and race, reductions in total hip aBMD Z-scores were positively associated with changes in BMI, lean mass, estrone, FAI, and ghrelin, and inversely with changes in sclerostin.. Decreases in total vBMD of the radius and tibia were associated positively with decreases in BMI. Increases in CTX were associated with decreases in BMI, lean mass, and ghrelin, and increases in sclerostin.

CONCLUSION

Bone loss after SG in youth is associated with changes in body composition, sex steroids, sclerostin, and enteric peptides. These are potential targets for future preventative or therapeutic strategies.

Physical Fitness and Frailty in Males after Allogeneic Hematopoietic Stem Cell Transplantation in Childhood: A Long-Term Follow-Up Study

Purpose and methods: To analyze physical fitness, physical activity and the prevalence of frailty in male long-term survivors of pediatric allogeneic hematopoietic stem cell transplantation (HSCT). We performed a Nordic two-center study of 98 male survivors (mean age 28.7 years, range 18.5–47.0) treated with pediatric allogeneic hematopoietic stem cell transplantation (HSCT) 1980–2010 in denmark or finland. physical fitness was evaluated by the dominant hand grip-strength, timed up-and-go, sit-to-stand, gait speed and two-minute walk tests. Results: Survivors presented significantly lower muscle strength and muscle endurance in the dominant hand-grip strength (median Z-score −0.7, range −4.3–3.9) and sit-to-stand tests (median Z-score −1.5, range −3.5–2.5) compared to age and sex matched normative values of the tests. However, mobility and gait speed were not affected on a group level. The prevalence of frailty (pre-frail 20% or frail 10%) was high among the survivors. In multiple regression analysis, chronic graft-versus-host disease, shorter stature, higher body fat mass and hazardous drinking predicted prefrail/frail status. Common cardiovascular risk factors, such as increased levels of serum triglycerides, higher resting heart rate and diastolic blood pressure, were associated with lower physical fitness. Conclusion: Low muscle strength and a high incidence of frailty were observed in survivors of pediatric HSCT. There is a predominant risk of cardiovascular and metabolic diseases in the long-term.

Considerations for Sex-Cognizant Research in Exercise Biology and Medicine

As the fields of kinesiology, exercise science, and human movement developed, the majority of the research focused on male physiology and extrapolated findings to females. In the medical sphere, basing practice on data developed in only males resulted in the removal of drugs from the market in the late 1990s due to severe side effects (some life-threatening) in females that were not observed in males. In response to substantial evidence demonstrating exercise-induced health benefits, exercise is often promoted as a key modality in disease prevention, management, and rehabilitation. However, much like the early days of drug development, a historical literature knowledge base of predominantly male studies may leave the exercise field vulnerable to overlooking potentially key biological differences in males and females that may be important to consider in prescribing exercise (e.g., how exercise responses may differ between sexes and whether there are optimal approaches to consider for females that differ from conventional approaches that are based on male physiology). Thus, this review will discuss anatomical, physiological, and skeletal muscle molecular differences that may contribute to sex differences in exercise responses, as well as clinical considerations based on this knowledge in athletic and general populations over the continuum of age. Finally, this review summarizes the current gaps in knowledge, highlights the areas ripe for future research, and considerations for sex-cognizant research in exercise fields.

Endogenous Androgens Diminish Food Intake and Activation of Orexin A Neurons in Response to Reduced Glucose Availability in Male Rats

Sex steroids modify feeding behavior and body weight regulation, and androgen reportedly augments food intake and body weight gain. To elucidate the role of endogenous androgens in the feeding regulation induced by reduced glucose availability, we examined the effect of gonadectomy (orchiectomy) on food intake and orexin A neuron’s activity in the lateral hypothalamic/perifornical area (LH/PFA) in response to reduced glucose availability (glucoprivation) induced by 2-deoxy-d-glucose (2DG) administration in male rats. Rats (7W) were bilaterally orchiectomized (ORX group) or sham operated (Sham group). Seventeen days after the surgery, food intake response to 2DG (400 mg/kg, i.v.) was measured for 4 h after the infusion. The same experiment was performed for the immunohistochemical examination of c-Fos-expressing orexin A neurons in the LH/PFA and c-Fos expression in the arcuate nucleus (Arc). Food intake induced by glucoprivation was greater in the ORX group than the Sham group, and the glucoprivation-induced food intake was inversely correlated with plasma testosterone concentration. Glucoprivation stimulated c-Fos expression of the orexin A neurons at the LH/PFA and c-Fos expression in the dorsomedial Arc. The number and percentage of c-Fos-expressing orexin A neurons in the LH/PFA and c-Fos expression in the dorsomedial Arc were significantly higher in the ORX group than the Sham group. This indicates that endogenous androgen, possibly testosterone, diminishes the food intake induced by reduced glucose availability, possibly via the attenuated activity of orexin A neuron in the LH/PFA and neurons in the dorsomedial Arc.

The Effect of Whole Egg Intake on Muscle Mass: Are the Yolk and Its Nutrients Important?

Whole egg may have potential benefits for enhancing muscle mass, independent of its protein content. The yolk comprises ∼40% of the total protein in an egg, as well as containing several nonprotein nutrients that could possess anabolic properties (e.g., microRNAs, vitamins, minerals, lipids, phosphatidic acid and other phospholipids). Therefore, the purpose of this narrative review is to discuss the current evidence as to the possible effects of egg yolk compounds on skeletal muscle accretion beyond those of egg whites alone. The intake of whole egg seems to promote greater myofibrillar protein synthesis than egg white intake in young men. However, limited evidence shows no difference in muscle hypertrophy when comparing the consumption of whole egg versus an isonitrogenous quantity of egg white in young men performing resistance training. Although egg yolk intake seems to promote additional acute increases on myofibrillar protein synthesis, it does not seem to further enhance muscle mass when compared to egg whites when consumed as part of a high-protein dietary patterns, at least in young men. This conclusion is based on very limited evidence and more studies are needed to evaluate the effects of egg yolk (or whole eggs) intake on muscle mass not only in young men, but also in other populations such as women, older adults, and individuals with muscle wasting diseases.

Total testosterone is not associated with lean mass or handgrip strength in pre-menopausal females

The aim of this study was to examine the relationship between endogenous testosterone concentrations and lean mass and handgrip strength in healthy, pre-menopausal females. Testosterone has been positively associated with lean mass and strength in young and older males. Whether this relationship exists in pre-menopausal females is unknown. Secondary data from the 2013-2014 National Health and Nutrition Examination Survey were used to test this relationship. Females were aged 18-40 (n = 716, age 30 ± 6 years, mean ± SD) and pre-menopausal. Multivariate linear regression models were used to examine associations between total testosterone, lean mass index (LMI) and handgrip strength. Mean ± SD testosterone concentration was 1.0 ± 0.6 nmol L-1 and mean free androgen index (FAI) was 0.02 ± 0.02. In pre-menopausal females, testosterone was not associated with LMI (β = 0.05; 95%CI - 0.04, 0.15; p = 0.237) or handgrip strength (β = 0.01; 95%CI - 0.11, 0.12; p = 0.926) in a statistically significant manner. Conversely, FAI was associated with LMI (β = - 0.03; 95%CI - 0.05, - 0.02; p = 0.000) in a quadratic manner, meaning LMI increases with increasing FAI levels. Handgrip strength was not associated with FAI (β = 0.06; 95%CI - 0.02, 0.15; p = 0.137). These findings indicate that FAI, but not total testosterone, is associated with LMI in pre-menopausal females. Neither FAI nor total testosterone are associated with handgrip strength in pre-menopausal females when testosterone concentrations are not altered pharmacologically.

Improvement of testosterone deficiency by fermented Momordica charantia extracts in aging male rats

This study evaluated the efficacy of Momordica charantia (MC; bitter melon) extracts against andropause symptoms. We fermented MC with Lactobacillus plantarum and verified the ability of the fermented MC extracts (FMEs) to control testosterone deficiency by using aging male rats as an animal model of andropause. FME administration considerably increased total and free testosterone levels, muscle mass, forced swimming time, and total and motile sperm counts in aging male rats. In contrast, sex hormone-binding globulin, retroperitoneal fat, serum cholesterol, and triglyceride levels were significantly reduced in the treated groups compared to the non-treated control aging male rats. Furthermore, we observed that FME enhanced the expression of testosterone biosynthesis-related genes but reduced the expression of testosterone degradation-related genes in a mouse Leydig cell line. These results suggest that FME has effective pharmacological activities that increase and restore free testosterone levels and that FME may be employed as a promising natural product for alleviating testosterone deficiency syndrome.

Supplementary Information

The online version contains supplementary material available at 10.1007/s10068-020-00872-x.

Association between Serum Testosterone Levels and Body Composition among Men 20-59 Years of Age

INTRODUCTION

Sex hormones play an important role in the development and maintenance of bone and muscle mass. However, studies regarding serum testosterone levels, osteoporosis, and sarcopenia in men are relatively sparse and have led to contradictory conclusions. Therefore, this study aimed to investigate the association between serum testosterone levels and body composition, including bone mineral density (BMD), appendicular lean mass index (ALMI), and appendicular fat mass index (AFMI), among men 20-59 years of age through a cross-sectional analysis of the National Health and Nutrition Examination Survey.

MATERIALS AND METHODS

Our analysis was based on the data for 3,875 men, 20-59 years of age. Weighted multiple regression analyses were used to estimate the independent association between serum testosterone levels and body composition. Weighted generalized additive models and smooth curve fittings were used to characterize the nonlinear associations between them.

RESULTS

The association between the serum testosterone level and lumbar BMD was positive in each multivariable linear regression model. In the model adjusted for age and race, the serum testosterone level was negatively associated with ALMI. However, in the models adjusted for body mass index, this association became positive. In addition, the association between the serum testosterone level and AFMI was negative in each multivariable linear regression model.

CONCLUSION

Our study demonstrated a positive association of serum testosterone level with lumbar BMD and ALMI, and a negative association with AFMI, among men 20-59 years of age, suggesting that increasing testosterone levels may be beneficial to skeletal health in young and middle-aged men with low testosterone levels.

High Luteinizing Hormone and Lower Levels of Sex Hormones in Younger Men With Distal Radius Fracture

This study investigates the sex steroid hormone profile in younger men with distal radius fracture (DRF) to elucidate if this could explain the low bone density and osteoporosis previously observed. In a case-control study, 73 men with DRF (mean age 38 ± 9 years; range, 20-51) was compared with 194 age-matched, population controls. Performed assays: total testosterone (TT), calculated free testosterone (cFT), luteinizing hormone (LH), follicle-stimulating hormone (FSH), sex hormone-binding globulin (SHBG), and total estradiol (E2). BMD hip and spine were measured. Fracture cases had lower cFT (298 versus 329 pmol/L; p = 0.008), but not TT, compared with controls. FSH and SHBG were not statistically different. LH was almost 30% higher (5.7 versus 4.5 IU/L; p < 0.001) and a lower E2 was observed (80.0 versus 87.1; p = 0.098). Men with DRF had a lower E2/SHBG ratio compared with controls (2.3 versus 2.9; p = 0.013). A higher proportion of the fracture group had low TT (<10.5 nmol/L; 21% versus 11%; p = 0.052), low cFT (<220 pmol/L; 18% versus 8%; p = 0.017), and low E2 (<73 pmol/L; 48% versus 35%; p = 0.044). Odds ratio (OR) for fracture when having low cFT was 2.3 (95% CI, 1.02-5.49; p = 0.044); with low E2, the OR was 1.7 (95% CI, 0.96-2.96). In this study in young men with DRF exploring sex hormone levels, we find that sex hormone profiles may be disturbed with a lower E2/SHBG ratio, lower cFT, and higher LH. Estrogen is also a strong determinant of bone mass in men; hence, low levels of E2 may be contributing to the observed lower BMD and these differences may be relevant to fracture risk. © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Advanced Chronic Kidney Disease is a Strong Predictor of Hypogonadism and is Associated with Decreased Lean Tissue Mass

Purpose

In patients with chronic kidney disease (CKD), hypogonadism is more frequent than in the general population and its prevalence ranges between 40% and 60%. The aim of the study was to investigate the prevalence of hypogonadism and its association with kidney function, body composition, inflammatory markers and lipid disorders in patients with CKD.

Materials and Methods

The study population consisted of 112 men aged ≥40 years in different stages of CKD: 33 participants with eGFR ≥60 mL/min/1.73 m², 27 men with eGFR 30–59 mL/min/1.73 m², 17 predialysis patients with eGFR <30 mL/min/1.73 m², and 35 men on hemodialysis therapy three times a week for more than 3 months (G5D stage). Total testosterone (TT) levels were measured and free testosterone (FT) levels were calculated. Body composition was assessed using bioimpedance spectroscopy (Body Composition Monitor, FMC). Statistical analysis was performed using Statistica version 13.1.

Results

CKD stage was a strong predictor of hypogonadism (providing an information value of 0.83). The weight of evidence technique allowed us to differentiate the high-risk group, which was a group of patients with advanced CKD, defined as eGFR <30 mL/min/1.73 m². In this group, the likelihood of hypogonadism was 69.23%. Another significant predictor of hypogonadism was lean tissue index (LTI). TT and FT levels were significantly lower in the advanced CKD group in comparison to the control group, whereas prolactin, luteinizing hormone and C-reactive protein levels were significantly higher in the advanced CKD group. The LTI was significantly lower in advanced CKD and was positively correlated with TT and FT.

Conclusion

Decreased eGFR and decreased LTI are predictors of hypogonadism associated with CKD. The study results suggest that hypogonadism screening should be carried out when eGFR deceases below 30 mL/min/1.73 m².

The Effect of Exercise on Body Composition and Physical Performance in Prostate Cancer Patients Undergoing Androgen Deprivation Therapy (ADT): A Narrative Synthesis

OBJECTIVE

This review sought to synthesize evidence examining the effect of exercise on prostate cancer patients undergoing androgen deprivation therapy (ADT).

DATA SOURCES

A systematic literature search was conducted in electronic databases (CINAHL, MEDLINE, APA PsychINFO, Scopus, SPORTDiscus, and Cochrane Library) from their inception to March 31, 2020. Inclusion criteria were randomized controlled trials (RCTs) testing the effect of exercise on body composition, muscle strength and physical performance. Fourteen RCTs were included. Participant numbers within the individual RCTs ranged from 19 to 163 with heterogeneity in prostate cancer stage (localized and locally advanced diagnoses) with age of participants ranging from 43 to 90 years. The length of the interventions ranged from 12 weeks to 12 months, with the number of sessions per week ranging from 2 to 5. Resistance training intensity ranged from 60% to 90% 1RM and the aerobic training ranged from 60% to 90% HR_max.

CONCLUSIONS

Resistance training and sport (football) in the form of small sided games (SSGs) played an important role in preserving bone mineral density and lean mass as well as improving muscle strength and physical performance outcomes in men affected by prostate cancer undergoing ADT.

IMPLICATIONS FOR NURSING PRACTICE

Multimodal exercise, including resistance exercise and activity that includes repeated sprints (SSGs), benefit the maintenance of bone mineral density and lean mass as well as increase strength and physical performance in men affected by prostate cancer undergoing ADT. Based on this evidence, nurses should coordinate timely referrals to qualified exercise physiologists or physiotherapist with expertise in cancer care.

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.

Changes in nucleus accumbens gene expression accompany sex-specific suppression of spontaneous physical activity in aromatase knockout mice

Aromatase catalyzes conversion of testosterone to estradiol and is expressed in a variety of tissues, including the brain. Suppression of aromatase adversely affects metabolism and physical activity behavior, but mechanisms remain uncertain. The hypothesis tested herein was that whole body aromatase deletion would cause gene expression changes in the nucleus accumbens (NAc), a brain regulating motivated behaviors such as physical activity, which is suppressed with loss of estradiol. Metabolic and behavioral assessments were performed in male and female wild-type (WT) and aromatase knockout (ArKO) mice. NAc-specific differentially expressed genes (DEGs) were identified with RNAseq, and associations between the measured phenotypic traits were determined. Female ArKO mice had greater percent body fat, reduced spontaneous physical activity (SPA), consumed less energy, and had lower relative resting energy expenditure (REE) than WT females. Such differences were not observed in ArKO males. However, in both sexes, a top DEG was Pts, a gene encoding an enzyme necessary for catecholamine (e.g., dopamine) biosynthesis. In comparing male and female WT mice, top DEGs were related to sexual development/fertility, immune regulation, obesity, dopamine signaling, and circadian regulation. SPA correlated strongly with Per3, a gene regulating circadian function, thermoregulation, and metabolism (r = -0.64, P = .002), which also correlated with adiposity (r = 0.54, P = .01). In conclusion, aromatase ablation leads to gene expression changes in NAc, which may in turn result in reduced SPA and related metabolic abnormalities. These findings may have significance to post-menopausal women and those treated with an aromatase inhibitor.

Measuring testosterone and testosterone replacement therapy in men receiving androgen deprivation therapy for prostate cancer: A survey of UK uro-oncologists' opinions and practice

AIM

To explore the practice and attitudes of uro-oncologists in the UK regarding monitoring testosterone levels and the use of testosterone replacement therapy (TRT) in their prostate cancer patients treated with androgen deprivation therapy (ADT).

METHODS

An expert-devised online questionnaire was completed by the members of the British Uro-oncology Group (BUG).

RESULTS

Of 160 uro-oncologists invited, 84 completed the questionnaire. Before initiating ADT in patients with non-metastatic prostate cancer, only 45% of respondents measured testosterone levels and 61% did not measure testosterone at all during ADT in the adjuvant or neoadjuvant setting. However, in men with metastatic prostate cancer, 71% of the uro-oncologists measured testosterone before starting ADT and the majority continued testing during treatment. Approximately two-thirds of respondents did not prescribe TRT for their patients who were in remission following neo(adjuvant) ADT and who had castration levels of testosterone.

DISCUSSION

Among UK uro-oncologists, the measurement of testosterone levels before and during ADT was not typically part of routine practice in the management of patients with prostate cancer. However, testosterone levels were checked more frequently for patients with metastatic disease than disease at an earlier stage. Testing could be conducted in parallel with PSA measurement as testosterone levels are linked to biochemical failure. The majority of specialists participating in the survey did not prescribe TRT for their patients in remission following ADT.

CONCLUSION

Uro-oncologists in the UK do not generally measure testosterone as part of their patient management and they remain cautious about the possible benefits of TRT in men with prostate cancer.

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.

Association of sarcopenia and fractures in community-dwelling older adults: a systematic review and meta-analysis of cohort studies

To our knowledge, no comprehensive meta-analysis has examined the association between sarcopenia and the risk of fractures. This systematic review and meta-analysis of prospective cohort studies aims to summarize whether sarcopenia is a risk factor for fractures among community-dwelling older adults. We searched four electronic literature databases (Ovid MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, PubMed) for relevant publications from inception to December 2017, using relevant keywords. We conducted a pooled analysis of the association between sarcopenia and the risk of fractures by employing a random-effects model. Subgroup analyses were conducted based on definitions of sarcopenia and gender. In total, nine studies were included in our systematic review and meta-analysis. The prevalence of sarcopenia ranged from 4.3 to 33.1%. The pooled RR of fractures for the sarcopenic versus the nonsarcopenic was 1.34 (95% CI = 1.13-1.58, P = 0.001, I² = 5.5%, P-heterogeneity = 0.391). Subgroup analyses showed that associations between sarcopenia and fractures were significant when using the AWGS definition (combined effect size = 1.78, 95% CI = 1.25-2.54, P = 0.001), and studies in males (combined effect size = 1.39, 95% CI = 1.13-1.71, P = 0.002). In conclusion, we found that compared to nonsarcopenic, the association between sarcopenia and fractures among community-dwelling older people was significant when using the AWGS definition, and only for males. Future studies are needed to establish a possible association between sarcopenia definitions and risk of fractures of different sites.

Physical activity, body mass index and waist circumference change, and normal-range glycated hemoglobin on incident diabetes: Jackson Heart Study

OBJECTIVES

The purpose of this study was to 1) evaluate whether physical activity has a protective effect on incident diabetes among African Americans across combinations of body mass index (BMI) and waist circumference (WC), 2) evaluate the effect of changes on BMI and WC on incident diabetes, and 3) evaluate the effect of 'normal range' glycated hemoglobin (A1C) on incident diabetes.

METHODS

Data from the prospective Jackson Heart Study were evaluated, with baseline data assessed between 2001 and 2004 and follow-up data occurring between 2009 and 2013. Physical activity was assessed via a validated questionnaire, with measured BMI, WC and A1C assessed via standard procedures.

RESULTS

The sample included 2,450 adults who did not have evidence of diabetes at the baseline assessment, with 286 incident diabetes cases occurring at the follow-up assessment. Physical activity did not have a protective effect against incident diabetes across different BMI and WC combinations. Notably, BMI change from baseline to follow-up was associated with incident diabetes (HR = 1.08; 95% CI: 1.03-1.13). Further, higher levels of A1C within the 'normal-range' was associated with incident diabetes (HR = 7.51, 95% CI = 2.66-21.25).

CONCLUSION

Increases in BMI over time and higher A1C within the normal range were associated with incident diabetes. Serial monitoring of BMI, as well as A1C, even among those with a 'normal' A1C, may be warranted by clinicians. Future work evaluating this novel three-way model (physical activity, BMI and WC) should consider utilizing an objective measure of physical activity.

Sex differences in athletic performance emerge coinciding with the onset of male puberty

BACKGROUND

Male performance in athletic events begins to exceed that of age-matched females during early adolescence, but the timing of this divergence relative to the onset of male puberty and the rise in circulating testosterone remains poorly defined.

DESIGN

This study is a secondary quantitative analysis of four published sources which aimed to define the timing of the gender divergence in athletic performance and relating it to the rise in circulating testosterone due to male puberty.

DATA

Four data sources reflecting elite swimming and running and jumping track and field events as well as hand-grip strength in nonathletes were analysed to define the age-specific gender differences through adolescence and their relationship to the rising circulating testosterone during male puberty.

RESULTS

The onset and tempo of gender divergence were very similar for swimming, running and jumping events as well as the hand-grip strength in nonathletes, and all closely paralleled the rise in circulating testosterone in adolescent boys.

CONCLUSIONS

The gender divergence in athletic performance begins at the age of 12-13 years and reaches adult plateau in the late teenage years with the timing and tempo closely parallel to the rise in circulating testosterone in boys during puberty.