scholarly journals Relationship of Anabolic Hormones With Motor Unit Characteristics in Quadriceps Muscle in Healthy and Frail Aging Men

2020 ◽  
Vol 105 (7) ◽  
pp. e2358-e2368 ◽  
Author(s):  
Agnieszka Swiecicka ◽  
Mathew Piasecki ◽  
Daniel Stashuk ◽  
David Jones ◽  
Frederick Wu ◽  
...  
Keyword(s):  
Motor Unit ◽  
Compound Muscle Action Potential ◽  
Free Testosterone ◽  
Quadriceps Muscle ◽  
Community Dwelling ◽  
Total Testosterone ◽  
Motor Unit Potential ◽  
Vastus Lateralis Muscle ◽  
Anabolic Hormones ◽  
Aging Men

Abstract Context Anabolic hormones are important factors in maintaining muscle mass for aging men, but their role in overall motor unit structure and function is unclear. Objective The objective of this work is to determine associations of anabolic and reproductive hormone levels with motor unit characteristics in quadriceps muscle in older healthy and frail men. Design This work is an observational cohort study of community-dwelling men. Participants Participants included healthy and frail men younger than 65 years. Intervention No intervention was performed. Outcome measure Quantitative assessments of electromyography-derived motor unit potential size (MUP) and compound muscle action potential size (CMAP) of the vastus lateralis muscle. Results We studied 98 men (mean ± SD: age 73 ± 6 years; body mass index [BMI] 25.7 ± 4.0 kg/m2; diabetes 11%) of whom 45% were prefrail and 18% frail. After adjusting for age, BMI, and prevalent diabetes, higher total and free testosterone levels were significantly related to larger CMAP (total testosterone: β [95% CI]: 0.3 [0.08-0.53]; free testosterone: 0.34 [0.13-0.56]). Exploratory analysis showed the relationship between free testosterone and CMAP was stronger in frail rather than robust men. In univariate analyses, estradiol was associated with CMAP size (0.37 [0.16-0.57]); and vitamin D was associated with MUP size (0.22 [0.01-0.43]) but these relationships were no longer significant after adjusting for potential confounders. Conclusion Our data highlight the associations between androgen levels and the electrophysiological characteristics of older men, particularly in the frail. Clinical trials involving administration of androgens will help to elucidate the potential benefits of intervention on neuromuscular function and/or frailty status.

scholarly journals Exercise training improves free testosterone in lifelong sedentary aging men

2017 ◽  
Vol 6 (5) ◽  
pp. 306-310 ◽  
Author(s):  
Lawrence D Hayes ◽  
Peter Herbert ◽  
Nicholas F Sculthorpe ◽  
Fergal M Grace
Keyword(s):  
Interval Training ◽  
Free Testosterone ◽  
Sex Hormone Binding Globulin ◽  
Total Testosterone ◽  
High Intensity Interval Training ◽  
Baseline Phase ◽  
Aging Men ◽  
High Intensity Interval ◽  
The Impact ◽  
Older Males

As the impact of high-intensity interval training (HIIT) on systemic hormones in aging men is unstudied to date, we investigated whether total testosterone (TT), sex hormone-binding globulin (SHBG), free testosterone (free-T) and cortisol (all in serum) were altered following HIIT in a cohort of 22 lifelong sedentary (62 ± 2 years) older men. As HIIT requires preconditioning exercise in sedentary cohorts, participants were tested at three phases, each separated by six-week training; baseline (phase A), following conditioning exercise (phase B) and post-HIIT (phase C). Each measurement phase used identical methods. TT was significantly increased following HIIT (~17%; P < 0.001) with most increase occurring during preconditioning (~10%; P = 0.007). Free-T was unaffected by conditioning exercise (P = 0.102) but was significantly higher following HIIT compared to baseline (~4.5%; P = 0.023). Cortisol remained unchanged from A to C (P = 0.138). The present data indicate a combination of preconditioning, and HIIT increases TT and SHBG in sedentary older males, with the HIIT stimulus accounting for a small but statistically significant increase in free-T. Further study is required to determine the biological importance of small improvements in free-T in aging men.

scholarly journals Total estradiol, rather than testosterone levels, predicts osteoporosis in aging men

2009 ◽  
Vol 53 (8) ◽  
pp. 1020-1025 ◽  
Author(s):  
Ruth Clapauch ◽  
Tatiana Martins Mattos ◽  
Patrícia Silva ◽  
Lizanka Paola Marinheiro ◽  
Salo Buksman ◽  
...  
Keyword(s):  
Case Control Study ◽  
Free Testosterone ◽  
Sex Hormone ◽  
Sex Hormone Binding Globulin ◽  
Total Testosterone ◽  
Relative Risks ◽  
Aging Men ◽  
Osteoporosis Risk ◽  
Control Study ◽  
Cutoff Levels

OBJECTIVE: To study and establish sex hormone cutoff levels for osteoporosis risk in men over 50 years old. METHODS: Case-control study of 216 men > 50 years, 110 with osteoporosis (O) and 106 with normal bone density (C). We measured estradiol (E2), sex hormone binding globulin (SHBG), total testosterone (TT) and albumin. Free testosterone (FT) and bioavailable testosterone (BT) were calculated through Vermeulen's formula. RESULTS: There was no difference in TT between groups. Relative risks of osteoporosis were 1.89 for E2 < 37 pg/mL (p = 0.02); 1.91 for SHBG > 55 nmol/L (p = 0.019); 2.5 for FT < 7 ng/dL (p = 0.015); 2.7 for BT < 180 ng/dL (p = 0.0003). CONCLUSIONS: In men over 50 years old, TT was not indicative of osteoporosis risk while E2 < 37 ng/mL was. SHBG > 55 nmol/L, FT < 7 ng/dL and BT < 180 ng/dL can represent additional indications for osteoporosis screening in men over 50 years old.

scholarly journals Motor unit changes in children with symptomatic spinal muscular atrophy treated with nusinersen

2020 ◽  
Vol 92 (1) ◽  
pp. 78-85 ◽  
Author(s):  
Didu Kariyawasam ◽  
Arlene D'Silva ◽  
James Howells ◽  
Karen Herbert ◽  
Peter Geelan-Small ◽  
...  
Keyword(s):  
Spinal Muscular Atrophy ◽  
Motor Unit ◽  
Therapeutic Response ◽  
Muscular Atrophy ◽  
Compound Muscle Action Potential ◽  
Motor Unit Potential ◽  
Abductor Pollicis Brevis ◽  
Electrophysiological Response ◽  
Single Motor Unit ◽  
Motor Unit Number Estimation

ObjectivesTo elucidate the motor unit response to intrathecal nusinersen in children with symptomatic spinal muscular atrophy (SMA) using a novel motor unit number estimation technique.MethodsMScanFit MUNE studies were sequentially undertaken from the abductor pollicis brevis muscle after stimulation of the median nerve in a prospective cohort of symptomatic children with SMA, undergoing intrathecal treatment with nusinersen at a single neuromuscular centre from June 2017 to August 2019. Electrophysiological measures included compound muscle action potential (CMAP), motor unit number estimation (MUNE), motor unit number contributing to 50%–100% of CMAP (N50) and measures of collateral reinnervation including largest single motor unit potential (LSMUP) and amplitude of the smallest unit contributing to N50 (A50).ResultsTwenty children (median age 99 months, range 4–193) were followed for a median of 13.8 (4–33.5) months. Therapeutic intervention was an independent and significant contributor to an increase in CMAP (p = 0.005), MUNE (p = 0.001) and N50 (p = 0.04). The magnitude of this electrophysiological response was increased in children with shorter disease durations (p<0.05). Electrophysiological changes delineated children who were functionally stable from those who attained clinically significant gains in motor function.InterpretationNusinersen therapy facilitated functional innervation in SMA through recovery of smaller motor units. Delineation of biomechanisms of therapeutic response may be the first step in identifying potential novel targets for disease modification in this and other motor neuropathies. MScanFit MUNE techniques may have a broader role in establishing biomarkers of therapeutic response in similar adult-onset diseases.

Effects of Seasonal Vitamin D3 Supplementation on Strength, Power, and Body Composition in College Swimmers

2020 ◽  
Vol 30 (2) ◽  
pp. 165-173 ◽  
Author(s):  
Michelle S. Rockwell ◽  
Madlyn I. Frisard ◽  
Janet W. Rankin ◽  
Jennifer S. Zabinsky ◽  
Ryan P. Mcmillan ◽  
...  
Keyword(s):  
Vitamin D ◽  
Body Composition ◽  
Vertical Jump ◽  
Free Testosterone ◽  
Fat Free Mass ◽  
Sex Hormone Binding Globulin ◽  
Total Testosterone ◽  
Hormone Binding ◽  
Anabolic Hormones ◽  
Fall Season

The purpose of this study was to evaluate the impact of fall season vitamin D3 supplementation on strength/power, body composition, and anabolic hormones in swimmers with optimal vitamin D status at summer’s end. Male and female National Collegiate Athletic Association Division I swimmers (N = 19) with optimal 25-hydroxyvitamin D [25(OH)D] randomly received 5,000 IU of vitamin D3 (VITD) or placebo (PLA) daily for 12 weeks while participating in swimming and strength and conditioning training (August–November). Before and after the intervention, the participants underwent blood sampling for analysis of serum 25(OH)D, parathyroid hormone, total testosterone, free testosterone, sex hormone-binding globulin, and insulin-like growth factor 1, dual-energy X-ray absorptiometry, and strength/power testing (bench press, squat, dead lift, standing broad jump, vertical jump, and dips and pull-ups). Sex was used as a covariate for analyses. The 25(OH)D was decreased by 44% in PLA (p < .05) and increased by 8% in VITD over the 12 weeks. Fat-free mass increased in VITD (56.4–59.1 kg; p < .05), but not PLA (59.4–59.7 kg; p < .01). Significant Group × Time interaction effects were observed for dead lift (F = 21.577, p < .01) and vertical jump (F = 11.219, p < .01), but no other strength/power tests. Total testosterone decreased similarly in both groups, but free testosterone decreased and sex hormone-binding globulin increased only in PLA (p < .01). There were no group differences or changes in insulin-like growth factor 1 with the intervention. The findings suggest that vitamin D supplementation is an efficacious strategy to maintain 25(OH)D during the fall season training and to enhance some aspects of strength/power and fat-free mass in swimmers. Further research on the relationship between vitamin D and anabolic hormones is needed.

scholarly journals Lower serum testosterone is independently associated with insulin resistance in non-diabetic older men: the Health In Men Study

2009 ◽  
Vol 161 (4) ◽  
pp. 591-598 ◽  
Author(s):  
Bu B Yeap ◽  
S A Paul Chubb ◽  
Zoë Hyde ◽  
Konrad Jamrozik ◽  
Graeme J Hankey ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Waist Circumference ◽  
Central Obesity ◽  
Free Testosterone ◽  
Older Men ◽  
Community Dwelling ◽  
Sex Hormone ◽  
Mass Action ◽  
Total Testosterone ◽  
Testosterone Levels

ObjectiveInsulin resistance is associated with metabolic syndrome and type 2 diabetes, representing a risk factor for cardiovascular disease. This relationship may be modulated to some extent by age-related changes in sex hormone status. We examined whether lower testosterone or sex hormone-binding globulin (SHBG) levels in older men are associated with insulin resistance independently of measures of central obesity.DesignCross-sectional analysis of 2470 community-dwelling non-diabetic men aged ≥70 years.MethodsAge, body mass index (BMI) and waist circumference were measured. Early morning sera were assayed for total testosterone, SHBG, LH and insulin levels. Free testosterone was calculated using mass action equations, and insulin resistance was assessed using a homeostatic model (HOMA2-IR).ResultsTotal testosterone, free testosterone and SHBG declined progressively across increasing quintiles of HOMA2-IR (all P<0.001) and correlated inversely with log HOMA2-IR (r=−0.27, −0.14 and −0.24 respectively, all P<0.001). After adjusting for age, BMI, waist circumference, high-density lipoprotein and triglyceride levels, total testosterone was independently associated with log HOMA2-IR (β=0.05, P<0.001), while SHBG was not. Serum total testosterone <8 nmol/l was associated with HOMA2-IR in the highest quintile (odds ratio (OR) 1.67, 95% confidence interval (CI) 1.02–2.73) as was total testosterone ≥8 and <15 nmol/l (OR 1.29, 95% CI 1.03–1.63).ConclusionsIn older men, lower total testosterone is associated with insulin resistance independently of measures of central obesity. This association is seen with testosterone levels in the low to normal range. Further studies are needed to evaluate interventions that raise testosterone levels in men with reduced insulin sensitivity.

scholarly journals Lower sex hormone-binding globulin is more strongly associated with metabolic syndrome than lower total testosterone in older men: the Health in Men Study

2008 ◽  
Vol 158 (6) ◽  
pp. 785-792 ◽  
Author(s):  
S A Paul Chubb ◽  
Zoë Hyde ◽  
Osvaldo P Almeida ◽  
Leon Flicker ◽  
Paul E Norman ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Free Testosterone ◽  
Older Men ◽  
Community Dwelling ◽  
Sex Hormone ◽  
Mass Action ◽  
Sex Hormone Binding Globulin ◽  
Total Testosterone ◽  
Hormone Binding ◽  
Cross Sectional

BackgroundReduced circulating testosterone and sex hormone-binding globulin (SHBG) are implicated as risk factors for metabolic syndrome. As SHBG increases with age while testosterone declines, we examined the relative contributions of SHBG and testosterone to the risk of metabolic syndrome in older men.MethodsWe conducted a cross-sectional study of 2502 community-dwelling men aged ≥70 years without known diabetes. Metabolic syndrome was defined using the National Cholesterol Education Program-Third Adult Treatment Panel (NCEP-ATPIII) criteria. Early morning fasting sera were assayed for total testosterone, SHBG and LH. Free testosterone was calculated using mass action equations.ResultsThere were 602 men with metabolic syndrome (24.1%). The risk of metabolic syndrome increased for total testosterone <20 nmol/l, SHBG <50 nmol/l and free testosterone <300 pmol/l. In univariate analyses SHBG was associated with all five components of metabolic syndrome, total testosterone was associated with all except hypertension, and free testosterone was associated only with waist circumference and triglycerides. In multivariate analysis, both total testosterone and especially SHBG remained associated with metabolic syndrome, with odds ratios of 1.34 (95% confidence interval (CI): 1.18–1.52) and 1.77 (95% CI: 1.53–2.06) respectively. Men with hypogonadotrophic hypogonadism (total testosterone <8 nmol/l, LH ≤12 IU/l) had the highest prevalence of metabolic syndrome (53%,P<0.001).ConclusionsLower SHBG is more strongly associated with metabolic syndrome than lower total testosterone in community-dwelling older men. SHBG may be the primary driver of these relationships, possibly reflecting its relationship with insulin sensitivity. Further studies should examine whether measures that raise SHBG protect against the development of metabolic syndrome in older men.

scholarly journals Safety, Tolerability, and Effect of Nusinersen Treatment in Ambulatory Adults With 5q-SMA

2021 ◽  
Vol 12 ◽  
Author(s):  
Bakri Elsheikh ◽  
Steven Severyn ◽  
Songzhu Zhao ◽  
David Kline ◽  
Matthew Linsenmayer ◽  
...  
Keyword(s):  
Adverse Events ◽  
Motor Unit ◽  
Rating Scale ◽  
Muscular Atrophy ◽  
Compound Muscle Action Potential ◽  
Motor Unit Potential ◽  
Serious Adverse Events ◽  
Significant Treatment ◽  
Single Motor Unit ◽  
Isometric Muscle Contraction

Objective: To determine the safety and tolerability of nusinersen treatment in ambulatory adults with spinal muscular atrophy (SMA) and investigate the treatment effect on muscle strength, physical function, and motor unit physiology.Methods: Individuals aged 18 years or older with genetically confirmed 5q SMA, three or more copies of the SMN2 gene, and the ability to ambulate 30 feet were enrolled. Safety outcomes included the number of adverse events and serious adverse events, clinically significant vital sign or laboratory parameter abnormalities. Outcome assessments occurred at baseline (prior to the first dose of nusinersen) and then 2, 6, 10, and 14 months post-treatment.Results: Six women, seven men (mean age: 37 ± 11, range: 18–59 years) were included for analyses. The most common side effects were headache and back pain, but overall procedures and treatments were well-tolerated. No serious adverse events were reported. Maximal Voluntary Isometric Muscle Contraction Testing (MVICT) and 6-min walk test (6MWT) both showed overall stability with significant increases at 2, 6, and 10 months for the 6MWT. More consistent significant treatment effects were noted on the Hammersmith Functional Motor Scale Expanded, SMA-Functional Rating Scale, and forced vital capacity. Treatment resulted in progressively increased ulnar compound muscle action potential and average single motor unit potential amplitudes, but motor unit number estimation remained stable.Conclusions: Nusinersen treatment is safe and well-tolerated in ambulatory adults with SMA. Treatment resulted in improved motor function and electrophysiological findings suggest that this improvement may be occurring via improved motor unit reinnervation capacity.

scholarly journals Safety, Tolerability, and Effect of Nusinersen in Non-ambulatory Adults With Spinal Muscular Atrophy

2021 ◽  
Vol 12 ◽  
Author(s):  
Bakri Elsheikh ◽  
Steven Severyn ◽  
Songzhu Zhao ◽  
David Kline ◽  
Matthew Linsenmayer ◽  
...  
Keyword(s):  
Adverse Events ◽  
Spinal Muscular Atrophy ◽  
Motor Unit ◽  
Muscular Atrophy ◽  
Compound Muscle Action Potential ◽  
Motor Unit Potential ◽  
Single Motor Unit ◽  
Single Motor ◽  
Clinically Significant ◽  
Tract Infections

Objective: Investigation of the safety, tolerability, and treatment effect of nusinersen treatment in non-ambulatory adults with spinal muscular atrophy (SMA).Methods: Non-ambulatory individuals, aged 18 years or older with genetically confirmed 5q SMA were enrolled. In participants with spinal fusion, fluoroscopy guided cervical C1–C2 lateral approach was used. Outcomes at 2, 6, 10, and 14 months post-treatment were compared with baseline assessment. Forced vital capacity (FVC) was the primary outcome, and RULM, HFMSE, the modified SMA-FRS, and ulnar nerve electrophysiology [compound muscle action potential (CMAP), single motor unit size, and motor unit number] were secondary. Adverse and serious adverse events and clinically significant vital sign or lab abnormalities were recorded.Results: Results from 12 women and 7 men (mean age: 39.7 ± 13.9, range: 21–64 years) were analyzed. No clinically significant changes of vital signs or laboratory parameters were observed. Five participants were hospitalized for pneumonia. Other adverse events included headache, back pain, cervical injection site pain, and upper respiratory and urinary tract infections. High baseline protein/creatinine ratio without significant change on treatment noted in 4 participants. FVC was feasible in all participants. HFMSE and RULM were not feasible in the majority of participants. FVC and functional outcomes were stable without improvement. CMAP and single motor unit potential sizes showed enlargement while motor unit numbers were stable.Conclusions: Nusinersen, including C1/C2 delivery, was safe overall and well-tolerated. Several outcome measures were limited by floor effect. Overall, treatment resulted in stability of motor outcomes, but motor unit and CMAP size were increased.

scholarly journals The Relationship between Selected Bioelements and Depressiveness Associated with Testosterone Deficiency Syndrome in Aging Men

Medicina ◽  
2020 ◽  
Vol 56 (3) ◽  
pp. 125
Author(s):  
Iwona Rotter ◽  
Adrian Wiatrak ◽  
Aleksandra Rył ◽  
Katarzyna Kotfis ◽  
Żaneta Ciosek ◽  
...  
Keyword(s):  
Depressive Symptoms ◽  
Emotional Disorders ◽  
Free Testosterone ◽  
Dehydroepiandrosterone Sulfate ◽  
Deficiency Syndrome ◽  
Total Testosterone ◽  
Testosterone Deficiency ◽  
Aging Men ◽  
Testosterone Deficiency Syndrome ◽  
The Relationship

Background and Objectives: Abnormal concentrations of bioelements (magnesium, manganese, chromium, copper, zinc) have been associated with physical and emotional dysfunctions, including depression. This association, however, has not been analyzed in testosterone deficiency syndrome (TDS) or patients with depressiveness, i.e., when individual symptoms do not form the picture of a full-syndrome depressive disorder. This study aimed to assess the relationship between concentrations of selected bioelements and the incidence of depressive symptoms in men aged 50 years and older with a concurrent testosterone deficiency syndrome. Material and Methods: Blood samples were taken from 314 men; the mean age of the population was 61.36 ± 6.38 years. Spectrophotometric method for biochemical analysis of magnesium (Mg), manganese (Mn), chromium (Cr), copper (Cu), and zinc (Zn) was used. The diagnosis of testosterone deficiency syndrome (TDS) was based on the total testosterone (TT), free testosterone (FT), estradiol (E2), and dehydroepiandrosterone sulfate (DHEAS) levels by ELISA. Each participant completed the Androgen Deficiency in Aging Male (ADAM) questionnaire, as well as the Beck Depression Inventory (BDI-Ia) measuring the severity of depressive symptoms. Results: Emotional disturbances manifested as depressive symptoms were diagnosed in 28.7% of all participants and testosterone deficiency syndrome in 49.3%. In the TDS group, the analysis showed a significant correlation between the level of manganese (R = 0.225, p = 0.005) and chromium (R = 0.185, p = 0.021) with the incidence of depression. Conclusions: The results of our study demonstrated a relationship between manganese and chromium concentrations with the incidence of depression in men aged 50 years and older with a concurrent testosterone deficiency syndrome. This may indicate that there is a correlation between these bioelements, as well as emotional disorders manifested as depressive symptoms in aging men with a diagnosed testosterone deficiency.

scholarly journals Associations between physical activity and the androgenic/estrogenic status of men

2010 ◽  
pp. 757-763
Author(s):  
M Slowinska-Lisowska ◽  
P Jozkow ◽  
M Medras
Keyword(s):  
Physical Activity ◽  
Free Testosterone ◽  
Total Testosterone ◽  
Physical Effort ◽  
Physically Active ◽  
Low Level ◽  
Age Related ◽  
Aging Men ◽  
Caucasian Men ◽  
Serum Androgens

Concentrations of numerous hormones decrease with age. Some authors imply that a syndrome of partial endocrine deficiency may occur in the aging men. Among many lifestyle factors that influence hormonal status is physical activity. Especially interesting are relations between physical activity and the androgenic/estrogenic status of men. The aim of this study was to evaluate age-related changes of serum androgens, estradiol and SHBG in men presenting different levels of physical activity. Hormonal parameters were measured in a cohort of 387 healthy Caucasian men (aged from 24 to 72 years) from one administrative region of Poland. Their level of physical activity was determined by means of the International Physical Activity Questionnaire (IPAQ). We have found that contrary to SHBG concentration, total testosterone, free testosterone, bioavailable testosterone, calculated free testosterone and estradiol were negatively associated with age in the investigated subjects. Apart from estradiol, physical activity did not influence concentrations of the studied parameters. In younger (24-48 years), physically active males estradiol was significantly higher than in subjects characterized by a low level of physical activity. The situation was opposite in older males (48-72 years). In this age group low level of physical activity was associated with lower concentration of estradiol. Undertaking physical effort increased the decline of estradiol level with age.

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