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1.
Ann Intern Med ; 177(6): 768-781, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38739921

RESUMO

BACKGROUND: Whether circulating sex hormones modulate mortality and cardiovascular disease (CVD) risk in aging men is controversial. PURPOSE: To clarify associations of sex hormones with these outcomes. DATA SOURCES: Systematic literature review to July 2019, with bridge searches to March 2024. STUDY SELECTION: Prospective cohort studies of community-dwelling men with sex steroids measured using mass spectrometry and at least 5 years of follow-up. DATA EXTRACTION: Independent variables were testosterone, sex hormone-binding globulin (SHBG), luteinizing hormone (LH), dihydrotestosterone (DHT), and estradiol concentrations. Primary outcomes were all-cause mortality, CVD death, and incident CVD events. Covariates included age, body mass index, marital status, alcohol consumption, smoking, physical activity, hypertension, diabetes, creatinine concentration, ratio of total to high-density lipoprotein cholesterol, and lipid medication use. DATA SYNTHESIS: Nine studies provided individual participant data (IPD) (255 830 participant-years). Eleven studies provided summary estimates (n = 24 109). Two-stage random-effects IPD meta-analyses found that men with baseline testosterone concentrations below 7.4 nmol/L (<213 ng/dL), LH concentrations above 10 IU/L, or estradiol concentrations below 5.1 pmol/L had higher all-cause mortality, and those with testosterone concentrations below 5.3 nmol/L (<153 ng/dL) had higher CVD mortality risk. Lower SHBG concentration was associated with lower all-cause mortality (median for quintile 1 [Q1] vs. Q5, 20.6 vs. 68.3 nmol/L; adjusted hazard ratio [HR], 0.85 [95% CI, 0.77 to 0.95]) and lower CVD mortality (adjusted HR, 0.81 [CI, 0.65 to 1.00]). Men with lower baseline DHT concentrations had higher risk for all-cause mortality (median for Q1 vs. Q5, 0.69 vs. 2.45 nmol/L; adjusted HR, 1.19 [CI, 1.08 to 1.30]) and CVD mortality (adjusted HR, 1.29 [CI, 1.03 to 1.61]), and risk also increased with DHT concentrations above 2.45 nmol/L. Men with DHT concentrations below 0.59 nmol/L had increased risk for incident CVD events. LIMITATIONS: Observational study design, heterogeneity among studies, and imputation of missing data. CONCLUSION: Men with low testosterone, high LH, or very low estradiol concentrations had increased all-cause mortality. SHBG concentration was positively associated and DHT concentration was nonlinearly associated with all-cause and CVD mortality. PRIMARY FUNDING SOURCE: Medical Research Future Fund, Government of Western Australia, and Lawley Pharmaceuticals. (PROSPERO: CRD42019139668).


Assuntos
Doenças Cardiovasculares , Causas de Morte , Di-Hidrotestosterona , Estradiol , Hormônio Luteinizante , Globulina de Ligação a Hormônio Sexual , Testosterona , Humanos , Masculino , Doenças Cardiovasculares/mortalidade , Doenças Cardiovasculares/sangue , Testosterona/sangue , Globulina de Ligação a Hormônio Sexual/análise , Globulina de Ligação a Hormônio Sexual/metabolismo , Estradiol/sangue , Hormônio Luteinizante/sangue , Di-Hidrotestosterona/sangue , Incidência , Fatores de Risco , Idoso , Pessoa de Meia-Idade
2.
Physiol Rev ; 97(1): 135-187, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27807202

RESUMO

Estrogens and androgens influence the growth and maintenance of the mammalian skeleton and are responsible for its sexual dimorphism. Estrogen deficiency at menopause or loss of both estrogens and androgens in elderly men contribute to the development of osteoporosis, one of the most common and impactful metabolic diseases of old age. In the last 20 years, basic and clinical research advances, genetic insights from humans and rodents, and newer imaging technologies have changed considerably the landscape of our understanding of bone biology as well as the relationship between sex steroids and the physiology and pathophysiology of bone metabolism. Together with the appreciation of the side effects of estrogen-related therapies on breast cancer and cardiovascular diseases, these advances have also drastically altered the treatment of osteoporosis. In this article, we provide a comprehensive review of the molecular and cellular mechanisms of action of estrogens and androgens on bone, their influences on skeletal homeostasis during growth and adulthood, the pathogenetic mechanisms of the adverse effects of their deficiency on the female and male skeleton, as well as the role of natural and synthetic estrogenic or androgenic compounds in the pharmacotherapy of osteoporosis. We highlight latest advances on the crosstalk between hormonal and mechanical signals, the relevance of the antioxidant properties of estrogens and androgens, the difference of their cellular targets in different bone envelopes, the role of estrogen deficiency in male osteoporosis, and the contribution of estrogen or androgen deficiency to the monomorphic effects of aging on skeletal involution.


Assuntos
Androgênios/metabolismo , Osso e Ossos/metabolismo , Osso e Ossos/fisiopatologia , Estrogênios/metabolismo , Osteoporose/fisiopatologia , Animais , Feminino , Homeostase/fisiologia , Humanos , Masculino , Osteoporose/metabolismo
3.
Am J Kidney Dis ; 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38796137

RESUMO

RATIONALE & OBJECTIVE: Kidneys are vital for vitamin D metabolism, and disruptions in both production and catabolism occur in chronic kidney disease. Although vitamin D activation occurs in numerous tissues, the kidneys are the most relevant source of circulating active vitamin D. This study investigates extrarenal vitamin D activation and the impact of kidney transplantation on vitamin D metabolism in patients who are anephric. STUDY DESIGN: Case series. SETTING & PARTICIPANTS: Adult patients with previous bilateral nephrectomy (anephric) not receiving active vitamin D therapy evaluated at the time of (N=38) and 1 year after (n=25) kidney transplantation. ANALYTICAL APPROACH: Chromatography with tandem mass spectrometry was used to measure vitamin D metabolites. Activity of CYP24A1 [24,25(OH)2D/25(OH)D] and CYP27B1 [1α,25(OH)2D/25(OH)D] is expressed as metabolic ratios. Differences between time points were evaluated by paired t-test or Wilcoxon matched-pairs signed-rank test. RESULTS: At time of transplantation, 1α,25(OH)2D was detectable in all patients (4-36pg/mL). There was a linear relationship between 25(OH)D and 1α,25(OH)2D levels (r=0.58, P<0.001), with 25(OH)D explaining 34% of the variation in 1α,25(OH)2D levels. There were no associations between 1α,25(OH)2D and biointact parathyroid hormone (PTH) or fibroblast growth factor 23 (FGF-23). One year after transplantation, 1α,25(OH)2D levels recovered (+205%), and CYP27B1 activity increased (+352%). Measures of vitamin D catabolism, 24,25(OH)2D and CYP24A1 activity increased 3- to 5-fold. Also, at 12 months after transplantation, 1α,25(OH)2D was positively correlated with PTH (ρ=0.603, P=0.04) but not with levels of 25(OH)D or FGF-23. LIMITATIONS: Retrospective, observational study design with a small cohort size. CONCLUSIONS: Low-normal levels of 1α,25(OH)2D was demonstrated in anephric patients, indicating production outside the kidneys. This extrarenal CYP27B1 activity may be more substrate driven than hormonally regulated. Kidney transplantation seems to restore kidney CYP27B1 and CYP24A1 activity, as evaluated by vitamin D metabolic ratios, resulting in both increased vitamin D production and catabolism. These findings may have implications for vitamin D supplementation strategies in the setting of kidney failure and transplantation. PLAIN-LANGUAGE SUMMARY: Vitamin D activation occurs in multiple tissues, but the kidneys are considered the only relevant source of circulating levels. This study investigates vitamin D activation outside the kidneys by measuring vitamin D metabolites in 38 patients without kidneys. Active vitamin D was detectable in all patients, indicating production outside of the kidneys. There was a strong relationship between active and precursor vitamin D levels, but no association with mineral metabolism hormones, indicating that vitamin D production was more substrate dependent than hormonally regulated. One year after kidney transplantation, active vitamin D levels increased 2-fold and breakdown products increased 3-fold, indicating that production and degradation of the hormone recovers after kidney transplantation. These findings are relevant for future research into vitamin D supplementation in kidney failure.

4.
Artigo em Inglês | MEDLINE | ID: mdl-38829475

RESUMO

Empirical evidence for a low normal or reference interval for serum prolactin (PRL) is lacking for men, while the implications of very low PRL levels for human health have never been studied. A clinical state of "PRL deficiency" has not been defined except in relation to lactation. Using data from the European Male Ageing Study (EMAS), we analyzed the distribution of PRL in 3,369 community-dwelling European men, aged 40-80 years at phase-1 and free from acute illnesses. In total, 2,948 and 2,644 PRL samples were collected during phase-1 and phase-2 (3 to 5.7 years later). All samples were analysed in the same centre with the same assay. After excluding individuals with known pituitary diseases, PRL ≥ 35 ng/ml, and PRL-altering drugs including antipsychotic agents, selective serotonin reuptake inhibitors, or dopamine agonists, 5,086 data points (2,845 in phase-1 and 2,241 in phase-2) were available for analysis. The results showed that PRL declined minimally with age (slope = -0.02) and did not correlate with BMI. The positively skewed PRL distribution was log-transformed to a symmetrical distribution (skewness reduced from 13.3 to 0.015). Using two-sigma empirical rule (2[]SD about the mean), a threshold at 2.5% of the lower end of the distribution was shown to correspond to a PRL value of 2.98ng/ml. With reference to individuals with PRL levels of 5-34.9 ng/ml (event rate = 6.3%), the adjusted risk of developing type 2 diabetes increased progressively in those with PRL levels of 3-4.9 ng/ml: event rate = 9.3%, OR (95% CI) 1.59 (0.93-2.71), and more so with PRL levels of 0.3-2.9 ng/ml: event rate = 22.7%, OR 5.45 (1.78-16.62). There was also an increasing trend in prediabetes and diabetes based on fasting blood glucose levels was observed with lower categories of PRL. However, PRL levels were not associated with cancer, cardiovascular diseases, depressive symptoms or mortality. Our findings suggest that a PRL level below 3 ng/ml (64 mlU/l) significantly identifies European men with a clinically-important outcome (of type 2 diabetes), offering a lower reference-value for research and clinical practice.

5.
Br J Dermatol ; 2024 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-38913652

RESUMO

BACKGROUND: Observational studies in cutaneous melanoma have indicated an inverse relationship between levels of 25-hydroxy vitamin D and Breslow thickness, as well as a protective effect of high 25- hydroxy vitamin D levels on clinical outcome. OBJECTIVES: To evaluate whether high dose vitamin D supplementation in curatively resected cutaneous melanoma reduces melanoma relapse. METHODS: In a prospective, randomized, double-blind, placebo-controlled trial, 436 patients with resected cutaneous melanoma stage IA to III (8th American Joint Committee on Cancer staging) were randomized. Among them, 218 received a placebo while 218 received monthly 100,000 IU cholecalciferol for a minimum of 6 months and a maximum of 42 months (treatment arm). Following randomization, patients were followed for a median of 52 months, with a maximum follow-up of 116 months. The primary endpoint was relapse-free survival. Secondary endpoints were melanoma-related mortality, overall survival, and the evolution of 25-hydroxy vitamin D serum levels over time. RESULTS: In our population (mean age 55 years, 54% female) Vitamin D supplementation increased 25- hydroxy vitamin D serum levels after 6 months of supplementation in the treatment arm by a median 17 ng/ml (95%CI: 9; 26) compared to 0 ng/ml (95%CI: -6; 8) in the placebo arm (P < 0.001; Wilcoxon test) and remained at a steady state during the whole treatment period. The estimated event rate for relapse-free survival at 72 months after inclusion was 26.51% in the vitamin D supplemented arm (95% CI: 19.37; 35.64) versus 20.70% (95%CI: 14.26; 29.52) in the placebo arm, [hazard ratio 1.27 (95%CI 0.79; 2.03), P = 0.32]. After adjusting for confounding factors (including baseline stage, body mass index, age, gender, and baseline season), the hazard ratio was 1.20 (95% CI 0.74; 1.94, P = 0.46). Deaths from progression of cutaneous melanoma and non-melanoma related deaths were similar in both vitamin D supplemented and placebo group (n = 10 and 11 and n = 3 and 2, respectively). No major adverse events were observed during the study. CONCLUSION: In cutaneous melanoma patients, monthly high dose vitamin D supplementation was safe, resulted in a sustained increase in 25-hydroxy vitamin D levels during the treatment period, but did not improve relapse-free survival, melanoma-related death or overall survival.

6.
Aging Male ; 27(1): 2346322, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38676285

RESUMO

Insulin-like peptide 3 (INSL3) is a circulating biomarker for Leydig cell functional capacity in men, also indicating Leydig Cell Insufficiency (LCI) and potential primary hypogonadism. Using results from large cohort studies we explore sources of biological and technical variance, and establish a reference range for adult men. It is constitutively secreted with little within-individual variation and reflects testicular capacity to produce testosterone. The main INSL3 assays available indicate good concordance with low technical variance; there is no effect of ethnicity. INSL3 declines with age from 35 years at about 15% per decade. Like low calculated free testosterone, and to a lesser extent low total testosterone, reduced INSL3 is significantly associated with increasing age-related morbidity, including lower overall sexual function, reflecting LCI. Consequently, low INSL3 (≤0.4 ng/ml; ca. <2 SD from the population mean) might serve as an additional biochemical marker in the assessment of functional hypogonadism (late-onset hypogonadism, LOH) where testosterone is in the borderline low range. Excluding individuals with low LCI (INSL3 ≤ 0.4 ng/ml) leads to an age-independent (> 35 years) reference range (serum) for INSL3 in the eugonadal population of 0.4 - 2.3 ng/ml, with low INSL3 prospectively identifying individuals at risk of increased future morbidity.


Assuntos
Biomarcadores , Hipogonadismo , Células Intersticiais do Testículo , Proteínas , Testosterona , Humanos , Masculino , Hipogonadismo/sangue , Pessoa de Meia-Idade , Valores de Referência , Proteínas/análise , Testosterona/sangue , Biomarcadores/sangue , Idoso , Adulto , Insulinas/sangue , Insulina/sangue
7.
Ann Intern Med ; 176(9): 1221-1234, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37639720

RESUMO

BACKGROUND: Various factors modulate circulating testosterone in men, affecting interpretation of testosterone measurements. PURPOSE: To clarify factors associated with variations in sex hormone concentrations. DATA SOURCES: Systematic literature searches (to July 2019). STUDY SELECTION: Prospective cohort studies of community-dwelling men with total testosterone measured using mass spectrometry. DATA EXTRACTION: Individual participant data (IPD) (9 studies; n = 21 074) and aggregate data (2 studies; n = 4075). Sociodemographic, lifestyle, and health factors and concentrations of total testosterone, sex hormone-binding globulin (SHBG), luteinizing hormone (LH), dihydrotestosterone, and estradiol were extracted. DATA SYNTHESIS: Two-stage random-effects IPD meta-analyses found a nonlinear association of testosterone with age, with negligible change among men aged 17 to 70 years (change per SD increase about the midpoint, -0.27 nmol/L [-7.8 ng/dL] [CI, -0.71 to 0.18 nmol/L {-20.5 to 5.2 ng/dL}]) and decreasing testosterone levels with age for men older than 70 years (-1.55 nmol/L [-44.7 ng/dL] [CI, -2.05 to -1.06 nmol/L {-59.1 to -30.6 ng/dL}]). Testosterone was inversely associated with body mass index (BMI) (change per SD increase, -2.42 nmol/L [-69.7 ng/dL] [CI, -2.70 to -2.13 nmol/L {-77.8 to -61.4 ng/dL}]). Testosterone concentrations were lower for men who were married (mean difference, -0.57 nmol/L [-16.4 ng/dL] [CI, -0.89 to -0.26 nmol/L {-25.6 to -7.5 ng/dL}]); undertook at most 75 minutes of vigorous physical activity per week (-0.51 nmol/L [-14.7 ng/dL] [CI, -0.90 to -0.13 nmol/L {-25.9 to -3.7 ng/dL}]); were former smokers (-0.34 nmol/L [-9.8 ng/dL] [CI, -0.55 to -0.12 nmol/L {-15.9 to -3.5 ng/dL}]); or had hypertension (-0.53 nmol/L [-15.3 ng/dL] [CI, -0.82 to -0.24 nmol/L {-23.6 to -6.9 ng/dL}]), cardiovascular disease (-0.35 nmol/L [-10.1 ng/dL] [CI, -0.55 to -0.15 nmol/L {-15.9 to -4.3 ng/dL}]), cancer (-1.39 nmol/L [-40.1 ng/dL] [CI, -1.79 to -0.99 nmol/L {-51.6 to -28.5 ng/dL}]), or diabetes (-1.43 nmol/L [-41.2 ng/dL] [CI, -1.65 to -1.22 nmol/L {-47.6 to -35.2 ng/dL}]). Sex hormone-binding globulin was directly associated with age and inversely associated with BMI. Luteinizing hormone was directly associated with age in men older than 70 years. LIMITATION: Cross-sectional analysis, heterogeneity between studies and in timing of blood sampling, and imputation for missing data. CONCLUSION: Multiple factors are associated with variation in male testosterone, SHBG, and LH concentrations. Reduced testosterone and increased LH concentrations may indicate impaired testicular function after age 70 years. Interpretation of individual testosterone measurements should account particularly for age older than 70 years, obesity, diabetes, and cancer. PRIMARY FUNDING SOURCE: Medical Research Future Fund, Government of Western Australia, and Lawley Pharmaceuticals. (PROSPERO: CRD42019139668).


Assuntos
Hormônios Esteroides Gonadais , Globulina de Ligação a Hormônio Sexual , Humanos , Masculino , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Estudos Transversais , Estudos Prospectivos , Testosterona , Hormônio Luteinizante
8.
Ann Rheum Dis ; 82(8): 1049-1058, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37137672

RESUMO

OBJECTIVES: The phase 2 MANTA and MANTA-RAy studies aimed to determine if the oral Janus kinase 1 preferential inhibitor filgotinib affects semen parameters and sex hormones in men with inflammatory diseases. METHODS: MANTA (NCT03201445) and MANTA-RAy (NCT03926195) included men (21-65 years) with active inflammatory bowel disease (IBD) and rheumatic diseases (rheumatoid arthritis, spondyloarthritis or psoriatic arthritis), respectively. Eligible participants had semen parameters in the normal range per the WHO definition. In each study, participants were randomised 1:1 to receive once-daily, double-blind filgotinib 200 mg or placebo for 13 weeks for pooled analysis of the primary endpoint (proportion of participants with a ≥50% decrease from baseline in sperm concentration at week 13). Participants who met the primary endpoint were monitored over an additional 52 weeks for 'reversibility'. Secondary endpoints included change from baseline to week 13 in: sperm concentration, total motility, normal morphology, total count and ejaculate volume. Sex hormones (luteinising hormone, follicle stimulating hormone, inhibin B and total testosterone) and reversibility were exploratory endpoints. RESULTS: Across both studies, 631 patients were screened, and 248 were randomised to filgotinib 200 mg or placebo. Baseline demographics and characteristics were similar within indications between treatment groups. Numerically similar proportions of filgotinib-treated versus placebo-treated patients met the primary endpoint (8/120 (6.7%) vs 10/120 (8.3%)), Δ-1.7% (95% CI -9.3% to 5.8%)). There were no clinically relevant changes from baseline to week 13 in semen parameters or sex hormones, or patterns of reversibility between treatment groups. Filgotinib was well tolerated, with no new safety events. CONCLUSIONS: Results suggest that once daily filgotinib 200 mg for 13 weeks has no measurable impact on semen parameters or sex hormones in men with active IBD or inflammatory rheumatic diseases.


Assuntos
Artrite Reumatoide , Doenças Inflamatórias Intestinais , Inibidores de Janus Quinases , Humanos , Masculino , Sêmen , Artrite Reumatoide/tratamento farmacológico , Inibidores de Janus Quinases/uso terapêutico , Hormônios Esteroides Gonadais/uso terapêutico , Doenças Inflamatórias Intestinais/tratamento farmacológico , Doenças Inflamatórias Intestinais/induzido quimicamente , Método Duplo-Cego , Resultado do Tratamento
9.
Clin Endocrinol (Oxf) ; 99(6): 559-565, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37718889

RESUMO

DESIGN: The androgen receptor (AR) mediates peripheral effects of testosterone. Previous data suggests an association between the number of CAG repeats in exon-1 of the AR gene and AR transcriptional activity. The aim of this analysis was to determine the association between the number of AR CAG repeats and all-cause mortality in men and the influence of testosterone level on the association. PATIENTS AND MEASUREMENTS: Follow-up data to 27 January 2018 were available for men aged 40-79 years recruited across six countries of the European Male Aging Study between 2003 and 2005. Cox proportional hazards modelling was used to determine the association between CAG repeat number/mortality. Results were expressed as hazard ratios (HR)/95% confidence intervals (CI). RESULTS: One thousand nine hundred and seventy-seven men were followed up. Mean baseline age was 60 ± 11.1 years. Mean duration of follow-up was 12.2 years. At follow up 25.1% of men had died. CAG repeat length ranged from 6 to 39, with the highest proportion of CAG repeat number at 21 repeats (16.4%). In a multivariable model, compared to men with 22-23 AR CAG repeats: for men with <22 and >23 AR CAG HR, 95% CI for mortality were, <22 CAG repeats 1.17 (0.93-1.49) and >23 CAG repeats 1.14 (0.88-1.47). In a post-hoc analysis, the association was significant for men in the lowest tertile of baseline testosterone (<14.2 nmol/L) with >23 CAG repeats: in the adjusted model for <22 and >23 CAG repeats, respectively, 1.49 (0.97-2.27) and 1.68 (1.06-2.67) versus 22-23 repeats. CONCLUSIONS: Our European-wide cohort data overall found no association of androgen receptor CAG repeat number and mortality in men. However, post hoc analysis suggested that an association might be present in men with lower baseline testosterone concentrations, which merits further investigation.


Assuntos
Receptores Androgênicos , Repetições de Trinucleotídeos , Humanos , Pessoa de Meia-Idade , Masculino , Idoso , Receptores Androgênicos/genética , Repetições de Trinucleotídeos/genética , Envelhecimento , Testosterona
10.
EMBO Rep ; 22(12): e52764, 2021 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-34661369

RESUMO

Whereas dimerization of the DNA-binding domain of the androgen receptor (AR) plays an evident role in recognizing bipartite response elements, the contribution of the dimerization of the ligand-binding domain (LBD) to the correct functioning of the AR remains unclear. Here, we describe a mouse model with disrupted dimerization of the AR LBD (ARLmon/Y ). The disruptive effect of the mutation is demonstrated by the feminized phenotype, absence of male accessory sex glands, and strongly affected spermatogenesis, despite high circulating levels of testosterone. Testosterone replacement studies in orchidectomized mice demonstrate that androgen-regulated transcriptomes in ARLmon/Y mice are completely lost. The mutated AR still translocates to the nucleus and binds chromatin, but does not bind to specific AR binding sites. In vitro studies reveal that the mutation in the LBD dimer interface also affects other AR functions such as DNA binding, ligand binding, and co-regulator binding. In conclusion, LBD dimerization is crucial for the development of AR-dependent tissues through its role in transcriptional regulation in vivo. Our findings identify AR LBD dimerization as a possible target for AR inhibition.


Assuntos
Receptores Androgênicos , Animais , Sítios de Ligação/genética , Dimerização , Ligantes , Masculino , Camundongos , Receptores Androgênicos/química , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Ativação Transcricional
11.
Clin Chem Lab Med ; 61(1): 78-85, 2023 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-36279170

RESUMO

OBJECTIVES: Vitamin D-binding protein (VDBP), a serum transport protein for 25-hydroxyvitamin D [25(OH)D], has three common proteoforms which have co-localized amino acid variations and glycosylation. A monoclonal immunoassay was found to differentially detect VDBP proteoforms and methods using liquid chromatography-tandem mass spectrometry (LC-MS/MS) might be able to overcome this limitation. Previously developed multiple reaction monitoring LC-MS/MS methods for total VDBP quantification represent an opportunity to probe the potential effects of proteoforms on proteolysis, instrument response and quantification accuracy. METHODS: VDBP was purified from homozygous human donors and quantified using proteolysis or acid hydrolysis and LC-MS/MS. An interlaboratory comparison was performed using pooled human plasma [Standard Reference Material® 1950 (SRM 1950) Metabolites in Frozen Human Plasma] and analyses with different LC-MS/MS methods in two laboratories. RESULTS: Several shared peptides from purified proteoforms were found to give reproducible concentrations [≤2.7% coefficient of variation (CV)] and linear instrument responses (R2≥0.9971) when added to human serum. Total VDBP concentrations from proteolysis or amino acid analysis (AAA) of purified proteoforms had ≤1.92% CV. SRM 1950, containing multiple proteoforms, quantified in two laboratories resulted in total VDBP concentrations with 7.05% CV. CONCLUSIONS: VDBP proteoforms were not found to cause bias during quantification by LC-MS/MS, thus demonstrating that a family of proteins can be accurately quantified using shared peptides. A reference value was assigned for total VDBP in SRM 1950, which may be used to standardize methods and improve the accuracy of VDBP quantification in research and clinical samples.


Assuntos
Espectrometria de Massas em Tandem , Proteína de Ligação a Vitamina D , Humanos , Cromatografia Líquida/métodos , Espectrometria de Massas em Tandem/métodos , Proteólise , Vitamina D , Proteínas Sanguíneas/metabolismo , Aminoácidos/metabolismo
12.
J Musculoskelet Neuronal Interact ; 23(2): 236-262, 2023 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-37259664

RESUMO

Axial loading in rodents provides a controlled setting for mechanical loading, because load and subsequent strain, frequency, number of cycles and rest insertion between cycles, are precisely defined. These methodological aspects as well as factors, such as ovariectomy, aging, and disuse may affect the outcome of the loading test, including bone mass, structure, and bone mineral density. This review aims to overview methodological aspects and modifying factors in axial loading on bone outcomes. A systematic literature search was performed in bibliographic databases until December 2021, which resulted in 2183 articles. A total of 144 articles were selected for this review: 23 rat studies, 74 mouse studies, and 47 knock out (KO) mouse studies. Results indicated that peak load, frequency, and number of loading cycles mainly affected the outcomes of bone mass, structure, and density in both rat and mouse studies. It is crucial to consider methodological parameters and modifying factors such as age, sex-steroid deficiency, and disuse in loading protocols for the prediction of loading-related bone outcomes.


Assuntos
Roedores , Tíbia , Feminino , Ratos , Camundongos , Animais , Osso e Ossos , Densidade Óssea , Suporte de Carga , Estresse Mecânico
13.
BMC Geriatr ; 23(1): 813, 2023 12 06.
Artigo em Inglês | MEDLINE | ID: mdl-38057724

RESUMO

BACKGROUND: Previous studies have suggested an association between sleep disturbance and frailty. The mechanism is unknown, although it has been suggested that hormonal factors may play a role. METHODS: The aim was to determine the association between sleep duration, sleep quality and frailty, and to determine whether testosterone influenced this association. Males aged 40-79 years were recruited from eight European centres to the European Male Aging Study (EMAS). Subjects completed an interviewer-assisted questionnaire including questions regarding sleep quality and duration. Sleep quality was scored 0-20 and categorised as 0-4, 5-9, 10-14, and 15-20, with higher scores indicating poorer quality. A 39-component frailty index (FI) was constructed. Total testosterone levels were measured. The association between sleep duration, sleep quality and the FI was assessed using negative binomial regression, with adjustment for putative confounders including testosterone level. RESULTS: Two thousand three hundred ninety-three participants contributed data to the analysis. The mean age was 63.3 years and mean sleep duration was 7.01 h. The mean frailty index was 0.15. Mean testosterone levels declined with decreasing sleep quality. After adjustment, compared to those with a sleep score of 0-4, the FI was 57% (95% CI 38%, 78%) higher among those with a sleep score of 15-20. After adjustment compared to those with normal sleep duration (6-9 h), those with a short (< 6 h) and long (≥ 9 h) sleep duration had a 16% (95% CI 6%, 28%) and 11% (95% CI 0%, 23%) higher FI, respectively. Adjustment for testosterone did not influence the strength of either association. CONCLUSION: Frailty is associated with impaired sleep quality and sleep duration. The association cannot, however, be explained by variation in testosterone levels.


Assuntos
Fragilidade , Idoso , Humanos , Masculino , Fragilidade/diagnóstico , Fragilidade/epidemiologia , Idoso Fragilizado , Testosterona , Envelhecimento , Sono
14.
Ann Intern Med ; 175(2): 159-170, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34958606

RESUMO

BACKGROUND: The influence of testosterone on risk for cardiovascular events in men is uncertain. Previous observational studies of sex hormones and incident cardiovascular disease in men have reported inconsistent findings, limited by cohort sizes and different selection criteria. OBJECTIVE: To analyze associations of serum total testosterone and sex hormone-binding globulin (SHBG) with incident cardiovascular events in men. DESIGN: Cohort study. SETTING: UK Biobank prospective cohort. PARTICIPANTS: Community-dwelling men aged 40 to 69 years. MEASUREMENTS: Testosterone and SHBG were assayed, and free testosterone was calculated. Cox proportional hazards regression was done, with outcomes of incident myocardial infarction (MI), hemorrhagic stroke (HS), ischemic stroke (IS), heart failure (HF), and major adverse cardiovascular events (MACE), adjusted for sociodemographic, lifestyle, and medical factors. RESULTS: Of 210 700 men followed for 9 years, 8790 (4.2%) had an incident cardiovascular event. After adjustment for key variables, lower total testosterone concentrations (quintile 1 vs. quintile 5) were not associated with incident MI (fully adjusted hazard ratio [HR], 0.89 [95% CI, 0.80 to 1.00]), HS (HR, 0.94 [CI, 0.70 to 1.26]), IS (HR, 0.95 [CI, 0.82 to 1.10]), HF (HR, 1.15 [CI, 0.91 to 1.45]), or MACE (HR, 0.92 [CI, 0.84 to 1.00]). Men with lower calculated free testosterone values had a lower incidence of MACE (HR, 0.90 [CI, 0.84 to 0.97]). Lower SHBG concentrations were associated with higher incidence of MI (HR, 1.23 [CI, 1.09 to 1.38]) and lower incidence of IS (HR, 0.79 [CI, 0.67 to 0.94]) and HF (HR, 0.69 [CI, 0.54 to 0.89]), but not with HS (HR, 0.81 [CI, 0.57 to 1.14]) or MACE (HR, 1.01 [CI, 0.92 to 1.11]). LIMITATION: Observational study; single baseline measurement of testosterone and SHBG. CONCLUSION: Men with lower total testosterone concentrations were not at increased risk for MI, stroke, HF, or MACE. Calculated free testosterone may be associated with risk for MACE. Men with lower SHBG concentrations have higher risk for MI but lower risk for IS and HF, with causality to be determined. PRIMARY FUNDING SOURCE: Western Australian Health Translation Network, Medical Research Future Fund, and Lawley Pharmaceuticals.


Assuntos
Insuficiência Cardíaca , Infarto do Miocárdio , Idoso , Austrália/epidemiologia , Estudos de Coortes , Insuficiência Cardíaca/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Infarto do Miocárdio/epidemiologia , Estudos Prospectivos , Fatores de Risco , Globulina de Ligação a Hormônio Sexual , Testosterona
15.
Rev Endocr Metab Disord ; 23(6): 1173-1208, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-35841491

RESUMO

Osteoporosis does not only affect postmenopausal women, but also ageing men. The burden of disease is projected to increase with higher life expectancy both in females and males. Importantly, osteoporotic men remain more often undiagnosed and untreated compared to women. Sex steroid deficiency is associated with bone loss and increased fracture risk, and circulating sex steroid levels have been shown to be associated both with bone mineral density and fracture risk in elderly men. However, in contrast to postmenopausal osteoporosis, the contribution of relatively small decrease of circulating sex steroid concentrations in the ageing male to the development of osteoporosis and related fractures, is probably only minor. In this review we provide several clinical and preclinical arguments in favor of a 'bone threshold' for occurrence of hypogonadal osteoporosis, corresponding to a grade of sex steroid deficiency that in general will not occur in many elderly men. Testosterone replacement therapy has been shown to increase bone mineral density in men, however data in osteoporotic ageing males are scarce, and evidence on fracture risk reduction is lacking. We conclude that testosterone replacement therapy should not be used as a sole bone-specific treatment in osteoporotic elderly men.


Assuntos
Fraturas Ósseas , Osteoporose , Humanos , Masculino , Feminino , Idoso , Densidade Óssea , Osteoporose/epidemiologia , Osteoporose/tratamento farmacológico , Fraturas Ósseas/epidemiologia , Fraturas Ósseas/etiologia , Fraturas Ósseas/tratamento farmacológico , Hormônios Esteroides Gonadais , Envelhecimento , Testosterona , Esteroides/uso terapêutico
16.
Aging Male ; 25(1): 167-172, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35652888

RESUMO

INTRODUCTION: The androgen receptor (AR) mediates peripheral effects of testosterone. Evidence suggests that the number of CAG repeats in exon-1 of the AR gene negatively correlates with AR transcriptional activity. The aim of this analysis was to determine the association between CAG repeat number and mortality in men. METHODS: Men aged 40-79 years were recruited from primary care for participation in the UK arm of the European Male Aging Study between 2003 and 2005. Cox proportional hazards modelling was used to determine the association between CAG repeat number/mortality. Results were expressed as hazard ratios(HR)/95% confidence intervals (CI). RESULTS: 312 men were followed up. The mean baseline age was 59.5 years. At follow up, 85/312(27%) men had died. CAG repeat length ranged from 14 to 39, with the highest proportion of CAG repeat number at 21 repeats(16.4%). In a multivariable model, using men with CAG repeat numbers of 22-23 as the reference, men with a lower number of CAG repeats(<22) showed a trend for a higher mortality in the follow-up period (HR 1.46 (0.75, 2.81)) as did men with higher number of repeats (>23) (1.37 (0.65, 2.91)). CONCLUSION: Our data suggest that CAG repeat number may partially influence the risk of mortality in men. Further larger studies are required to quantify the effect.


Assuntos
Receptores Androgênicos , Repetições de Trinucleotídeos , Envelhecimento , Feminino , Humanos , Masculino , Receptores Androgênicos/genética , Testosterona , Repetições de Trinucleotídeos/genética
17.
Age Ageing ; 51(4)2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35429269

RESUMO

BACKGROUND: erectile dysfunction is associated with mortality, whereas the association between low testosterone (T) and higher mortality remains controversial. Sexual dysfunction and low T often coexist, but the relative importance of sexual symptoms versus low T in predicting mortality is not known. We studied the interrelationships between sex steroids and sexual symptoms with all-cause mortality in a large prospective cohort of European men. DESIGN: survival status was assessed in 1,788 community-dwelling men, aged 40-79, who participated in the European Male Ageing Study (EMAS). Sexual symptoms were evaluated via a validated questionnaire (EMAS-SFQ). Sex steroids were measured by mass spectrometry. Cox proportional hazard models were used to study the association between hormones, sexual symptoms and mortality. RESULTS: about 420 (25.3%) men died during a mean follow-up of 12.6 ± 3.1 years. Total T levels were similar in both groups, but free T was lower in those who died. Men with three sexual symptoms (erectile dysfunction, reduced morning erections and lower libido) had a higher mortality risk compared with men with none of these symptoms (adjusted hazard ratio (HR) and 95% confidence intervals: 1.75 (1.28-2.40, P = 0.001)). Particularly, erectile dysfunction and poor morning erections, but not lower libido, were associated with increased mortality (HR 1.40 (1.13-1.74, P = 0.002), 1.28 (1.04-1.59, P = 0.023) and 1.12 (0.90-1.39, P = 0.312), respectively). Further adjusting for total T, free T or oestradiol did not influence the observed risk. CONCLUSIONS: sexual symptoms, in particular erectile dysfunction, predict all-cause mortality independently of sex steroids and can be an early warning sign of a poor health status.


Assuntos
Disfunção Erétil , Idoso , Envelhecimento , Disfunção Erétil/diagnóstico , Feminino , Humanos , Libido , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Testosterona
18.
Acta Derm Venereol ; 102: adv00692, 2022 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-35312026

RESUMO

Vitamin D status is influenced by well-known determinants, but factors associated with low 25-hydroxyvitamin D levels in the cutaneous melanoma population are not well defined. The aim of this study was to confirm the well-known determinants and to assess new determinants for 25-hydroxyvitamin D levels in a cutaneous melanoma population. In a prospectively included cohort of 387 patients with cutaneous melanoma the association of 25-hydroxyvitamin D levels with sex, age, body mass index, time of blood withdrawal, Fitzpatrick phototype, vitamin D supplementation, score for intensity of lifetime sun exposure, smoking, education level, hair and skin colour, eye colour, total number of benign naevi, freckles and parameters of chronic sun damage was investigated. In addition, 25-hydroxyvitamin D levels were correlated with pathological parameters of the primary tumour and melanoma stage (8th edition of the American Joint Committee on Cancer (AJCC). Univariate and multivariate logistic regressions were performed using R software. The following factors had a significant effect on vitamin D status: body mass index, seasonal time of blood sampling, vitamin D supplementation, and a subtype of skin, and hair colour.


Assuntos
Melanoma , Neoplasias Cutâneas , Calcifediol , Humanos , Melanoma/patologia , Neoplasias Cutâneas/patologia , Vitamina D/análogos & derivados , Vitaminas , Melanoma Maligno Cutâneo
19.
Alzheimers Dement ; 18(10): 1907-1918, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-34978125

RESUMO

INTRODUCTION: The association of testosterone concentrations with dementia risk remains uncertain. We examined associations of serum testosterone and sex hormone-binding globulin (SHBG) with incidence of dementia and Alzheimer's disease. METHODS: Serum total testosterone and SHBG were measured by immunoassay. The incidence of dementia and Alzheimer's disease (AD) was recorded. Cox proportional hazards regression was adjusted for age and other variables. RESULTS: In 159,411 community-dwelling men (median age 61, followed for 7 years), 826 developed dementia, including 288 from AD. Lower total testosterone was associated with a higher incidence of dementia (overall trend: P = .001, lowest vs highest quintile: hazard ratio [HR] = 1.43, 95% confidence interval [CI] = 1.13-1.81), and AD (P = .017, HR = 1.80, CI = 1.21-2.66). Lower SHBG was associated with a lower incidence of dementia (P < .001, HR = 0.66, CI = 0.51-0.85) and AD (P = .012, HR = 0.53, CI = 0.34-0.84). DISCUSSION: Lower total testosterone and higher SHBG are independently associated with incident dementia and AD in older men. Additional research is needed to determine causality.


Assuntos
Doença de Alzheimer , Globulina de Ligação a Hormônio Sexual , Masculino , Humanos , Idoso , Pessoa de Meia-Idade , Incidência , Estudos Prospectivos , Doença de Alzheimer/epidemiologia , Bancos de Espécimes Biológicos , Testosterona , Reino Unido/epidemiologia , Fatores de Risco
20.
Am J Physiol Endocrinol Metab ; 320(3): E415-E424, 2021 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-33308013

RESUMO

Sex steroids are critical for skeletal development and maturation during puberty as well as for skeletal maintenance during adult life. However, the exact time during puberty when sex steroids have the highest impact as well as the ability of bone to recover from transient sex steroid deficiency is unclear. Surgical castration is a common technique to study sex steroid effects in rodents, but it is irreversible, invasive, and associated with metabolic and behavioral alterations. Here, we used a low dose (LD) or a high dose (HD) of gonadotropin-releasing hormone antagonist to either temporarily or persistently suppress sex steroid action in male mice, respectively. The LD group, a model for delayed puberty, did not show changes in linear growth or body composition, but displayed reduced trabecular bone volume during puberty, which fully caught up at adult age. In contrast, the HD group, representing complete pubertal suppression, showed a phenotype reminiscent of that observed in surgically castrated rodents. Indeed, HD animals exhibited severely impaired cortical and trabecular bone acquisition, decreased body weight and lean mass, and increased fat mass. In conclusion, we developed a rodent model of chemical castration that can be used as an alternative to surgical castration. Moreover, the transient nature of the intervention enables to study the effects of delayed puberty and reversibility of sex steroid deficiency.NEW & NOTEWORTHY We developed a rodent model of chemical castration, which can be used as an alternative to surgical castration. Moreover, the transient nature of the intervention enables to study the effects of delayed puberty and reversibility of sex steroid deficiency.


Assuntos
Desenvolvimento Ósseo , Osso e Ossos/fisiologia , Hormônios Esteroides Gonadais/deficiência , Hipogonadismo/patologia , Animais , Composição Corporal/efeitos dos fármacos , Desenvolvimento Ósseo/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Hormônios Esteroides Gonadais/farmacologia , Hormônio Liberador de Gonadotropina/antagonistas & inibidores , Hormônio Liberador de Gonadotropina/farmacologia , Antagonistas de Hormônios/farmacologia , Hipogonadismo/complicações , Hipogonadismo/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Orquiectomia , Maturidade Sexual/fisiologia , Fatores de Tempo
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