Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
1.
Clin Endocrinol (Oxf) ; 87(4): 336-343, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28561278

RESUMEN

BACKGROUND: Testosterone treatment in obese dieting men augments the diet-associated loss of fat mass, but protects against loss of lean mass. We assessed whether body composition changes are maintained following withdrawal of testosterone treatment. METHODS: We conducted a prespecified double-blind randomized placebo-controlled observational follow-up study of a randomized controlled trial (RCT). Participants were men with baseline obesity (body mass index >30 kg/m2 ) and a repeated total testosterone level <12 nmol/L, previously enrolled in a 56-week testosterone treatment trial combined with a weight loss programme. Main outcome measures were mean adjusted differences (MAD) (95% confidence interval), in body composition between testosterone- and placebo-treated men at the end of the observation period. RESULTS: Of the 100 randomized men, 82 completed the RCT and 64 the subsequent observational study. Median [IQR] observation time after completion of the RCT was 82 weeks [74; 90] in men previously receiving testosterone (cases) and 81 weeks [67;91] in men previously receiving placebo (controls), P=.51. At the end of the RCT, while losing similar amounts of weight, cases had, compared to controls, lost more fat mass, MAD -2.9 kg (-5.7, -0.2), P=.04, but had lost less lean mass MAD 3.4 kg (1.3, 5.5), P=.002. At the end of the observation period, the former between-group differences in fat mass, MAD -0.8 kg (-3.6, 2.0), P=1.0, in lean mass, MAD -1.3 kg (-3.0, 0.5), P=.39, and in appendicular lean mass, MAD -0.1 kg/m2 (-0.3, 0.1), P=.45, were no longer apparent. During observation, cases lost more lean mass, MAD -3.7 kg (-5.5, -1.9), P=.0005, and appendicular lean mass, MAD -0.5 kg/m2 (-0.8, -0.3), P<.0001 compared to controls. CONCLUSIONS: The favourable effects of testosterone on body composition in men subjected to a concomitant weight loss programme were not maintained at 82 weeks after testosterone treatment cessation.


Asunto(s)
Composición Corporal/efectos de los fármacos , Obesidad/tratamiento farmacológico , Obesidad/metabolismo , Testosterona/uso terapéutico , Adulto , Índice de Masa Corporal , Peso Corporal/efectos de los fármacos , Método Doble Ciego , Femenino , Humanos , Hormona Luteinizante/sangre , Masculino , Persona de Mediana Edad , Obesidad/sangre
2.
BMC Med ; 14(1): 153, 2016 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-27716209

RESUMEN

BACKGROUND: Whether testosterone treatment has benefits on body composition over and above caloric restriction in men is unknown. We hypothesised that testosterone treatment augments diet-induced loss of fat mass and prevents loss of muscle mass. METHODS: We conducted a randomised double-blind, parallel, placebo controlled trial at a tertiary referral centre. A total of 100 obese men (body mass index ≥ 30 kg/m2) with a total testosterone level of or below 12 nmol/L and a median age of 53 years (interquartile range 47-60) receiving 10 weeks of a very low energy diet (VLED) followed by 46 weeks of weight maintenance were randomly assigned at baseline to 56 weeks of 10-weekly intramuscular testosterone undecanoate (n = 49, cases) or matching placebo (n = 51, controls). The main outcome measures were the between-group difference in fat and lean mass by dual-energy X-ray absorptiometry, and visceral fat area (computed tomography). RESULTS: A total of 82 men completed the study. At study end, compared to controls, cases had greater reductions in fat mass, with a mean adjusted between-group difference (MAD) of -2.9 kg (-5.7 to -0.2; P = 0.04), and in visceral fat (MAD -2678 mm2; -5180 to -176; P = 0.04). Although both groups lost the same lean mass following VLED (cases -3.9 kg (-5.3 to -2.6); controls -4.8 kg (-6.2 to -3.5), P = 0.36), cases regained lean mass (3.3 kg (1.9 to 4.7), P < 0.001) during weight maintenance, in contrast to controls (0.8 kg (-0.7 to 2.3), P = 0.29) so that, at study end, cases had an attenuated reduction in lean mass compared to controls (MAD 3.4 kg (1.3 to 5.5), P = 0.002). CONCLUSIONS: While dieting men receiving placebo lost both fat and lean mass, the weight loss with testosterone treatment was almost exclusively due to loss of body fat. TRIAL REGISTRATION: clinicaltrials.gov, identifier NCT01616732 , registration date: June 8, 2012.


Asunto(s)
Terapia Combinada/métodos , Dieta Reductora/métodos , Obesidad/dietoterapia , Obesidad/tratamiento farmacológico , Testosterona/análogos & derivados , Absorciometría de Fotón , Tejido Adiposo/efectos de los fármacos , Composición Corporal/efectos de los fármacos , Peso Corporal/efectos de los fármacos , Método Doble Ciego , Humanos , Masculino , Persona de Mediana Edad , Testosterona/administración & dosificación
3.
Clin Endocrinol (Oxf) ; 82(5): 767-75, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25378236

RESUMEN

OBJECTIVE: Our objective was to characterize and evaluate prognostic implications of circulating sex steroids in patients at different stages of chronic kidney disease (CKD). DESIGN: Prospective observational cohort study. PATIENTS: We prospectively recruited patients with CKD III-IV, undergoing chronic dialysis and kidney transplant recipients (KTR) from a single centre in 2003-2004. MEASUREMENTS: Two stored samples taken 3 months apart were analysed for sex hormones using liquid chromatography/tandem mass spectrometry, and the mean of the two was used for analysis. We also measured novel biomarkers troponin T and NT-proBNP. Patients were followed until death, transplant or 30 June 2013, and survival analysis performed. RESULTS: In males, but not in females, both testosterone (P = 0·003) as well as oestradiol (P < 0·02) levels were lowest in dialysis patients and highest in KTR. Over a median follow up of 8·5 years (interquartile range 3·8-9·2), 52 men (36%) died and 24 (17%) received a kidney transplant. In Cox proportional hazards regression up to 9·6 years, an increase in total testosterone of 1 nmol/l was associated with a 9·8% (95% confidence interval 3·1-16·3) decrease in mortality independent of age, body mass index, stage of renal disease and circulating levels of NT-proBNP or troponin T. By contrast, sex steroid levels were not associated with mortality in females. CONCLUSIONS: Testosterone levels differ across stages of kidney disease and low testosterone levels predict mortality in males, independent of established and novel predictors of mortality.


Asunto(s)
Hormonas Esteroides Gonadales/sangre , Insuficiencia Renal Crónica/sangre , Insuficiencia Renal Crónica/terapia , Adulto , Anciano , Índice de Masa Corporal , Estradiol/sangre , Femenino , Humanos , Trasplante de Riñón , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Estudios Prospectivos , Diálisis Renal , Insuficiencia Renal Crónica/mortalidad , Factores Sexuales , Espectrometría de Masas en Tándem , Testosterona/sangre , Resultado del Tratamiento
4.
Artículo en Inglés | MEDLINE | ID: mdl-38335137

RESUMEN

OBJECTIVE: To determine the effect of testosterone vs placebo treatment on health-related quality of life (HR-QOL) and psychosocial function in men without pathologic hypogonadism in the context of a lifestyle intervention. DESIGN, SETTING, PARTICIPANTS: Secondary analysis of a 2-year, randomised controlled, testosterone therapy trial for prevention, or reversal of newly diagnosed, type 2 diabetes, enrolling men > 50 years at high risk for type 2 diabetes from six Australian centers. INTERVENTIONS: Injectable testosterone undecanoate or matching placebo on the background of a community-based lifestyle program. MAIN OUTCOMES: Self-reported measures of HR-QOL/psychosocial function. RESULTS: Of 1007 participants randomised into T4DM, 648 (64%) had complete data available for all HR-QOL/psychosocial function assessments at baseline and two years. Over 24 months, while most measures were not different between treatment arms, testosterone treatment, compared with placebo, improved subjective social status and sense of coherence. Baseline HR-QOL/psychosocial function measures did not predict the effect of testosterone treatment on glycemic outcomes, primary endpoints of T4DM. Irrespective of treatment allocation, larger decreases in body weight were associated with improved mental quality of life, mastery, and subjective social status. Men with better baseline physical function, greater sense of coherence, and less depressive symptoms experienced greater associated decreases in body weight, with similar effects on waist circumference. CONCLUSIONS: In this diabetes prevention trial, weight loss induced by a lifestyle intervention improved HR-QOL and psychosocial function in more domains than testosterone treatment. The magnitude of weight and waist circumference reduction were predicted by baseline physical function, depressive symptomology, and sense of coherence.

5.
J Clin Endocrinol Metab ; 106(8): e3143-e3158, 2021 07 13.
Artículo en Inglés | MEDLINE | ID: mdl-33693907

RESUMEN

CONTEXT: Testosterone treatment increases bone mineral density (BMD) in hypogonadal men. Effects on bone microarchitecture, a determinant of fracture risk, are unknown. OBJECTIVE: We aimed to determine the effect of testosterone treatment on bone microarchitecture using high resolution-peripheral quantitative computed tomography (HR-pQCT). METHODS: Men ≥ 50 years of age were recruited from 6 Australian centers and were randomized to receive injectable testosterone undecanoate or placebo over 2 years on the background of a community-based lifestyle program. The primary endpoint was cortical volumetric BMD (vBMD) at the distal tibia, measured using HR-pQCT in 177 men (1 center). Secondary endpoints included other HR-pQCT parameters and bone remodeling markers. Areal BMD (aBMD) was measured by dual-energy x-ray absorptiometry (DXA) in 601 men (5 centers). Using a linear mixed model for repeated measures, the mean adjusted differences (95% CI) at 12 and 24 months between groups are reported as treatment effect. RESULTS: Over 24 months, testosterone treatment, versus placebo, increased tibial cortical vBMD, 9.33 mg hydroxyapatite (HA)/cm3) (3.96, 14.71), P < 0.001 or 3.1% (1.2, 5.0); radial cortical vBMD, 8.96 mg HA/cm3 (3.30, 14.62), P = 0.005 or 2.9% (1.0, 4.9); total tibial vBMD, 4.16 mg HA/cm3 (2.14, 6.19), P < 0.001 or 1.3% (0.6, 1.9); and total radial vBMD, 4.42 mg HA/cm3 (1.67, 7.16), P = 0.002 or 1.8% (0.4, 2.0). Testosterone also significantly increased cortical area and thickness at both sites. Effects on trabecular architecture were minor. Testosterone reduced bone remodeling markers CTX, -48.1 ng/L [-81.1, -15.1], P < 0.001 and P1NP, -6.8 µg/L[-10.9, -2.7], P < 0.001. Testosterone significantly increased aBMD at the lumbar spine, 0.04 g/cm2 (0.03, 0.05), P < 0.001 and the total hip, 0.01 g/cm2 (0.01, 0.02), P < 0.001. CONCLUSION: In men ≥ 50 years of age, testosterone treatment for 2 years increased volumetric bone density, predominantly via effects on cortical bone. Implications for fracture risk reduction require further study.


Asunto(s)
Densidad Ósea/efectos de los fármacos , Hueso Cortical/efectos de los fármacos , Vértebras Lumbares/efectos de los fármacos , Testosterona/farmacología , Tibia/efectos de los fármacos , Absorciometría de Fotón , Anciano , Remodelación Ósea/efectos de los fármacos , Hueso Cortical/diagnóstico por imagen , Método Doble Ciego , Humanos , Vértebras Lumbares/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Tibia/diagnóstico por imagen
6.
Sci Rep ; 8(1): 9099, 2018 06 14.
Artículo en Inglés | MEDLINE | ID: mdl-29904126

RESUMEN

To assess the effect of testosterone treatment on bone remodelling and density in dieting obese men, 100 obese men aged 53 years (interquartile range 47-60) with a total testosterone level <12 nmol/L receiving 10 weeks of a very low energy diet (VLED) followed by 46 weeks of weight maintenance were randomly assigned at baseline to 56 weeks of intramuscular testosterone undecanoate (n = 49, cases) or matching placebo (n = 51, controls). Pre-specified outcomes were between-group differences (mean adjusted difference, MAD) in serum c-telopeptide (CTx), N-terminal propeptide of type 1 procollagen (P1NP) and bone mineral density (BMD). At trial end, CTx was significantly reduced in men receiving testosterone compared to placebo, MAD -66 ng/L (95% CI -113, -18), p = 0.018, and this was apparent already after the 10 week VLED phase, MAD -63 ng/L (95% CI -108, -18), p = 0.018. P1NP was marginally increased after VLED, MAD +4.2 ug/L (95% CI -0.01, +8.4), p = 0.05 but lower at study end, MAD -5.6 ug/L (95% CI -10.1, -1.1), p = 0.03. No significant changes in sclerostin, lumbar spine BMD or femoral BMD were seen. We conclude that in obese men with low testosterone levels undergoing weight loss, bone remodelling markers are modulated in a way that may have favourable effects on bone mass.


Asunto(s)
Densidad Ósea/efectos de los fármacos , Restricción Calórica , Fémur , Vértebras Lumbares , Obesidad , Testosterona/análogos & derivados , Proteínas Adaptadoras Transductoras de Señales , Proteínas Morfogenéticas Óseas/metabolismo , Fémur/diagnóstico por imagen , Fémur/metabolismo , Marcadores Genéticos , Humanos , Vértebras Lumbares/diagnóstico por imagen , Vértebras Lumbares/metabolismo , Masculino , Persona de Mediana Edad , Obesidad/diagnóstico por imagen , Obesidad/metabolismo , Obesidad/terapia , Testosterona/administración & dosificación
7.
J Endocr Soc ; 1(4): 302-312, 2017 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-29264488

RESUMEN

CONTEXT: In obese men with lowered testosterone levels, testosterone treatment augments diet-associated loss of body fat. OBJECTIVE: We hypothesized that testosterone treatment modulates circulating concentrations of hormonal mediators of fat mass and energy homeostasis in obese men undergoing a weight loss program. DESIGN: Prespecified secondary analysis of a randomized, double-blind, placebo-controlled trial. SETTING: Tertiary referral center. PARTICIPANTS: Obese men (body mass index ≥30 kg/m2) with a repeated total testosterone level ≤12 nmol/L. INTERVENTION: One hundred participants mean age 53 years (interquartile range 47 to 60 years) receiving 10 weeks of a very low-energy diet followed by 46 weeks of weight maintenance were randomly assigned at baseline to 56 weeks of intramuscular testosterone undecanoate (cases, n = 49) or matching placebo (controls, n = 51). Eighty-two men completed the study. MAIN OUTCOMES: Between-group differences in leptin, adiponectin, ghrelin, glucagon like peptide-1, gastric inhibitory polypeptide, peptide YY, pancreatic polypeptide, and amylin levels. RESULTS: At study end, compared with controls, cases had greater reductions in leptin [mean adjusted difference (MAD), -3.6 ng/mL (95% CI, -5.3 to -1.9); P < 0.001]. The change in leptin levels between cases and controls was dependent on baseline fat mass, as the between-group difference progressively increased with increasing fat mass [MAD, -0.26 ng/mL (95% CI, -0.31 to -0.26); P = 0.001 per 1 kg of baseline fat mass]. Weight loss-associated changes in other hormones persisted during the weight maintenance phase but were not modified by testosterone treatment. CONCLUSIONS: Testosterone treatment led to reductions in leptin beyond those achieved by diet-associated weight loss. Testosterone treatment may reduce leptin resistance in obese men.

8.
J Mol Med (Berl) ; 91(4): 507-12, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23090011

RESUMEN

Congenital polycythemias have diverse etiologies, including mutations in the hypoxia sensing pathway. These include HIF2A at exon 12, VHL gene (Chuvash polycythemia), and PHD2 mutations, which in one family was also associated with recurrent pheochromocytoma/paraganglioma (PHEO/PGL). Over the past two decades, we have studied seven unrelated patients with sporadic congenital polycythemia who subsequently developed PHEO/PGL with, until now, no discernible molecular basis. We now report a polycythemic patient with a novel germline HIF2A (F374Y) (exon 9) mutation, inherited from his mother, who developed PHEO/PGL. We show that this is a gain-of-function mutation and demonstrate no loss-of-heterozygosity or additional somatic mutation of HIF2A in the tumor, indicating HIF2A (F374Y) may be predisposing rather than causative of PHEO/PGL. This report, in view of two other concomitantly reported PHEO/PGL patients with somatic mutations of HIF2A and polycythemia, underscores the PHEO/PGL-promoting potential of mutations of HIF2A that alone are not sufficient for PHEO/PGL development.


Asunto(s)
Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Mutación de Línea Germinal , Paraganglioma/complicaciones , Paraganglioma/genética , Policitemia/complicaciones , Policitemia/genética , Anciano de 80 o más Años , Secuencia de Aminoácidos , Secuencia de Bases , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/química , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos Moleculares , Datos de Secuencia Molecular , Policitemia/congénito , Conformación Proteica , Alineación de Secuencia
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA