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1.
Clin Endocrinol (Oxf) ; 94(4): 551-562, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33249593

RESUMEN

OBJECTIVE: Previous studies suggested that recombinant human IGF-1 (rhIGF-1) administration affects carbohydrate and lipid metabolism in healthy people and in people with diabetes. This study aimed to determine the effects of rhIGF-1/rhIGF binding protein-3 (rhIGFBP-3) administration on glucose homeostasis and lipid metabolism in healthy recreational athletes. DESIGN AND SETTING: Randomized, double-blind, placebo-controlled rhIGF-1/rhIGFBP-3 administration study at Southampton General Hospital, UK. PARTICIPANTS: 56 recreational athletes (30 men, 26 women). METHODS: Participants were randomly assigned to receive placebo, low-dose rhIGF-1/rhIGFBP-3 (30 mg/day) or high-dose rhIGF-1/rhIGFBP-3 (60 mg/day) for 28 days. The following variables were measured before and immediately after the treatment period: fasting lipids, glucose, insulin, C-peptide and glycated haemoglobin. The homeostatic model assessment (HOMA-IR) was used to estimate insulin sensitivity and indirect calorimetry to assess substrate oxidation rates. The general linear model approach was used to compare treatment group changes with the placebo group. RESULTS: Compared with the placebo group, there was a significant reduction in fasting triglycerides in participants treated with high-dose rhIGF-1/rhIGFBP-3 (p = .030), but not in the low-dose group (p = .390). In women, but not in men, there were significant increases in total cholesterol (p = .003), HDL cholesterol (p = .001) and LDL cholesterol (p = .008). These lipid changes were associated with reduced fasting insulin (p = .010), C-peptide (p = .001) and HOMA-IR (p = .018) in women and reduced C-peptide (p = .046) in men. CONCLUSIONS: rhIGF-1/rhIGFBP-3 administration for 28 days reduced insulin concentration, improved insulin sensitivity and had significant effects on lipid profile including decreased fasting triglycerides.


Asunto(s)
Atletas , Proteínas Portadoras , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina , Factor I del Crecimiento Similar a la Insulina , Metabolismo de los Hidratos de Carbono , Método Doble Ciego , Femenino , Humanos , Insulina , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/farmacología , Factor I del Crecimiento Similar a la Insulina/farmacología , Metabolismo de los Lípidos , Masculino , Proteínas Recombinantes/farmacología
2.
BMC Med Res Methodol ; 16(1): 147, 2016 10 28.
Artículo en Inglés | MEDLINE | ID: mdl-27793179

RESUMEN

BACKGROUND: The GH-2000 score has been developed as a powerful and unique technique for the detection of growth hormone misuse by sportsmen and women. The score depends upon the measurement of two growth hormone (GH) sensitive markers, insulin-like growth factor-I (IGF-I) and the amino-terminal pro-peptide of type III collagen (P-III-NP). With the collection and establishment of an increasingly large database it has become apparent that the score shows a positive age effect in the male athlete population, which could potentially place older male athletes at a disadvantage. METHODS: We have used results from residual analysis of the general linear model to show that the residual of the GH-2000 score when regressed on the mean-age centred age is an appropriate way to proceed to correct this bias. As six GH-2000 scores are possible depending on the assays used for determining IGF-I and P-III-NP, methodology had to be explored for including six different age effects into a unique residual. Meta-analytic techniques have been utilized to find a summary age effect. RESULTS: The age-adjusted GH-2000 score, a form of residual, has similar mean and variance as the original GH-2000 score and, hence, the developed decision limits show negligible change when compared to the decision limits based on the original score. We also show that any further scale-transformation will not change the adjusted score. Hence the suggested adjustment is optimal for the given data. The summary age effect is homogeneous across the six scores, and so the generic adjustment of the GH-2000 score formula is justified. CONCLUSIONS: A final revised GH-2000 score formula is provided which is independent of the age of the athlete under consideration.


Asunto(s)
Atletas , Biometría/métodos , Doping en los Deportes/estadística & datos numéricos , Hormona de Crecimiento Humana/administración & dosificación , Deportes , Detección de Abuso de Sustancias/métodos , Adulto , Factores de Edad , Algoritmos , Anabolizantes/administración & dosificación , Doping en los Deportes/prevención & control , Femenino , Humanos , Factor I del Crecimiento Similar a la Insulina/análisis , Modelos Lineales , Masculino , Modelos Teóricos , Fragmentos de Péptidos/análisis , Procolágeno/análisis , Adulto Joven
3.
Anal Bioanal Chem ; 405(30): 9669-83, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23934394

RESUMEN

To athletes, insulin-like growth factor-I (IGF-I) is an attractive performance-enhancing drug, particularly as an alternative to growth hormone (GH) because IGF-I mediates many of the anabolic actions of GH. IGF-I has beneficial effects on muscle protein synthesis and glycogen storage that could enhance performance in several sporting disciplines. Recombinant human IGF-I (rhIGF-I) is used in clinical practice, but a variety of IGF-I compounds and IGF-I analogues are also advertised on the internet and many have been available on the black market for several years. Although methods for detecting GH misuse are now well established and there have been several cases in which athletes have tested positive for GH, no test is yet in place for detecting IGF-I misuse. The GH-2004 research group has been investigating methods for detection of IGF-I misuse and a test is being developed on the basis of the principles of the successful GH-2000 marker method, in which markers from the IGF axis and markers of collagen and bone turnover are used to detect GH misuse. Commercial immunoassays for these markers have been validated for anti-doping purposes but new methods, including IGF-I measurement by use of mass spectrometry, should improve the performance of the tests and help in the detection of athletes who are doping with these peptide hormones.


Asunto(s)
Atletas , Biomarcadores/análisis , Doping en los Deportes/métodos , Factor I del Crecimiento Similar a la Insulina/administración & dosificación , Sustancias para Mejorar el Rendimiento/análisis , Detección de Abuso de Sustancias/métodos , Humanos , Factor I del Crecimiento Similar a la Insulina/análisis
5.
Endocr Rev ; 28(6): 603-24, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17785429

RESUMEN

The syndrome of adult GH deficiency and the effects of GH replacement therapy provide a useful model with which to study the effects of the GH/IGF-I axis on exercise physiology. Measures of exercise performance including maximal oxygen uptake and ventilatory threshold are impaired in adult GH deficiency and improved by GH replacement, probably through some combination of increased oxygen delivery to exercising muscle, increased fatty acid availability with glycogen sparing, increased muscle strength, improved body composition, and improved thermoregulation. In normal subjects, in addition to the long-term effects of GH/IGF-I status, there is evidence that the acute GH response to exercise is important in regulating substrate metabolism after exercise. Administration of supraphysiological doses of GH to athletes increases fatty acid availability and reduces oxidative protein loss, particularly during exercise, and increases lean body mass. Despite a lack of evidence that these metabolic effects translate to improved performance, GH abuse by athletes is widespread. Tests to detect GH abuse have been developed based on measurement in serum of 1) indirect markers of GH action, and 2) the relative proportions of the two major naturally occurring isoforms (20 and 22kDa) of GH. There is evidence that exercise performance and strength are improved by administration of GH and testosterone in combination to elderly subjects. The potential benefits of GH in these situations must be weighed against potential adverse effects.


Asunto(s)
Ejercicio Físico/fisiología , Hormona de Crecimiento Humana/fisiología , Factor I del Crecimiento Similar a la Insulina/fisiología , Deportes/fisiología , Relación Dosis-Respuesta a Droga , Hormona del Crecimiento/administración & dosificación , Hormona del Crecimiento/farmacología , Hormona del Crecimiento/uso terapéutico , Hormona de Crecimiento Humana/deficiencia , Humanos , Trastornos Relacionados con Sustancias
7.
Clin Endocrinol (Oxf) ; 72(4): 520-6, 2010 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19650783

RESUMEN

BACKGROUND: Growth Hormone is abused by athletes for its lipolytic and anabolic properties. Its use is prohibited by the World Anti-Doping Agency. The GH-2000 project developed a methodology to detect its abuse using the concentrations of two GH-dependent biomarkers, IGF-I and type 3 procollagen (P-III-P). The sensitivity of this method may be improved by considering intra-individual variability. AIM: The aim of this study was to examine the intra-individual variability of IGF-I, P-III-P and the GH-2000 score. SUBJECTS AND METHODS: IGF-I, P-III-P and GH-2000 score were evaluated in four longitudinal studies involving 303 elite and 78 amateur athletes. Samples were collected over a period of up to 12 months from a total of 238 men and 143 women aged between 17 and 53 years (mean 24.2). RESULTS: The four studies showed good agreement with no apparent difference in within-individual variation between amateur and elite athletes. The intra-individual variability for IGF-I ranged between 14-16% while the variability for P-III-P was 7-18%. No athlete tested positive for growth hormone during any of the studies. The overall mean intra-individual variability of the GH-2000 score was less than 0.6 units in all studies. CONCLUSIONS: The high stability of marker levels suggests that concentrations are largely genetically determined. Adopting a test based on the concept of an athlete's 'passport' or 'profiling' would take advantage of this and most likely increase the sensitivity of the test. These data also provide strong evidence that a positive test result for GH abuse would not occur as a result of chance variability.


Asunto(s)
Biomarcadores/análisis , Hormona de Crecimiento Humana/análisis , Factor I del Crecimiento Similar a la Insulina/análisis , Fragmentos de Péptidos/sangre , Procolágeno/sangre , Detección de Abuso de Sustancias/métodos , Adolescente , Adulto , Análisis de Varianza , Doping en los Deportes/métodos , Femenino , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Sensibilidad y Especificidad
8.
Clin Endocrinol (Oxf) ; 70(1): 161-8, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18616716

RESUMEN

CONTEXT: A method based on the two GH dependent markers, IGF-I and procollagen III peptide (P-III-P) has been proposed to detect exogenously administered GH. As previous studies involved predominantly white European elite athletes, it is necessary to validate the method in other ethnic groups. OBJECTIVE: To examine serum IGF-I and P-III-P in elite athletes of different ethnicities within 2 h of competing at national or international events. DESIGN: Cross-sectional observational study. SETTING: National and International sporting events. SUBJECTS: 1085 elite athletes of different ethnicities. INTERVENTION: Serum IGF-I and P-III-P were measured and GH-2000 discriminant function score was calculated. Effect of ethnicity was assessed. RESULTS: In men, IGF-I was 21.7 +/- 2.6% lower in Afro-Caribbeans than white Europeans (P < 0.0001) but there were no differences between other ethnic groups. In women, IGF-I was 14.2 +/- 5.1% lower in Afro-Caribbeans (P = 0.005) and 15.6 +/- 7.0% higher in Orientals (P = 0.02) compared with white Europeans. P-III-P was 15.2 +/- 3.5%, 26.6 +/- 6.6% and 19.3 +/- 5.8% lower in Afro-Caribbean (P < 0.0001), Indo-Asian (P < 0.0001) and Oriental men (P = 0.001), respectively, compared with white European men. In women, P-III-P was 15.7 +/- 4.7% lower in Afro-Caribbeans compared to white Europeans (P =0.0009) but there were no differences between other ethnicities. Despite these differences, most observations were below the upper 99% prediction limits derived from white European athletes. All GH-2000 scores lay below the cut-off limit proposed for doping. CONCLUSIONS: The GH-2000 detection method based on IGF-I and P-III-P would be valid in all ethnic groups.


Asunto(s)
Etnicidad , Hormona de Crecimiento Humana/análisis , Factor I del Crecimiento Similar a la Insulina , Fragmentos de Péptidos , Procolágeno , Deportes , Detección de Abuso de Sustancias/métodos , Adolescente , Adulto , Envejecimiento , Pueblo Asiatico/genética , Población Negra/genética , Doping en los Deportes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Fragmentos de Péptidos/sangre , Procolágeno/sangre , Población Blanca/genética
9.
J Clin Endocrinol Metab ; 93(8): 3066-74, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18477661

RESUMEN

CONTEXT: Alterations of protein turnover may contribute to the progressive decline of muscle mass with aging. OBJECTIVE: Our objective was to examine the effects of near-physiological recombinant human GH and/or testosterone (T) administration to older men on whole body protein kinetics and muscle gene expression. DESIGN, SETTINGS, AND PARTICIPANTS: A 6-month randomized, double-blind, placebo-controlled trial in 21 healthy elderly men aged 65-75 yr, was performed. Participants were randomized to receive placebo GH and placebo T, rhGH and placebo T (GH), T and placebo GH (T), or rhGH and T (GHT). INTERVENTIONS: The leucine rate of appearance (index of proteolysis), nonoxidative leucine disposal rate (an index of protein synthesis), and leucine oxidation rate were measured with an infusion of l-[1-(13)C] leucine. Muscle biopsies for the measurement of gene expression were performed. Body composition and aerobic capacity (maximal oxygen capacity) were measured. RESULTS: Serum IGF-I levels increased significantly with GH and GHT (P < 0.001) compared with placebo. T increased significantly only in the T group (P = 0.028). Leucine rate of appearance and nonoxidative leucine disposal rate increased with GH (P = 0.015, P = 0.019) and GHT (P = 0.017, P = 0.02), but leucine oxidation did not change significantly in any treatment group. Midthigh muscle mass and maximal oxygen capacity increased (P < 0.04) with GHT only. Expression of muscle function genes did not change significantly, but the within-group comparisons revealed a significant increase of androgen receptor expression in the GHT group (P = 0.001). CONCLUSION: This study showed that 6-month treatment with low-dose GH alone or with T in healthy elderly men produces comparable increments in whole body protein turnover and protein synthesis.


Asunto(s)
Hormona de Crecimiento Humana/uso terapéutico , Músculo Esquelético/metabolismo , Proteínas/metabolismo , Testosterona/uso terapéutico , Anciano , Método Doble Ciego , Expresión Génica , Hormona de Crecimiento Humana/efectos adversos , Humanos , Masculino , Fuerza Muscular , Consumo de Oxígeno/efectos de los fármacos
10.
J Clin Endocrinol Metab ; 93(7): 2760-3, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18413420

RESUMEN

CONTEXT: A method to detect exogenously administered growth hormone (GH) based on the measurement of two GH-dependent markers, IGF-I and type 3 procollagen (P-III-P) has been proposed. Skeletal or soft tissue injury may alter these markers. Elevations in either of these proteins after injury might lead to a false accusation of doping with GH. OBJECTIVE: The objective of the study was to assess the effect of musculoskeletal or soft tissue injury on IGF-I and P-III-P concentrations in amateur and elite athletes and assess the effect of injury on the proposed GH detection method. DESIGN: This was a longitudinal observational study after sporting injury. SETTING: The study was conducted at Southampton General Hospital and British Olympic Medical Centre. SUBJECTS: Subjects included elite and amateur athletes after an injury. INTERVENTION: Interventions included measurement of IGF-I and P-III-P and application of the GH-2000 discriminant function score up to 84 d after an injury as well as classification of injury by type and severity. OUTCOME MEASURES: IGF-I and P-III-P concentration and ability to detect GH abuse in athletes without the risk of false accusation because of an injury were measured. RESULTS: There was no change in IGF-I concentration after an injury. By contrast, P-III-P concentrations rose by 41.1 +/- 16.6%, reaching a peak around 14 d after an injury. The rise in P-III-P varied according to injury type and severity. This rise had a trivial effect on the GH-2000 discriminant function score, and no subject reached the threshold needed for a doping offense. CONCLUSIONS: Although there was a rise in P-III-P after injury, this was insufficient to invalidate the GH-2000 detection method based on IGF-I and P-III-P concentrations.


Asunto(s)
Traumatismos en Atletas/sangre , Colágeno Tipo III/sangre , Doping en los Deportes , Hormona de Crecimiento Humana/metabolismo , Factor I del Crecimiento Similar a la Insulina/análisis , Trastornos Relacionados con Sustancias/diagnóstico , Adolescente , Adulto , Anciano , Femenino , Curación de Fractura , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad
11.
BMC Res Notes ; 11(1): 650, 2018 Sep 05.
Artículo en Inglés | MEDLINE | ID: mdl-30185229

RESUMEN

OBJECTIVE: The GH-2000 biomarker test has been introduced by the World Anti-Doping Agency as a method of detecting growth hormone misuse in professional sport. The test involves the measurement insulin-like growth factor-I and the amino-terminal pro-peptide of type III collagen (P-III-NP) which increase in a dose-dependent manner in response to GH. These measurements are combined in sex specific formulae that include an age adjustment. The original age adjustment overcorrects the effect of age in male athletes and could potentially place older men at a disadvantage. The purpose of this note is to investigate the performance of a previously suggested correction term in two new and larger data sets. RESULTS: The GH-2000 score was calculated for 7307 samples obtained from 15 accredited WADA laboratories in 2017 and 3916 samples measured at Drug Control Centre, King's College London, UK between 2013 and 2017. The GH-2000 scores were investigated for positive age effects using standard regression modelling. As previously, all analyses confirmed a positive age effect. Applying the earlier suggested correction term of 0.032 × age showed a significant over-correction leading to a negative association of the GH-2000 score with age. We now suggest a smaller age correction of 0.020 × age, which corresponds to the smallest effect found in the earlier studies.


Asunto(s)
Doping en los Deportes , Hormona del Crecimiento/uso terapéutico , Hormona de Crecimiento Humana/análisis , Detección de Abuso de Sustancias , Femenino , Hormona del Crecimiento/análisis , Humanos , Factor I del Crecimiento Similar a la Insulina/análisis , Masculino , Procolágeno , Valores de Referencia
12.
Artículo en Inglés | MEDLINE | ID: mdl-29445518

RESUMEN

BACKGROUND: Endocrine profiles have been measured on blood samples obtained immediately post-competition from 693 elite athletes from 15 Olympic Sports competing at National or International level; four were subsequently excluded leaving 689 for the current analysis. METHODS: Body composition was measured by bioimpedance in a sub-set of 234 (146 men and 88 women) and from these data a regression model was constructed that enabled 'estimated' lean body mass and fat mass to be calculated on all athletes. One way ANOVA was used to assess the differences in body composition and endocrine profiles between the sports and binary logistical regression to ascertain the characteristic of a given sport compared to the others. RESULTS: The results confirmed many suppositions such as basketball players being tall, weightlifters short and cross-country skiers light. The hormone profiles were more surprising with remarkably low testosterone and free T3 (tri-iodothyronine) in male powerlifters and high oestradiol, SHBG (sex hormone binding globulin) and prolactin in male track and field athletes. Low testosterone concentrations were seen 25.4% of male elite competitors in 12 of the 15 sports and high testosterone concentrations in 4.8% of female elite athletes in 3 of the 8 sports tested. Interpretation of the results is more difficult; some of the differences between sports are at least partially due to differences in age of the athletes but the apparent differences between sports remain significant after adjusting for age. The prevalence of 'hyperandrogenism' (as defined by the IAAF (International Association of Athletics Federations) and IOC (International Olympic Committee)) amongst this cohort of 231 elite female athletes was the highest so far recorded and the very high prevalence of 'hypoandrogenism' in elite male athletes a new finding. CONCLUSIONS: It is unclear whether the differences in hormone profiles between sports is a reason why they become elite athletes in that sport or is a consequence of the arduous processes involved. For components of body composition we know that most have a major genetic component and this may well be true for endocrine profiles.

13.
Growth Horm IGF Res ; 17(5): 416-23, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17584513

RESUMEN

CONTEXT: The detection of exogenously administered growth hormone (GH) poses a formidable challenge but a detection method based on the measurement of two GH-dependent markers, IGF-I and type 3 pro-collagen (P-III-P) has been proposed. The measurement of multiple markers in conjunction with discriminant functions can improve the sensitivity and specificity of detection compared with single marker analysis. OBJECTIVE: To provide further validation of the GH-dependent marker approach. DESIGN: Analysis of discriminant function scores for GH detection on independent datasets. SETTING: Two independent (GH-2000 and Kreischa) double blind, placebo controlled, hGH administration studies. SUBJECTS: Healthy active male volunteers. INTERVENTION: GH-2000 proposed a discriminant function involving IGF-I and P-III- P while the Kreischa function involved IGF-I, P-III-P and IGFBP-3. After adjustment for assay differences the formulae were applied to the other dataset. OUTCOME MEASURES: Ability to detect GH use in independent datasets using a predefined specificity of approximately 1 in 10000. RESULTS: The GH-2000 formula was able to detect 90% of those receiving GH in the Kreischa study at one or more time points during the study period. This sensitivity was similar to that obtained on the original GH-2000 dataset. The Kreischa formula correctly identified 41% of individuals receiving GH in the GH-2000 study. CONCLUSIONS: The study provides further validation that the test proposed by GH-2000 based on IGF-I and P-III-P concentrations can be used to detect subjects receiving exogenous GH.


Asunto(s)
Doping en los Deportes , Hormona de Crecimiento Humana/sangre , Hormona de Crecimiento Humana/farmacología , Adulto , Método Doble Ciego , Humanos , Masculino , Placebos , Proteínas Recombinantes/sangre , Proteínas Recombinantes/farmacología , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Trastornos Relacionados con Sustancias/diagnóstico
14.
Drug Test Anal ; 9(1): 30-37, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26888146

RESUMEN

Insulin-like growth factor-I (IGF-I) is abused by elite athletes for its metabolic and anabolic effects. We have previously shown that it is possible to detect IGF-I misuse by measuring serum IGF-I and procollagen type III amino-terminal propeptide (P-III-NP) but a pilot study suggested measuring IGF-II, IGF binding protein-2 (IGFBP-2) and acid-labile subunit (ALS) may improve the detection of IGF-I administration. The aim of the study was to assess this in a randomized controlled trial. Twenty-six female and 30 male recreational athletes were randomized to 28 days' treatment with placebo or recombinant human (rh)IGF-I/rhIGF binding protein-3 (IGFBP-3) complex (30 mg/day or 60 mg/day), followed by 56 days' washout. IGF-II, IGFBP-2 and ALS (women only) were measured using commercial immunoassays. IGFBP-2 increased and IGF-II decreased in response to both low and high dose rhIGF-I/rhIGFBP-3 in both women and men while ALS decreased in women in response to high dose rhIGF-I/rhIGFBP-3. Two days after discontinuing treatment, significant differences remained between the three treatment groups in IGFBP-2 and IGF-II, but not ALS. Thereafter there were no significant differences between the three treatment groups in any of the markers. Combining IGF-I with IGF-II and/or IGFBP-2 improved the performance of the test to detect rhIGF-I/rhIGFBP-3 administration in both women and men. Copyright © 2016 John Wiley & Sons, Ltd.


Asunto(s)
Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/sangre , Detección de Abuso de Sustancias/métodos , Adolescente , Adulto , Método Doble Ciego , Femenino , Humanos , Proteína 3 de Unión a Factor de Crecimiento Similar a la Insulina/administración & dosificación , Factor I del Crecimiento Similar a la Insulina/administración & dosificación , Masculino , Efecto Placebo , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/sangre , Adulto Joven
15.
J Clin Endocrinol Metab ; 91(2): 477-84, 2006 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16332938

RESUMEN

CONTEXT: Declines in GH and testosterone (Te) secretion may contribute to the detrimental aging changes of elderly men. OBJECTIVE: To assess the effects of near-physiological GH with/without Te administration on lean body mass, total body fat, midthigh muscle cross-section area, muscle strength, aerobic capacity, condition-specific quality of life (Age-Related Hormone Deficiency-Dependent Quality of Life questionnaire), and generic health status (36-Item Short-Form Health Survey) of older men. DESIGN, SETTINGS, AND PARTICIPANTS: A 6-month, randomized, double-blind, placebo-controlled trial was performed on 80 healthy, community-dwelling, older men (age, 65-80 yr). INTERVENTIONS: Participants were randomized to receive 1) placebo GH or placebo Te, 2) recombinant human GH (rhGH) and placebo Te (GH), 3) Te and placebo rhGH (Te), or 4) rhGH and Te (GHTe). GH doses were titrated over 8 wk to produce IGF-I levels in the upper half of the age-specific reference range. A fixed dose of Te (5 mg) was given by transdermal patches. RESULTS: Lean body mass increased with GHTe (P = 0.008) and GH (P = 0.004), compared with placebo. Total body fat decreased with GHTe only (P = 0.02). Midthigh muscle (P = 0.006) and aerobic capacity (P < 0.001) increased only after GHTe. Muscle strength changes were variable; one of six measures significantly increased with GHTe. Significant treatment group by time interactions indicated an improved Age-Related Hormone Deficiency-Dependent Quality of Life questionnaire score (P = 0.007) in the GH and GHTe groups. Bodily pain increased with GH alone, as determined by the Short-Form Health Survey (P = 0.003). There were no major adverse effects. CONCLUSION: Coadministration of low dose GH with Te resulted in beneficial changes being observed more often than with either GH or Te alone.


Asunto(s)
Composición Corporal/fisiología , Hormona de Crecimiento Humana/farmacología , Músculo Esquelético/efectos de los fármacos , Músculo Esquelético/fisiología , Aptitud Física/fisiología , Testosterona/farmacología , Anciano , Anciano de 80 o más Años , Composición Corporal/efectos de los fármacos , Método Doble Ciego , Fuerza de la Mano/fisiología , Hormona de Crecimiento Humana/efectos adversos , Humanos , Factor I del Crecimiento Similar a la Insulina/metabolismo , Masculino , Calidad de Vida , Encuestas y Cuestionarios , Testosterona/efectos adversos
16.
Eur J Endocrinol ; 154(3): 459-66, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16498060

RESUMEN

BACKGROUND: Epidemiological studies suggest that hypopituitary patients have an increased risk for cardiovascular mortality. The dyslipidaemia associated with this condition is often characterised by an increase in total cholesterol (TC) and low-density lipoprotein (LDL) cholesterol (LDL-C) and may contribute to these findings. The underlying mechanisms are not fully elucidated. MATERIALS AND METHODS: LDL apolipoprotein B (apoB) production rate and metabolic clearance rate were measured in seven patients with hypopituitarism (including GH deficiency) under stable conventional replacement therapy (three males and four females; age 40-16.1 years; body mass index 29.0-6.1 kg/m(2) (means +/- s.d.)) and seven age-, gender- and body mass index-matched control subjects with an infusion of 1-(13)C-leucine. Fasting lipid profile and lipid composition of LDL were also measured. RESULTS: Fasting TC, triglycerides (TG), high-density lipoprotein-C, LDL-C and free fatty acid concentrations were not different between hypopituitary patients and control subjects. LDL-TG (P < 0.006) and LDL-TG/LDL apoB ratio (P < 0.02) were significantly increased in hypopituitary patients. LDL apoB pool size was not statistically different between patients and control subjects. In the hypopituitary patients, LDL apoB metabolic clearance rate (P < 0.05) and LDL apoB production rate (P < 0.02) were lower than in the control subjects. CONCLUSIONS: The present results suggest that LDL apoB turnover and LDL composition is altered in hypopituitary patients. Whether these findings explain the increased risk for cardiovascular disease in hypopituitary patients remains to be established.


Asunto(s)
Apolipoproteínas B/metabolismo , Hormona de Crecimiento Humana/deficiencia , Hipopituitarismo/metabolismo , Adulto , Factores de Edad , Apolipoproteínas E/sangre , Índice de Masa Corporal , Isótopos de Carbono , Dislipidemias/complicaciones , Femenino , Hormona del Crecimiento/uso terapéutico , Terapia de Reemplazo de Hormonas , Humanos , Hipopituitarismo/tratamiento farmacológico , Lípidos/sangre , Lipoproteínas LDL/sangre , Masculino , Persona de Mediana Edad , Caracteres Sexuales
17.
Growth Horm IGF Res ; 16(2): 125-31, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16644256

RESUMEN

OBJECTIVE: Ambient temperature alters exercise induced GH secretion. It is unknown whether temperature affects GH secretion at exercise intensities above the anaerobic threshold when other factors may override the relationship seen at lower intensities. DESIGN: Cross-over study of ambient temperature on exercise induced GH in swimmers and rowers. SETTING: St Thomas Hospital, London. SUBJECTS: Ten healthy men (age 21.7+/-0.8 yrs). Five swimmers and five rowers. INTERVENTION: Forty-minute exercise test at 105% of anaerobic threshold at room temperature (RT) and at 4 degrees C. MEASUREMENTS: Cutaneous and core body temperature. Serum GH concentration. RESULTS: Cutaneous body temperature increased during exercise at RT but decreased in the cold. Although core temperature rose in both settings, the rise was greater at RT (p=0.021). GH increased at both temperatures but the onset was delayed by the cold. Peak GH tended to be higher at RT (17.4+/-3.6 microg/L vs. 9.5+/-1.5 microg/L, p=0.07). Total GH secretion was greater at RT (353.3+/-99.1 microg min/L) than 4 degrees C (128.3+/-21.0 microg min/L), p=0.038. Change in core temperature correlated with log peak GH (r=0.66, p=0.039) and log incremental GH (r=0.67, p=0.032) when exercising at 4 degrees C. There was no difference between swimmers and rowers. CONCLUSIONS: Exercise at 4 degrees C reduces GH secretion during exercise at intensities above the anaerobic threshold. A change in core body temperature may be one mechanism by which exercise induces GH secretion. The difference in GH between swimmers and rowers during their respective events relates to the conditions under which they compete.


Asunto(s)
Umbral Anaerobio/fisiología , Frío , Ejercicio Físico/fisiología , Hormona de Crecimiento Humana/sangre , Temperatura Cutánea/fisiología , Adulto , Hormona de Crecimiento Humana/metabolismo , Humanos , Masculino , Deportes/fisiología
18.
Growth Horm IGF Res ; 16(5-6): 308-17, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-17029996

RESUMEN

OBJECTIVE: To assess the effects of low dose recombinant growth hormone (GH), testosterone (T) and combined GH and T, on lipid profiles and very low density lipoprotein apolipoprotein B (VLDL apoB) metabolism. DESIGN AND PATIENTS: Sixty-nine healthy elderly men (65-80 yr) were studied in a six month double-blind, placebo-controlled trial. Participants were randomised to placebo GH and placebo T (P), GH and placebo T (GH), T and placebo GH (T) or GH and T (GHT). MEASUREMENTS: Plasma lipid profiles were assessed before treatment and at 6 months. VLDL apoB absolute secretion rate (ASR) and fractional catabolic rate (FCR) were measured in a subset of 21 men: P (n=5); GH (n=5); T (n=6); GHT (n=5), with an infusion of 1-(13)C leucine. Fat mass (FM) was measured by DEXA and intra-abdominal fat (IAF) by CT scan. RESULTS: IGF-I levels increased in the GH and GHT (P<0.001) groups: testosterone increased in the T (P=0.029) and GHT (P=0.05) groups. There was no change in total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides, apolipoprotein A-I, apolipoprotein B or lipoprotein(a) in the GH, GHT or T groups. In the subset of 21 men, IGF-I levels increased similarly with GH and GHT (P<0.01) but T levels increased only with T (P<0.03). FM and IAF decreased significantly only with GHT (P<0.01, P=0.01). Treatment with GH, T or GHT had no effect on VLDL apoB ASR or VLDL FCR. CONCLUSION: Co-administration of GH and T in near physiological doses in healthy elderly men resulted in favourable changes in body composition without altering the plasma lipid profile or VLDL apoB metabolism.


Asunto(s)
Apolipoproteína B-100/sangre , Hormona de Crecimiento Humana/farmacología , Lípidos/sangre , Lipoproteínas VLDL/sangre , Testosterona/farmacología , Anciano , Anciano de 80 o más Años , Composición Corporal/efectos de los fármacos , Método Doble Ciego , Hormona de Crecimiento Humana/administración & dosificación , Humanos , Factor I del Crecimiento Similar a la Insulina/metabolismo , Masculino , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/farmacología , Testosterona/administración & dosificación
19.
Health Qual Life Outcomes ; 4: 16, 2006 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-16553952

RESUMEN

BACKGROUND: Psychometric properties of two measures of psychological well-being were evaluated for adults with growth hormone deficiency (GHD): the General Well-being Index, (GWBI)--British version of the Psychological General Well-being Index, and the 12-item Well-being Questionnaire (W-BQ12). METHODS: Reliability, structure and other aspects of validity were investigated in a cross-sectional study of 157 adults with treated or untreated GHD, and sensitivity to change in a randomised placebo-controlled study of three months' growth hormone (GH) withdrawal from 12 of 21 GH-treated adults. RESULTS: Very high completion rates were evidence that both questionnaires were acceptable to respondents. Factor analyses did not indicate the existence of useful GWBI subscales, but confirmed the validity of calculating a GWBI Total score. However, very high internal consistency reliability (Cronbach's alpha = 0.96, N = 152), probably indicated some item redundancy in the 22-item GWBI. On the other hand, factor analyses confirmed the validity of the three W-BQ12 subscales of Negative Well-being, Energy, and Positive Well-being, each having excellent internal reliability (alphas of 0.86, 0.86 and 0.88, respectively, N from 152 to 154). There was no sign of item redundancy in the highly acceptable Cronbach's alpha of 0.93 (N = 148) for the whole W-BQ12 scale. Whilst neither questionnaire found significant differences between GH-treated and non-GH-treated patients, there were correlations (for GH-treated patients) with duration of GH treatment for GWBI Total (r = -0.36, p = 0.001, N = 85), W-BQ12 Total (r = 0.35, p = 0.001, N = 88) and for all W-BQ12 subscales: thus the longer the duration of GH treatment (ranging from 0.5 to 10 years), the better the well-being. Both questionnaires found that men had significantly better overall well-being than women. The W-BQ12 was more sensitive to change than the GWBI in the GH-Withdrawal study. A significant between-group difference in change in W-BQ12 Energy scores was found [t(18) = 3.25, p = 0.004, 2-tailed]: patients withdrawn from GH had reduced energy at end-point. The GWBI found no significant change. CONCLUSION: The W-BQ12 is recommended in preference to the GWBI to measure well-being in adult GHD: it is considerably shorter, has three useful subscales, and has greater sensitivity to change.


Asunto(s)
Actitud Frente a la Salud , Indicadores de Salud , Terapia de Reemplazo de Hormonas/psicología , Hormona de Crecimiento Humana/deficiencia , Psicometría/instrumentación , Calidad de Vida/psicología , Síndrome de Abstinencia a Sustancias/psicología , Encuestas y Cuestionarios , Adulto , Edad de Inicio , Niño , Estudios Transversales , Interpretación Estadística de Datos , Depresión/psicología , Análisis Factorial , Femenino , Hospitales Urbanos , Hormona de Crecimiento Humana/uso terapéutico , Humanos , Londres , Masculino , Fatiga Mental/psicología , Persona de Mediana Edad , Estudios Prospectivos
20.
J Eval Clin Pract ; 12(5): 501-14, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16987112

RESUMEN

OBJECTIVES: The objectives were (1) to report the preliminary development of the Hormone Deficiency-dependent Quality of Life (HDQoL) questionnaire, a new individualized questionnaire in which respondents rate personally applicable domains for importance and impact of hormonal deficiency and its treatment; (2) to evaluate the HDQoL's psychometric properties for adults with hypopituitarism including growth hormone deficiency (GHD). METHODS: Internal consistency reliability, aspects of validity, and sensitivity to change of the HDQoL were investigated in: (1) a cross-sectional survey of 157 adults with treated or untreated GHD; (2) a randomized, placebo-controlled study of 3 months' growth hormone (GH) withdrawal from 12 of 21 GH-treated adults. RESULTS: Thirteen of the original 18 HDQoL domains were relevant and important for GH-deficient adults. The shorter 13-item HDQoL had excellent internal reliability (Cronbach's alpha coefficient = 0.914, n = 109), and was sensitive to sex differences (cross-sectional study): women perceived worse present QoL than men [t(149.8) = 2.33, P = 0.021]. The HDQoL was sensitive to change (GH-withdrawal study) with a significant between-group difference in change in domain scores for things I can do physically[t(16) = 2.47, P = 0.025, 2-tailed], patients withdrawn from GH reporting greater negative impact of hormone deficiency on this domain at end-point. Qualitative work resulted in the addition of seven new HDQoL domains, including energy and bodily pain. CONCLUSION: The HDQoL, although at an early stage of development, proved useful in identifying expected changes following GH withdrawal. The extended 20-item version is recommended for further evaluation in assessing the impact of hypopituitarism on QoL.


Asunto(s)
Hipopituitarismo , Calidad de Vida , Encuestas y Cuestionarios , Adulto , Estudios Transversales , Femenino , Humanos , Síndrome de Laron , Masculino , Persona de Mediana Edad , Psicometría , Medicina Estatal , Reino Unido
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