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Male Ageing Study (male + ageing_study)

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Medical Sciences	100%

Selected Abstracts

Genetic variation in the RANKL/RANK/OPG signaling pathway is associated with bone turnover and bone mineral density in men

JOURNAL OF BONE AND MINERAL RESEARCH, Issue 8 2010
Delnaz Roshandel
Abstract The aim of this study was to determine if single-nucleotide polymorphisms (SNPs) in RANKL, RANK, and OPG influence bone turnover and bone mineral density (BMD) in men. Pairwise tag SNPs (r2,,,0.8) were selected for RANKL, RANK, and OPG and their 10-kb flanking regions. Selected tag SNPs plus five SNPs near RANKL and OPG, associated with BMD in published genome-wide association studies (GWAS), were genotyped in 2653 men aged 40 to 79 years of age recruited for participation in a population-based study of male aging, the European Male Ageing Study (EMAS). N-terminal propeptide of type I procollagen (PINP) and C-terminal cross-linked telopeptide of type I collagen (CTX-I) serum levels were measured in all men. BMD at the calcaneus was estimated by quantitative ultrasound (QUS) in all men. Lumbar spine and total-hip areal BMD (BMDa) was measured by dual-energy X-ray absorptiometry (DXA) in a subsample of 620 men. Multiple OPG, RANK, and RANKL SNPs were associated with bone turnover markers. We also identified a number of SNPs associated with BMD, including rs2073618 in OPG and rs9594759 near RANKL. The minor allele of rs2073618 (C) was associated with higher levels of both PINP (,,=,1.83, p,=,.004) and CTX-I (,,=,17.59, p,=,4.74,×,10,4), and lower lumbar spine BMDa (,,=,,0.02, p,=,.026). The minor allele of rs9594759 (C) was associated with lower PINP (,,=,,1.84, p,=,.003) and CTX-I (,,=,,27.02, p,=,6.06,×,10,8) and higher ultrasound BMD at the calcaneus (,,=,0.01, p,=,.037). Our findings suggest that genetic variation in the RANKL/RANK/OPG signaling pathway influences bone turnover and BMD in European men. © 2010 American Society for Bone and Mineral Research [source]

Cortisol levels and measures of body composition in middle-aged and older men

CLINICAL ENDOCRINOLOGY, Issue 1 2007
Thomas G. Travison
Summary Introduction, Similarities in the symptomatic expressions of excess adiposity and hypercortisolaemic conditions suggest that elevated glucocorticoid exposure may influence the pathogenesis of obesity. Circulating cortisol levels are not typically elevated in obese subjects, but data from large prospective samples are rare. We undertook an analysis to determine both cross-sectional and longitudinal associations between body composition and serum cortisol concentrations in a randomly chosen group of 999 community-dwelling men, aged 40,79 years. Methods, Data were obtained from the two follow-up waves of the Massachusetts Male Ageing Study (T2: 1995,97; T3: 2002,04). Partial correlation and multivariate regression analyses were used to estimate cross-sectional (T2) and longitudinal associations between serum cortisol concentrations and a range of measures of subjects' body composition, including weight, body mass index (BMI), waist circumference (WC), waist-to-hip girth ratio (WHR), and percentage body fat (measured by bioelectrical impedance at T3); similar analyses were conducted to assess the association between change (T2 to T3) in serum cortisol and simultaneous change in body composition parameters. Results, We observed weak negative associations between cortisol concentrations and all body composition parameters, with the exception of percentage body fat. Longitudinal results demonstrated similar relationships but associations were of lesser magnitude. T2 cortisol concentrations were not associated with change in body composition over time, whereas T2 body size was positively associated with longitudinal changes in cortisol concentrations, providing limited evidence that weight change drives changes in cortisol concentrations, rather than vice versa. Results were unchanged when age and other covariate effects were controlled. Conclusions, Circulating cortisol concentrations are somewhat lower in obese than in nonobese community-dwelling men. There is some evidence that excess adiposity presages increases in cortisol concentrations, rather than the reverse. However, this observation should be greeted with caution, as age-related weight loss , and not gain , was associated with simultaneous increases in serum cortisol concentrations. [source]

Body mass index, waist circumference and waist to hip ratio and change in sex steroid hormones: the Massachusetts Male Ageing Study

CLINICAL ENDOCRINOLOGY, Issue 1 2006
Carol A. Derby
Summary Objective, Cross-sectional data suggest that obesity, particularly central obesity, may be associated with decreased production of sex steroid hormones in men. However, longitudinal hormone data on men in relation to obesity status are limited. Previous studies have not consistently demonstrated whether sex steroids are associated specifically to body mass index or to measures of central obesity. Our objective was to examine the relation of obesity (body mass index > 30 kg/m2), and of central obesity (waist circumference > 100 cm or waist to hip ratio > 0·95) to longitudinal change in sex steroid hormones in men. Design, Prospective follow-up of a population-based sample of men in Boston. Patients, Nine hundred forty-two (942) men in the Massachusetts Male Ageing Study with complete anthropometry and hormone data at baseline (1987,1989, ages 40,70) and follow-up (1995,1997). Measurements, Free and total testosterone (FT and TT), dehydroepiandrosterone sulphate (DHEAS), and sex hormone-binding globulin (SHBG) were assessed using standardized methods. Health behaviours and medical history were obtained by structured interview. Repeated measures regression was used to describe trends in steroid hormones and SHBG in relation to obesity status, adjusting for age, smoking, alcohol, comorbidities, and physical activity. Results, Obesity was associated with decreased levels of total and free testosterone, and of SHBG at follow-up relative to baseline. For any given baseline concentration of TT, FT or SHBG, follow-up levels were lowest among men who remained obese or who became obese during follow-up. This was true for all three indices of obesity. Central adiposity was associated with lower DHEAS levels at follow-up, while elevated body mass index was not. Conclusions, Obesity may predict greater decline in testosterone and SHBG levels with age. Central adiposity may be a more important predictor of decline in DHEAS than is body mass index. [source]