Context:No large studies of young men have examined circulating sex hormones in relation to visceral and sc adipose tissues.Objective: The aim of this study was to investigate the role of visceral adipose tissue and sc adipose tissue on circulating sex hormones and the impact of obesity on sex hormone reference intervals.Design, Setting, and Participants: Population-based study of 783 Danish 20-to 29-yr-old men was performed using dual-energy x-ray absorptiometry in all men and magnetic resonance imaging in 406 men. Main Outcome Measures:Total, bioavailable, and free testosterone, dihydrotestosterone (DHT), total and bioavailable estradiol, SHBG, and LH were measured. Results:In multiple regressions, visceral adipose tissue was an independent, inverse correlate of bioavailable and free testosterone. Subcutaneous adipose tissue correlated negatively with SHBG and positively with bioavailable estradiol adjusted for total testosterone.Both visceral adipose tissue and sc adipose tissue correlated inversely with total testosterone and DHT. Adjusting for SHBG, only visceral adipose tissue remained significantly correlated. Low total testosterone in viscerally obese men was not accompanied by increased LH. The androgen reference intervals were significantly displaced toward lower limits in obese vs. nonobese men (total testosterone: 8.5-29.3 vs. 12.5-37.6 nmol/liter; bioavailable testosterone: 6.1-16.9 vs. 7.6 -20.7 nmol/liter; free testosterone: 0.23-0.67 vs. 0.29 -0.78 nmol/liter; and DHT: 0.63-2.5 vs. 0.85-3.2 nmol/liter), whereas total estradiol (36.5-166 pmol/liter) and bioavailable estradiol (23.4 -120 pmol/liter) reference intervals were not. In obese men, 22.9% had total testosterone less than 12.5 nmol/liter. Conclusions:Visceral adipose tissues correlate independently with bioavailable and free testosterone in young men. The inverse relationship between total testosterone and sc adipose tissue seems to be accounted for by variations in SHBG. The reference intervals for total testosterone, bioavailable testosterone, free testosterone, and DHT are displaced toward lower limits in obese men.

SAT rather than VAT was inversely associated with adiponectin levels, and, interestingly, fat on the lower extremities was positively associated with adiponectin. Focusing on insulin resistance, SAT rather than VAT and TFA independently predicted a higher HOMA-IR. The observation that adiponectin was independently associated with lower HOMA-IR must be repeated in other populations.

the study showed a high prevalence of detrimental life style factors including smoking, excessive alcohol consumption and physical inactivity in elderly Danish men. Except for diabetes and respiratory disease, chronic diseases were underreported and in particular erectile dysfunction and osteoporosis were underdiagnosed in the study population, underlining the importance of awareness of chronic diseases among both the general population and physicians.

Reference intervals for TT were comparable in healthy young and elderly men, but reference intervals for FT and BT were lower in elderly men due to higher levels of SHBG. Androgens and SHBG were lower in elderly men with chronic disease and inversely associated with CFM.

Background: The number of CAG repeats (CAG n ) within the CAG repeat polymorphism of the androgen receptor gene correlates inversely with the transactivation of the receptor. Objective: To examine the impact of CAG n on muscle, fat distribution, and circulating androgen levels. Design, settings and participants: Population-based, cross-sectional study of 783 Danish men aged 20-29 years. Methods: Genotyping was performed in 767 men. Areas of thigh and lower trunk muscle (muscle thigh and muscle lower trunk ), subcutaneous adipose tissues (SAT thigh and SAT lower trunk ), and deep adipose tissues (i.m. and visceral) were measured in 393 men by magnetic resonance imaging (MRI). Lean body mass (LBM) and fat mass (FM) were measured in all men by whole body dual-energy X-ray absorptiometry (DEXA). The absolute areas acquired by MRI were the main outcomes. The absolute DEXA measurements and relative assessments of both modalities were considered as the secondary outcomes. Results: CAG n (range: 10-32) correlated inversely with absolute muscle thigh (rZK0.108), absolute muscle lower trunk (rZK0.132), relative muscle thigh (rZK0.128), relative muscle lower trunk (rZK0.126), relative LBM lower extremity (rZK0.108), and relative LBM total (rZK0.082), and positively with relative SAT thigh (rZ0.137), relative SAT lower trunk (rZ0.188), relative FM lower extremity (rZ0.107), and relative FM total (rZ0.082). These relationships remained significant, controlling for physical activity, smoking, chronic disease, and age. CAG n did not correlate with any circulating androgen. Conclusions: The CAG repeat polymorphism affects body composition in young men: absolute muscle thigh and absolute muscle lower trunk increase as CAG n decreases. Expressed relatively, muscle areas and LBM increase, while SAT and FM decrease as CAG n decreases. The polymorphism does not affect deep adipose tissues or circulating androgen levels in young men.

Purpose To investigate the impact of the Ala1330Val (rs3736228, exon 18) and Val667Met (rs4988321, exon 9) polymorphisms of the low-density lipoprotein receptorrelated protein 5 (LRP5) gene on peak bone mass in young men. Methods The Odense Androgen Study (OAS) is a population-based study comprising 783 Caucasian men aged 20-30 years. Genotyping was performed using real-time polymerase chain reaction (PCR) or fluorescence polarization. Bone mineral density (BMD) measurements were performed using dual-energy X-ray absorptiometry. Results The CC, CT, and TT genotypes in Ala1330Val were found in 75.6%, 21.8%, and 2.6% of the participants, respectively. Similarly, the GG, GA, and AA genotypes of Val667Met were found in 89.7%, 9.8%, and 0.5%, respectively. For the Ala1330Val polymorphism, no significant differences between the genotypes were found regarding BMD in the overall study population. However, when analysis was restricted to non-sedentary men (n = 589), a significant association between the number of T-alleles and BMD in the spine and whole body were found. Each copy of the T-allele changed the Z-score of the spine by (median and 95% confidence interval) -0. Family and twin studies have demonstrated that genetic factors account for 50-80% of the inter-individual variation in bone mineral density (BMD) in both women and men [1][2][3][4][5][6][7][8][9]. Polymorphisms in a number of genes affect the bone phenotype regarding BMD, bone size, or fracture risk [10]. Only a small part of the overall variation in BMD, however, has been explained by the polymorphisms identified so far.The transmembrane proteins low-density lipoprotein receptor-related protein 5 (LRP5) and LRP6 are essential in

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Locally derived reference values are important to avoid false positive or false negative findings during work-up in patients evaluated for osteoporosis.