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This study was performed to evaluate the associations between estradiol, dehydroepiandrosterone sulfate (DHEAS), free and total testosterone levels, and anthropometric parameters of general adiposity (body mass index, BMI) and fat distribution (waist/hip ratio, WHR), separately in two subgroups of healthy Polish men: younger (aged 22-39 years, n = 95) and older (aged 40 years and over, n = 141) subjects. Sex steroid levels were assessed using radioimmunoassay (RIA). BMI was used as a measure of general adiposity. WHR was used to estimate distribution of adipose depots. The relationships between sex steroids, BMI, WHR and age were evaluated by use of non-parametric statistics (Spearman coefficients). Aging was related to a reduction of all hormone levels (correlation coefficients with age: free testosterone r = -0.52, p < 0.001; total testosterone r = -0.25, p < 0.001; estradiol r = -0.18, p < 0.001; DHEAS r = -0.45, p < 0.001) and an increase of BMI and WHR for BMI r = 0.23, p < 0.001; for WHR r = 0.47, p < 0.001). A one way analysis of co-variance (ANCOVA) was applied separately in the two subgroups of subjects to assess the relationships between hormonal and anthropometric variables. In men aged 22-39 years, the total (but not free) testosterone and DHEAS (when controlled for age) significantly differentiated BMI values. In subjects aged 40 years and over, no associations between sex steroids and BMI were revealed. In younger males DHEAS differentiated WHR values (even when controlled for age and BMI), whereas after the age of 40 years an increased WHR was accompanied by increases in both estradiol and DHEAS levels. The associations between the androgen - estrogen activity and the anthropometric parameters of adiposity vary in younger versus older healthy men.

The aim of the study was to evaluate the independent 'net' effects of hormonal variables (estradiol, free testosterone and dehydroepiandrosterone sulfate (DHEAS) levels) and lifestyle variables (alcohol consumption, coffee drinking, cigarette smoking, physical activity and muscle strength) on trabecular, cortical and total bone mineral content (BMC) in a group of 236 healthy males, aged 22-67 years. The men were occupationally active inhabitants of the city of Wroclaw, Lower Silesia, Poland. Trabecular, cortical and total bone mineral content, at the distal radius of the non-dominant hand, were assessed by peripheral quantitative computed tomography (pQCT) using the Stratec 960 apparatus. Sex steroids levels were measured using standard immunoassays. Data on lifestyle variables (alcohol consumption, cigarette smoking, coffee drinking and physical activity) were obtained through a questionnaire. Hand-grip strength of the dominant hand was assessed using a standard dynamometer. All statistical analyses were made separately in two subgroups, younger males (aged 22-39 years) and older males (aged 40 years and over). The impact of a particular independent variable on BMC and the extent of determination on BMC by the complex of chosen variables were evaluated using a path analysis. In younger males, the effects of physical activity and muscle strength were the most important among all the factors that influenced BMC, as they contributed to 16.2%, 16.9% and 16.5% of the variability of trabecular, cortical and total BMC, respectively. Taking into consideration cigarette smoking, alcohol and coffee drinking together, the coefficients of determination of the variability in trabecular, cortical and total BMC were 10.6%, 11.3% and 16.1%, respectively. The variances in trabecular, cortical and total BMC levels were determined in only 5.8%, 11.5% and 13.0% by sex steroids, respectively. The influence of free testosterone on trabecular BMC was greater compared with that of dehydroepiandrosterone sulfate (DHEAS) and estradiol; for cortical BMC, the impacts of estradiol and DHEAS were similar and greater than that of free testosterone, and the variability of total BMC was affected mainly by estradiol. In contrast, in older men the effects of physical activity and muscular strength were the least important among all the complexes of independent variables, as they contributed to 4.5%, 7.8% and 7.0% of the variability in trabecular, cortical and total BMC, respectively. Taking into consideration the influences of cigarette smoking, alcohol and coffee drinking, the coefficients of determination of the variability in trabecular, cortical and total BMC were 16.5%, 14.8% and 17.4%, respectively. Among the older men, the variances in trabecular, cortical and total BMC were determined in only 9.4%, 6.3% and 13.6% by sex steroid levels, respectively. The influence of DHEAS on trabecular BMC was greater when compared with that of estradiol and free testosterone, whereas the variability of both cortical and total BMC in older men was affected mainly by estradiol. It is quite striking that, in younger healthy subjects, both physical activity and muscle strength contributed to a greater extent to BMC variance when compared with sex steroids levels, whereas, in older men, physical activity and muscular strength were less important than androgen- estrogen activity in determining the variability of BMC. This may suggest that the tropic effect of mechanical force influences bone structure mainly in younger men; probably male bone tissue becomes less prone to mechanical stimuli during aging. It is astonishing that both in younger and older men the coefficients of determination of physical activity and muscle strength were the highest for cortical BMC, which would indicate the greatest response of that part of the bone tissue to mechanical force. It is worth noting that the coefficients of determination of the complex of lifestyle factors (alcohol consumption, cigarette smoking and coffee drinking) were higher in older men compared to younger Polish males. This can be explained by the longer exposure of male bone to environmental influences (ethanol, nicotine, caffeine) during a lifetime. Our study revealed that all the evaluated variables were related to the variability in BMC in healthy Polish men, but the coefficients of determination differed depending on the age of the examined subject and on the BMC of a particular bone component. This suggests that the responsiveness of male bone tissue to environmental factors changes with age, and that these effects vary significantly between particular parts of the male bone structure.

In this study, age-related changes in bone mineral content (BMC) were investigated in the context of alterations of total testosterone, estradiol and dehydroepiandrosterone sulfate (DHEAS) during normal male aging. An anthropologically homogeneous group of 236 males, aged 22-67 years, was subdivided into eight 5-year age categories. The men were healthy and occupationally active inhabitants of the city of Wroclaw, Lower Silesia, Poland. The investigated hormones were measured using standard immunoassays. Trabecular, cortical and total BMC at the distal radius of the non-dominant hand were separately assessed by peripheral quantitative computed tomography (pQCT) using the Stratec 960 apparatus. All correlations among hormone and densitometric parameters and age were evaluated by use of non-parametric statistics (Spearman coefficient). Reductions in trabecular, cortical and total BMC of approximately 40.0%, 28. 1%and 30.8%, respectively, were found in the peak mass between the age category with maximal BMC values and men aged 55 years and older. The declines in trabecular and total BMC with age appeared to be statistically significant, whereas no analogous correlation between cortical BMC and age was found. We observed a decrease in total testosterone, DHEAS and estradiol levels of approximately 45%, 55% and 32%, respectively, in the maximal concentrations between the age category with peak values and men aged 55 years and older. A distinct decline in hormone levels commenced around 25 years of age. All evaluated steroids demonstrated a significant reduction with age. In our findings, the total testosterone level did not correlate at all with either trabecular, cortical or total BMC at the distal radius. DHEAS levels appeared to be insignificant for mineralization of cortical BMC, whereas a significant correlation was demonstrated between DHEAS and both total (r = 0.18; p = 0.02) and trabecular BMC (r = 0.22; p = 0.003). The last association was the strongest relationship established in the entire study. Estradiol levels, but not total testosterone values, appeared to correlate with all trabecular (r = 0.16; p = 0.02), cortical (r = 0.14; p = 0.04) and total BMC (r = 0.16; p = 0.02) at the distal radius. Total testosterone levels appeared to be insignificant for the degree of age-related changes in male bone mineralization. From the three sex steroids measured in healthy males, the adrenal androgen (dehydroepiandrosterone sulfate) seems to be the best endocrinological measure of the degree of male skeletal mineralization, especially of the trabecular component, which is clearly the most sensitive to all hormonal fluctuations. However, BMC is traditionally associated with gonadalfunctions, and is not always monitored reliably by total testosterone levels (and by concentrations of estradiol, which is usually converted peripherally from testosterone).

Multivariate genetic models were fitted to data from 44 pairs of MZ and 42 pairs of DZ twin girls on weight, height, and skeletal maturation at the age of menarche, in order to obtain information on genetic relationships of those measures with the age of menarche. The relationships of all three physical measures with this age were largely genetically controlled, but a genetic system controlling skeletal maturity was identified as the only genetic determinant of menarcheal age, independent of those systems of the two remaining physical measures. Heritabilities of all individual traits considered in the study were uniformly high. Possible links of genetic information with hormonal functions determining menarche are discussed.