Variability in total testosterone levels in ageing men with symptoms of androgen deficiency.

The aim of this study was to determine the variability in total testosterone (TT) levels in healthy, non-obese ageing men with symptoms of androgen deficiency. Men aged ≥55 years were recruited from the community. Morning TT levels were measured on four occasions in a 12-month period. In all, 96 men aged 62.7 ± 6.8 years were studied. Geometric mean values (95% confidence interval) of TT levels for the cohort at each time point were 14.5 (13.4-15.7), 14.6 (13.5-15.8), 15.5 (14.4-16.8) and 15.0 (13.9-16.2) nmol/L. The maximum intra-individual difference in TT between the four samples was 4.1 nmol/L (interquartile range: 2.9-6.4). Using the average of two baseline TT values reduces the maximum difference to 2.3 nmol/L (1.0-3.8). Only 1 of 25 men with a documented TT <10 nmol/L at baseline had TT levels <10 nmol/L at all subsequent time points. A single TT level is a reliable predictor of repeat measures taken within a 12-month period for a cohort of healthy ageing men with symptoms of androgen deficiency. However, given that the diagnostic criteria for androgen deficiency are, in part, predicated upon serum TT, there is sufficient intra-subject variability to warrant repeat sampling to confirm an initial low TT level. Using an average of two baseline TT values reduces this variability.

Testosterone therapy increases sexual desire in ageing men with low-normal testosterone levels and symptoms of androgen deficiency.

Although decline in sexual function is a common reason for ageing men to seek advice regarding testosterone therapy, placebo-controlled trial data have been unable to show a consistent, beneficial role for testosterone. The objective of this study was to determine the effect of testosterone therapy on sexual function in non-obese ageing men with symptoms of androgen deficiency and low-normal serum testosterone levels. A total of 60 men aged 55 years or older in good general health with total testosterone (TT) levels <15 nM, and with symptoms suggestive of androgen deficiency, were randomized in a double-blinded protocol to transdermal testosterone patches or placebo for 12 months. Sexual function was assessed using the International Index of Erectile Function at weeks 0, 26 and 52. In men receiving testosterone TT levels increased by 30% (P=0.01) and luteinizing hormone decreased by 50% (P<0.001). Relative to placebo, testosterone therapy improved sexual desire (P=0.04); however other parameters of sexual function including erectile function were unaffected by the treatment. Ageing men in good general health and with symptoms of androgen deficiency and low-normal serum testosterone levels receiving 12 months of transdermal testosterone therapy experienced, relative to placebo, improved sexual desire but no effect on other parameters of sexual function.

Testosterone therapy prevents gain in visceral adipose tissue and loss of skeletal muscle in nonobese aging men.

BACKGROUND: Trials of testosterone therapy in aging men have demonstrated increases in fat-free mass (FFM) and skeletal muscle and decreases in fat mass (FM) but have not reported the impact of baseline body composition. OBJECTIVE: The objective of the study was to determine the effect, in nonobese aging men with symptoms of androgen deficiency and low-normal serum testosterone levels, of testosterone therapy on total and regional body composition and hormonal and metabolic indices. METHODS: Sixty healthy but symptomatic, nonobese men aged 55 yr or older with total testosterone (TT) levels less than 15 nm were randomized to transdermal testosterone patches or placebo for 52 wk. Body composition, by dual-energy x-ray absorptiometry (FM, FFM, skeletal muscle) and magnetic resonance imaging (abdominal sc and visceral adipose tissue, thigh skeletal muscle, and intermuscular fat) and hormonal and metabolic parameters were measured at wk 0 and 52. RESULTS: Serum TT increased by 30% (P = 0.01), and LH decreased by 50% (P < 0.001). Relative to placebo, total body FFM (P = 0.03) and skeletal muscle (P = 0.008) were increased and thigh skeletal muscle loss was prevented (P = 0.045) with testosterone therapy and visceral fat accumulation decreased (P = 0.001) without change in total body or abdominal sc FM; change in visceral fat was correlated with change in TT levels (r2 = 0.36; P = 0.014). There was a trend to increasing total and low-density lipoprotein cholesterol with placebo. CONCLUSION: Testosterone therapy, relative to placebo, selectively lessened visceral fat accumulation without change in total body FM and increased total body FFM and total body and thigh skeletal muscle mass. Further studies are needed to determine the impact of these body compositional changes on markers of metabolic and cardiovascular risk.