Effect of Testosterone Treatment on Body Composition and Muscle Strength in Men Over 65 Years of Age¹

Abstract

As men age, serum testosterone concentrations decrease, the percentage of body mass that is fat increases, the percentage of lean body mass decreases, and muscle strength decreases. Because these changes are similar to those that occur in hypogonadal men, we hypothesized that increasing the serum testosterone concentration of men over 65 yr of age to that in young men would decrease their fat mass, increase their lean mass, and increase their muscle strength. We randomized 108 men over 65 yr of age to wear either a testosterone patch or a placebo patch in a double blind study for 36 months. We measured body composition by dual energy x-ray absorptiometry and muscle strength by dynamometer before and during treatment. Ninety-six men completed the entire 36-month protocol. Fat mass decreased (-3.0+/-0.5 kg) in the testosterone-treated men during the 36 months of treatment, which was significantly different (P = 0.001) from the decrease (-0.7+/-0.5 kg) in the placebo-treated men. Lean mass increased (1.9+/-0.3 kg) in the testosterone-treated men, which was significantly different (P < 0.001) from that (0.2+/-0.2 kg) in the placebo-treated men. The decrease in fat mass in the testosterone-treated men was principally in the arms (-0.7+/-0.1 kg; P < 0.001 compared to the placebo group) and legs (-1.1+/-0.2 kg; P < 0.001), and the increase in lean mass was principally in the trunk (1.9+/-0.3 kg; P < 0.001). The change in strength of knee extension and flexion at 60 degrees and 180 degrees angular velocity during treatment, however, was not significantly different between the two groups. We conclude that increasing the serum testosterone concentrations of normal men over 65 yr of age to the midnormal range for young men decreased fat mass, principally in the arms and legs, and increased lean mass, principally in the trunk, but did not increase the strength of knee extension and flexion, as measured by dynamometer.

Proof of the effect of testosterone on skeletal muscle

“…Although testosterone supplementation is associated with greater gains in grip strength than are achieved with placebo treatment, it remains unclear whether physiologic testosterone replacement can produce meaningful changes in muscle performance and physical function. In a recent study by Snyder et al (1999), testosterone treatment of older men did not increase muscle strength or improve physical function, but these men were not uniformly hypogonadal and were unusually fit for their age. In addition, their muscle strength was measured by a method (Biodex dynamometer) that did not demonstrate a response even in frankly hypogonadal younger men treated with testosterone .…”

“…Some studies of young, hypogonadal men have reported a decrease in fat mass with testosterone replacement therapy (Brodsky et al 1996, Katznelson et al 1996, whereas others , Bhasin et al 1997 found no change. In contrast, long-term studies of testosterone supplementation in older men have consistently demonstrated a decrease in fat mass (Snyder et al 1999). Epidemiologic studies (Barrett-Connor & Khaw 1988, Seidell et al 1990 have shown that serum testosterone levels are lower in middle-aged men with visceral obesity.…”

“…Several studies (Tenover 1992, 2000, Morley et al 1993, Sih et al 1997, Snyder et al 1999 have now established that the use of testosterone supplementation to increase the testosterone in older men with low testosterone concentrations to values that are mid-normal for healthy young men is associated with a significant increase in lean body mass and a reduction in fat mass (Table 2). Although testosterone supplementation is associated with greater gains in grip strength than are achieved with placebo treatment, it remains unclear whether physiologic testosterone replacement can produce meaningful changes in muscle performance and physical function.…”

Testosterone inhibits tumor necrosis factor‐α‐induced vascular cell adhesion molecule‐1 expression in human aortic endothelial cells

“…There is agreement that T levels decline progressively with advancing age, and that many of the physiological changes that occur with aging are similar to those associated with androgen deficiency in young men. Some studies have reported that T administration to older men with low or low normal T levels improves various physiological indices [1,2]. However, it is premature to make a general recommendation about T replacement in these men, because the risks of long‐term T administration, particularly the risk of cardiovascular disease, are unknown.…”

Osteoporosis in Men - A Crucial Role of Sex Hormones

“…In this elderly population, effects of testosterone treatment on BMD have been inconsistent, with the most convincing effects being observed in men with very low serum testosterone (Katznelson et al1996;Snyder et al 2000;Wang et al 2001). In elderly men, testosterone treatment may have additional beneficial effects on muscle mass and strength, which may help decrease fracture risk through a reduced propensity to fall (Snyder et al 1999). Nevertheless, the effect of testosterone treatment on fracture risk is unknown.…”