It's well known that postmenopausal women tend to lose lean muscle mass, while at the same time gaining adipose tissue. Researchers now say postmenopausal women who take low doses of methyltestosterone can increase lean body mass by as much as four to six percent while decreasing adipose tissue by two to four percent. Dr. Adrian Dobs, associate professor and vice-chair of clinical research at Johns Hopkins University School of Medicine in Baltimore, presented the findings from this study at ENDO 99, the annual meeting of the Endocrine Society, in San Diego. Dr. Dobs explained postmenopausal women typically increase their body fat by more than 20 percent and lose four percent of muscle within the first three years of menopause. Besides increasing the woman's susceptibility to other health problems such as cardiovascular disease and diabetes, this change may also leave women at higher risk of general physical weakness, osteoporosis, falling and perhaps breaking limbs. The Johns Hopkins study found that healthy postmenopausal women who take oral methyltestosterone in addition to their hormone replacement therapy achieved a double benefit.

"Postmenopausal women often experience an increase in fat tissue and a decrease in muscle tissue," Dr. Dobs said. "These data show that estrogen-androgen therapy may improve body composition in healthy women, but further study is needed to determine if this therapy is effective in other groups, including women with chronic conditions such as diabetes and cancers." The study involved 40 women, all taking normal doses of hormone replacement therapy (0.625 mg estrogen per day) who were given either 1.25 mg of esterified estrogen (Estratab) or 2.5 mg of methyltestosterone (Estratest) plus the Estratab for a four-month period. The women ranged in age from 48 to 62 years. Both groups started the study with compatible hormone profiles, yet at the end of the four-month period, there were significant differences in estradiol levels, particularly in the group that received Estratab. In the group that received both Estratest and Estratab, there were significant increases in both total testosterone and bio-available testosterone, which were not evident in the Estratab alone group. There were highly statistically-significant increases in lean muscle mass in the trunk legs and arms of women taking Estratab and Estratest, in combination, as well as significant decreases in fat deposits in the trunk and legs of the women in the combination group. The women who were in the Estratab alone group did not show any significant increases in muscle or fat at any location on the body. The body's production of androgen and estrogen drops off after menopause, but the impact of post-menopausal androgen depletion has not been studied to any great extent.

It has been previously reported that combined androgen-estrogen therapy can help increase bone mineral density, which may help prevent fractures in older women who are at risk of developing osteoporosis. The increase in lean muscle mass and decrease in adipose tissue in these women does not necessarily mean they lost weight. Indeed, no decrease in adipose tissue was seen on the well-known skin fold test. It was seen, however, on a much more sophisticated test, DUAL (Dual Energy X-ray absorptiometry) which measures deposits of muscle and fat deeper within the body.