Testosterone Can Improve Muscle Mass and Function in Men, But Can this Therapy Work for Women?

by Chael Needle

LifeGuide [Treatment Horizons]

According to a report published in the April 26th issue of the Archives of Internal Medicine, women living with HIV/AIDS who have low body weight may have a new option to increase their muscle strength: testosterone-replacement therapy. Testosterone-replacement therapy has been long approved and used by men to regain HIV-related loss of muscle; testosterone is primarily considered to be a male hormone, responsible for muscle growth, energy levels, and libido, among other things, but it is also found in women (at levels of ten percent of those seen in men). Though the treatment is not FDA-approved for women, that may change if this and other studies build enough evidence as to its safety and efficacy. Though antiretroviral therapy has decreased the overall numbers of those with body wasting, roughly one-quarter of the estimated 300,000 HIV-positive women in the United States suffer from HIV-related muscle wasting.

The search for more treatment options is important because muscle is an essential part of surviving HIV. Muscle helps to regulate hormones and to fight off and recover from infections. Opportunistic infections often drain energy levels; if the protein needed to fight off an infection is not present in nutritional intake, for example, the body will feed off of the protein in muscle.

 The impetus for this study arose because “[p]rior studies have shown that testosterone levels are low in HIV-infected women and correlate with decreased muscle mass and function,” says the lead author of the study, Steven Grinspoon, M.D., an Associate Professor of Medicine and Director of the Massachusetts General Hospital Program in Nutritional Metabolism in Boston. Increased muscle mass is important, says Dr. Grinspoon, because it “translates into improved functional status; thus patients should be able to do more and feel better with increased muscle mass.” Quality of life, in other words, is at stake.

In the randomized study, the fifty-seven participants had lost an average of eighteen percent of their pre-illness weight or weighed less than ninety percent of the ideal weight for women their age, and had total testosterone levels below the median of the reference range of 10–55 ng/dL. They also showed loss of muscle function. Most were currently taking antiretrovirals and all were on approved birth control; twenty-five percent had an undetectable viral load. They received testosterone at levels normal for women or placebo twice weekly for six months via a 4mg transdermal patch.

Significant improvement was shown in those who had received the potential adjunctive treatment versus those who had received placebo. Participants treated with the patch demonstrated significant improvements in shoulder flexion, elbow flexion, knee extension, and knee flexion compared with subjects who received placebo. Testosterone levels in blood significantly were increased into the upper half of or slightly above the normal range for most participants. Women who used the patch showed a trend toward increased muscle mass; the change, however, did not reach statistical significance. Total weight did not increase, nor were significant changes in either total body fat or abdominal fat reported.

The treatment was well-tolerated and did not adversely affect glucose and lipid metabolism, liver function, or body composition. The testosterone patch did not produce signs of masculinization—hirsutism, voice deepening, menstrual irregularities, among others. 

Says Dr. Grinspoon: “In general, testosterone levels are lower with more advanced disease, e.g., with higher viral load, lower CD4 count, and weight loss.  These patients with advanced disease and lower testosterone may therefore benefit from testosterone treatment. We have not seen any negative effects of testosterone on viral load or CD4 count.”

What’s the next step for this study? Says Dr. Grinspoon: “We are currently performing a larger, longer study to see if the effects are sustained over time and to determine if testosterone may help to improve bone density.” 

Chael Needle wrote about biological therapy candidate, VRX496, in the June issue.

July 2004