June 23, 2011
Testosterone To Reverse Muscle Loss
By Lydia Jennings, Ivanhoe Health Correspondent
(Ivanhoe Newswire) -- Along with aging comes the consequence of losing muscle mass too. A common treatment used to reverse the loss of lean muscle tissue are anabolic steroids. However, anabolic steroids can have many unwanted side effects. Now, new research shows that nine proteins, isolated from blood, alter with age and that the profile of some of these proteins can be reversed by testosterone treatment.
"One of the universal features of aging is natural decline in muscle, with declines in muscle there's an increase risk for frailty, fractures, hospitalization, all together an undesirable outcome," Dr. Monty Montano, Ph.D. of Boston University School of Medicine, Infectious Diseases, and study author, told Ivanhoe.
The study involved comparing protein levels in serum samples from two groups of men, ages 18-35 and 60-75. Seven proteins, which were either growth factors (IGF-1, IL-7, IL-12p40, PDGFÃÅ¸), or were involved in immune response (ENA78, MIP-1ÃÅ¸, IP-10), and pro-collagen (PIIINP) were all reduced in older men. In contrast the monokine MIG, also involved in immune activity, was elevated.
For both groups of men, the testosterone treatment increased lean muscle mass, and levels of the appetite suppressing hormone leptin. Testosterone also increased levels of PIIINP and IGF-1 in young men and the researchers saw a similar increase in a small group of older men.
"The blood proteins we found that altered with healthy aging also have links to maintenance of muscle, such as IGF-1 and pro-collagen, or are involved in regulation of the immune system, possibly reducing T-cell and neutrophil responses with age. Additionally all of the proteins we found are involved with the signaling pathways controlled by AKT, NF?ÃÅ¸ and TGFÃÅ¸ which are known to be associated with aging," Dr. Montano said.
"It is no simple matter to find a one size fits all test for aging "“ our results suggest that there is a difference in response to anabolic steroids between young and older men, despite both groups increasing in muscle mass. It seems that testosterone replacement does not necessarily mean a restoration of full testosterone functionality for the older man," Dr. Montano said.
Dr. Montano believes there is a need for newer anabolic formulations that frail older men can tolerate as well. "The real challenge to medial research, is understanding how these different approaches might synergize with each other. We think that testosterone plus exercise will actually improve the strength and ability that you see in younger people, more than testosterone alone or exercise alone, but we don't know for sure. Those studies need to be done and the biomarkers that reflect healthy aging need to be measured alongside," Dr. Montano said. He hopes to assemble a larger list of proteins associated with healthy aging, and to identify new therapeutics that can restore the levels of some of the healthy aging biomarkers.
SOURCE: Immunity and Aging, June 22, 2011