Loss of muscle mass is not only associated with disease, such as HIV and cancer, but also with the normal aging process. Anabolic steroids are sometimes used to reverse loss of lean muscle tissue but they can have unwanted side effects. New research, published in BioMed Central's open access journal Immunity and Aging, 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.
In a combined study, researchers from Boston University School of Medicine and University of Texas Medical Branch compared protein levels in serum samples from two groups of healthy men - young men aged 18-35 and older men aged 60-75. Seven proteins, which were either growth factors (IGF-1, IL-7, IL-12p40, PDGFβ), or were involved in immune response (ENA78, MIP-1β, IP-10), and pro-collagen (PIIINP) were all reduced in older men. In contrast the monokine MIG, also involved in immune activity, was elevated.
Testosterone treatment increased lean muscle mass, and levels of the appetite suppressing hormone leptin, for both groups of men. 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.
Dr Monty Montano said, "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, NFκβ and TGFβ which are known to be associated with aging."
Dr Montano continued, "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."
Notes to Editors
1. Identification of serum biomarkers for aging and anabolic response
Camellia Banerjee, Jagadish Ulloor, Edgar L Dillon, Qusai Dahodwala, Brittani Franklin, Paola Sebastiani, Melinda Sheffield-Moore, Randall J Urban, Shalender Bhasin and Monty Montano
Immunity & Ageing (in press)
Please name the journal in any story you write. If you are writing for the web, please link to the article. All articles are available free of charge, according to BioMed Central's open access policy.
Article citation and URL available on request at firstname.lastname@example.org on the day of publication.
2. Immunity & Ageing is an Open Access, peer-reviewed, online journal that considers manuscripts on all aspects of ageing examined from an immunological point of view.
3. BioMed Central (http://www.biomedcentral.com/) is an STM (Science, Technology and Medicine) publisher which has pioneered the open access publishing model. All peer-reviewed research articles published by BioMed Central are made immediately and freely accessible online, and are licensed to allow redistribution and reuse. BioMed Central is part of Springer Science+Business Media, a leading global publisher in the STM sector.
AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert! system.