A new study, Testosterone in Older Men with Mobility Limitation (also known as the TOM Trial), has become the very first scientific study to not only suggest a significant association between the male sex hormone testosterone and mobility in older men who are otherwise healthy, but also to back up these claims with what appears to be quite solid findings.
While further studies are required to fully understand the extent of the testosterone effect, this new study has provided hope to many older men who struggle to complete physical, every tasks such as walking, climbing stairs, or standing for long periods. Many men manage their mobility issues successfully in the home through the use of mobility aids such as stairlifts, but lack confidence when outdoors which can potentially limit time spent away from the home, and have a significant impact upon an individual's social life.
The study explained
The study is question focused upon peak VO2 levels, or the maximum oxygen uptake during periods of physical exercise. Oxygen uptake is the amount of oxygen that is absorbed by the body when breathing. VO2 tends to peak around age 20, when the maximum oxygen uptake is, on average, around 55 ml/kg/minute. Peak levels then begin to drop, averaging around 30 ml/kg/minute at age 60, and continuing with a 10 percent decrease per decade. High intensity exercise has been found to reduce this age-related decline by up to 50 percent in both young and middle aged men, but even the most active of exercises have not been able to slow the decreasing rate in older men. Prior to this study, it was widely believed that there was little, if anything, that could be done to counteract VO2 decline in older men.
The male participants in this new study presented with an average baseline maximum oxygen uptake of 20.5 ml/kg/minute - considered to be very low to the point where exercise would near a near impossibility for the participants due to breathing difficulties. The participants were treated with 10 mg/day of testosterone gel over a 6 month period, and showed an almost steady maintenance in peak VO2 following this period (in fact, the maximum oxygen levels actually increased slightly to 21.1 ml/kg/minute). The results were not the same, however, for the control group who were instead treated with a placebo across the 6 month trial. Not only did the control group fail to maintain peak VO2 levels, they actually declined by an average of 0.7 ml/kg/minute. This shows a clear association between testosterone levels and oxygen uptake, and also provides the strongest evidence yet of a link between testosterone and mobility.
How and why it works
The big question is - how and why does testosterone treatment work? While there is so far no definite reasoning, there are two potential explanations that stand out. The first is that testosterone has long been thought to have an anabolic effect. An anabolic state occurs when the body utilises energy from dietary nutrients to grow muscles and maintain a healthy mass, and it is possible that greater levels of testosterone can encourage the body to use its nutrients in much more efficient and effective ways. This was seen in a study of men who produced very small amounts, if any, of sex hormones. The men were treated with 100 mg/week of testosterone, and muscle mass was reported to have increased by an average of 4.9kg by the end of the study. It is thought that greater muscle mass can make exercise easier, and can give the muscles the underlying force they need to work, allowing for smoother mobility.
A second possible reason for testosterone helping to improve mobility is because of the relaxing effect the hormone has on the blood vessels in the body. Research has found that testosterone can increase the width of coronary arteries by 0.08mm, which, given the tiny size of arteries, is quite remarkable. In this instance, testosterone mimics the effects of exercise, which dilates the blood vessels allowing for greater blood flow to the muscles and increasing the levels of oxygen and glucose in these vital areas which is important for muscle growth and repair. Once again, the stronger and healthier the muscle, the fewer problems that should be faced with regard to mobility in older adults without additional health complaints.
More research into appropriate treatment methods is required before testosterone can be used as a way of managing restricted mobility. In 2010, the Boston Medical Center and the National Institute on Ageing attempted to conduct a TOM trial looking at a link between testosterone and sarcopenia (age-related muscle loss), but were forced to cut short the study due to findings that indicated that the level of testosterone used to treat the participants was potentially increasing the risk of high blood pressure and heart attacks. The starting dose for testosterone was listed as 10 g/day - much higher than the 10 mg/day used in the new TOM trial. It appears that even small doses can have big effects when it comes to improving mobility in the elderly.
So what does this new study mean for today's older population? While we shouldn't be expecting to ditch the canes any time soon, it does provide a ray of hope that there are ways to counteract some of the more common effects of ageing that are often seen as the norm - something that's supposed to happen. While an age-related decline in mobility occurs in most of the population, those who are hit more severely can suffer devastating effects. Mobility issues in the elderly are often cited as contributing to loneliness, isolation, and depression amongst other serious concerns relating to mental health, as well as to the increase in physical injury resulting from trips and falls. This study provides hope that, in the future, physical treatments may be able to compliment existing methods of managing limited mobility, including wheelchairs, stairlifts, grab rails, and hoists.