Assessing the Prevalence of Sarcopenia
Sarcopenia is the name given to the characteristic loss of muscle mass and strength that accompanies aging, though formal definitions under development tend towards including only those with the greatest degree of loss. This is something of a political problem in the research and medical community; the tendency to describe some level of aging as normal and therefore not treatable, while classifying greater degrees of exactly the same process and symptoms as a disease. Along with the failure of the immune system and loss of bone strength, sarcopenia is one of the most evident forms of age-related frailty. A good many research groups are involved in the attempt to find ways to slow or reverse this decline, most of which are focused on mechanisms of stem cell activity and tissue regeneration rather than fundamental damage after the SENS model of aging. Of the present options outside the SENS portfolio, gene therapies or antibody therapies that target the muscle growth regulators of myostatin and follistatin appear most promising in the short term, given the rapid progress taking place in the broader field of genetic editing.
Sarcopenia, an age-related decline in muscle mass and function, is one of the most important health problems in elderly with a high rate of adverse outcomes. However, several studies have investigated the prevalence of sarcopenia in the world, the results have been inconsistent. The current systematic review and meta- analysis study was conducted to estimate the overall prevalence of sarcopenia in both genders in different regions of the world.
Electronic databases were searched between January 2009 and December 2016. The population- based studies that reported the prevalence of sarcopenia in healthy adults aged ≥ 60 years using the European Working Group on Sarcopenia in Older People (EWGSOP), the International Working Group on Sarcopenia (IWGS) and Asian Working Group for Sarcopenia (AWGS) definitions, were selected. According to these consensual definitions, sarcopenia was defined by presence of low muscle mass (adjusted appendicular muscle mass for height) and muscle strength (handgrip strength) or physical performance (the usual gait speed). The random effect model was used for estimation the prevalence of sarcopenia.
Thirty-five articles met our inclusion criteria, with a total of 58,404 individuals. The overall estimates of prevalence was 10% in men and 10% in women, respectively. The prevalence was higher among non-Asian than Asian individuals in both genders especially, when the Bio-electrical Impedance Analysis (BIA) was used to measure muscle mass (19% vs 10% in men; 20% vs 11% in women). Despite the differences encountered between the studies, regarding diagnostic tools used to measure of muscle mass and different regions of the world for estimating parameters of sarcopenia, present systematic review revealed that a substantial proportion of the old people has sarcopenia, even in healthy populations. However, despite sarcopenia being a consequence of the aging progress, early diagnosis can prevent some adverse outcomes.
I'm just wondering isn't resistance exercise an easy way to reverse the effects of sarcopenia? I'm in my 60ties and doing it for years at least three times a week, and this has just done well to me.
@bardu: Resistance exercise has been shown to help. See for example:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5303008/
There is certainly a component of sarcopenia that is due to lack of suitable exercise in older people. But it is only a component. There are underlying processes that exercise can't help with.
Not just resistance exercise, any sufficiently vigorous exercise will do. I'm a 51yo lifelong distance runner and am still pretty muscular. The trick to keeping going is to realise that you can no longer take ANY muscle for granted. You have to tone all of them.
For eg I was getting pains in my vastus medialis accessorius muscles (medial to the kneecap) and eventually figured out it was because my hip adductors (bring the knees together) were weak and I was walking and running with my knees/feet too far apart. Simply through natural sarcopenia. Running is very linear forward motive exercise. The muscles either side of the legs, adductors and abductors, do not get used as much extensors and flexors.
Having realised the problem a week spent consciously activating my adductors when walking fixed the problem. I bought an exercise band of the sort which can be fixed in a door and regularly use it to work both adductors and abductors (always to equal amounts, imbalances not wanted here).
This shows that accepting sarcopenia as inevitable and giving in to it is the wrong response. My days of sustained 7 minute miles are likely behind me but I can still train and improve.
Person I look up to most in the exercise world is not Arnold nor Dwayne. I admire Jack Lalanne because he kept at it until he died in his 90's. Not old did he exercise for many decades, but also focused on eating and drinking (juices) healthy.
Although I know exercise will not guaranteed no death, at least it will extend it and reduce liklihood of chronic illness. So, not only should one do strength training, but also cardio. And, stretching/yoga won't hurt either.
@Reason I would add this as well
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3289515/
For me, it seems one can do a lot to extend lifespan and healthspan until SENS-style rejuvenation therapies become available.
My strategy is a good lifestyle, healthy diet ( I'm on Paleo diet for a decade ), exercise and fasting (to get rid of senescent cells to some degree).
However, it needs a lot of power of will and persistence to get there.
I wonder what the prevalence of senescent cells in skeletal muscle is as we age?
Given that muscle fibres are long and thin, any muscle cells going senescent (and then being cleared) could result in a break and loss of the effectiveness of that fibre.
I seem to remember reading that as you get older you lose the numbers of fibres you have overall, even with exercise, but that the remaining fibres can be strengthened (thickened) to compensate. This seems to fit with the senescent cell explanation I've outlined above and also highlights the importance of Stem Cell therapy to be used alongside Senescent Cell clearance in aged individuals...
I think you need to concentrate on exercise/foods/supplements that maintain muscle mass...flexibility (tendons and joints)...bone strength.
And there are certain foods/supplements that are likely to help.
For myself the difference between no exercise and a fairly unimpressive 2 half-hour sessions per week is the difference between night and day.
In all things aging...it's use it or lose it?
You need to have the brain to understand this...