"Strength genes" protected against disease and premature death
Finnish researchers have concluded that genes affecting hand grip strength have far-reaching implications for human life and health.
Scientists have known for a long time that muscle strength can correlate with health indicators. However, genetic studies have not been conducted on a large sample. Scientists from the University of Jyväskylä (Finland) decided to correct this deficiency.
Their work involved 342,443 people whose data were taken from the Finnish biobank FinnGen Data Freeze 10 (53.2 per cent of the subjects were women). The participants ranged in age from 40 to 108 years old. The researchers focused on the combined genotype of the volunteers and registry data on their health.
"To our knowledge, this is the first study to examine the link between genetic predisposition to muscle strength and various diseases of this magnitude," said Päivi Herranen, first author of the paper published in The Journals of Gerontology.
The team of scientists used what is known as a polygenic score, or polygenic score (PGS), a number that summarises the estimated influence of many genetic variants on an individual's phenotype. The researchers compared the health indicators of participants who were genetically more or less predisposed to handgrip strength.
The researchers looked at 27 life and health indicators, including some non-communicable diseases (lung, musculoskeletal, connective tissue, cardiovascular, cancer, fractures, mental disorders) and premature mortality.
It turned out that a higher polygenic index of handgrip strength was associated with a 2-10 per cent lower risk of death from any cause, primarily cardiovascular disease. In addition, participants of both sexes with high levels of PGS handgrip strength were found to be less prone to depression. The same level of polygenic score correlated with low body mass index in women, but not in men.
The effect was most significant for polyarthrosis, a degenerative joint disease, as well as vascular dementia caused by restricted blood flow to the brain (a consequence of strokes). Compared to those participants who ranked lowest in PGS handgrip strength, those at the top had a 23 per cent lower risk of polyarthrosis and a 21 per cent lower risk of vascular dementia.
Overall, the scientists concluded that muscle strength, cognitive function and depressive disorders may be partially regulated by the same genetic background.
"The genetic predisposition of muscle strength seems to reflect to a greater extent a person's intrinsic ability to resist and protect themselves from pathological changes that occur during body aging than the ability to recover from adversity," Päivi Herranen told us.
It should be noted that due to environmental changes, the strength of people in our era is rapidly declining.