The strength of the hands is determined by genes
Scientists have found a genetic correlate of grip strength
Denis Strigun, Naked Science
An important criterion for the physical development of a person is the strength of the grip. Thus, in the framework of static load tests, it allows relatively reliable prediction of the quality of life in old age and even the status of patients after surgery for a fracture of the proximal epiphysis of the hip. In addition, loosening of the grip is believed to indicate an increased risk of cardiovascular diseases and mortality. At the same time, the trait has a high heritability – 30-65 percent, but so far its genetic correlate is unclear. Due to relatively small samples (up to 27 thousand people), the results of such studies – two have been conducted to date – remain unreliable.
To clarify the genetic correlate of grip strength, the authors of the new work used data from two large projects – the UK Biobank and CHARGE (a total of eight additional studies). The final sample included samples of 195,180 people aged 20 and over, most of whom, however, were significantly older, and there were no non-Europeans among the UK Biobank participants. The grip strength of the latter was measured using a wrist dynamometer, after which it was compared with gender, age and body mass index (BMI) using a Bayesian network. Scientists analyzed biomaterials by genome-wide association search.
The results showed that the heritability of single–nucleotide variations (SNV) associated with the trait is slightly less than previously thought - about 23.9 percent. At the first stage, the analysis of only samples from the Biobank allowed the authors to identify 21, and the inclusion of 53,145 other people in the consideration – to reduce the indicator to 16 specific loci. They attributed variations in the genes POLD3, TGFA, ERP27, HOXB3, GLIS1, PEX14, MGMT, LRPPRC, SYT1, GBF1, KANSL1, SLC8A1, IGSF9B, ACTG1 to universal high-frequency ones. Less often, the association with grip strength was demonstrated by variations of DEC1 and HLA genes. It is noteworthy that in total their positive correlation was stronger in men and was not observed for age.
It is known that a number of these loci are involved in maintaining muscle tone. Thus, ACTG1 affects skeletal muscles through a dystrophin-associated glycoprotein complex, the disruption of which can lead to dystrophy. SLC8A1, in turn, determines electromechanical coupling (contraction due to the action potential of cell membranes in fibers), whereas mutations in PEX14 are accompanied by peroxisomal diseases, one of the symptoms of which is muscle weakness. Subsequent analysis also revealed 25 transcripts (RNA) that are expressed in at least one type of tissue associated with grip strength, including the brain, and correlate with each other.
Additionally, the authors tested the hypothesis of a causal relationship between grip strength and the risk of death. Neither for cardiovascular diseases, nor for all causes, it was not confirmed. At the same time, the mineral density of the femoral head positively correlated with the genetic markers of the trait (it is located on the proximal epiphysis, rehabilitation after a fracture of which, as reported above, can be tracked by the strength of the hands). The data obtained clarify the contribution of genetic factors to physical development and their relationship with age-related disorders and mortality.
Article by Willems et al. Large-scale GWAS identifies multiple loci for hand grip strength providing biological insights into muscular fitness published in the journal Nature Communications.
Portal "Eternal youth" http://vechnayamolodost.ru
13.07.2017