Association between muscle strength and executive function in Tibetan adolescents at high altitude in China: Results from a cross-sectional study at 16-18 years of age

BackgroundIn recent years, adolescents have shown a trend of decreasing muscle strength, especially in the upper limbs, and it affects the development of executive functions. However, few studies have been conducted on Tibetan adolescents in high-altitude regions of China. To this end, this study investigated upper limb muscle strength and executive function in Tibetan adolescents in Tibetan regions of China and analyzed the association between them. MethodsA three-stage stratified whole-group sampling method was used to test and investigate grip strength, executive function, and basic information in 1093 Tibetan adolescents from Tibet, a high-altitude region of China. A chi-square test and one-way ANOVA were used to compare the basic status and executive function of Tibetan adolescents with different muscle strength. Multiple linear regression analysis and logistic regression analysis were used to analyze the correlations that existed between muscle strength and each sub-function of executive function. ResultsThe differences between the inconsistently and congruent reaction times of Tibetan adolescents with different grip strength levels (<P-25, P25-75, >P-75) at high altitude in China were statistically significant (F-values of 32.596 and 31.580, respectively; P-values <.001). The differences between the 1-back and 2-back response times for the refresh memory function were also statistically significant (F-values of 9.055 and 6.610, respectively; P-values <.01). Linear regression analysis showed that after adjusting for the relevant covariates, the 1-back reaction time of Tibetan adolescents in the grip strength < P-25 group increased by 91.72 ms (P < .01); the 2-back reaction time of Tibetan adolescents in the grip strength < P-25 group increased by 105.25 ms (P < 0.01), using grip strength > P-75 as the reference group. Logistic regression analysis showed that, after adjusting for relevant covariates, Tibetan adolescents in the grip strength < P-25 group had a higher risk of developing 2-back dysfunction (OR = 1.89, 95% CI: 1.24,2.88), using grip strength >P-75 as the reference group (P < .01). The risk of cognitive flexibility dysfunction (OR = 1.86, 95% CI: 1.16, 2.98) was also increased (P < .05). ConclusionThere was a significant correlation between grip strength and executive function of refresh memory function and cognitive flexibility in Tibetan adolescents in high altitude areas of China. Those with higher upper limb muscle strength had shorter reaction time, that is, better executive function. In the future, we should focus on improving the upper limb muscle strength of Tibetan adolescents at high altitude in China to better promote the development of executive function.