Relationship Between Automatic Nervous Function And Physical Performance In Elderly

Background: The increasing aging of the elderly is usually accompanied by the occurrence of many diseases,increasing the burden of medical care and economy for the society.Autonomic nervous function(ANS)is a progressive degenerative process in the elderly and associated with many diseases of the elderly(such as hypertension,diabetes,hyperlipidemia,obesity,etc.).Declines in physical performance,such as in muscle strength,walking speed,and balance function,are also common in older adults and also associated with varieties of diseases,which are characterized by progressive degeneration.The correlation between these two is still inconclusive,especially in the elderly under different conditions,so further in-depth research is needed to provide references for clinical prevention and rehabilitation treatment.Objective: The purpose of this study was to investigate the correlation between ANS function and physical performance(including muscle strength,walking speed,balance function,etc.)in health status and severe disease status of the elderly.1.To explore the possible risk factors for ANS function in healthy elderly living in Chinese communities,especially the correlation with physical performance;2.Through retrospective study and prospective study,the relationship between ANS function and physical performance was found;3.We observed the relationship between ANS function and physical performance in the elderly under the condition of severe illness.Methods: Our study included elderly people living in communities in Tianjin,China,aged 60 and above.We used the heart rate variability(HRV)and sleep condition these two indexes which were recognized as better response of ANS function to study.Among HRV indexes,we mainly used LF/HF(low frequency/high frequency)for analysis(other indexes include SDNN,RMSSD,LF,HF,etc.),and it was divided into three groups of low,middle and high groups according to the third-grade division of population values.Sleep duration was taken as the main study indicator,it was grouped according to <7h(short time),7-8h(medium time),>8-9,and >9h(long time).A total of 1,722 elderly people were collected,with an average age of 65.4�5.8 years,48.3% of them were male.We assessed grip strength,4 m walking speed and TUGT as measures of muscle strength,walking speed and balance function.Results: 1.In our observations,LF/HF,as the main indicator of ANS balance,is associated with many related risk factors,such as age,widowhood,diabetes,stroke,coronary heart disease,kidney disease,grip strength,etc.Further analysis showed that compared with the moderate ANS function,the high LF/HF group presented higher grip strength 24.8(23.4-26.1)and longer TUGT duration 9.1(8.7-9.6),while the low LF/HF group presented lower grip strength 22.7(21.3-24.0).In terms of sleep duration,there was a general correlation between sleep duration and physical performance ability.2.A retrospective study of HRV and physical performance found that compared with moderate ANS function,the low LF/HF group and the high LF/HF group were associated with an inverted u-shaped decline in grip strength-11.15(-12.68,-4.29),-5.52(-10.68,3.31),and-10.91(-12.87,-3.38).Further correction revealed a significant decrease in grip strength of-13.62(-17.42,-3.69)in the low LF/HF group.In the prospective study of sleep and physical performance,there was a significant decrease in muscle mass in the short sleep group of-9.96(-13.63,-5.86)compared to the medium sleep group,and short and long sleep was associated with a u-shaped risk of new falls,3.67(2.59,5.42),1.24(0.73,2.01),and 2.35(1.29,3.52).3.In elderly patients with coronary heart disease surgery observed the predictive value of grip strength,using AUC analysis,found grip strength recovery value(0.837,P<0.001)and cardiac complications have significant difference,cut-off point is 83.92%,then according to the grouping tangent point values,the poor grip strength recovery groups,HRV is lower than normal grip strength recovery group whole,SDNN(31.70�18.57 vs.47.72�29.37,P=0.027),HF(98.81�57.71 vs.212.82�82.12,P=0.024),LF(101.55�45.04 vs.210.57�145.05,P=0.015)were especially significant.Conclusion: ANS function in the elderly is associated with a variety of risk factors,and is associated with a variety of diseases in the elderly(hypertension,diabetes,cardiovascular disease,etc.).It is suggested that the lifestyle of sleep can be used as a potential pathway in clinical work,which may improve the relationship between ANS and physical fitness,facilitate early screening of diseases in the elderly,and prevent the deterioration of the disease or complications.In cardiac surgery prospective studies show that poor grip strength recovery of elderly patients have a higher risk of complications within 30 days after discharge,poor autonomic nervous function and perioperative recovery associated with poor grip,which in turn affect the incidence of postoperative complications,the findings provide a reference for clinical early detection and prevention of physical decline.