Association Of Cystatin C With Chronic Disease,Creatinine/Cystatin C With Disability In Middle-aged And Elderly People In A Community Based On CHARLS Data

BackgroundCystatin C(Cys-C)is a low molecular weight protein that is stably expressed in all human nucleated cells.Studies have shown that Cys-C is associated with diseases such as cardiovascular,cerebrovascular,depression,and cognitive function in the elderly.In recent years,studies have shown that low skeletal muscle mass or sarcopenia in community-dwelling older adults can be identified by predicting Cr/Cys-C levels for muscle mass.Grip strength is one of the important evaluation indexes of basic physical activity ability in middle-aged and elderly people,and low grip strength is a prerequisite for the diagnosis of sarcopenia.The study showed that the basic physical activity ability of the elderly is not only an early warning indicator of disability in the elderly,but also a powerful predictor of multiple adverse health outcomes in the elderly.But the study on the effect of basic physical activity ability on the occurrence of disability in the elderly is in its infancy and lacks systematicness,and the effect of Cr/Cys-C on the disability was seldom studied.ObjectiveThis study will analyze the association between Cys-C and the prevalence of common chronic diseases,the association between Cr/Cys-C ratio and grip strength,and the association between Cr/Cys-C,basic physical activity and disability,providing help for clinical chronic disease diagnosis and comprehensive management of middleaged and elderly people.Materials and MethodsThe original data were obtained from the 2015 CHARLS database,and people aged 45 years and above who completed the relevant blood studentization examinations were be selected。Use the χ2 test,and logistic regression and ROC curves to compare the conditions of different characteristics and analyze the association between Cys-C and the prevalence of common chronic diseases,the association between Cr/Cys-C ratio and grip strength,he association between Cr/Cys-C ratio,basic physical activity ability and disability.Results1,Of the 6111 study subjects,509 had high Cys-C levels,including 361 males and 148 females,and the overall high Cys-C level ratio was 8.33%,including 10.99%in males and 5.24%in females,and the high Cys-C level ratio was higher in males than in females(P<0.05).After controlling for confounders,high Cys-C levels had an effect on hypertension[OR(95%CI)=2.00(1.59-2.52)],pulmonary disease[OR(95%CI)=1.35(1.03-1.78)],depression[OR(95%CI)=1.25(1.02-1.53)],hyperuricemia[OR(95%CI)=3.33(2.62-4.25)],and hyperlipidemia[OR(95%CI)=1.34(1.09-1.66)](P<0.05),but not on diabetes,stroke,cardiovascular disease,and cognitive impairment(P>0.05).Male high Cys-C level had an effect on hypertension[OR(95%CI)=2.25(1.71-2.97)],hyperuricemia[OR(95%CI)=3.13(2.344.20)],and hyperlipidemia[OR(95%CI)=1.58(1.21-2.05)](P<0.05).Female high Cys-C level had an effect on hypertension[OR(95%CI)=1.69(1.11-2.57)]and hyperuricemia[OR(95%CI)=4.30(2.76-6.70)](P<0.05).2,In>50 years old Chinese adults,the Cr/Cys-C ratio was positively and linearly correlated with grip strength,but in multivariate analysis such as age,BMI,Cr,CysC,C-reactive protein,hemoglobin,hypertension,hyperlipidemia,diabetes,cardiovascular disease,stroke,pulmonary disease,cognitive function,depression,and hyperuricemia at addition,the Cr/Cys-C ratio was negatively correlated with grip strength.The Cr/Cys-C ratio seems isn’t an useful biomarker for identifying low grip strength,based on ROC curve analysis.3.Bring into 4368 middle-aged and elderly people,the incidence of disability was 11.9%,12%in men and 11.8%in women,with a mean age of 67.7 years.Cr/CysC ratio,grip strength,sitting up test,and pace had a statistically significant effect on disability in middle-aged and elderly people,but after adjusting for age and gender,they had little effect on disability in middle-aged and elderly people(P=0.054),but ROC curve analysis of each influencing variable in middle-aged and elderly people showed that Cr/Cys-Cratio predicted the probability of disability in middle-aged and elderly people better than grip strength.ConclusionThe high Cys-C level in middle-aged and elderly people in China affects the prevalence of hypertension,pulmonary disease,depression,hyperuricemia and hyperlipidemia in middle-aged and elderly people in China.The rate of high Cys-C in males is higher than that in females.In addition,Cr/Cys-C ratio has a positive linear correlation with grip strength and a significant independent correlation with low grip strength.Its combination of gait speed,sitting ability and other conditions can be used to predict disability in middle-aged and elderly people.It is suggested that the concentration of Cr and Cys-C should be routinely detected in the health examination,and targeted intervention measures should be taken for this part of the population to early detect and reduce the prevalence of related chronic common diseases and minimize the severity of their disability or delay their disability occurrence of middle-aged and elderly people.