Geographical Distribution Of High-sensitivity C-reactive Protein And Brain Natriuretic Peptide Reference Values ??in Middle-aged And Elderly People

With high incidence,high mortality and complex treatment,cardiovascular and cerebrovascular disease has been the focus of attention of researchers.The aging of the body is an important reason for the decline of cardiovascular and cerebrovascular function.In addition,the study found that the incidence of cardiovascular and cerebrovascular diseases have a younger trend,so the evaluation of cardiovascular and cerebrovascular function among the middle-aged and elderly healthy people is particularly important.Lots of the researchers have studied the effects of physiological changes on cardiovascular and cerebrovascular function from a medical point of view,but few of them took geographical factors into consideration.In fact,in the dynamic balance human-nature system,the residents' physical function differed from one region to another.Using the same standard system of reference value is leading to inaccurate clinical diagnosis.In this study,with the middle-aged and elderly healthy people as research objects,we chose high sensitive C reactive protein(hs-CRP)and brain natriuretic peptide(BNP)as medical indices for they can reflect cardiovascular and cerebrovascular function sensitively and specifically.In addition,totally twelve geographical indices were selected here including the altitude,annual sunshine hours,annual mean temperature,soil pH and so on.Then,the relationship between these two medical indices and relevant geographic data were analyzed by qualitative and quantitative analysis.What we found were as follows:(1)The normal reference values of hs-CRP and BNP among the middle-aged and elderly healthy Chinese have strong spatial autocorrelation,which mean that the geographical indices do have important influence on them.What's more,the normal reference values of hs-CRP are significantly correlated with altitude,annual sunshine hours,annual mean temperature,annual precipitation,annual temperature difference,annual mean wind speed,topsoil pH and surface clay soil cation exchange capacity,while the normal reference values of BNP correlated significantly with altitude,annual mean temperature,annual average relative humidity,annual precipitation,annual temperature difference and annual mean wind speed.(2)To establish predictive models among the normal reference values of hs-CRP and BNP and relevant geographical indices data,including the partial least squares regression model,the ridge regression model,the artificial neural network model,the support vector machine model,and a combined forecasting model based on these four single models,respectively.Which shows that the combined predictive model of hs-CRP and BNP can reach the best fitting effect among these models.(3)The spatial distribution maps show that the normal reference values of hs-CRP and BNP both have obvious differences in spatial distribution.What's more,the normal reference values of hs-CRP distributed from northeast to southwest,while the normal reference values of BNP is descending from southeast to northwest.The above conclusions fully prove that the geographical environment have important influence on the cardiovascular and cerebrovascular function of middle aged and elderly Chinese.Therefore,it's quite necessary to take the geographic factors into consideration while fumualting the standard system of the normal reference range of hs-CRP and BNP to improve the accuracy of clinical diagnosis.