Abstract:

Objective
To reveal the geographical distributing rule and supply a scientific basis for unifying the reference value standard of left atrial diameter (LAD) of Chinese presenile women in various region of China. Methods The LAD reference values were collected from 4 943 healthy presenile women in 154 areas of China. The correlation between the measured values of LAD and the geographical factors was analyzed with correlation analysis method.Applying the method of regression analysis and principal components analysis,one best regression equation was inferred by using T-test.Results The reference value of LAD was correlated with the geographical environment.The linear regression equation deduced from principal components analysis was:Y=30.53－0.001 104X₁　+0.001 060X₂－0.129 5X₃－0.043 92X₄－0.000 912 3X₅+0.103 5X₆+0.899 3X₇;　in the above equation,Ywas normal reference value of Chinese presenile women left atrial diameter (mm),X₁ was altitude,X₂ was annual sunshine duration（h）,X₃ was annual average temperature （℃）,X₄ was annual mean relative humidity（%）,X₅ was annual precipitation amount（mm）,X₆ was annual range of air temperature（℃）,X₇ was annual average wind speed (m·s^-1),the geography distribution figures of Chinese presenile women LAD reference values were exactly inserted with methods of Kriging.Conclusion If the geographical factors of a particular area are obtained,the LAD reference value of Chinese presenile women in this area can be calculated using this model and the normal LAD reference values of Chinese presenile women anywhere in China can be obtained from geography distribution figure.

Key words: principal component analysis;presenile women;reference value of left atrial diameter;geographical factors