P0223AGING CHANGES OF RENAL FUNCTION AND EVALUATION OF DIFFERENT GLOMERULAR FILTRATION RATE ESTIMATION EQUATIONS IN HEALTH PEOPLE IN BEIJING
Authors: Xu Lengnan , Mao Yonghui , Chen Aiqun , Zhao Ban 
Published: June 2020

Abstract

Background and Aims
The kidney is an important organ that removes metabolites and certain wastes and poisons from the body, and retains water and other useful substances through reabsorption. Its aging and function decline have a significant impact on the human health.Rather than simply depending on serum creatinine, glomerular filtration rate (GFR) assessment equation should be given priority in evaluating renal function. Different evaluated GFR (eGFR) equations sometimes have great differences in assessing the true value of GFR, especially for the elderly. The purpose of this study was to analyze the aging changes of renal function in normal people in Beijing and to compare the significance of different eGFR equations in evaluating renal function in Chinese population.

Method
The age, sex and serum creatinine were recorded in the population who underwent routine physical examination in our hospital from January 2012 to December 2014. Kidney function was assessed by CKD-EPI, MDRD, MDRDc, FAS and BIS equations, respectively.

Results
A total of 46 713 persons were enrolled in this study, of whom 27 249 (58.33%) were males. They were followed up for 3 years, ranging in age from 16 to 100 years. Both men and women showed age-related change in serum creatinine: serum creatinine and its standard deviation gradually increases parallel with age, indicating that the range of serum creatinine changes in the elderly was larger. Whether male or female, there were differences in eGFR change between different age groups (male: Χ2=141.28, P=0.000; female: Χ2=97.55, P=0.000). For male, eGFR decreased more in the elderly, and it was more common for young people to keep the eGFR constant or increase. However, in female, eGFR remained unchanged in most old people, and increased or decreased in the majority of the young. For all age groups, the ICC was very consistent among the equations, 0.849 for males and 0.817 for females. The whole population was divided into three groups according to serum creatinine &lt; 1mg/dL, &gt; 1mg/dL and &lt; 1.5mg/dL, &gt; 1.5mg/dL. The CKD-EPI equation gave higher stages of CKD than other equations. There was no clear age-related change trend in the 3-year average eGFR change rate of all age groups. For the elderly over 70 years of age, the MDRD and MDRDc equations had higher GFR evaluation results than the other three equations. The BIS equation had the lowest results of all equations. The ICC was very consistent among the equations, 0.966 for males and 0.957 for females.

Conclusion
we believed that the annual change of GFR varied from person to person and had little to do with age. GFR needed to be calculated more accurately in order to formulate corresponding medical strategies. Those eGFR equations the above-mentioned can be used to evaluate renal function, but the results were very different for different populations and serum creatinine levels. The use of different eGFR equations may lead to large differences in drug dose adjustment and the risk of serious adverse reactions. For the elderly in China, which equation was more suitable was inconclusive and further research was urgently needed.