Results of a comparative study of urinary creatinine analysis methods

Abstract

Background: Creatinine is an endogenous product of muscle metabolism. In normal, that is excreted in the urine at a rate of 0.1-0.5 g/l and an average of 1g/day. Many factors affect the amount of creatinine excreted in the urine. Therefore, it has been studied that countries differ depending on national characteristics, customs, and diet. In our country, it is likely that the amount of muscle mass varies depending on the diet, lifestyle and diseases of the population. Also, by determining the amount of creatinine excreted in the urine, it is important in the diagnosis of disorders (sarcopenia) that occur due to muscle mass loss among the population. Aim: To study the methods of analyzing the amount of creatinine excreted in the urine. Materials and Methods: The study was conducted using a cross-sectional stude method. The study included 350 people aged 30-60 who are being treated at the Mongolian National University of Medical Sciences, Mongolian-Japanese Hospital SOM, MNUMS. The amount of creatinine in 24-hour urine and first morning specimen was analyzed by biochemical and clinical chemistry methods and the correlation between the tests was studied. Results: A total of 350 people participated in the study, and the mean age was 42.3±5.5. The 46.6% (n=163) of the respondents were male and 53.4% (n=187) of the respondents were female. In the study of the relationship between the results of the methods of determining creatinine in urine, there is a strong correlation between the first morning specimen by biochemical method and the first morning specimen by chemical analysis of urine (r=0.816), and the 24-hour urine analysis by biochemical method and the method of 24-hour urinary creatinine determination by chemical analysis of urine. There is a strong correlation between them (r=0.864) P<0.001. In a study examining the concordance of urine creatinine determination methods, first morning urinalysis by biochemical and urinalysis had moderate compliance (κ=0.585) Biochemistry and urinalysis with 24-hour urinalysis had moderate compliance (κ=0.481). Conclusions: Biochemical and clinical chemistry analysis for first morning specimen and 24-hour urinary creatinine were statistically significant.