Relevance of Gender, Age and the Body Mass Index to Changes in Urinary Creatinine Concentration in Korean Adults

Dept. of Environmental Education, Kongju National University*Dept. of Health Science, Dongduk Women's University(Received March 28, 2010/Revised April 30, 2010/Accepted June 10, 2010)ABSTRACTThe purpose of this study was to investigate the relevance of gender, age, and BMI (Body Mass Index) to changesin the urinary creatinine concentration in Korean adults. We recruited and surveyed 2,156 persons ≥20 years of age from98 districts across the country, and collected urine samples for analyzing the creatinine concentration. Participants were41.6% men and 58.4% women. In terms of age, the percentage of the population in their 20’s and ≥60 years of agewas relatively similar, with 13.6% and 17.8%, respectively, while the percentages in their 30’s, 40’s and 50’s were alsorelatively similar, with 22.0%, 24.0%, and 22.6%, respectively. The proportion of participants in their 20’s and 30’s whowere underweight (according to the BMI) was 25% and 19.2%, respectively, but only 6.2~6.4% of those ≥40 years ofage were underweight. This showed that the underweight proportion in elder generations was less than that in youngergenerations. Meanwhile, the proportion who were overweight was 13.7%, 18.8%, 28.6%, 27.9%, 32.0% when theparticipants were in their 20’s, 30’s, 40’s, 50’s and ≥60 years of age, respectively (p<0.000). This showed that theoverweight proportion increased along with increasing age. The overall urinary creatinine concentration was 10 mg/dl(arithmetic mean: AM), and 92.2 mg/dl (geometric mean: GM). The urinary creatinine concentration in men (132.6 mg/dl, AM) was significantly higher than that in women (93.3 mg/dl, AM (p<0.000)). Showing a similar trend in men andwomen, urinary creatinine concentrations were highest when the participants were in their 20’s (135.6 mg/dl, AM), andtended to decrease with increasing age. Urinary creatinine concentrations in overweight and obese subjects (AM of117.9 mg/dl and 118.0 mg/dl, respectively) were significantly higher than in other groups, and this trend was similarin men and women. In conclusion, we found that urinary concentrations were significantly affected by gender, age, andBMI, and that care should therefore be exercised when correcting urinary metabolites according to the urinary creatinineconcentration. Keywords: Urinary creatinine concentration, gender, age, BMI (Body Mass Index)