Reference intervals for serum creatinine for healthy adults in central Africa: a post-hoc analysis

Abstract Background Despite current interest in creatinine-based equations for estimating glomerular filtration rate, the evaluation of creatinine reference intervals remains relevant. The present study aimed to establish such reference intervals from a healthy Congolese adult. Methods This study was based on post-hoc data of previous epidemiology study conducted in the general population of Kinshasa. Serum Creatinine measurement was performed with enzymatic IDMS-traceable method. The creatinine values being not normally distributed, the median values and interquartile range and the 2.5th and 97.5th percentiles were considered. A value of p < 0.05 is the threshold of statistical significance. Results Of 2,504 Congolese adults screened, 506 (males, 67.7%) were healthy and were involved in this study. Their mean BSA was 1.64 ± 0.15 m2. In males, the median of creatinine was 0.96 [0.87;1.05] mg/dl and percentiles 2.5th and 97.5th were 0.65 and 1.22 mg/dL, respectively. The reference intervals were between 0.65 (95%CI 0.68 to 0.72) and 1.23 (1.20 to 1.24) mg/dL for the lower and the upper limits, respectively. In females, the median of creatinine was 0.72 [0.66;0.80] mg/dl and percentiles 2.5th and 97.5th were 0.50 and 0.95 mg/dL, respectively. The reference intervals were between 0.52 (95%CI 0.50 to 0.54) and 0.95 (0.91 to 0.96) mg/dL for the lower and the upper limits respectively. Conclusion The reference intervals for Congolese adults seem close to these of White Europeans, with slightly higher values in Congolese compared to Caucasians, but lower than those of the African-Americans.