Effect of socio-demographic factors on endogenous biomarkers (cystatin C and creatinine) among elderly chronic kidney disease patients: a cross-sectional study

Purpose Creatinine is normally used to evaluate kidney function among elderly patients in clinical practice, which has been reported to be affected by socio-demographic factors like BMI and age. Cystatin C a newly introduced biomarker may be more efficient in identifying kidney function in obese and aged CKD patients. The aim of the current study was to assess the effect of BMI on endogenous biomarkers (cystatin C and creatinine) among elderly CKD patients in Malaysia, a first such study in the country. Methods The current study was conducted at the Hospital University Sains Malaysia, Kelantan. A total of 300 elderly Malay participants >= 65 years, with CKD, were taken in study. Demographic data, blood pressure, weight, and height were documented. Serum creatinine was assayed by Chemistry Analyzer Model Architect-C8000 (Jaffe Method), while serum cystatin C was examined by Human cystatin C ELISA kit (Sigma-Aldrich) using Thermo Scientific Varioskan Flash ELISA reader. Results The study participants were divided into three groups on the basis of age. There was a statistically significant difference at the p value < 0.05 in serum creatinine level for the three age groups [F (2, 297) = 1.98, p value 0.045]. Patients were divided into four groups on the basis of BMI. The results of one-way ANOVA revealed a statistically significant difference at the p value < 0.05 in the mean serum creatinine level for the four groups [F (3, 396) = 2.99, p value 0.032]. However, no statistically significant differences between mean serum cystatin C levels were observed on the basis of patient's age and BMI. Conclusion Cystatin C is not related to BMI and age among elderly chronic kidney disease patients. The study clearly evaluates the role of serum cystatin C as a good competitor of creatinine among the elderly CKD patients.