Abstract
Background and Aims
Glomerular filtration rate (GFR) is estimated traditionally from 24-hour urinary creatinine clearance. Creatinine is mainly filtered by glomerulus. The collection of 24-hour urinary sample is a difficult task with many patients fail to collect all the urine samples. As measuring GFR is cumbersome, expensive, and not easily available in all centers, various equations are developed for estimating GFR from creatinine like MDRD, CKD EPI creatinine. GFR obtained from serum creatinine shows wide variation as muscle mass and dietary protein intake are important determinants of serum creatinine concentration. Literature shows very few studies with GFR estimation with reference to age in Indian population. Hence, this study is planned to develop age specific nomogram for GFR in healthy kidney donor population as well as to study agreement between GFR obtained by 99m Tc DTPA three sample method and GFR estimated by 24-hour urinary creatinine. The aim of this stidy was to develop age-specific nomogram GFR in healthy kidney donor population and to study the agreement between the GFR measured by Technetium-99m diethylene triamine pentaacetic acid (99m Tc DTPA) and 24-hour urinary creatinine method.
Method
This study was conducted at Sir Ganga Ram hospital, New Delhi. All healthy individuals aged more than 20 years and less than 65 years, undergoing evaluation as prospective kidney donor at our hospital were the part of this study. GFR was measured by 99m Tc DTPA clearance using 3 sample method. GFR measured by DTPA method was used to develop nomogram. Creatinine Clearance was calculated from 24-hour urinary creatinine by formula U x V/P where, U is urinary creatinine level, P is plasma creatinine level and V is total volume of urine. Nomogram was developed with respect to these 3 Age groups; namely, 20 to 40 years, 40 to 50 years and 50 to 65 years
Results
Total 100 kidney donors were included in this study. Enrolled subjects were divided into 3 age groups; 20 to 40 years (n=28), 40 to 50 years (n=46) and 50 to 65 years (n=26). Majority of the donors were females (n=80). The agreement between GFR obtained by 99m Tc DTPA and 24-hour urinary creatinine clearance methods was 92.6 vs. 94 ml/min, 80.4 vs. 76 ml/min and 76.3 vs. 70 ml/min in respective age groups.
Conclusion
In the younger age group (20 to 40 years), there is better agreement in GFR measured by 99m Tc DTPA method and 24-hour urinary creatinine clearance methods.
Comparison between two-sample method with 99mTc-diethylenetriaminepentaacetic acid, Gates' method and estimated glomerular filtration rate values by formula based methods in healthy kidney donor population