Age-Based High GFR Associates with Clinical Risk Among Potential Living Donors, but Only with Increased Nephron Number Among Approved Donors.
1Mayo Clinic, Arizona
2Mayo Clinic, Rochester
3Cleveland Clinic, OH.
Meeting: 2016 American Transplant Congress
Abstract number: A119
Keywords: Biopsy, Donation, Glomerular filtration rate (GFR), Kidney
Session Information
Session Name: Poster Session A: Kidney Donor Outcomes
Session Type: Poster Session
Date: Saturday, June 11, 2016
Session Time: 5:30pm-7:30pm
Presentation Time: 5:30pm-7:30pm
Location: Halls C&D
Background:Association of high GFR with clinical and kidney structural characteristics among living donors has not been studied.
Methods: Study cohort:potential kidney donors evaluated at Mayo Clinic Minnesota and Cleveland Clinic between 2000 and 2011 with an iothalamate clearance to measure GFR. High GFR was defined as either above the overall 95th percentile or the age-based 95th percentile by quantile regression. We studied the association of high GFR (overall or age-based) with clinical characteristics, cortical volume on CT, micro-structure on implantation biopsy and nephron number (cortical volume [times] glomerular density).
Results: 3,468 potential donors were evaluated, of whom 1556 were approved donors with an implantation biopsy. The overall-threshold for high GFR was > 134 ml/min/1.73 m2 and age-based thresholds were >151 ml/min/1.73 m2 for age 18 y decreasing linearly to > 109 ml/min/1.73 m2 for age 76 y. Table 1 compares characteristics of overall vs age-based GFR. Age-based high GFR was associated with albuminuria/proteinuria, higher BP and BMI. However, among the approved donors, these associations (HTN, proteinuria, and BMI) were not present (p>0.25 for all), however, there was association of high GFR and nephron number.
| Characteristic | Overall-threshold | Age-based threshold | ||||
| High GFR | Normal | P value | High GFR | Normal | P value | |
| Age, years | 36 | 44 | <0.01 | 44 | 44 | 0.99 |
| Male, % | 44 | 42 | 0.56 | 42 | 42 | 0.90 |
| BMI, kg/m2 | 28 | 28 | 0.20 | 29 | 28 | 0.03 |
| Active Ambulatory SBP, mmHg | 123 | 123 | 0.83 | 125 | 122 | 0.01 |
| Active Ambulatory DBP, mmHg | 74 | 75 | 0.31 | 76 | 75 | 0.04 |
| 24 hr urine protein | 41.2 | 39.4 | 0.58 | 48.3 | 39.0 | <0.01 |
| 24 hr urine albumin | 7.4 | 6.8 | 0.71 | 11.2 | 6.6 | <0.01 |
| Cortex volume, mm^3 | 251017 | 207593 | <0.01 | 250003 | 207767 | <0.01 |
| Approved Donors | ||||||
| Glom. Density, per mm^3 | 17 | 16 | 0.28 | 18 | 16 | 0.01 |
| % glomerulosclerosis | 3 | 3 | 0.76 | 3 | 3 | 0.90 |
| Nephron number | 1107371 | 870167 | <0.01 | 1215260 | 866678 | <0.01 |
Conclusion: Among potential kidney donors, age-based high GFR was significantly associated with clinical risk factors including proteinuria, higher BP and BMI. However, among those approved for donation, these associations were absent; high GFR associated only with increased nephron number.
CITATION INFORMATION: Chakkera H, Poggio E, Denic A, Mathew J, Kremers W, Larson J, Amer H, Cosio F, Stegall M, Taler S, Rule A. Age-Based High GFR Associates with Clinical Risk Among Potential Living Donors, but Only with Increased Nephron Number Among Approved Donors. Am J Transplant. 2016;16 (suppl 3).
To cite this abstract in AMA style:
Chakkera H, Poggio E, Denic A, Mathew J, Kremers W, Larson J, Amer H, Cosio F, Stegall M, Taler S, Rule A. Age-Based High GFR Associates with Clinical Risk Among Potential Living Donors, but Only with Increased Nephron Number Among Approved Donors. [abstract]. Am J Transplant. 2016; 16 (suppl 3). https://atcmeetingabstracts.com/abstract/age-based-high-gfr-associates-with-clinical-risk-among-potential-living-donors-but-only-with-increased-nephron-number-among-approved-donors/. Accessed May 21, 2025.« Back to 2016 American Transplant Congress