Abstract: TH-PO662
The Difference Between eGFR by Cystatin C vs. Creatinine Provides Clinical Information About Frailty in CHS
Session Information
- Geriatric Nephrology
November 07, 2019 | Location: Exhibit Hall, Walter E. Washington Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Geriatric Nephrology
- 1100 Geriatric Nephrology
Authors
- Potok, O. Alison, UCSD, San Diego, California, United States
- Katz, Ronit, University of Washington, Seattle, Washington, United States
- Bansal, Nisha, Kidney Research Institute, Seattle, Washington, United States
- Siscovick, David, University of Washington, Seattle, Washington, United States
- Ix, Joachim H., UCSD, San Diego, California, United States
- Shlipak, Michael, San Francisco VA Medical Center, San Francisco, California, United States
- Rifkin, Dena E., UCSD, San Diego, California, United States
Background
Kidney function is typically assessed using serum creatinine. Cystatin C is an alternative marker of kidney function. The clinical significance of having a difference in estimated glomerular filtration rate (eGFR) by these 2 measures is unknown. We hypothesized that the magnitude of this difference is associated with frailty.
Methods
In 4101 community-dwelling older adults from the Cardiovascular Health Study (CHS) cohort, we investigated the cross-sectional association of the difference in eGFR by cystatin C vs. by creatinine (eGFRDiff) at baseline with prevalent frailty, using logistic regression, and the longitudinal association of eGFRDiff with incident frailty and mortality at 5 years, using Poisson regression. eGFR was calculated using CKD-EPI equations based on either measure (eGFRCr and eGFRCys respectively), and eGFRDiff was eGFRCys - eGFRCr. Frailty was assessed based on the Fried frailty score.
Results
Mean (±SD) age was 72 (±5) years, eGFRCr was 73 (±17) and mean eGFRDiff was -1.4 (range -68.0 to 70.6) mL/min/1.72m2. 39% were males, 5% African-American, 72% non-diabetics. Per 10-point increment in eGFRDiff, the prevalence of moderate frailty was 19% lower, and that of severe frailty was 36% lower, in fully adjusted model (Table 1). Higher eGFRDiff (per 10 mL/min/1.73m2) was associated with lower incidence rate ratio for moderate (IRR 0.93, 95%CI [0.87; 0.99]) and severe (IRR 0.59, 95%CI [0.47; 0.74]) frailty, as well as lower risk of mortality (IRR 0.65, 95%CI [0.57; 0.76], p<0.0001).
Conclusion
Those with a lower eGFRCys than eGFRCr were more likely to have prevalent frailty and were at higher risk for incident frailty and mortality. Considering eGFRDiff as a marker of patients’ functional status may be a useful clinical tool to assess important geriatric outcomes.
Association of eGFRDiff (per 10-point increment) with frailty at baseline
Outcome: Frailty (n = 2084) | Moderately Frail (n=1832) | Severely Frail (n=252) | ||
OR (95% CI) | p value | OR (95% CI) | p value | |
Unadjusted | 0.78 (0.74; 0.82) | <0.0001 | 0.64 (0.58; 0.71) | <0.0001 |
Fully adjusted * | 0.81 (0.76; 0.85) | <0.0001 | 0.64 (0.57; 0.72) | <0.0001 |
*adjusted for age, gender, race, body mass index, hypertension, diabetes, anti-hypertensives at baseline, cholesterol, smoking, chronic kidney disease stage by eGFRCr
Funding
- Other NIH Support