Kidney Week

Abstract: TH-PO827

eGFRcr, eGFRcys, Muscle Mass, and All-Cause Mortality in Kidney Transplant Recipients: Post-Hoc Analyses from a Randomized Controlled Trial

Session Information

• Transplantation: Clinical - I
  November 02, 2023 | Location: Exhibit Hall, Pennsylvania Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Transplantation

• 2102 Transplantation: Clinical

Authors

• Curran, Gabriel Alexander, University of Glasgow, Glasgow, United Kingdom

Gabriel Alexander Curran,

• Mcneilly, Jane D., NHS Greater Glasgow and Clyde, Glasgow, Glasgow, United Kingdom

Jane D. Mcneilly,

• Rankin, Alastair J., NHS Greater Glasgow and Clyde, Glasgow, Glasgow, United Kingdom

Alastair J. Rankin,

• Mayne, Kaitlin J., University of Glasgow, Glasgow, United Kingdom

Kaitlin J. Mayne,

• Edy, Elbert, Manchester University NHS Foundation Trust, Manchester, United Kingdom

Elbert Edy,

• Mark, Patrick Barry, University of Glasgow, Glasgow, United Kingdom

Patrick Barry Mark,

• Lees, Jennifer S., University of Glasgow, Glasgow, United Kingdom

Jennifer S. Lees,

Background

We explored eGFRcr, eGFRcys and pectoral muscle cross-sectional area (PMA: a muscle mass surrogate) in kidney transplant recipients (KTR) and assessed relationships: i) between parameters and ii) with all-cause mortality.

Methods

Participants were from the ViKTORIES randomised controlled trial (ISRCTN22012044) in prevalent KTR. eGFRcr (2009) and eGFRcys (2012) were calculated from creatinine and cystatin C respectively at baseline. PMA was calculated as the mean pectoral muscle area from slice 1 (the first slice in which the full pectoral muscle became visible), 3 and 5 on non-contrast axial thoracic computed tomography (CT) scans taken at baseline. Follow-up data were extracted from the electronic record. Linear regression tested associations between eGFR measures and PMA. Cox proportional hazards models tested associations between eGFR measures, PMA and death.

Results

Of 90 ViKTORIES participants, 90 had available serum/plasma samples and 89 had CT data for analysis. Mean (±SD) age was 57.6 ± 9.6 years and 63 (70%) were male. The proportion with pre-existing cardiovascular disease (21.1%) and diabetes (22.2%) was lower than observed in UK KTR populations. Over median follow-up of 4.8 (IQR 4.5 - 5.1) years, there were 14 deaths. Mean eGFRcys (40.9 ± 18.3 mL/min/1.73m²) was lower on average than eGFRcr (52.5 ± 21.0 mL/min/1.73m²; Figure). PMA was inversely associated with eGFRcr (adjusted β per 1cm² increase in PMA: -0.326, p=0.007), but not eGFRcys (adjusted β: -0.172, p=0.165). eGFRcys (but not eGFRcr nor PMA) was significantly associated with death (aHR per 10mL/min/1.73m² decrease: 1.62, 95% CI 1.05-1.92).

Conclusion

In this population of KTR with lower-than-expected cardiometabolic comorbidity, eGFRcys was lower than eGFRcr, was not associated with muscle mass but was strongly associated with mortality. As seen in the general population, eGFRcys is a valuable marker to stratify risk of death in KTR.

Density plots of eGFRcr and eGFRcys in the ViKTORIES trial

Funding

• Private Foundation Support