Simple Tests for Assessing Kidney and Cardiovascular Function in Chromic Kidney Disease Patients (Stages 2, 3 and 4)

Reliable measurement of glomerular filtration rate (GFR) is an important aspect of clinical decision making and forms the basis of classification for kidney function. Moreover the interpretation of risk factors for progression of CKD linked to cardiovascular disease (CVD) remains difficult, particularly in older subjects. To address this GFR and the cardiovascular parameters arterial stiffness, heart rate variability (HRV) and natriuretic peptides (NT- proBNP and NT-proCNP) were measured in a cohort of CKD patients of stages 2,3 and 4. The primary aim however of the thesis was to measure the Kidney Functional Reserve (KFR) of CKD3 and CKD4 patients as it has been thought of as analogous to cardiac functional reserve. CysC, creatinine clearance (CrCl) and with simultaneous radionuclide 99technetium diethylenetriaminepentaacetatic acid (Tc-99m) measured GFR (mGFR) of KFR in 19 CKD Stage 3 and 21 CKD Stage 4 patients yielded good agreement. KFR was not correlated with baseline kidney function. Eight CKD Stage 3 (42%) and 11 CKD Stage 4 (52%) subjects reached their lowest serum CysC concentration 4 hours after OPL. CysC KFR and baseline serum creatinine (sCr) predicted Major Adverse Kidney Event, death or dialysis (MAKE-T) and MAKE-F (fast progression with GFR decrease > 5ml/min/year) with a respective area under the curve (AUC) of 0.73 (95% confidence interval [CI] 0.48 – 0.890) and 0.71 (95% CI: 0.51–0.84). Including CysC KFR, age, baseline sCr and nadir CysC predicted a decrease in sCr-estimated GFR >1.2 ml/min/year (MAKE-S) with an AUC of 0.89. In the latter case the inclusion of cardiovascular variables; “Recovery” (1-4 minutes post exercise) RMSSD, urinary and serum NT-proCNP concentration and whether CysC GFR reserve was early or late in nadir improved the AUC to 1.00 (AICc =15.41). In conclusion serial CysC may facilitate monitoring of KFR in clinical practice along with the use of a portable exercise stress test to increase c-f-PWV (carotid-femoral Pulse Wave Velocity) and identify CKD patients with serious/subliminal vascular stiffening. Future research may confirm this studies other preliminary finding that urinary NT-proCNP concentration may relate to renal haemodynamic function in CKD stages, as this correlated with stimulated mGFR (R2 = 0.41). In short this thesis has furthered the premise that the heart and kidney are interlinked via cardiovascular physiology which likely can be used to predict CKD progression.

Grantor dc:publisher

UNSW, Sydney

Year dc:date

2023

Author dc:creator

• Simpson, Charles William

• GFR
• HRV
• Arterial Stiffness
• Natriuretic Peptides
• CKD Progression
• anzsrc-for: 42 HEALTH SCIENCES
• anzsrc-for: 320225 Sports medicine
• anzsrc-for: 320899 Medical physiology not elsewhere classified

Statement dc:rights

• open access
• CC BY 4.0
• free_to_read

Licence

• https://purl.org/coar/access_right/c_abf2
• https://creativecommons.org/licenses/by/4.0/

Language dc:language

en

Identifier

https://doi.org/10.26190/unsworks/25125

OAI identifier oai:identifier

oai:unsworks.library.unsw.edu.au:1959.4/101418