Functional renal reserve capacity in different stages of chronic kidney disease.
OBJECTIVE
There is conflict in published reports on the extent of availability of the functional renal reserve (RR) in healthy adults and in various stages of chronic kidney disease (CKD). The aim of the present study was to determine the RR in various stages of CKD.


METHODS
Baseline glomerular filtration rate (GFR) and 'stimulated GFR' following amino acid infusion were measured in 25 volunteers and 100 patients at various stages of CKD by measuring plasma clearance of Tc99m diethyl triamine pentaacetic acid. Any obtained difference between stimulated and basal GFR was considered as RR and expressed as percentage.


RESULTS
The mean renal reserve was 23.4% in the healthy control group, 19.08% in CKD stage 1, 15.4% in CKD stage 2, 8.9% in CKD stage 3 and 6.7% in CKD stage 4, respectively.


CONCLUSIONS
Renal reserve falls relentlessly with progression of CKD from 23.4% in normal to 6.7% in stage 4 CKD. However, RR may also get completely exhausted even with a normal or with a minimal decline basal GFR. Kidneys may retain some RR even up to the GFR level of 15 mL/min.
Barai
Sukanta
S
Department of Nuclear Medicine, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India. dazing@rediffmail.com
Gambhir
Sanjay
S
Prasad
Narayan
N
Sharma
Raj Kumar
RK
Ora
Manish
M
D000328:Adult; D000465:Algorithms; D016022:Case-Control Studies; D002908:Chronic Disease; D004044:Dietary Proteins / Q000008:administration & dosage / Q000378:metabolism; D018450:Disease Progression; D005919:Glomerular Filtration Rate; D006305:Health Status Indicators; D006801:Humans; D007262:Infusions, Intravenous; D007668:Kidney / Q000378:metabolism / Q000503:physiopathology*; D007674:Kidney Diseases / Q000097:blood / Q000503:physiopathology*; D008875:Middle Aged; D008954:Models, Biological; D019275:Radiopharmaceuticals; D012720:Severity of Illness Index; D016284:Technetium Tc 99m Pentetate; D055815:Young Adult
D004044:Dietary Proteins; D019275:Radiopharmaceuticals; D016284:Technetium Tc 99m Pentetate