Effect of a cooked meat meal on serum creatinine and estimated glomerular filtration rate in diabetes-related kidney disease.
OBJECTIVE
Fasting is not routinely recommended for renal function tests, despite the known effects of cooked meat on creatinine. We therefore studied variation in creatinine and estimated glomerular filtration rate (eGFR) after a standardized cooked meat meal in 80 subjects: healthy volunteers and diabetic patients with chronic kidney disease (CKD) stages 1 and 2, 3a, 3b, and 4 (n = 16/group).


METHODS
The interventions were a standardized cooked meat and a nonmeat meal, each providing ∼54 g protein, together with 250 mL water, on separate days. Fasting and postprandial blood samples at 1, 2, and 4 h were drawn for creatinine measurement using a kinetic alkaline picrate assay on an Olympus AU640 analyzer. The modified four-variable Modification of Diet in Renal Disease equation traceable to isotope dilution mass spectrometry creatinine was used to calculate eGFR.


RESULTS
Consumption of a standardized cooked meat meal significantly increased serum creatinine and resulted in significant fall in eGFR in all stages of CKD studied; 6 of 16 CKD 3a patients were misclassified as CKD 3b. This effect of cooked meat on serum creatinine disappears after 12 h of fasting in all study participants.


CONCLUSIONS
Creatine in meat is converted to creatinine on cooking, which is absorbed, causing significant increases in serum creatinine. This could impact management, as threshold for commencing and withdrawing certain medications and expensive investigations is defined by eGFR. eGFR calculated using fasting serum creatinine would be a better reflection of kidney function in these patients.
Corresponding author: Sunil Nair, sunil.nair1@liv.ac.uk.
Sunil
S
Nair
Sarah V
SV
O'Brien
Katharine
K
Hayden
Bhavna
B
Pandya
Paulo J G
PJ
Lisboa
Kevin J
KJ
Hardy
John P H
JP
Wilding
D000328:Adult; D000368:Aged; D003296:Cooking; D003404:Creatinine / Q000097:blood*; D003928:Diabetic Nephropathies / Q000097:blood / Q000503:physiopathology*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007677:Kidney Function Tests; D008297:Male; D008461:Meat Products; D008875:Middle Aged; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000503:physiopathology*
D003404:Creatinine