Influence of renal function on serum and urinary heart fatty acid-binding protein levels.
BACKGROUND
Serum heart fatty acid-binding protein (H-FABP) has been reported to be a sensitive and early indicator of myocardial damage. However, circulating H-FABP may be cleared considerably from kidney, similar to that found for myoglobin. Therefore, the possibility exists that any change in renal function affects serum H-FABP concentration, and thus leads to erroneous interpretation. To evaluate the influence of renal function on H-FABP levels, we conducted a prospective study.


METHODS
Nineteen patients undergoing isolated primary coronary artery bypass grafting were enrolled in this study. The patients were classified by the preoperative creatinine clearance into two groups: the control group (n=12); patients with creatinine clearance of 40 mL/min or greater, and the renal dysfunction group (n=7); patients with creatinine clearance of less than 40 mL/min. Serum H-FABP, CK-MB, troponin-T and urinary H-FABP levels were measured perioperatively.


RESULTS
None of the patients had perioperative myocardial infarction. No significant differences were found in CK-MB and troponin-T levels between the groups. The renal dysfunction group resulted in significantly (p<0.05) higher serum H-FABP levels and lower urinary H-FABP levels than those in the control group, postoperatively. The creatinine clearance correlated inversely with the peak levels of serum H-FABP (r=-0.75, p=0.0001) and correlated with the peak levels of urinary H-FABP (r=0.64, p=0.003).


CONCLUSIONS
The results indicate that the kidneys play an important role in the clearance of serum H-FABP. Thus, caution must be taken in interpreting this marker for myocardial damage during cardiac surgery in patients with renal dysfunction.
Nayashida
N
N
Department of Surgery, Kurume University, Fukuoka, Japan. nobuhiko@med.kurume-u.ac.jp
Chihara
S
S
Tayama
E
E
Akasu
K
K
Kai
E
E
Kawara
T
T
Aoyagi
S
S
D000368:Aged; D015415:Biomarkers / Q000097:blood / Q000652:urine; D002352:Carrier Proteins / Q000097:blood* / Q000652:urine*; D016022:Case-Control Studies; D001026:Coronary Artery Bypass; D003402:Creatine Kinase / Q000097:blood; D052279:Creatine Kinase, MB Form; D003404:Creatinine / Q000097:blood; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000097:blood* / Q000652:urine*; D005260:Female; D006801:Humans; D007430:Intraoperative Care; D007527:Isoenzymes / Q000097:blood; D007674:Kidney Diseases / Q000097:blood / Q000503:physiopathology* / Q000652:urine; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins; D011446:Prospective Studies; D020107:Troponin T / Q000097:blood; D025521:Tumor Suppressor Proteins
D015415:Biomarkers; D002352:Carrier Proteins; C107608:FABP7 protein, human; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D007527:Isoenzymes; D009363:Neoplasm Proteins; D020107:Troponin T; D025521:Tumor Suppressor Proteins; D003404:Creatinine; D003402:Creatine Kinase; D052279:Creatine Kinase, MB Form