Cardiac troponin I in patients with chronic kidney disease treated conservatively or undergoing long-term haemodialysis.
BACKGROUND
Cardiac troponin I (cTnI) has been shown to be a specific marker of myocardial damage in the general population. In patients suffering from chronic kidney disease (CKD) cTnI may be increased in serum without other signs of acute myocardial damage confusing the diagnosis.


OBJECTIVE
To compare cTnI concentration in CKD patients, treated conservatively or with haemodialysis, with healthy controls, and to evaluate the cardiovascular risk factor profile in these groups.


METHODS
The study population consisted of three groups: group I (n=10, 5 women, 5 men, mean age 32+/-4 years) - healthy, young volunteers without kidney diseases with creatinine clearance (CrCl) 97.13+/-23.24 ml/min; group II (n=21, 8 women, 13 men, mean age 51+/-15 years) - patients with CKD in stages 3-5 with CrCl=34.04+/-18.34 ml/min; and group III (n=30, 14 women, 16 men, mean age 50+/-14 years) - patients on long-term haemodialysis. The cTnI level was measured using an AxSYM analyzer (Abbott). In group III blood was taken before the haemodialysis session. The high sensitivity C-reactive protein (hsCRP), haemoglobin, parathyroid hormone (PTH) and phosphorus levels were determined. Blood pressure was also recorded. Echocardiography was performed and left ventricular mass index (LVMI) was calculated on the basis of the Devereux and Reichek formula.


RESULTS
Compared with controls, the cTnI values were significantly higher in patients from group III and tended to be higher in patients from group II (0.01+/-0.03 vs. 0.063+/-0.08 and 0.066+/-0.162 ng/ml, respectively, p <0.05 and NS). In 46% of haemodialysed patients cTnI concentration was above the value of the 99th percentile in the apparently, healthy population but did not exceed the acute myocardial infarction diagnostic cut-off. The high sensitivity C-reactive protein value was significantly higher in groups III and II versus controls (4.92+/-5.12 and 2.26+/-2 vs. 0.85+/-0.48 mg/dl, p <0.05 respectively). The LVMI values were significantly higher in groups III and II than in controls (159+/-46 and 113+/-35 vs. 81+/-14 g/m2, respectively). There was a significant correlation between hsCRP and LVMI in group II (r=0.49, p <0.05). Blood pressure was significantly higher in groups III and II compared to controls (129+/-25 and 137+/-19 vs. 116+/-7 mmHg, respectively). Patients from group III had significantly decreased haemoglobin value and increased PTH as well as phosphorus concentration compared to subject from group II and controls.


CONCLUSIONS
Chronic kidney disease is associated with accumulation of cardiovascular risk factors and increased cTnI concentration.
Flisiński
Mariusz
M
Department of Nephrology, Hypertension and Internal Disease, Nicolaus Copernicus University in Toruń, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Poland. flis3@wp.pl
Strózecki
Paweł
P
Stefańska
Anna
A
Zarzycka-Lindner
Grazyna
G
Brymora
Andrzej
A
Manitius
Jacek
J
D000328:Adult; D000368:Aged; D001794:Blood Pressure; D002097:C-Reactive Protein / Q000032:analysis; D002318:Cardiovascular Diseases / Q000097:blood* / Q000209:etiology; D016022:Case-Control Studies; D005260:Female; D006454:Hemoglobins; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000150:complications / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D010281:Parathyroid Hormone / Q000097:blood; D010758:Phosphorus / Q000097:blood; D006435:Renal Dialysis; D012307:Risk Factors; D019210:Troponin I / Q000097:blood*
D006454:Hemoglobins; D010281:Parathyroid Hormone; D019210:Troponin I; D010758:Phosphorus; D002097:C-Reactive Protein