Clinical Significance of Creatine Kinase-MB Elevation in Patients with Chronic Kidney Disease before Initiation of Hemodialysis

Aim: To measure creatine kinase – myocardial band (CK-MB) concentration in stable patients with chronic kidney disease who had not commenced hemodialysis and determine its relationship with cardiac Troponin I and cardiovascular risk factors.

Study Design: Cross-sectional study.

Place and Duration of Study: Renal Unit, Department of Internal Medicine, University of Port Harcourt Teaching Hospital, Rivers State, Nigeria from January 2014 to December 2015.

Methodology: Blood pressure, serum CK-MB, cardiac Troponin I, HDL-cholesterol, total cholesterol, triglyceride, fasting plasma glucose, urine and serum albumin, urine and serum creatinine concentrations were analysed in 83 diagnosed chronic kidney disease patients attending the renal clinic and 83 age- and sex-matched healthy control subjects. Body mass index (BMI), estimated GFR (eGFR), urinary albumin-creatinine ratio (UACR) and LDL-cholesterol were calculated.

Results: CKD patients had higher CK-MB, higher cardiac troponin I, higher blood pressure, higher serum creatinine, higher triglyceride, higher UACR, lower serum albumin, lower HDL and lower eGFR compared to controls. Sixteen (19.3%) patients versus 11 (13.3%) controls had elevated CK-MB. Among patients, CK-MB was positively associated with UACR, low HDL and dyslipidemia but not associated with cardiac Troponin I.

Conclusion: CK-MB elevation was associated with albuminuria, low HDL and dyslipidemia. However, CK-MB lacked association with cardiac troponin I, which is a more cardiac-specific biomarker. This shows that serum CK-MB levels may not be suitable for diagnosing myocardial injury in CKD patients.