Is chronic kidney disease comparable to diabetes as a coronary artery disease risk factor?

Background: Chronic kidney disease (CKD) is one of the known risk factors for coronary heart disease (CHD). Though electrocardiograms (ECGs) have limited accuracy in determining the true prevalence of CHD, we wondered whether CKD and diabetes mellitus (DM) controlled for hypertension (HTN), had similar prevalences of ECG abnormalities that could reflect underlying coronary heart disease.

Method: Data were collected for 5,942 men and women aged 30 to 69 years in the Tehran Lipid and Glucose Study (TLGS), a crosssectional phase of a large epidemiologic study first initiated in 1999. ECG findings of all subjects were coded according to Minnesota ECG coding criteria. The Whitehall criteria for abnormal ECG findings that could represent ischemia were utilized. Creatinine clearance (Crcl) was estimated using the Cockroft-Gault equation and diabetes was defined according to the American Diabetic Association (ADA) criteria. Subjects with moderate CKD and without DM were compared with the patients with DM without CKD. HTN prevalence was similar. The analysis was performed for all Whitehall ECG ischemia abnormalities combined, and separately for pathologic Q waves.

Results: In spite of an overall similar prevalence of smoking, and a lower incidence of dyslipidemia and HTN, moderate CKD patients had a higher prevalence of Whitehall criteria abnormal ECG findings compared with the patients with DM. Over 19% of patients with CKD had abnormal ECG findings while 14.7% of diabetic patients had abnormal ECGs (P = 0.02). The prevalence of Q waves was 11.5% in patients with CKD and 10.8% in patients with DM. In an age-matched subgroup of patients with DM and no CKD, the prevalence of ECG abnormalities was 19.3%, similar to the patients with moderate CKD and no DM (19.7%) (P = 0.9). The prevalence of pathologic Q waves in an age-matched group was 11.45%, compared with 11.5%, respectively.

Conclusion: Moderate CKD is a major risk factor for the development of the Whitehall ECG criteria which have been associated with ischemic heart disease. The importance of CKD as a risk factor for ECG abnormalities is comparable with DM. Patients with moderate CKD probably are candidates for aggressive CHD risk modification.