Association of High Serum Creatinine and Anemia Increases the Risk of Coronary Events: Results from the Prospective Community-based Atherosclerosis Risk in Communities (ARIC) Study

Coronary heart disease (CHD) is a major cause of morbidity and mortality in patients with chronic kidney disease or anemia. The purpose of this study was to examine whether the association between renal function and risk of CHD is modified by hemoglobin (Hgb) status. Analyses were based on data from the Atherosclerosis Risk in Communities study, a community-based study of risk factors for CHD in middle-aged people. People with known CHD at baseline were excluded from the analysis. Participants were followed for 9 yr for the occurrence of CHD. Anemia was defined as Hgb <13 g/dl in men and <12 g/dl in women. Cox proportional hazards models were used to assess the relative risk (RR) of CHD occurrence according to Hgb status, after adjusting for other risk factors (demographics, lipids, diabetes, hypertension, smoking, body mass index, and carotid intima-media thickness). A total of 13,329 participants were included. The interaction between Hgb concentration and serum creatinine (Scr) was significant (P = 0.02). Among people with anemia, a Scr >/=1.2 mg/dl in women or >/=1.5 mg/dl in men was associated with a higher risk of CHD (RR, 2.74; 95% confidence interval, 1.42 to 5.28) than those with normal Scr. In contrast, among those without anemia, this association was not noted (RR, 1.20; 95% confidence interval, 0.86 to 1.67). In conclusion, this study indicates that high Scr is associated with almost a threefold risk of CHD among middle-aged people with anemia, whereas no increased risk is found in people with high Scr in the absence of anemia.