Serum caeruloplasmin as a coronary risk factor in the elderly: the Rotterdam Study

Serum Cu and caeruloplasmin levels have been suggested to be independent ri sk factors for CHD operating through oxidative modification of LDL. However , given its function as an acute-phase protein, the question has been raise d whether an elevated caeruloplasmin level is not merely an indicator of in flammation. In the current study, we investigated whether serum caeruloplas min was associated with subsequent myocardial infarction, taking into accou nt indices of inflammation. The study population consisted of 210 cases of first myocardial infarction and controls, frequency-matched on age (5-year categories) and sex, selected from the population-based cohort of the Rotte rdam Study. Serum caeruloplasmin levels were significantly elevated in case s of myocardial infarction compared with controls (510 (SD 110) v. 470 (SD 100) mg/l; P = 0.007). Risk of myocardial infarction for the highest compar ed with the lowest quartile of caeruloplasmin was 2.46 (95 % CI 1.04, 6.00; P-trend = 0.043) after adjustment for age, sex, BMI, pack-years smoked, se rum cholesterol, systolic blood pressure, and income. The relative risk was most evident in current smokers. Adjustment for C-reactive protein and leu cocyte count reduced the excess risk by 33 %. This suggests that a substant ial part of the observed association between serum caeruloplasmin and CHD m ay be attributed to inflammation processes rather than to the pro-oxidant a ctivity of caeruloplasmin.