Fluorescent Oxidation Products and Risk of Coronary Heart Disease: A Prospective Study in Women

BACKGROUND: Oxidative stress is implicated in the etiology of coronary heart disease (CHD). New measures to capture oxidative stress are warranted. Fluorescent oxidation products (FlOPs) can be measured in plasma and have been shown to reflect levels of oxidative stress and to predict risk of CHD in men over 6 years of follow‐up. The objective of this study is to determine whether measures of FlOPs are associated with risk of CHD in women over an extended follow‐up period. METHODS AND RESULTS: We measured FlOP by spectrofluorometer in a nested case–control study within the Nurses' Health Study, with baseline blood collection in 1990 and follow‐up of 397 incident CHD cases through 2004 matched 1:2 with controls. Level of FlOPs was independently associated with CHD. The relative risk across extreme quintiles was 1.64 (95% confidence interval [CI], 1.06 to 2.53) when adjusted for lifestyle factors, lipids and C‐reactive protein (P trend across quintiles=0.01). A slightly stronger association was observed when analyses were restricted to women fasting >8 hours at blood draw (RR, 1.91; 95% CI, 1.16 to 3.15). In exploratory time to event analyses, high levels of FlOPs measured ≥5 years before the CHD event, but not closer to the CHD event, were associated with the risk of CHD. CONCLUSIONS: Higher levels of FlOPs were associated with the risk of CHD in women. The association appeared strongest for long‐term prediction of CHD events.