Abstract MP14: Long-chain Monounsaturated Fatty Acids and Incidence of Coronary Heart Disease: The Cardiovascular Health Study

Abstract

Background: Decades-old animal experiments demonstrated that consumption of large amounts of long-chain monounsaturated fatty acids (LCMUFA, 22:1 and 24:1 fatty acids) caused cardiotoxicity. We recently found that plasma phospholipid 22:1 and 24:1 were associated with higher incidence of congestive heart failure (CHF) in two independent cohorts: the Cardiovascular Health Study (CHS) and the Atherosclerosis Risk in Communities Study. However, their association with incident CHD is unknown. Aim: to investigate association of plasma phospholipid 22:1 and 24:1 levels with incident CHD. Methods: The study included 3,221 adults free of CHD (age=74.9±5.2) in CHS in whom plasma phospholipid LCMUFA were measured in 1992. Incident CHD events from 1992 to 2006 were centrally adjudicated, and we assessed total CHD, including fatal CHD (fatal MI and other CHD deaths) and non-fatal MI. We examined prospective associations of LCMUFA with incident CHD using Cox proportional hazards. We further evaluated potential confounding or mediation by baseline risk factors and incident CHF. Results: Mean±SD phospholipid levels of 22:1 and 24:1 were 0.03±0.01 and 1.96±0.44 percent of total fatty acids. During 34,776 person-years, 628 incident CHD events occurred, including 309 fatal CHD and 401 non-fatal MIs. After multivariable adjustment, higher levels of both 22:1 and 24:1 were associated with higher risk of total incident CHD. Hazard ratios (95% CI) for quintiles 5 vs. 1 of 22:1 and 24:1 levels were 1.48 (1.07-2.06, p trend=0.005) and 1.65 (1.16-2.34, p trend=0.001). The associations with CHD were largely specific to fatal CHD rather than non-fatal MI (Figure). These associations did not change after adjustment for incident CHF and baseline risk factors including circulating lipids, blood pressure, and inflammatory markers. Conclusions: Higher levels of circulating 22:1 and 24:1 LCMUFA were associated with higher incidence of CHD, in particular fatal CHD, supporting the possibility of cardiotoxicity by current levels of LCMUFA exposure.