Abstract 9558: Twenty Five-Year Trends of Serum Cholesterol Levels and Incidence of Atrial Fibrillation: The Kuakini Honolulu Heart Program

Introduction: Several studies have indicated high cholesterol is paradoxically associated with low prevalence of atrial fibrillation (AF). However, the etiology is uncertain. One potential explanation might be the different trends in serum total cholesterol (TC) between AF and non-AF groups. Hypothesis: There are different 25-year trends in TC levels in older men with vs. without incident AF during the 25-year period. Methods: We used data from the Kuakini Honolulu Heart Program, a longitudinal cohort study since 1965. Participants were 3,741 Japanese-American men living in Hawaii who participated in the 4th exam cycle. TC level was repeatedly measured at baseline (mid-life, ages 45-68 years) and after 25 years (late-life, ages 71-93 years). The amount of TC reduction between mid- and late-life was categorized into quartiles. AF was diagnosed by 12-lead ECG at mid- and late-life. We excluded participants who were diagnosed with AF at mid-life (prevalent cases). Results: AF incidence was 4.4% over 25 years. Mid-life TC levels were similar between those with incident AF vs. those without (218.6±36.0mg/dl vs 218.6±35.4mg/dl, p=0.91). However, in those with incident AF, the drop in TC levels between mid- and late-life was significantly larger than in those without AF (-39.4±35.8mg/dl vs -27.9±38.0mg/dl, p<0.001) (Fig1). Moreover, after multivariable adjustment, there was a biological gradient between AF incidence and reduction of TC levels over 25 years (P for tend p<0.001). As a result, the group with incident AF showed significantly lower late-life TC levels compared with the non-AF group (179.7±32.9mg/dl vs 190.3±33.0mg/dl, p<0.001) at late-life (Fig1). Conclusions: Incident AF over 25 years was associated with a greater decrease in serum TC levels between mid- and late-life. The paradoxical associations between AF prevalence and low TC levels might be explained by the different trends in drop from mid- to late-life TC between those with vs. without incident AF.