Date Published: April 24, 2019
Publisher: Public Library of Science
Author(s): Eun Roh, Hye Soo Chung, Ji Sung Lee, Jung A. Kim, You-Bin Lee, So-hyeon Hong, Nam Hoon Kim, Hye Jin Yoo, Ji A. Seo, Sin Gon Kim, Nan Hee Kim, Sei Hyun Baik, Kyung Mook Choi, Stefan Kiechl.
Long-term variability of cardiometabolic risk factors have been suggested as the risk factors for cardiovascular disease and mortality. However, the effect of long-term variability of total cholesterol (TC) on incident atrial fibrillation (AF) has not been examined.
We explored whether visit-to-visit TC variability are associated with the risk of incident AF in 160,165 Korean adults, using the population-based Korean National Health Insurance Service–Health Screening Cohort (NHIS-HEALS) database, over a median duration of 8.4 years. TC variability was measured as coefficients of variance (TC-CV), standard deviation (TC-SD), and variability independent of the mean (TC-VIM). Kaplan–Meier analysis demonstrated a decreased disease-free probability in the highest quartile group of TC variability compared to that in the other groups. In the multivariate Cox proportional hazard analysis, the risk of AF increased significantly in the highest quartile group of TC variability. After multivariate adjustment for confounding variables including mean TC levels, the hazard ratio for incident AF was 1.15 (95% confidence interval 1.05–1.25; P = 0.0035) when comparing the highest with the lowest TC variability quartile (TC-CV). These relationships were consistent with TC variability defined using TC-SD or TC-VIM. Subgroup analyses, including age, sex, body mass index, and cardiometabolic disorders, showed similar results.
The present study is the first to demonstrate that high TC variability was associated with an increased risk of AF.
A worldwide epidemic of atrial fibrillation (AF) is nowadays recognized as a pivotal health threat. Previous studies have shown that AF is associated with an increased risk of stroke, cardiovascular disease (CVD), and mortality . Park et al. reported that the prevalence of AF is 1.3% and that it increases with age in Korea . In a Chinese population aged over 60 years, the prevalence of AF was 2.0% in men and 1.6% in women , and the total number of individuals with AF in China had exceeded 5 million in 2010 due to the large population size . In the United States, the prevalence of AF was 1.1% in men and 0.8% in women, and it is estimated that the number of patients with AF will increase 2.5-fold to more than 5.6 million by 2050 . In the age stratum of 55–59 years, the prevalence of AF was 1.3% in men and 1.7% in women, and the number of patients aged ≥55 years with AF will double by 2060 in the European Union .
The present study provides the first demonstration that high visit-to-visit TC variability was significantly associated with the risk of AF after extensive adjustments for possible confounding factors, including mean TC levels in the Korean population. In the multivariate Cox proportional hazard analysis, the risk of AF increased significantly in the highest quartile group of TC variability. There were no significant differences to AF risk between subjects in the lower three quartiles, implying that a threshold may exist at some level of TC variability.