Background and Objectives: Although the adverse cardiovascular effect of anemia has been well described, the effect of polycythemia on the incident atrial fibrillation (AF) remain unclear. The objective of this study is to identify the association between increased hemoglobin and incident AF. Methods: This was a retrospective-cohort study with 434,269 subjects who underwent national health examinations from the Korean National Sample Cohort. We estimated the risk of incident AF according to hemoglobin-based four-categories. Results: During 3.9-year of follow-up, polycythemia group showed higher incidences of AF (hazard ratio[HR] with 95% confidence interval[CI], 1.50 [1.28-1.76] and 1.69 [1.13-2.56]; in men and women, respectively) than normal hemoglobin group (each p<0.001). In the normal hemoglobin and polycythemia groups, a 1 g/dL increase in hemoglobin level was associated with increased risks of incident AF (1.12 [1.07-1.17] and 1.18 [1.10-1.26] in men and women, each p<0.001). To investigate the specific hemoglobin concentration related to greater AF incidence, we analyzed the sensitivity/specificity of different hemoglobin levels: ≥16.0 g/dL in men and ≥14.5 g/dL in women showed the highest Youden's index, with c-indices of 0.83 and 0.82, respectively. Kaplan-Meier cumulative-event curves according to these specific hemoglobin levels (≥16.0 g/dL in men and ≥14.5 g/dL in women) also showed consistent results in both sexes (each p<0.05). Conclusions: Even in the Korean general population, increased hemoglobin was significantly associated with higher rate of incident AF. Especially, subjects with hemoglobin levels ≥14.5 g/ dL in women and ≥16.0 g/dL among men were associated with increased risk of incident AF.
Bibliographical noteFunding Information:
This study was financially supported by the “Lee Kyu Suk” Faculty Research Assistance Program of Yonsei University College of Medicine for 2014 (6-2014-0192), the “Lee Kyu Suk” Faculty Research Assistance Program of Gangnam Severance Hospital for 2020 (DHHD000070), and was supported by research grants from the Korean Healthcare Technology R&D project funded by the Ministry of Health & Welfare (HI15C1200, HC19C0130), a faculty research grant of Department of Internal Medicine, Yonsei University College of Medicine for 2019-8020-80717-4323130, a faculty research grant of Yonsei University College of Medicine for 6-2020-0158, and a research grant from the Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (NRF-2017R1A2B3003303).
Copyright © 2020. The Korean Society of Cardiology This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (https://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
All Science Journal Classification (ASJC) codes
- Internal Medicine
- Cardiology and Cardiovascular Medicine