title: Relation of hypothyroidism and incident atrial fibrillation (from the Framingham Heart Study).
abstract: BACKGROUND
  Hyperthyroidism has a well-described association with atrial fibrillation (AF). However, the relation of hypothyroidism to AF has had limited investigation. Hypothyroidism is associated with cardiovascular risk factors, subclinical cardiovascular disease, and overt cardiovascular disease, all of which predispose to AF. We investigated 10-year incidence of AF in a community-dwelling cohort.
  
  
  METHODS
  Among 6,653 Framingham heart Study participants, 5,069 participants, 52% female, with mean age of 57 ± 12 years, were eligible after excluding those with missing thyroid-stimulating hormone (TSH), TSH <0.45 μU/L (hyperthyroid), TSH >19.9 μU/L, or prevalent AF. Thyroid-stimulating hormone was categorized by range (≥0.45 to <4.5, 4.5 to <10.0, 10.0 to ≤19.9 μU/L) and by quartiles. We examined the associations between TSH and 10-year risk of AF using multivariable-adjusted Cox proportional hazards analysis.
  
  
  RESULTS
  Over 10-year follow-up, we observed 277 cases of incident AF. A 1-SD increase in TSH was not associated with increased risk of AF (hazard ratio 1.01, 95% CI 0.90-1.14, P = .83). In categorical analysis, using TSH ≥0.45 to <4.5 μU/L as the referent (equivalent to euthyroid state), we found no significant association between hypothyroidism and 10-year AF risk. Comparing the highest (2.6 < TSH < 19.9 μU/L) to lowest (0.45 < TSH < 1.3 μU/L) quartiles of TSH further did not identify a significant association between TSH levels and 10-year risk of AF.
  
  
  CONCLUSIONS
  In conclusion, we did not identify a significant association between hypothyroidism and 10-year risk of incident AF in a community-based study.
authors: Department of Medicine, Boston University School of Medicine, Boston, MA.
authors: Eun-Jeong
authors: EJ
authors: Kim
authors: National Heart Lung and Blood Institute's and Boston University's Framingham Heart Study, Framingham, MA; Department of Mathematics and Statistics, Boston University, Boston MA.
authors: Asya
authors: A
authors: Lyass
authors: Data Coordinating Center, Boston University School of Public Health, Boston, MA.
authors: Na
authors: N
authors: Wang
authors: National Heart Lung and Blood Institute's and Boston University's Framingham Heart Study, Framingham, MA; Department of Mathematics and Statistics, Boston University, Boston MA.
authors: Joseph M
authors: JM
authors: Massaro
authors: National Heart Lung and Blood Institute's and Boston University's Framingham Heart Study, Framingham, MA; Division of Endocrinology and Metabolism, Brigham and Women's Hospital and Harvard Medical School, Boston, MA.
authors: Caroline S
authors: CS
authors: Fox
authors: National Heart Lung and Blood Institute's and Boston University's Framingham Heart Study, Framingham, MA; Department of Medicine, Section of Cardiovascular Medicine, Boston University School of Medicine, Boston, MA; Department of Medicine, Preventive Medicine Section, Boston University School of Medicine, Boston, MA; Department of Epidemiology, Boston University School of Public Health, Boston, MA.
authors: Emelia J
authors: EJ
authors: Benjamin
authors: National Heart Lung and Blood Institute's and Boston University's Framingham Heart Study, Framingham, MA; Department of Medicine, Section of Cardiovascular Medicine, Boston University School of Medicine, Boston, MA. Electronic address: jmagnani@bu.edu.
authors: Jared W
authors: JW
authors: Magnani
mesh_terms: D000328:Adult; D001281:Atrial Fibrillation / Q000097:blood / Q000453:epidemiology*; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012307:Risk Factors; D013972:Thyrotropin / Q000097:blood
chemical_list: D013972:Thyrotropin