Emerging risk factors and the dose-response relationship between physical activity and lone atrial fibrillation: a prospective case-control study.
OBJECTIVE
The role of high-intensity exercise and other emerging risk factors in lone atrial fibrillation (Ln-AF) epidemiology is still under debate. The aim of this study was to analyse the contribution of each of the emerging risk factors and the impact of physical activity dose in patients with Ln-AF.


RESULTS
Patients with Ln-AF and age- and sex-matched healthy controls were included in a 2:1 prospective case-control study. We obtained clinical and anthropometric data transthoracic echocardiography, lifetime physical activity questionnaire, 24-h ambulatory blood pressure monitoring, Berlin questionnaire score, and, in patients at high risk for obstructive sleep apnoea (OSA) syndrome, a polysomnography. A total of 115 cases and 57 controls were enrolled. Conditional logistic regression analysis associated height [odds ratio (OR) 1.06 [1.01-1.11]], waist circumference (OR 1.06 [1.02-1.11]), OSA (OR 5.04 [1.44-17.45]), and 2000 or more hours of cumulative high-intensity endurance training to a higher AF risk. Our data indicated a U-shaped association between the extent of high-intensity training and AF risk. The risk of AF increased with an accumulated lifetime endurance sport activity ≥ 2,000 h compared with sedentary individuals (OR 3.88 [1.55-9.73]). Nevertheless, a history of <2000 h of high-intensity training protected against AF when compared with sedentary individuals (OR 0.38 [0.12-0.98]).


CONCLUSIONS
A history of ≥ 2,000 h of vigorous endurance training, tall stature, abdominal obesity, and OSA are frequently encountered as risk factors in patients with Ln-AF. Fewer than 2000 total hours of high-intensity endurance training associates with reduced Ln-AF risk.
Unitat de Fibril.lació Auricular, Hospital Clínic, Universitat de Barcelona, Barcelona, Catalonia, Spain Institut d'Investigacions Biomédiques August Pi i Sunyer (IDIBAPS), Catalonia, Spain.
Naiara
N
Calvo
Unitat de Fibril.lació Auricular, Hospital Clínic, Universitat de Barcelona, Barcelona, Catalonia, Spain Institut d'Investigacions Biomédiques August Pi i Sunyer (IDIBAPS), Catalonia, Spain.
Pablo
P
Ramos
Unitat de Fibril.lació Auricular, Hospital Clínic, Universitat de Barcelona, Barcelona, Catalonia, Spain Institut d'Investigacions Biomédiques August Pi i Sunyer (IDIBAPS), Catalonia, Spain.
Silvia
S
Montserrat
Unitat de Fibril.lació Auricular, Hospital Clínic, Universitat de Barcelona, Barcelona, Catalonia, Spain Institut d'Investigacions Biomédiques August Pi i Sunyer (IDIBAPS), Catalonia, Spain.
Eduard
E
Guasch
Unitat de Fibril.lació Auricular, Hospital Clínic, Universitat de Barcelona, Barcelona, Catalonia, Spain Institut d'Investigacions Biomédiques August Pi i Sunyer (IDIBAPS), Catalonia, Spain.
Blanca
B
Coll-Vinent
Institut d'Investigacions Biomédiques August Pi i Sunyer (IDIBAPS), Catalonia, Spain Unitat d'Hipertensió i Risc Vascular, Hospital Clínic, Catalonia, Spain.
Mònica
M
Domenech
Unitat de Fibril.lació Auricular, Hospital Clínic, Universitat de Barcelona, Barcelona, Catalonia, Spain Institut d'Investigacions Biomédiques August Pi i Sunyer (IDIBAPS), Catalonia, Spain.
Felipe
F
Bisbal
Institut d'Investigacions Biomédiques August Pi i Sunyer (IDIBAPS), Catalonia, Spain.
Sara
S
Hevia
Institut d'Investigacions Biomédiques August Pi i Sunyer (IDIBAPS), Catalonia, Spain.
Silvia
S
Vidorreta
Institut d'Investigacions Biomédiques August Pi i Sunyer (IDIBAPS), Catalonia, Spain.
Roger
R
Borras
Unitat de Fibril.lació Auricular, Hospital Clínic, Universitat de Barcelona, Barcelona, Catalonia, Spain Institut d'Investigacions Biomédiques August Pi i Sunyer (IDIBAPS), Catalonia, Spain.
Carles
C
Falces
Unitat de Fibril.lació Auricular, Hospital Clínic, Universitat de Barcelona, Barcelona, Catalonia, Spain Institut d'Investigacions Biomédiques August Pi i Sunyer (IDIBAPS), Catalonia, Spain Unitat del Son. Servei Pneumologia, Hospital Clínic, CIBERES Barcelona, Catalonia, Spain.
Cristina
C
Embid
Unitat de Fibril.lació Auricular, Hospital Clínic, Universitat de Barcelona, Barcelona, Catalonia, Spain Institut d'Investigacions Biomédiques August Pi i Sunyer (IDIBAPS), Catalonia, Spain Unitat del Son. Servei Pneumologia, Hospital Clínic, CIBERES Barcelona, Catalonia, Spain.
Josep Maria
JM
Montserrat
Unitat de Fibril.lació Auricular, Hospital Clínic, Universitat de Barcelona, Barcelona, Catalonia, Spain Institut d'Investigacions Biomédiques August Pi i Sunyer (IDIBAPS), Catalonia, Spain.
Antonio
A
Berruezo
Unitat de Fibril.lació Auricular, Hospital Clínic, Universitat de Barcelona, Barcelona, Catalonia, Spain Institut d'Investigacions Biomédiques August Pi i Sunyer (IDIBAPS), Catalonia, Spain Unitat d'Hipertensió i Risc Vascular, Hospital Clínic, Catalonia, Spain.
Antonio
A
Coca
Unitat de Fibril.lació Auricular, Hospital Clínic, Universitat de Barcelona, Barcelona, Catalonia, Spain Institut d'Investigacions Biomédiques August Pi i Sunyer (IDIBAPS), Catalonia, Spain.
Marta
M
Sitges
Unitat de Fibril.lació Auricular, Hospital Clínic, Universitat de Barcelona, Barcelona, Catalonia, Spain Institut d'Investigacions Biomédiques August Pi i Sunyer (IDIBAPS), Catalonia, Spain.
Josep
J
Brugada
Unitat de Fibril.lació Auricular, Hospital Clínic, Universitat de Barcelona, Barcelona, Catalonia, Spain Institut d'Investigacions Biomédiques August Pi i Sunyer (IDIBAPS), Catalonia, Spain lmont@clinic.ub.es.
Lluís
L
Mont
D001281:Atrial Fibrillation / Q000175:diagnosis / Q000453:epidemiology*; D016022:Case-Control Studies; D015897:Comorbidity; D015444:Exercise; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D017678:Sex Distribution; D020181:Sleep Apnea, Obstructive / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology*; D013030:Spain / Q000453:epidemiology; D013177:Sports
Abdominal obesity; Endurance training; Exercise; Lone atrial fibrillation; OSA; Risk factors