Objective:
To investigate the association between low forced expiratory volume in 1 second (FEV
1
) and incident atrial fibrillation (AF) in a population-based cohort.
Background:
Impaired FEV
1
, a complex measure indicating genetic, developmental, obstructive and restrictive airway disease, musculoskeletal function, and motivation, has been inconsistently associated with an increased risk of cardiovascular disease mortality. Also, extant reports do not provide separate estimates for African Americans, who surprisingly have lower AF incidence than Caucasians.
Methods:
We examined 15,282 middle-aged African Americans (26%) and Caucasians, men (45%) and women from four U.S. communities enrolled in the Atherosclerosis Risk in Communities (ARIC) cohort study. Lung volumes by standardized spirometry and information on covariates were collected on these participants at the baseline visit (1987-1989). Prevalent AF cases were excluded by 12-lead ECG at baseline. Incident AF was defined as the first event identified from the following: ICD codes for AF from hospital discharge records or death certificates, or ECGs performed during three triennial follow-up visits.
Results:
Over an average follow-up of 17.5 years, a total of 1,733 (11%) participants developed new-onset AF. The rate of incident AF increased monotonically and inversely by tertiles of FEV
1
in each of the 4 gender-race strata. The unadjusted average incidence rates of AF per 100 person years of follow up by tertiles of FEV
1
(from lowest to highest tertile) were 13.6, 8.3, and 5.7 for white men; 8.7, 4.5, and 3.4 for white women; 8.2, 5.5, and 3.8 for black men; 6.9, 4.1, and 2.4 for black women. After multivariable adjustment for traditional cardiovascular disease risk factors and height, hazard ratios (95% CI) of AF comparing the lowest with the highest tertile of FEV
1
were 1.44 (1.16,1.78) among white men, 1.45 (1.12, 1.87) among white women, 1.81 (1.09, 3.02) among black men, and 1.84(1.20, 2.82) among black women. The trend estimate for per 1 Standard-Deviation lower FEV
1
for the corresponding race and gender groups were 1.21 (1.12, 1.32), 1.38 (1.25, 1.54), 1.45 (1.18, 1.76), and 1.35 (1.12, 1.63), respectively. The above associations were observed across all smoking status categories (current, former, and never). The association between low lung function and incidence of AF was similarly unchanged after exclusion of participants with heart failure (n = 689) or CHD (n = 558) at baseline. The hazard of AF was about 50% higher among those with FEV1/FVC ratio below 0.7.
Conclusions:
In this large population-based cohort study with a long term follow-up, reduced FEV
1
is strongly associated with a higher AF risk, independent of race, gender, smoking, and several other CVD risk factors. These findings suggest the need for research on mechanisms underlying the observed association to seek broader opportunities for prevention of AF.
Hypertension and the Risk of Incident Gout in a Population-Based Study: The Atherosclerosis Risk in Communities Cohort
