Poole, Charles

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.

Background— Reduced low forced expiratory volume in 1 second (FEV 1 ) is reportedly associated with an increased risk of atrial fibrillation (AF). Extant reports do not provide separate estimates for never smokers or for blacks, who incongruously have lower AF incidence than whites. Methods and Results— We examined 15 004 middle-aged blacks and whites enrolled in the Atherosclerosis Risk in Communities (ARIC) cohort study. Standardized spirometry data were collected at the baseline examination. Incident AF was identified from the first among the following: International Classification of Diseases codes for AF on hospital discharge records or death certificates or 12-lead ECGs performed during 3 triennial follow-up visits. Over an average follow-up of 17.5 years, a total of 1691 participants (11%) developed new-onset AF. The rate of incident AF was inversely associated with FEV 1 in each of the 4 race and sex groups. After multivariable adjustment for traditional cardiovascular disease risk factors and height, hazard ratios of AF comparing the lowest with the highest quartile of FEV 1 were 1.37 (95% confidence interval, 1.02–1.83) for white women, 1.49 (95% confidence interval, 1.16–1.91) for white men, 1.63 (95% confidence interval, 1.00–2.66) for black women, and 2.36 (95% confidence interval, 1.30–4.29) for black men. The above associations were observed across all smoking status categories. Moderate/severe airflow obstruction (FEV 1 /forced vital capacity <0.70 and FEV 1 < 80% of predicted value) was also associated with higher AF incidence. Conclusions— In this large population-based study with a long-term follow-up, reduced FEV 1 and obstructive respiratory disease were associated with a higher AF incidence after adjustment for measured confounders.

AbstractOver 22,000 cases of ovarian cancer were diagnosed in 2007 in the United States, but only a fraction of them can be attributed to mutations in highly penetrant genes such as BRCA1. To determine whether low-penetrance genetic variants contribute to ovarian cancer risk, we genotyped 1,536 single nucleotide polymorphisms (SNP) in several candidate gene pathways in 848 epithelial ovarian cancer cases and 798 controls in the North Carolina Ovarian Cancer Study (NCO) using a customized Illumina array. The inflammation gene interleukin-18 (IL18) showed the strongest evidence for association with epithelial ovarian cancer in a gene-by-gene analysis (P = 0.002) with a &lt;25% chance of being a false-positive finding (q value = 0.240). Using a multivariate model search algorithm over 11 IL18 tagging SNPs, we found that the association was best modeled by rs1834481. Further, this SNP uniquely tagged a significantly associated IL18 haplotype and there was an increased risk of epithelial ovarian cancer per rs1834481 allele (odds ratio, 1.24; 95% confidence interval, 1.06-1.45). In a replication stage, 12 independent studies from the Ovarian Cancer Association Consortium (OCAC) genotyped rs1834481 in an additional 5,877 cases and 7,791 controls. The fixed effects estimate per rs1834481 allele was null (odds ratio, 0.99; 95% confidence interval, 0.94-1.05) when data from the 12 OCAC studies were combined. The effect estimate remained unchanged with the addition of the initial North Carolina Ovarian Cancer Study data. This analysis shows the importance of consortia, like the OCAC, in either confirming or refuting the validity of putative findings in studies with smaller sample sizes. (Cancer Epidemiol Biomarkers Prev 2008;17(12):3567–72)