PURPOSE: Although impaired lung function as measured by FEV1% has been associated with increased mortality from cardiovascular (CV) disease, individuals with impaired lung function may include a broad spectrum of individuals with and without airway obstruction. Since patients with airway obstruction may differ in a systematic fashion from those with low FEV1% from any cause in CV risk profile, we set out to determine the association between abnormal lung function, as measured by either FEV1% alone or the FEV1/FVC ratio, and the presence of CV risk factors including systolic hypertension, hyperlipidemia, obesity, metabolic syndrome/diabetes mellitus.
METHODS: Cross-sectional study of adults 40 years of age and older in the NHANES III database with valid FEV1, FVC, and CV risk factor measurements who had fasted for at least 8 hours (n=3905). Logistic regression adjusted for demographics and other potential confounders.
RESULTS: Individuals in the lowest quartile of FEV1% predicted (mean ± SE FEV1% 69.8 ± 0.6%) as compared to the highest quartile FEV1% predicted (114.1 ± 0.3%) had significantly increased odds of multiple cardiac risk factors including systolic hypertension, obesity, hypertriglyceridemia, and the metabolic syndrome, after adjustment for potential confounders. However, individuals in the lowest quartile of FEV1/FVC (0.62 ± <0.01) as compared to the highest quartile of FEV1/FVC (0.85 ± <0.01) did not show significantly increased odds of these risk factors after adjustment for confounders, and had lower adjusted odds of DM and obesity. The results did not change substantially when the GOLD criteria to define airway obstruction were applied.
CONCLUSION: Measures of lung function are differentially associated with cardiac risk factors. Aside from smoking, traditional cardiac risk factors are not associated with airway obstruction as measured by FEV1/FVC ratio, while factors related to metabolic syndrome are strongly associated with FEV1% predicted.
CLINICAL IMPLICATIONS: The association of low FEV1% of any cause with cardiovascular disease may be confounded by the association between this measure and the metabolic syndrome.
DISCLOSURE: Matthew Jankowich, No Financial Disclosure Information; No Product/Research Disclosure Information