Chronic obstructive pulmonary disease as an independent risk factor for cardiovascular morbidity

RATIONALE: Recent studies described association between chronic obstructive pulmonary disease (COPD) and increased risk of cardiovascular diseases (CVD). In their analysis none of these studies accounted for sociodemographic factors, health behaviors, and patient comorbidities simultaneously. OBJECTIVE: To study whether COPD diagnosis is an independent risk factor for CVD. METHODS: Subjects aged 40 years and older (N = 18,342) from the sample adult file of the 2002 National Health Interview Survey (NHIS) were included in the analysis. Chi-squared tests and odds ratios (OR) were utilized to compare the data. Multiple logistic regression was employed to analyze the association between COPD and CVD with simultaneous control for sociodemographic factors (age, gender, race, marital status, education, income), health behaviors (tobacco use, alcohol consumption, physical activity), and patient comorbidities (diabetes, hypertension, high cholesterol, and obesity). The analysis employed NHIS sampling weights to generate data representative of the entire US population. RESULTS: The COPD population had increased prevalence of CVD (56.5% vs 25.6%; P < 0.0001). Adjusted logistic regression showed that COPD patients (N = 958) were at higher risk of having coronary heart disease (OR = 2.0, 95% CI: 1.5–2.5), angina (OR = 2.1, 95% CI: 1.6–2.7), myocardial infarction (OR = 2.2, 95% CI: 1.7–2.8), stroke (OR = 1.5, 95% CI: 1.1–2.1), congestive heart failure (OR = 3.9, 95% CI: 2.8–5.5), poor circulation in lower extremities (OR = 2.5, 95% CI: 2.0–3.0), and arrhythmia (OR = 2.4, 95% CI: 2.0–2.8). Overall, the presence of COPD increased the odds of having CVD by a factor of 2.7 (95% CI: 2.3–3.2). CONCLUSIONS: These findings support the conclusion that COPD is an independent risk factor for CVD.