BACKGROUND: Cardiovascular diseases (CVDs) and chronic obstructive pulmonary disease (COPD) often occur comorbidly, sharing similar risk factors and symptom presentations. However, the influence of comorbid CVD on health-related quality of life (HRQoL) along the gradient of airflow limitation severity found within COPD is understudied. OBJECTIVE: The objective of this study was to identify if comorbid CVD demonstrates a significant moderating influence on HRQoL at each distinct stage of airflow limitation presenting among a sample of individuals living with COPD. METHODS: A cross-sectional secondary analysis of N = 1609 participants enrolled in the SubPopulations and InteRmediate Outcome Measures in COPD Study observational cohort study using a 4 × 2 factorial analysis of variance. RESULTS: There were significant differences in HRQoL among those with and without comorbid CVD at Global Initiative for Chronic Lung Diseases Stages I (P <
.001) and II (P <
.001)
however, there were no significant differences at Stages III (P = .182) or IV (P = .138). CONCLUSIONS: The moderating influence of comorbid CVD on HRQoL may be variable among the various stages of airflow limitation present within COPD. Future studies should further examine comorbid illness interactions within the context of their gradients of severity.