Background: Impaired lung function is associated with increased cardiovascular (CV) risk although the underlying mechanisms remain unclear. We have previously shown that lung function is inversely related to arterial stiffness in older men, and that patients with chronic obstructive pulmonary disease (COPD) have increased arterial stiffness. Furthermore, arterial stiffness is associated with impaired diastolic function in individuals with COPD. Our aim was therefore to examine the relationship between cardiac function and lung function in a population-based cross-sectional study.

Methods: Data from 1026 individuals, aged between 50–92 years, from the Anglo Cardiff Collaborative Trial, were available for the current analyses. Spirometry was performed (Vitalograph) to assess the degree of airways obstruction by measuring forced expiratory volume in 1 second: forced vital capacity ratio (FEV1:FVC). Peripheral blood pressure was recorded (Omron 711) in the supine position according to BHS guidelines. Cardiac function was assessed by measuring stroke volume (SV), using a non-invasive, inert gas re-breathing technique (InnoCor, Innovision A/S, Denmark).

Results: After entering all confounding factors of FEV1:FVC ratio (age, height, gender, smoking status, body surface area, heart rate, peripheral vascular resistance and mean arterial pressure) into a stepwise multivariate linear regression model, SV remained independently related to lung function (R=0.28, P=0.025).

Discussion: Stroke volume is independently associated with impaired lung function in this population based study, suggesting a mechanism whereby impaired lung function may increase CV risk. Increased arterial stiffness, which is associated with impaired lung function, may be an important mechanism mediating the relationship between cardiac function and lung function.