Abstract 15726: Reduced Lung Function in Adults with Cardiovascular Disease: The Strong Heart Study

Abstract

Objective: The aim of this study was to test whether reduced lung function is independently associated with cardiovascular disease (CVD) and whether it independently predicts subsequent incident CVD in American Indians (AI), the US population with highest prevalence of obesity.

Methods: The Strong Heart Study (SHS), a multicenter, population-based study of CVD and its risk factors among AI adults, enrolled 4549 men and women 45-74 years old at the 1^st examination (SHS1) in 1989 to 1992. The present analysis utilized lung function assessment by standard spirometry at the SHS 2^nd examination (SHS2,1993-95) in 352 CVD and 2873 non-CVD adults free of overt lung disease (mean age 60 years).

Results: AI with CVD had significantly lower pulmonary function than non-CVD AI. Differences remained significant after adjustment for age, gender, abdominal obesity, smoking, physical activity index, SHS field center, hypertension, insulin resistance, non-HDL cholesterol, and albuminuria. Significant negative associations were observed between CV abnormalities, insulin resistance, markers of inflammation, renal function, and FVC and FEV1 (P_trend <0.01, Table 1). In further Cox models, among 2873 participants who were CVD-free at SHS2, development of CVD in 841 by the end of 2008 was not predicted by either FVC or FEV1 independent of multiple CVD risk factors. However, among all 3225 participants who underwent pulmonary function assessment, 412 (298 without baseline CVD) died from CVD by the end of 2008. In models adjusted for multiple CVD risk factors and baseline CVD, lower FEV1 (as % of predicted) predicted CVD mortality (HR=0.99, 95% CI 0.98-0.99, p<0.0001).

Conclusions: In this AI population, lower lung function was independently associated with prevalent CVD, and its impairment predicted CVD mortality many years later. Additional research is needed to identify pathophysiologic mechanisms and to determine the clinical significance of this finding.