Original Contribution Why Does Lung Function Predict Mortality? Results From the Whitehall II Cohort Study

The authors examined the extent to which socioeconomic position, behavior-related factors, cardiovascular risk factors, inflammatory markers, and chronic diseases explain the association between poor lung function andmortality in 4,817 participants (68.9 % men) from the Whitehall II Study aged 60.8 years (standard deviation, 5.9), on average. Forced expiratory volume in 1 second (FEV1) was used to measure lung function in 2002–2004. A total of 139 participants died during a mean follow-up period of 6.4 years (standard deviation, 0.8). In a model adjusted for age and sex, being in the lowest tertile of FEV1/height 2 was associated with a 1.92-fold (95 % confidence interval: 1.35, 2.73) increased risk of mortality compared with being in the top 2 tertiles. Once age, sex, and smoking history were taken into account, the most important explanatory factors for this association were inflammatory markers (21.3% reduction in the FEV1/height 2-mortality association), coronary heart disease, stroke, and diabetes (11.7 % reduction), and alcohol consumption, diet, physical activity, and body mass index (9.8 % reduction). The contribution of socio-economic position and cardiovascular risk factors was small (3.5 % reduction). Taken together, these factors explained 32.5 % of the association. Multiple pathways link lung function to mortality; these results show inflammatory markers to be particularly important