Lung development genes, adult lung function and cardiovascular comorbidities

The association between lower adult lung function and increased cardiovascular comorbidity has not been adequately explained. We investigated whether shared developmental signalling pathways, critical to lung development and repair, could partly explain it.

In UK Biobank (UKB), we performed pairwise colocalisation analysis of variants in 55 lung development genes associated with adult forced vital capacity (FVC) or forced expiratory volume in 1 s (FEV₁)/FVC, to see if these are also associated with coronary heart disease (CHD), blood pressure (systolic, diastolic, hypertension), pulse pressure, Arterial Stiffness index and carotid intima-media thickness. For CHD, we meta-analysed data from UKB and the CARDIoGRAM consortium.

We found that 12 of the 55 genes shared the same variant between one (or more) lung function trait and one (or more) cardiovascular trait (H4colocalisation). The direction of effects was always in keeping with our hypothesis (lower lung function-higher cardiovascular risk) for FVC, but not always for FEV₁/FVC. The seven signals for hypertension and CHD all replicated nominally in the FinnGen study, while replication was poor in the China Kadoorie Biobank (CKB) study. In addition, we found a further 10 genes where genetic associations with lung function and cardiovascular traits were within the same gene but involved different variants (H3 colocalisation). Interestingly, six of all 22 genes (H4 and H3 colocalisation) were novel for cardiovascular traits; four replicated in FinnGen, three in CKB.

Lung function and cardiovascular traits have shared developmental pathways that may partly explain why lower lung function, especially FVC, is associated with increased cardiovascular risk.