Fig. 1

Schematic overview of the study design. In the current paper, previously identified CpGs by the largest available EWAS [6] and genes by the largest available TWAS [8] associated with current versus never smokers were used to test the link between smoking and cardio-metabolic traits. To this end, we first examined the association between smoking and alterations in gene expression (a). Second, we checked the association between the smoking-related CpGs and the smoking-related gene expression probes (a). Third, the smoking-related CpGs and gene expression probes that were in eQTM with each other were tested for their association with cardio-metabolic traits (b)