Fig. 2.

Contingency table and dot plot of lipid-laden macrophages (LLM). (a) LLM were classified as positive (>10 LLM index) and negative. E-cig users were significantly more likely to test positive compared to never-smokers and significantly less likely compared to smokers (Fisher's exact test). (b) Each dot represents one participant, never-smokers in blue (n = 28), e-cig users in green (n = 13), and smokers in red (n = 23). Closed green circles are former smokers; open circles are never smoking e-cig users (n = 4). Box plots show medians with interquartile range for never-smokers (blue), e-cig users (green), and smokers (red). Open green circle represents ever-smoking e-cig users. Kruskal–Wallis test was used for overall p-values. Mann–Whitney test was used for two-group comparisons. All statistical tests were performed using batch-removed LLM.