Figure 1. Metabolites associated with habitual smoking. Each plot displays the P-value derived from a mixed-model analysis, where the dependent variable (fixed effect) is the concentration of 1 of the 94 metabolites (log-transformed). The independent variable (fixed effect) represents smoking habits (never smokers [reference] and current cigarette smokers). Covariates (fixed effects) account for age, systolic blood pressure, body mass index, HbA1c, triglycerides, and alcohol and coffee consumption. The random effect pertains to the measurement batch in metabolomics analysis. The horizontal line indicates a false discovery rate P-value = 0.05. FDR, false discovery rate.
