In the multivariate logistic regression analysis, current smoking (OR 1.73, 95% CI 1.06–2.84; p = 0.030) and beta blocker use (OR 1.81, 95% CI 1.04–3.16; p = 0.036) were significant determinants of high circulating MPO levels, independent of age, sex, obesity, OSA, history of AMI, and CABG at baseline (Figure 2). This evidence concerns the gene MPO and obstructive sleep apnea syndrome.