MPO and diabetes mellitus: CRP is a global measure of inflammation and oxidative stress even in apparently “healthy” populations[28] and MPO is a lysosomal enzyme in neutrophils that has been associated with coronary plaque instability[29] and therefore increased cardiovascular risk.[30] As expected, MPO levels have been shown to be higher in people with diabetes compared to controls.[31] MMPI treatment resulted in a significant decrease in both CRP and MPO by the end of the study whereas PL had no effect, supporting the anti-inflammatory properties of doxycycline.