The effect of subantimicrobial-dose–doxycycline periodontal therapy on serum biomarkers of systemic inflammation : A randomized, double-masked, placebo-controlled clinical trial

ABSTRACTBackgroundPeriodontitis has been reported to be associated with coronary artery disease (CAD). Research is needed to determine if therapies that improve periodontal health also reduce systemic measures of inflammation associated with both diseases.MethodsThe study registrar randomly assigned 128 eligible postmenopausal women with chronic periodontitis to a twice-daily regimen of subantimicrobial-dose–doxycycline (SDD) or placebo tablets for two years as an adjunct to periodontal maintenance therapy. Through a supplement to the main trial, in which they investigated alveolar bone and clinical attachment level changes, the authors assayed inflammatory mediators and lipid profiles in baseline, one-year and two-year serum samples. The authors analyzed the data by using generalized estimating equations.ResultsIn the intent-to-treat analysis across two years, SDD treatment reduced median high-sensitivity C-reactive protein (hs-CRP) by 18 percent (primary outcome; P = .02) and reduced serum matrix metalloproteinase (MMP)-9 (92 kilodalton gelatinase; difference in mean scanning units, −28.44; P < .001), with no significant effect on serum lipids. However, in women more than five years postmenopausal, SDD elevated the level of high-density lipoprotein (HDL) cholesterol (difference in means [milligrams per deciliter], 5.99; P = .01).ConclusionA two-year SDD regimen in postmenopausal women significantly reduced the serum inflammatory biomarkers hs-CRP and MMP-9 and, among women more than five years postmenopausal, increased the HDL cholesterol level.Clinical ImplicationsSDD significantly reduced the systemic inflammatory biomarkers hs-CRP and MMP-9. More research is needed to determine whether SDD has a role in managing the care of patients at risk of developing CAD.