Efficacy of sub-antimicrobial dose doxycycline in post-menopausal women: clinical outcomes

Abstract

Aims: To determine the clinical efficacy of a 2-year continuous sub-antimicrobial dose doxycycline (SDD; 20 mg bid) in post-menopausal, osteopenic, oestrogen-deficient women on periodontal maintenance.

Materials and methods: One-hundred and twenty-eight subjects were randomized to SDD (n=64) or placebo (n=64). Clinical measurements were performed at posterior interproximal sites at baseline and every 6 months during this 2-year randomized, double-blind, placebo-controlled clinical trial with adjunctive, no-cost 3-4-month periodontal maintenance. Statistical analyses of secondary outcomes from this clinical trial used Generalized Estimating Equations in primarily intent-to-treat analyses.

Results: For the placebo group, 3.4% of the sites showed improvement in clinical attachment levels (CAL) and 2.7% had progressive loss in CAL; for the SDD group, 5.0% of the sites showed an improvement in CAL and 2.2% had progressive loss in CAL. This difference (2.1% of sites) was more favourable in the SDD group than in the placebo [odds ratio (OR)=0.81 [corrected] 95% confidence interval (CI): 0.67-0.97, p=0.03] in these well-maintained patients, whereas probing depths, bleeding on probing and supragingival plaque did not differ significantly between groups (p>0.2). However, in exploratory subgroup analysis of non-smokers, SDD showed reduced bleeding versus placebo (27%versus 33%; p=0.05). In protocol-adherent subjects, the odds of bleeding were 34% lower for SDD (p=0.05).

Conclusions: Analyses of secondary outcomes of this clinical trial indicated that SDD may be of benefit in reducing progressive attachment loss in post-menopausal females; additional research is needed to confirm these findings. Protocol registered at (ClinicalTrials.gov). Identifier:NCT00066027.

Figures

Figure 1

Percent of sites in study subjects (placebo or subantimicrobial dose doxycycline [SDD]) which demonstrated significant change (≥ 1.5 mm loss [A] or gain [B]) in relative clinical attachment level (RCAL) during 2 years of periodontal maintenance (based on intent-to-treat). 92−95% of sites showed no significant change at each of the study visits. Significant change was based on two times the standard deviation of replicate measurements.

Figure 2

Percent of sites in study subjects which demonstrated significant change (≥ 2.0 mm loss [A] or gain [B]) in probing depth (PD) during 2 years of periodontal maintenance (intent-to-treat). 90−93% of sites showed no significant change at each of the study visits. Significant change was based on two times the standard deviation of replicate measurements.

Figure 3

Percent of sites in study subjects which bled on probing during 2 years of periodontal maintenance (intent-to-treat). * indicates significant reduction from baseline across both treatment groups with p

Figure 4

Percent of sites in study subjects according to smoking status which bled on probing during 2 years of periodontal maintenance (exploratory subgroup analyses; placebo non-smoker n=49, SDD non-smoker n=44, placebo smoker n=13, SDD smoker n=11). A significant difference between nonsmoker groups existed at p = 0.05 across all time points combined.

Figure 5

Percent of sites in study subjects which demonstrated supragingival interproximal plaque (PL) during 2 years of periodontal maintenance (intent-to-treat).