A subantimicrobial dose of doxycycline effectively controls periodontitis in diabetics, reducing A1c and resulting in a significant decrease in tooth pocket depth. At the 32nd annual meeting of the American Association of Dental Research in San Antonio, Texas, researchers reported that this treatment is actually more effective in diabetics than nondiabetics with periodontal disease.
Dr. Sebastian G. Ciancio of the University of Buffalo presented results of a randomized placebo-controlled trial of 20 adult diabetics with stable blood glucose levels and generalized periodontitis. Half the patients received doxycycline 20 mg bid and the other half placebo bid for 12 weeks. All patients underwent scaling and root planing.
Dr. Ciancio reported that not only did doxycycline therapy reduce tooth pocket depth by 1.7 mm, it also reduced glycated hemoglobin levels (HbA1c). Active treatment was 25% more effective in reducing pocket depth than was scaling and root planing alone, he added.
In previous studies of nondiabetics with periodontitis, Dr. Ciancio said that sub-antimicrobial doses of doxycycline reduced tooth pocket depth by 0.4 mm. “Periostat (doxycycline) achieved results that were 75% better in the diabetics than in nondiabetic patients.”
This dose of doxycycline inhibits collagenase and elastase, resulting in a strengthening of bone and connective tissue, Dr. Ciancio explained. But he stressed that the dose given in this study “is not antibiotic. It is 20 mg per dose, and it must be given twice a day. Otherwise, you get into bacterial problems.”
Dr. Ciancio and his colleagues have been discussing the possible mechanism by which sub-antimicrobial doxycycline reduces HbA1c. “It probably has a molecular basis, but I don’t know what it is, to be honest…One of my colleagues thinks that maybe it reduces inflammation–that is probably how it works.”
The Buffalo researcher added that active treatment lowered IL-2 levels significantly at the 6-week mark and lowered C-reactive protein levels at 12 weeks, “but not significantly.”