Does Periodontal Treatment Improve Glycemic Control in Diabetic Patients? A Meta-analysis of Intervention Studies

Does Periodontal Treatment Improve Glycemic Control in Diabetic Patients? A Meta-analysis of Intervention Studies
2005
S.-J. Janket1,2,*, A. Wightman3, A.E. Baird4, T.E. Van Dyke5, and J.A. Jones1,6
Journal of Dental Research

© 2005 International and American Associations for Dental Research

1 Department of General Dentistry, Boston University, Goldman School of Dental Medicine, 100 East Newton Street, Boston, MA 02118, USA;
2 Harvard School of Public Health, Department of Nutrition, Boston, MA, USA;
3 US Air Force 59th Dental Squadron, San Antonio, TX, USA;
4 Stroke Neuroscience Unit, NINDS, National Institutes of Health, Bethesda, MD, USA;
5 Clinical Research Center/Periodontology and Oral Biology, Boston University Goldman School of Dental Medicine, Boston, MA, USA; and
6 VA Center for Health Quality, Outcomes and Economic Research, Bedford, MA, USA

* corresponding author, sjanket@post.harvard.edu

ABSTRACT

Previous analyses regarding effects of periodontal treatment on glycemic control included studies where causal association might not be assumed, or the results were reported non-quantitatively. We initiated this meta-analysis of 10 intervention studies to quantify the effects of periodontal treatment on HbA1c level among diabetic patients, to explore possible causes for the discrepant reports, and to make recommendations for future studies. Data sources were MEDLINE (January, 1980, to January, 2005), the EBMR, Cochrane Register, and bibliographies of the published articles. Three investigators extracted data regarding intervention, outcomes, and effect size. A total of 456 patients was included in this analysis, with periodontal treatment as predictor and the actual change in hemoglobin A1c level as the outcome. The weighted average decrease in actual HbA1c level was 0.38% for all studies, 0.66% when restricted to type 2 diabetic patients, and 0.71% if antibiotics were given to them. However, none was statistically significant.

KEY WORDS: meta-analysis Ô inflammatory mediators Ô hemoglobin A1c Ô non-surgical periodontal treatment Ô antibiotics treatment

INTRODUCTION

Over 20 million Americans have diabetes mellitus, with one million new patients being diagnosed each year (ADA, 2005). Inflammatory processes involving pro-inflammatory cytokines, C-reactive protein, and TNF- have been implicated in the pathogenesis of diabetes mellitus. Several dental researchers have postulated that IL-1?, IL-6, and CRP from periodontal infection might contribute to the total inflammatory burden (Craig et al., 2003; DÌAiuto et al., 2005). One early study showed that exodontia (removing teeth with advanced decay), a source of possible inflammatory mediators, improved glycemic control (Williams and Mahan, 1960).

Since WilliamsÌ and MahanÌs study, over 60 studies have examined the relationship between oral infection and glycemic control among diabetic patients. However, most of them were cross-sectional studies where causal association could not be inferred, and not all published reports were in agreement. These results have been summarized in several reviews (Grossi and Genco, 1998; Taylor, 2001, 2003), and only one review assessed longitudinal studies where causal association might be assumed, but the results were summarized without quantification (Taylor, 2003). Thus, we commenced this meta-analysis to review all published evidence systematically and to quantify the impact of periodontal treatment on HbA1c. Further, we explored the possible causes for the discrepant reports. We tested the null hypothesis that "periodontal treatment does not affect glycemic control in patients with diabetes".

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