Association between periodontal disease and chronic obstructive pulmonary disease: a reality or just a dogma?

BACKGROUND In the past few years, the association between chronic obstructive pulmonary disease (COPD) and periodontal disease has been promulgated. The present study is aimed at determining the association between these two diseases. METHODS This observational study includes 501 individuals consisting of 102 patients (case group) having COPD and 399 individuals as controls. Individuals in the case group were well-functioning and ambulatory patients having COPD as determined by their history and their values of forced expiratory volume in 1 second (FEV1) and forced vital capacity. Periodontal status was evaluated by the following five indices: 1) plaque index; 2) oral hygiene index (OHI); 3) gingival index (GI); 4) probing depth (PD); and 5) clinical attachment level (CAL). Lung function test was performed by all the patients (case group), who were then graded into mild, moderate, severe, and very severe. RESULTS Preliminary analysis was performed to identify the covariates in this study. Individuals in the case group had significantly higher CAL, PD, and OHI (P <0.0001) compared with the control group after adjusting for covariates. A significant negative correlation was observed between FEV1 values and CAL, PD, and GI, thus indicating a trend in which severity of lung obstruction increased as these periodontal indices worsened. CONCLUSION Although the present study cannot ascertain causal association, it provides substantial evidence that poor periodontal health is associated with obstructive lung disease.