Periodontal disease and risk of psoriasis among nurses in the United States

Objective. Periodontal disease has been associated with systemic inflammation and may be a risk factor for autoimmune diseases. This study evaluated the association between periodontal disease and the risk of incident psoriasis in a large prospective cohort study. Material and methods. Self-reported history of periodontal bone loss, from 1998-2008, was evaluated as a risk factor for incident psoriasis among 60,457 women in the Nurses' Health Study. Secondary analyses examined associations between history of tooth loss and number of natural teeth and psoriasis risk. Cox proportional hazards models were used to assess multivariate estimates, adjusting for age, cigarette smoking, body mass index, alcohol intake and physical activity. Results. An increased multivariate risk of psoriasis was observed for those with mild periodontal bone loss (RR = 1.35, 95% CI = 1.03-1.75) and moderate-to-severe periodontal bone loss (RR = 1.49, 95% CI = 1.08-2.05), as compared to those without periodontal bone loss, after adjusting for age, cigarette smoking, body mass index, alcohol intake, physical activity and tooth loss. Number of natural teeth and tooth loss were not associated with risk of psoriasis in this study. Conclusion. This study shows that a history of periodontal bone loss may increase risk of subsequent psoriasis. A limitation of this study is that it is based on self-reported measures.