Prevention of Primary Event

Tooth loss, hypertension and risk for stroke in a Korean population

Tooth loss has been suggested as a potential risk factor for stroke. We conducted a prospective cohort study of stroke in Korea on hypertension, diabetes, smoking, and tooth loss to characterize their independent effects and interactions. The overall risk of stroke and the risk of different subtypes of stroke were evaluated in relation to tooth loss using Cox proportional hazards models among 867,256 Korean men and women, aged 30-95 years, who received health insurance from the National Health Insurance Corporation and were medically evaluated between 1992 and 1995, with tooth loss measured. The overall prevalence of having at least one tooth removed among the people in the study was 29.8% (31.9% for men and 22.3% for women). During a 14-year follow-up, 28,258 strokes with 5105 fatal strokes occurred. For men and women, tooth loss was associated with total stroke and stroke subtypes. In a multivariable model adjusting for selected covariates, a graded association between higher tooth loss and higher risk of total stroke was observed in men [> or =7 lost teeth versus 0 (hazard ratio (HR)=1.3; 95% confidence interval (CI), 1.2-1.4)] and in women (HR=1.2; 95% CI, 1.0-1.3). The HRs for ischemic and hemorrhagic stroke were also similar in men and women. There was evidence of interaction of hemorrhagic stroke risk with hypertension and tooth loss. Tooth loss is independently associated with increased risk of stroke and hypertension does interact antagonistically, particularly for hemorrhagic stroke.

Periodontal disease, tooth loss, and incidence of ischemic stroke

BACKGROUND AND PURPOSE

Periodontal and other infections have been suggested as potential risk factors for stroke. This study evaluates periodontal disease and tooth loss as risk factors for ischemic stroke.

METHODS

The study population consisted of 41 380 men who were free of cardiovascular disease and diabetes at baseline. Periodontal disease history was assessed by mailed validated questionnaires. During 12 years of follow-up, stroke incidence was assessed and subclassified by use of medical history, medical records, and imaging reports. Hazard ratios (HRs) were adjusted for age, amount smoked, obesity, alcohol, exercise, family history of cardiovascular disease, multivitamin use, vitamin E use, profession, baseline reported hypertension, and hypercholesterolemia. Sex and socioeconomic status were inherently controlled for by restriction. Confounding variables were updated in the analyses for each 2-year follow-up interval.

RESULTS

We documented 349 ischemic stroke cases during the follow-up period. Men who had < or =24 teeth at baseline were at a higher risk of stroke compared to men with > or =25 teeth (HR=1.57; 95% CI, 1.24 to 1.98). There was little evidence of an increased risk with recent tooth loss during follow-up. A modest association was seen between baseline periodontal disease history and ischemic stroke (HR=1.33; 95% CI, 1.03 to 1.70). Addition of dietary factors to the model changed the HR only slightly.

CONCLUSIONS

Our results suggest that periodontal disease and fewer teeth may be associated with increased risk of ischemic stroke.