Improved oral hygiene care and chronic kidney disease occurrence A nationwide population-based retrospective cohort study

Oral diseases or poor oral hygiene have close connections with systemic inflammatory reaction, which is one of major mechanism in the development of chronic kidney disease (CKD). We conducted a research assuming that better oral hygiene care would be negatively related with the risk of developing new-onset CKD. From 2003 to 2004, a total of 158,495 participants from the Korean national health insurance data sharing service which provides health screening data including variables as age, sex, vascular risk factors, medication information, indicators regarding oral hygiene, and laboratory results. The diagnosis of CKD and vascular risk factors were defined according to the International Statistical Classification of Diseases and Related Health Problems codes-10(th) revision. The follow-up period for the study subject was until the occurrence of CKD, until death, or Dec 31, 2015. Approximately 13.3% of the participants suffered from periodontal disease, and 40.7% brushed their teeth at least three times a day. With a median of 11.6 (interquartile range 11.3-12.2) years' follow-up, the cohort included 3223 cases of incident CKD. The 10-year incidence rate for CKD was 1.80%. In multivariable analysis with adjustment for age, sex, demographics, vascular risk factors, blood pressure, and blood laboratory results, frequent tooth brushing (>= 3 times a day) was negatively related to occurrence of CKD (hazard ratio: 0.90, 95% confidence interval [0.83-0.99], P = .043, P value for trend = .043).Participants with improved oral hygiene (>= 3 times a day) have showed less risk of CKD. Additional interventional studies are in need to establish causative relationship between oral hygiene and risk of CKD.