Frequency of Tooth Brushing as a Predictive Factor for Future Kidney Function Decline

Abstract

BackgroundTooth brushing is important for maintaining oral health and preventing periodontal diseases, which commonly arise in patients with chronic kidney disease (CKD). However, the association between tooth brushing frequency and kidney function decline remains unclear. MethodsWe conducted a retrospective longitudinal study at St Luke’s International Hospital, Japan, and participants who underwent health examinations at the Centre for Preventive Medicine from 2005 to 2011 were included. Participants’ tooth brushing frequencies were assessed; multivariate analyses were conducted using a generalized estimating equation to evaluate the association between tooth brushing frequency and a composite renal outcome – composed of a 25% eGFR reduction, an eGFR of <15 mL/min/1.73 m², and a requirement for regular dialysis – after adjusting for potential covariates. We also stratified participants by baseline CKD risk category to perform sub-analyses. ResultsOverall, 76,472 participants were included (mean age of 45.9 years) and 38,233 (50%) were male. During follow-up, 8,219 participants (10.8%) experienced composite renal outcomes. Brushing teeth at least once to twice a day was associated with significantly lower incidences of composite renal outcomes than brushing teeth less frequently (adjusted odds ratio [OR]: 0.26; 95% confidence interval [CI]: 0.24–0.28 for once to twice a day; adjusted OR: 0.65; 95% CI: 0.62–0.69 for after every meal). In our sub-analyses, brushing at least once to twice a day related to a decreased likelihood of composite renal outcomes; however, this effect was only observed within the low and moderate baseline risk groups. ConclusionFrequent tooth brushing benefits oral health and may prevent kidney function decline, which could have implications for other systemic diseases. However, a longitudinal cohort study is required to confirm whether tooth brushing can prevent poor renal outcomes.

Association between periodontitis and chronic kidney disease

“…A series of studies has shown that poor oral hygiene (evidenced by the increased biofilm/calculus index) was significantly more prevalent in patients with renal disease, 90,91 those undergoing in‐center hemodialysis, 91,92 and those receiving kidney transplant 91,93 compared with non‐renal controls. A recent, large‐scale, retrospective study that included 8219 Japanese patients with impaired renal function showed a significantly lower incidence of renal outcomes (defined as a 25% reduction in the estimated glomerular filtration rate) when patients brushed their teeth twice a day (odds ratio 0.26; 95% confidence interval 0.24‐0.28; P < .05) or after each meal (odds ratio 0.65; 95% confidence interval 0.62‐0.69; P < .05) compared with less frequent brushing after adjusting for several systemic comorbidities (hypertension, diabetes mellitus, and cancer) 94 . Poor oral hygiene (defined as a higher tertile of debris index‐simplified measurements) in patients undergoing in‐center hemodialysis was associated with a significantly higher risk of all‐cause mortality after adjusting for confounding factors (hazard ratio 3.04; 95% confidence interval 1.50‐6.17; P = .002) 95 …”

Periodontal Disease Risk Factors Assessment in Association with Frequency of Tooth Brushing

“…Besides certain known risk factors involved, oral hygiene practices particularly tooth brushing has revealed to be the most neglected risk factor in the severity and progression of this disease 2 . It is the second most common oral disease after dental caries [1][2][3] . Periodontitis is the commonest of oral disease, showing global prevalence of 11.2% 4 .…”