Oral health and chronic kidney disease in Brazil: a population-based analysis of the 2019 National Health Survey.

BACKGROUND

Emerging evidence suggests a bidirectional relationship between oral health and chronic kidney disease (CKD), yet population-based data from upper-middle-income countries remain limited. This study aimed to evaluate the association between oral health indicators and CKD in a nationally representative sample of Brazilian adults.

METHODS

We conducted a cross-sectional, nationally representative analysis using data from the 2019 Brazilian National Health Survey (PNS), which employed a three-stage stratified cluster sampling design. The outcome was CKD, and the main exposures were self-related oral health, tooth loss, toothbrushing frequency, and eating difficulty due to oral conditions. Multivariable survey-weighted logistic regression models were used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs), controlling for age, sex, race/ethnicity, diabetes, and hypertension.

RESULTS

The study included 279,382 individuals, representing a weighted population of over 209 million Brazilians. Poor self-rated oral health was associated with higher odds of CKD (OR: 2.15; 95% CI: 1.56-2.97). Complete tooth loss showed a trend toward an association with CKD (adjusted OR: 1.30; 95% CI: 1.00-1.69; p = 0.050), and oral health-related eating difficulty was associated with higher odds of CKD (adjusted OR: 2.06; 95% CI: 1.45-2.93). In contrast, brushing teeth three times per day was associated with lower odds of CKD (adjusted OR: 0.43; 95% CI: 0.14-0.81). Fewer than half of participants reported visiting a dentist within the past year, and only 22.6% utilized public dental services.

CONCLUSION

Oral health conditions, including poor hygiene practices, tooth loss, and eating difficulties are significantly associated with CKD. These findings highlight the need to integrate oral health into chronic disease prevention strategies, particularly within public health systems in upper-middle-income countries.