Adults with chronic kidney disease (CKD) were significantly more likely to have fewer than 20 teeth, according to findings from a national health survey in Korea involving 16,125 adults aged 40 to 79 years.

Individuals with CKD had 1.34 times greater odds of having fewer than 20 teeth compared with those without CKD (95% CI, 1.03–1.74), after adjusting for age, sex, income, education, smoking, alcohol use, body mass index, hypertension, diabetes, cardiovascular history, and oral hygiene behaviors.

The study used data from the 2013–2018 Korea National Health and Nutrition Examination Survey (KNHANES). CKD was defined by an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m², calculated using the 2021 CKD-EPI creatinine equation. Tooth count excluded third molars; having fewer than 20 teeth was classified as inadequate for masticatory function.

Among the participants, 428 (2.7%) had CKD. The mean number of teeth was 20.8 among those with CKD and 24.4 among those without. The prevalence of CKD was 6.3% in participants with fewer than 20 teeth and 2.0% among those with 20 or more.

Additional risk factors for having fewer than 20 teeth included older age (66–79 years; OR, 3.81; 95% CI, 3.33–4.36), smoking (OR, 2.03; 95% CI, 1.69–2.44), hypertension (OR, 1.30; 95% CI, 1.12–1.51), and diabetes (OR, 1.53; 95% CI, 1.31–1.77).

Oral hygiene behaviors were less common among individuals with CKD. Only 25.0% of participants with CKD underwent a dental exam in the past year, compared with 34.7% of those without CKD. Just 18.6% of those with CKD used floss or interdental brushes, versus 34.0% in the non-CKD group.

The study suggests that systemic inflammation may help explain the observed link. Elevated proinflammatory markers such as IL-6, TNF-α, and high-sensitivity C-reactive protein are associated with both CKD and periodontal disease. CKD can also impair bone metabolism, reduce salivary flow, and alter oral microbiota—factors that contribute to tooth loss.

Although causality cannot be confirmed due to the cross-sectional design, the association between CKD and fewer teeth remained significant after accounting for multiple confounders. The findings support including oral health evaluation and management in the care of patients with chronic kidney disease.

The authors reported no conflicts of interest.

Source: Renal Failure