A recent study published in Scientific Reports examined associations between periodontitis and allergic rhinitis (AR).

Study: Unique inverse association between allergic rhinitis and periodontitis: a nationwide population-based study. Image Credit: Lightspring/Shutterstock.com

Background

AR causes sneezing, postnasal drip, runny nose, nasal congestion, and concomitant ocular symptoms (eye redness and watering). Airborne allergens are deemed the most common trigger of AR.

The incidence of AR has increased in the past decade in South Korea, partly attributable to the increasing fine dust levels. Nasal congestion is among the common symptoms in AR and can lead to mouth breathing.

Mouth breathing has been reported to cause adverse effects by altering saliva and normal oral flora, resulting in halitosis, gingival inflammation, and altered dentofacial growth. Periodontitis is linked to an increased gingival inflammation index among mouth-breathing patients.

Thus, there could be a link between nasal congestion-induced mouth breathing and periodontal diseases in AR patients.

The study and findings

The present study investigated the associations between periodontitis and AR in South Koreans. The team included 6,129 adults aged over 19.

They obtained data on education level, income, smoking/alcohol status, history of treatment for periodontitis (HTP), body mass index (BMI), and other medical history.

The study population was well-balanced regarding sex, and their mean age was 46.9. Around 23% of the participants were smokers, and 59.3% reported alcohol consumption at least once a month. More than 50% of the cohort obtained higher education beyond high school. Hypertension, diabetes mellitus (DM), and osteoporosis were the most common systemic diseases.

Approximately 52% of the study population reported using an auxiliary oral hygiene device. HTP was documented for 22.8% of the participants, and AR was reported by 15.3%. Statistically significant differences were observed in age, education level, the history of DM, hypertension, AR, and osteoporosis between HTP and non-HTP groups.

Specifically, there were significantly more participants with an AR diagnosis in the non-HTP group (17.5%) than in the HTP group (11%). The researchers estimated that the risk of periodontal disease in the HTP subjects without an AR diagnosis was 1.5-fold higher than in those with a diagnosis of AR.

Multiple logistic regression analysis revealed a significant association of HTP with higher education level and diagnosis of AR or osteoporosis. HTP was not associated with age, BMI, alcohol status, or diagnosis of hypertension/DM.

In a sub-analysis, the authors observed a significant association between AR and HTP among individuals below 65 years, which was not observed for those above 65.

Conclusions

Taken together, the findings suggest that HTP was less prevalent among participants with an AR history, indicating a lower risk of periodontitis, particularly among those aged less than 65.

This was concordant with a study that reported an inverse association between allergic respiratory diseases and periodontitis. Higher education was associated with a lower periodontitis risk, whereas osteoporosis was associated with a higher risk.

Journal reference:

• Kim, D. et al. (2023) "Unique inverse association between allergic rhinitis and periodontitis: a nationwide population-based study", Scientific Reports, 13(1). doi: 10.1038/s41598-022-23543-9. https://www.nature.com/articles/s41598-022-23543-9