Table 1_Short sleep duration and incident self-reported severe periodontitis among Japanese adults: a nationwide prospective cohort study.docx

Although cross-sectional studies suggest an association between short sleep duration and periodontitis, longitudinal evidence remains limited. This study aimed to examine the association between sleep duration and self-reported incident severe periodontitis using data from a nationwide prospective cohort.</p>Methods<p>We conducted a prospective cohort study using longitudinal data from the 2023–2025 waves of the Japan COVID-19 and Society Internet Survey.

Participants without self-reported severe periodontitis at baseline were followed for self-reported incident severe periodontitis. Short sleep duration was defined as <6 h per night. Cox proportional hazards models were used as the primary analysis, and generalized estimating equations were used as a secondary analysis.</p>Results<p>Among 33,000 respondents to the 2023 survey, 8,144 individuals without self-reported severe periodontitis at baseline and with follow-up data were included in the study population.