AUTHOR=Ukawa Shigekazu , Kato Yusuke , Lee Yonggeun , Sugiyama Masaaki , Saito Hiroko , Ohara Kazuoki , Mori Kazuhiko 

TITLE=Daily sitting time and past-year falls in Japanese adults: an exploratory cross-sectional analysis

JOURNAL=Frontiers in Sports and Active Living

VOLUME=Volume 7 - 2025

YEAR=2025

URL=https://www.frontiersin.org/journals/sports-and-active-living/articles/10.3389/fspor.2025.1610010

DOI=10.3389/fspor.2025.1610010

ISSN=2624-9367

ABSTRACT=BackgroundSedentary behavior is a potentially modifiable risk factor for falls, yet the sitting time threshold linked to elevated fall risk remains unclear, particularly in Asian populations.ObjectiveThis study aimed (1) to examine the association between dichotomized daily sitting time and falls in the past year, and (2) to determine an optimal threshold above which the odds of falls significantly increase.MethodsA cross-sectional survey was conducted in 2022 in two aging Japanese communities. Data were collected from 1,331 adults (mean age 68.3 ± 15.2 years; 52.1% women) via self-administered questionnaires. The exposure was self-reported daily sitting time from the Global Physical Activity Questionnaire, and the outcome was at least one fall in the past year. Receiver operating characteristic (ROC) analysis identified the optimal threshold, and logistic regression estimated odds ratios (ORs).ResultsAmong 1,331 adults, 20.2% reported ≥1 fall in the past year. ROC analysis identified 4.08 h/day as the optimal cutoff (AUC = 0.52). In adjusted models, sitting ≥4.08 h/day was associated with higher odds of falls (crude OR = 1.44, 95% CI: 1.09–1.91; adjusted OR = 1.35, 95% CI: 1.01–1.81). Continuous sitting time was also positively associated with falls.ConclusionDaily sitting time of about 4 h or more was linked to increased odds of past-year falls, but its discriminatory ability was minimal (AUC ≈ 0.5). Adding measures such as muscle strength and balance may improve prediction, and this cutoff could serve as a population-level marker when combined with other risk indicators.