Sociodemographic factors and physical activity domains associated with sedentary behavior in older adults: evidence from a population-based study.

Sedentary behavior is a growing public health concern due to its association with chronic diseases and functional decline, especially among older adults. This study aimed to assess the prevalence of sedentary behavior among older adults living in São Paulo, Brazil, and to analyze its associations with sociodemographic characteristics and physical activity domains. Data were collected from the Health Survey in São Paulo City (ISA-Capital), with 1,010 individuals aged ≥ 60 years. Sedentary behavior was assessed using the International Physical Activity Questionnaire, considering total sitting time (both leisure and non-leisure) and categorized as ≤ 4h/day or > 4h/day. Sociodemographic variables and physical activity domains were examined using Poisson regression models. Overall, 43.7% of participants reported sedentary behavior of > 4h/day. Multivariate analyses revealed a higher likelihood of sedentary behavior among individuals aged 80 years or older, with an increase ranging from 41% to 58% compared to those aged 60-69 years. Men were 23% more likely to report sedentary behavior than women. Participants with four or more years of education had a 29% to 64% higher likelihood compared to those with up to three years. Individuals who self-identified as Indigenous or others had a 38% to 41% greater likelihood compared to white participants. Engaging in less than 150 min/week of commuting, domestic, and total physical activity was associated with a 41% to 67% increase in sedentary behavior. These results highlight sociodemographic disparities and the influence of specific physical activity domains on sedentary behavior among older adults, reinforcing the need for targeted public health interventions.