Associations between accelerometer-assessed occupational and leisure-time sitting and self-reported cognitive dysfunction in Swedish middle-aged adults: a cross-sectional analysis from the SCAPIS study.

BACKGROUND: The relationship between sedentary behavior and cognitive health remains insufficiently understood. The aim of this study was to examine associations between occupational and leisure-time sitting and self-reported cognitive dysfunction. METHODS: Data from men and women, aged 50-64 years old, participating in the Umeå site of the cross-sectional Swedish CArdioPulmonary bioImage Study (SCAPIS) was used. Occupational and leisure-time sitting were measured using a thigh-worn accelerometer over seven days. Work hours were reported in a diary. Cognitive dysfunction was measured using the Cognitive Dysfunction Questionnaire. A Hurdle model was used to firstly assess the association of domain-specific sitting time with any cognitive dysfunction (logistic regression) and secondly with the severity of cognitive dysfunction (beta-binomial regression). Analyses were adjusted for sex, age, educational level, moderate- to vigorous physical activity, sleep duration, risky alcohol intake and emotional health limitations. RESULTS: A total of 1559 participants were included. In the fully adjusted model, each additional hour of occupational sitting was associated with 8% lower odds of reporting cognitive dysfunction (odds ratio (OR) 0.92, 95% confidence interval (CI) 0.87-0.98), while each additional hour of leisure-time sitting was associated with 12% higher odds (OR 1.12, 95% CI 1.03-1.21). Neither occupational nor leisure-time sitting was significantly associated with the severity of cognitive dysfunction among individuals reporting any dysfunction. CONCLUSIONS: Domain-specific sitting time was associated with the occurrence, but not the severity, of self-reported cognitive dysfunction in middle-aged adults. The contrasting associations observed for occupational and leisure-time sitting suggest that the context of sedentary behavior may be relevant for cognitive health. Future longitudinal studies using device-based measurements are needed to clarify causality and to explore the potential role of cognitively active and passive sedentary behaviors.