Associations of domain-specific physical activities with insomnia symptoms among 0.5 million Chinese adults

Previous studies have demonstrated the association between physical activity and sleep quality. However, there is little evidence regarding different domains of physical activity. This study aimed to examine the associations between domain-specific physical activities and insomnia symptoms among Chinese men and women. Data of 452 024 Chinese adults aged 30-79 years from the China Kadoorie Biobank Study were analysed. Insomnia symptoms were assessed with self-reported difficulties in initiating or maintaining sleep, early morning awakening, daytime dysfunction and any insomnia symptoms. Physical activity assessed by questionnaire consisted of four domains, including occupational, commuting-related, household and leisure-time activities. Gender-specific multiple logistic regression models were employed to estimate independent associations of overall and domain-specific physical activities with insomnia symptoms. Overall, 12.9% of men and 17.8% of women participants reported having insomnia symptoms. After adjustment for potential confounders, a moderate to high level of overall activity was associated with reduced risks of difficulties in initiating or maintaining sleep and daytime dysfunction in both sexes (odds ratios range: 0.87-0.94, P < 0.05). As to each domain of physical activity, similar associations were identified for occupational, household and leisure-time activities in women but not men (odds ratios range: 0.84-0.94, P < 0.05). Commuting-related activity, however, was associated with increased risks of difficulties in initiating or maintaining sleep and any insomnia symptoms in both sexes (odds ratios range: 1.07-1.17, P < 0.05). In conclusion, a moderate to high level of physical activity was associated with lower risks of insomnia symptoms among Chinese adults. However, such associations varied hugely in different domains of physical activity and with gender differences, which could help with better policy-making and clinical practice.