The Role of Bedtime Procrastination, Rumination, Loneliness, and Positive Body Image in Predicting Sleep Quality Among University Students: A Sex-Specific Analysis.

Objective: This study aimed to analyze the impact of bedtime procrastination, rumination, loneliness, and positive body image on university students' sleep quality, and to explore potential mediating pathways and sex differences.

Methods: A total of 674 students from a university in southern China were recruited. Assessments of participants' body measurements were conducted, followed by the completion of a general information questionnaire, Pittsburgh Sleep Quality Index, Bedtime Procrastination Scale, Body Appreciation Scale, Body Image-Acceptance and Action Questionnaire, Ruminative Responses Scale, and University of Loneliness Scale. Stepwise multiple linear regression and mediation models were employed to separately analyze the associations between sleep quality and the aforementioned factors in males and females.

Results: Sex differences in sleep quality were apparent, with women having worse sleep quality than men (p < 0.05). In men, bedtime procrastination (β = 0.376, p < 0.01), loneliness (β = 0.339, p < 0.01), and rumination (β = 0.171, p < 0.01) were significant factors in predicting sleep quality. Loneliness played a partial mediating role in predicting poor sleep quality caused by bedtime procrastination, with a mediating effect of 18.95%. In women, bedtime procrastination (β = 0.399, p < 0.01), loneliness (β = 0.239, p < 0.01), body image flexibility (β = -0.153, p < 0.01), and body appreciation (β = -0.103, p < 0.05) were significant factors in predicting sleep quality. Loneliness and body appreciation played parallel mediating roles in predicting sleep quality through bedtime procrastination, with mediating effects of 9.24% and 5.19%, respectively.

Conclusions: Sleep quality and bedtime procrastination were worse in women than in men. The sleep quality of female students may be increased by focusing on enhancing positive body image, while for male students, managing rumination and reducing loneliness could be helpful.