Sleep time and quality associated with depression and social anxiety among children and adolescents aged 6–18 years, stratified by body composition

Sleep has been suggested as risk factors for depression and social anxiety in children and adolescents, but little is known about the role of individual body composition on these association. We conducted a cross-sectional survey of children and adolescents aged 6–18 years in Beijing, China, in 2020, and assessed body composition by using iDXA dual-energy X-ray bone densitometer. Generalized liner model (GLM) and restricted cubic spline (RCS) were employed to analyze the associations between sleep and depression and social anxiety with different body composition. The attributable fraction (AFs) to assess the benefits of improvements of sleep in reducing depression and social anxiety odds. Depression and social anxiety accounted for 13.1 % and 30.3 % of the study population. Sleep time was significantly associated with depression (HR = 2.35[1.58, 3.50]), and social anxiety (HR = 1.65[1.24, 2.20]); and sleep quality was significantly associated with depression (HR = 7.27[4.87, 10.84]), and social anxiety (HR = 2.54 [1.99, 3.25]) among children and adolescents. The exposure to both insufficient sleep time and poor sleep quality were associated with a higher odd of depression and social anxiety, but lower BF%, higher muscle rate and FFM/FM alleviated the adverse effects of sleep quality on depression and social anxiety. Conclusions about causality remain speculative because of the cross-sectional design. Insufficient sleep time, poor sleep quality, high BF%, low muscle rate and FFM/FM can jointly associate with anxiety and depression. This study provides new evidence support for accurate prevention and control of mental diseases in children and adolescents with different body types.