Association between body weight status and suicidal ideation among Chinese adolescents: the moderating role of the child's sex

Abstract

Purpose: Suicidality (ranging from suicidal ideation to suicidal attempts and completed suicide) is a major and preventable public health concern, and body weight is considered a modifiable factor which might be helpful to the early risk assessment of suicidal ideation. This study aimed to comprehensively evaluate the association of body weight status with suicidal ideation across sex among Chinese adolescents.

Methods: Data were drawn from the 2015 National School-based Chinese Adolescents Health Survey, and 54,640 students' questionnaires were completed and qualified for the survey. Body mass index z scores were calculated and categorized into four levels: underweight (less than the 5th percentile for sex and age), normal weight (between the 5th and 85th percentile), overweight (between the 85th and 95th percentile), and obese (above the 95th percentile).

Results: Of the total sample, 47.3% (25,852) were boys. The weighted prevalence of suicidal ideation among Chinese adolescents is 15.7% (14.6% in boys and 17.3% in girls). After adjusting for demographics, smoking, drinking, and depressive symptoms, our final multivariate logistic regression models demonstrated that only boys identified as underweight (Adjusted odds ratio [AOR] = 1.23, 95% CI = 1.06-1.44) or obese (AOR = 1.19, 95% CI = 1.02-1.38) were at a higher risk of suicidal ideation. Additionally, the association between weight status and suicidal ideation among boys might be moderated by academic pressure, smoking, and depressive symptoms.

Conclusions: There was a significant J-shaped association between relative body weight and suicidal ideation in boys. The child's sex should be taken into consideration when developing interventions against unhealthy weight and suicidal ideation.

Keywords: Body weight status; Chinese adolescents; Sex difference; Suicidal ideation.