Moderating and mediating effects of dysmenorrhea pain severity in the relationship between body mass index and body appreciation among adult women with primary dysmenorrhea.

Abstract

Objective: To investigate whether dysmenorrhea severity moderates and/or mediates the association between body mass index (BMI) and body appreciation among women with primary dysmenorrhea (PD).

Methods: Cross-sectional online study with 2026 women with PD. Participants were allocated into two groups according to their menstrual status: those who were menstruated and had current menstrual pain (CMP) and those who reported pain from their last menstrual period (LMP). We assessed bivariate relationships among BMI (Kg/cm²), pain severity (Numerical Rating Scale), and body appreciation (10-item Body Appreciation Scale), along with moderation and mediation for the same variables.

Results: In the LMP group, BMI was significantly and negatively correlated with body appreciation (r = -0.249, p < 0.001). Moderation analysis indicated that the negative association between BMI and body appreciation was stronger at lower pain severity (β = -0.045, p < 0.001), whereas higher pain severity attenuated this effect. Furthermore, mediation analysis revealed that dysmenorrhea severity partially mediated the relationship between BMI and body appreciation (indirect effect β = -0.001, 95 % CI [-0.002, -0.001]), accounting for approximately 3 % of the total effect. No significant moderation or mediation effects were observed in the CMP group.

Conclusions: Dysmenorrhea severity plays a dual role - acting as both moderator and mediator - in linking higher BMI to lower body appreciation. These findings underscore the importance of integrating pain management with interventions designed to improve body appreciation in women with PD. Future longitudinal studies should further clarify these relationships and underlying mechanisms.