Total cholesterol mediates the association between history of gestational diabetes mellitus and bone mineral density in US women aged 20–49 years

Objective The aim of this study is to investigate the potential association between a history of gestational diabetes mellitus (GDM) and lumbar bone mineral density (BMD) among premenopausal women, with an additional examination of the mediating role of serum total cholesterol (TC). Methods In this cross-sectional study, 1809 women aged 20–49 years with at least one live birth between 2011 and 2018, drawn from the NHANES dataset, were analyzed. GDM history was identified through questionnaires. Using weighted multiple linear regression, we assessed the relationship between GDM history and lumbar BMD. Additionally, mediation analysis was performed to investigate the potential mediating role of TC. Results The fully adjusted linear regression model revealed a negative association between a history of GDM and lumbar BMD, indicating a reduction in lumbar BMD (β = -0.023, 95% CI: -0.043, -0.003, P = 0.0275). Subgroup analysis highlighted a more pronounced trend in individuals aged ≥ 35 years and with a body mass index ≥ 30 kg/m². Furthermore, mediation analysis demonstrated a significant direct effect of a history of GDM on lumbar BMD ( P < 0.0001), with serum TC playing a partial mediating role in this interaction (5.33%, P = 0.028). Conclusions In women aged 20–49 years within the United States, a history of GDM was associated with diminished lumbar BMD, potentially mediated through serum TC.