Association of childhood maltreatment with DXA‑derived body composition in middle‑aged and older adults: mediating roles of unhealthy lifestyle and depression

Childhood maltreatment (CM) may shape health outcomes later in life, yet its association with body composition in mid-to-late adulthood remains incompletely characterized, particularly regarding sex differences and mechanistic pathways. We analyzed UK Biobank participants who underwent dual-energy X-ray absorptiometry (DXA) scans and grip strength assessment at imaging visits (2014 onward) and retrospectively reported CM in 2016. CM domains included physical and emotional neglect, as well as sexual, physical, and emotional abuse, assessed using the Childhood Trauma Screener. We examined DXA-derived indices of central adiposity and fat distribution (e.g., visceral adipose tissue [VAT]), lean soft-tissue indices (e.g., lean mass index [LMI]), and relative body-composition ratios (e.g., muscle-to-fat ratios [MFRs]), alongside grip strength/BMI as a functional measure. Linear regression models estimated associations between CM and body composition, adjusting for age, sex, ethnicity, socioeconomic factors, maternal smoking, and histories of diabetes, cardiovascular disease, and cancer. Mediation analyses examined the role of unhealthy lifestyle and depressive symptoms. P-values were corrected for multiple testing using the false discovery rate method. The study included 21,817 participants (mean age 64.5 ± 7.8 years; 52.7% women). After full adjustment, CM was associated with higher central adiposity and a less favorable muscle–adiposity profile, reflected by lower MFRs and lower grip strength/BMI. Physical abuse exhibited the strongest associations, including higher central adiposity (VAT β = 0.130; 95% CI, 0.097–0.162) and higher LMI (β = 0.152). Neglect domains showed smaller but generally significant associations. Muscle composition was consistently less favorable, characterized by lower MFRs (e.g., physical abuse β=−0.092; sexual abuse β=−0.060) and lower grip strength/BMI. Notably, sexual abuse showed stronger associations in women. A higher cumulative CM burden was associated with higher central adiposity and lower MFRs. In cross-sectional mediation analyses, unhealthy lifestyle and depressive symptoms were associated with attenuation of these associations by up to 31.6%. CM was associated with higher central adiposity, lower MFRs, and lower muscle-specific strength in mid-to-late adulthood. Physical abuse showed the strongest associations, while sexual abuse displayed stronger associations in women. Unhealthy lifestyle and depressive symptoms partially mediated these associations, highlighting potential prevention targets among individuals with CM exposure.