Sex Differences in the Association Between Body Composition, Sarcopenic Obesity, and Periodontitis: Mediating Role of...

This study aims to examine, in a sex-stratified manner, the associations of fat mass index (FMI), muscle mass index (MMI), and the muscle-to-fat ratio (MFR) with oral health as represented by periodontitis (PD), and to quantify the mediating role of systemic inflammatory and oxidative stress (OS) markers in these associations.

This research drew on cross-sectional data from the National Health and Nutrition Examination Survey (NHANES 2011-2014; n=3,553). Confounder-adjusted weighted logistic regression models determined sex-stratified associations. Restricted cubic spline (RCS) regression evaluated non-linear MFR-PD relationships. Mediation analysis quantified the contribution of OS markers.

Among women, lower MFR was associated with a statistically significantly increased PD risk (OR=0.49, 95% CI:0.34-0.72, p=0.001). Higher FMI (OR=1.59, 95% CI:1.15-2.19, p=0.008) and MMI (OR=1.86, 95% CI:1.13-3.07, p=0.018) also conferred increased risk. No statistically significant associations were observed in men. Serum albumin mediated 15.1% (p= 0.040) of the association between MFR and PD, 27.9% (p= 0.040) of the association between MMI and PD, and 23.4% (p0.001) of the association between FMI and PD. Subgroup analyses revealed no statistically significant interaction effects (all p> 0.05).

In women, a lower MFR is independently associated with higher PD prevalence, while higher FMI and MMI are also associated with elevated PD prevalence. Serum albumin partly explains these associations, suggesting that oxidative stress may be one of the pathways linking body composition imbalance to compromised oral health. No comparable associations were observed in men. For clinicians, MFR together with serum albumin may serve as accessible and low-cost markers for identifying women, particularly those in the peri-menopausal period, who could benefit from early periodontal screening and targeted nutritional or lifestyle interventions. Prospective cohort studies and interventional trials are warranted to confirm causality and to evaluate whether improving body composition translates into measurable benefits for oral health.