Sedentary behavior and type 2 diabetes in community-dwelling middle-aged and older adults: indirect cross-sectional correlation of sarcopenic obesity
Wenwen Zhao, Mingjie Meng, Yiheng Geng, Ruyue Qi, Jinjia Zhang, Min Zhang et al. · Frontiers in Endocrinology · 2026
Background: Type 2 diabetes mellitus (T2DM) represents a major public health challenge among middle-aged and older populations worldwide. The underlying mechanisms linking sedentary behavior to T2DM remain incompletely understood. Sarcopenic obesity (SO), a phenotype defined by concurrent low muscle mass and excess adiposity, may represent a key intermediate correlate linking sedentary behavior with T2DM in cross-sectional observations. This study aimed to explore the indirect cross-sectional correlation of SO in the correlation between sedentary behavior and T2DM and to clarify age- and sex-specific characteristics of this association.
Methods: A cross-sectional
Study design: was employed, consecutively enrolling 2, 480 community-dwelling middle-aged and older individuals (≥35 years) undergoing physical examinations. Daily sedentary time was assessed using the Sedentary Behavior Questionnaire (SBQ). Body composition was measured with the InBody 770 bioelectrical impedance analyzer. Logistic regression combined with bias-corrected, non-parametric Bootstrap
methods validated the statistical mediation, with sensitivity analyses stratified by sex, age, and the age-sex interaction.
Results: In the overall cohort, the statistical mediation of SO was significant (without covariates: mean ACME = 0.105, 95% CI: 0.078–0.130, proportion of the statistical indirect correlation = 22.43%; with covariates: mean ACME = 0.029, 95% CI: 0.013–0.043, proportion of the statistical indirect correlation = 14.97%;both P < 0.01). Stratified analyses revealed significant heterogeneity in the statistical mediation: the share of the statistical indirect correlation was higher in women (22.68%) than in men (9.08%), and significantly higher in those aged ≥65 years (19.14%) than in those aged <65 years (8.93%). In the age-sex interaction analysis, the statistical mediation was strongest in the ≥65-year female subgroup (mean ACME = 0.121, proportion of the statistical indirect correlation = 47.79%, P < 0.01), while the statistical mediation were not significant in the <65-year male ( P = 0.20) and <65-year female ( P = 0.11) subgroups.
Conclusion: Sedentary behavior is significantly associated with type 2 diabetes among community-dwelling middle-aged and older adults, and SO shows a significant statistical mediation in the cross-sectional correlation between sedentary behavior and T2DM. This statistical mediation shows distinct population differences and is most prominent among women aged 65 years or older.