Age, estimated basal metabolic rate, and subfoveal choroidal thickness: a cross-sectional study based on cataract patients.

To investigate the relationship between the basal metabolic rate (BMR) and subfoveal choroidal thickness (SFCT) and the statistical mediating role of the BMR in age-related changes in SFCT. This cross-sectional study included 119 cataract surgery patients. BMR was calculated by the Mifflin-St Jeor equation, and SFCT was measured via swept-source OCT and its integrated software. Covariates included metabolic indices (e.g., triglyceride-glucose index, hemoglobin level, platelet count, systolic blood pressure, and relevant comorbidities), comorbidities (hypertension, diabetes mellitus, and cardiovascular/cerebrovascular events), and ocular parameters (including intraocular pressure and axial length). Associations were evaluated using linear regression (with nested models for multicollinearity) and bootstrap mediation analysis. BMR was positively correlated with SFCT after adjusting for axial length according to both univariate and multivariate linear regression analyses (all P < 0.05), but significance was lost in the nested models including age and sex because of multicollinearity (VIF > 5). Mediation analysis revealed that age had a total effect on SFCT of -4.4641 (P < 0.01), with BMR mediating 27.71% of this effect (indirect effect: -1.2368, 95% CI: -2.0745 to -0.5340). In this cohort of cataract patients, BMR did not independently biological affect SFCT but served as a statistical mediating variable, partially elucidating the relationship between SFCT thinning and advancing age. A hypothesis was formulated that metabolic pathway regulation as a potential strategy for preserving age-related ocular health.