Significance of Serum Total Testosterone (T), Estradiol (E2), and T/E2 Ratio in Older Males With Metabolic Syndrome Across Different Age Cohorts: A Retrospective Review

Background The decline in glandular function among older males may contribute to the high prevalence of metabolic syndrome (MetS); however, research on the relationship between sex hormone levels and the progression of MetS in older men is scarce. This study aimed to elucidate the significance of serum total testosterone (T), estradiol (E2), and the T /E2 ratio in older men with MetS, with a specific focus on age‐specific variations. While low T is a known risk factor, the role of E2 and the T /E2 balance across different age cohorts remains poorly defined. Men aged ≥ 46 years who attended Harrison International Peace Hospital between June 2022 and December 2024 were enrolled in the study. A total of 405 patients were screened for a confirmed diagnosis of MetS (178 cases) and no MetS‐related component abnormalities (227 cases) and stratified by age into three groups: low age (46–64 years), middle age (65–74 years), and high age (≥ 75 years). Propensity score matching (PSM) was used to balance age, body mass index (BMI), cigarette smoking, alcohol consumption, and exercise habits, resulting in 125 pairs of participants successfully matched in a 1:1 ratio between the two groups in each age stratum (tolerance: 0.03). Comparisons were made between the T, E2, and T/E2 ratios across groups. Correlations between these three indicators and individual components of MetS were analyzed. The predictive roles of these three indicators combined with other high‐risk factors in the occurrence of MetS among middle‐aged and older men across different age groups were also explored. Results After PSM, the MetS group demonstrated significantly lower serum total testosterone (T) and T/E2 ratio compared to the non‐MetS group across all age strata (all p < 0.05), while estradiol (E2) levels showed no significant difference. A significant age‐dependent decline in T and T/E2 was observed within the MetS group. Correlation analyses revealed that T and T/E2 ratio were negatively associated with key MetS components (e.g., triglycerides [TG], fasting blood glucose), with the strength of these correlations attenuating in the oldest cohort (≥ 75 years). Multivariable models identified the T/E2 ratio as an independent risk factor, and receiver operating characteristic (ROC) analysis established age‐specific thresholds (e.g., T/E2 >12.33 for 46–64 years) with high predictive value (AUCs up to 0.866). Conclusion The T/E2 ratio provides significant predictive information beyond serum T alone for MetS in older men, particularly within the 46–74 year age window. These findings advocate for the incorporation of age‐specific assessment of the T/E2 ratio into clinical strategies for risk stratification and early intervention of MetS.