Sex-Specific Longitudinal Changes in Metabolic, Endocrine, Renal, Cardiovascular, and Inflammatory Biomarkers of Vaccinated COVID-19 Survivors: 30-Month Follow-Up Study

<i>Background and Objectives</i>: Sex-based disparities in COVID-19 outcomes are well-documented, with men experiencing greater acute severity and women showing increased vulnerability to post-viral syndromes. However, longitudinal immunometabolic trajectories in vaccinated individuals remain underexplored. In this study, sex-based differences in long-term metabolic, endocrine, renal, cardiovascular, and inflammatory responses were investigated among vaccinated individuals recovering from SARS-CoV-2 infection. <i>Materials and Methods</i>: This retrospective single-center cohort study included 426 adults (199 females, 227 males) with PCR-confirmed symptomatic COVID-19 and at least two vaccine doses. Serial assessments were conducted at baseline, 18-, 24-, and 30-month post-infection. Parameters included fasting glucose, HbA1c, lipid profile, thyroid function, renal markers, CRP, D-dimer, fibrinogen, troponin, and hematologic indices. Statistical analyses assessed longitudinal changes and sex-stratified correlations. <i>Results</i>: Fasting glucose and HbA1c levels significantly declined over time, more prominently in males. Glucose correlated with age and BMI only in females. Lipid levels remained largely unchanged, although males had higher baseline triglycerides. Females showed rising TSH levels and persistently lower free T3; males exhibited higher creatinine, urea, and troponin levels throughout. Inflammatory markers declined significantly in both sexes, with males displaying higher CRP and troponin, and females showing sustained fibrinogen elevation and a temporary lymphocyte surge. D-dimer was elevated in females at the 30-month point. <i>Conclusions</i>: Sex-specific physiological recovery patterns were evident among vaccinated COVID-19 survivors. Males exhibited earlier metabolic and cardiac alterations, while females had more persistent endocrine and inflammatory shifts. These findings underscore the need for sex-tailored long-term monitoring strategies prioritizing early metabolic and cardiac screening in men and prolonged immunoendocrine surveillance in women.