Long-Term Impact of COVID-19 on Osteoporosis Risk Among Patients Aged ≥50 Years with New-Onset Overweight, Obesity, or Type 2 Diabetes: A Multi-Institutional Retrospective Cohort Study

Background and Objectives : COVID-19 may have long-term adverse effects on bone health, particularly in individuals aged ≥50 years with obesity or diabetes, who are predisposed to impaired bone quality. Materials and Methods : This retrospective cohort study used TriNetX data from 141 healthcare organizations across North America and Western Europe. Patients aged ≥50 years with overweight (body mass index 25-30 kg/m 2 ), obesity (body mass index ≥ 30 kg/m 2 ), or type 2 diabetes (T2DM) and COVID-19 (2019-2024) were propensity score-matched to non-COVID-19 controls. Exclusion criteria included prior overweight, obesity, diabetes, osteoporosis, T-score ≤ -2.5, Z score ≤ -2.0, fractures, pneumonia, tuberculosis, and cancer. Outcomes included new-onset osteoporosis, fragility fractures, and low T-scores (≤-2.5). Cox regression estimated hazard ratios (HRs); sensitivity analyses assessed lag effects (1-4 years). Results : Among 327,933 matched pairs, COVID-19 was linked to increased osteoporosis risk at 3 years (HR, 1.039; 95% CI, 1.003-1.077) and 6 years (HR, 1.095; 95% CI, 1.059-1.133). Sensitivity analysis showed rising risk with longer lag times: HRs were 1.212, 1.379, 1.563, and 1.884 at 1 to 4 years, respectively. Subgroup analyses confirmed consistent trends. Conclusions : COVID-19 is independently associated with elevated long-term osteoporosis risk in older adults with new-onset overweight, obesity, or T2DM, peaking at 4 years post-infection and persisting through 6 years.