Background: Osteoporosis is a frequent, underdiagnosed complication of both Thalassemia and Chronic Kidney Disease (CKD), yet comparative dual-energy X-ray absorptiometry (DEXA) data across these two conditions from the same institution are limited.

Objective: To assess and compare bone mineral density (BMD) using DEXA in patients with Thalassemia and CKD, and to correlate DEXA findings with clinical and anthropometric parameters.

Materials and Methods: This prospective observational study enrolled 212 patients (107 Thalassemia, 105 CKD) at a tertiary care hospital in Jamnagar, Gujarat, over 18 months. DEXA of the lumbar spine (L1-L4) and proximal hip was performed as per ISCD 2023 protocols, with BMD classified using Z-scores. Statistical analysis used Student's t-test, the chi-square/Fisher's exact test, and correlation analysis (SPSS v27.0; p<0.05 considered significant).

Results: Low BMD for age (Z<=-2.0) was found in 56.6% of patients and osteopenia in 41.0%; only 2.4% had normal BMD. CKD patients had significantly lower BMD than Thalassemia patients at the lumbar spine (0.777 vs 0.833 g/cm2, p<0.001) and hip (0.818 vs 0.856 g/cm2, p<0.001), with more negative Z-scores at both sites (p<0.001 and p=0.0002 respectively). Thalassemia major patients had a nearly 19-fold higher prevalence of low BMD than non-major patients (75.6% vs 4.0%, p<0.001). Fracture history was present in 53.8% overall (CKD 70.5% vs Thalassemia 37.4%, p<0.001), and 86.8% of patients with fractures had low BMD (p<0.001).