Bone and Joint Involvement in Beta Thalassemic Patients: A Cross-sectional Study.

Abstract

Purpose: There is paucity of guidelines with inadequate data available about the extent and prevention of bone and joint disease in beta-thalassemic patients in Indian population. This study aims to determine bone and joint involvement in beta-thalassemic patients. It evaluates serum biochemical parameters of bone formation and resorption and correlates with the symptomatology in these patients. The study also determines their daily physical activity and find a correlation if any with bone mineral density.

Methods: The study was carried out on 40 regularly transfused beta thalassemic patients between 5 and 18 years of age under regular follow-up at our centre from June 2012 to June 2014. All patients were interviewed as per a well-structured proforma for symptoms relating to bone and joint disease as described by the patient/parents in past 1 year and physical activity by QAPACE questionnaire. Venous blood samples were drawn under aseptic conditions and used for estimation of biochemical parameters (calcium, phosphorus, alkaline phosphatase, vitamin D, parathyroid hormone and serum ferritin). Enrolled subjects were scanned for bone mineral density (BMD) at femur neck, trochanter and Ward's angle using dual-energy X-ray absorptiometry.

Results: A total of 40 patients were enrolled in the study (Male:Female = 80:20). Half the patients (n = 20) had symptoms pertaining to bone and joint disease. The most common symptom was leg pain (42.50%), followed by backache (22.50%). Asymptomatic patients had greater mean serum vitamin D as compared to the symptomatic patients (22.2 vs 15.08 ng/ml) (p = 0.225). Five patients were detected to have osteopenia, all above 10 years of age. The mean BMD in symptomatic patients at femur neck, trochanter and ward's angle was 0.781, 0.639 and 0.735 g/cm², respectively, as compared to 0.754, 0.635 and 0.722 g/cm² in asymptomatic patients. The difference was not statistically significant. Patients with low BMD had lower mean pre-transfusion Hb (< 9 g/dl) (p = 0.01). Eighty percent of osteopenic patients had sedentary lifestyle as compared to 44% of patients with normal BMD. Bone mineral density did not have any correlation with vitamin D levels, serum ferritin and type of chelation therapy.

Conclusion: Pre-transfusion hemoglobin of more than 9 gm/dL has a protective role in maintaining good bone health and bone mineral density. Engaging thalassemia patients in physical activity has a positive effect on bone mineral density. Low vitamin D levels contribute to symptoms of bone and joint involvement in thalassemia and the same needs to be determined and supplemented.