The prevalence of osteoporosis in patients referred for DEXA scans at Helen Joseph hospital: A retrospective descriptive analysis

Abstract

Purpose: Osteoporosis and fragility fractures are expected to rise in a rapidly aging South African population. However, there is limited prevalence and fracture data currently available. Methods: We assessed the prevalence of osteoporosis from all Dual-energy X-ray absorptiometry (DXA) scans done on referral at Helen Joseph Hospital in Johannesburg, Gauteng. All DXA scans between 01 January 2006 and 31 December 2021 were analysed. The World Health Organization (WHO) criteria were used to diagnose osteoporosis. Demographics, body parameters, and DXA measurements were collected. Results: Out of 2266 DXA scans analysed, 880 were osteoporotic (females 96.4%; males 3.6%). Overall, the prevalence of osteoporosis was 38.8% (CI 38.6-40.8). The incidence increased with age. Bone mineral density (BMD) T - scores were lower in subjects with lower body mass index (BMI). The vertebral body with the greatest prevalence of fractures was thoracic level T12. Wedge deformities occurred more often at the levels of T12, T8, and T7, compared to biconcave deformities which were seen in lower lumbar vertebrae L1- L3 levels. There were no significant differences when comparing T scores by various bony regions between males and females above age 50. Conclusion: Prevalence amongst those referred for DXA scans in this study was high however a true prevalence could not be appreciated due to the nature of the sampling. Further studies identifying the indications and risk factors in these patients will aid in understanding the epidemiology of osteoporosis in our context. Vertebral fracture prevalence varied at different vertebral body levels with the highest prevalence occurring at the level of T12. Underweight patients had more severe osteoporosis. Screening programs need emphasis and integration into routine clinical services. Further research, data capturing, and a fracture liaison service are needed to improve bone health in South Africa.