Striking Gender‐based Differences in Bone Mineral Density in a Resource‐Limited Setting

Abstract

The determination of bone health status is largely absent in South Africa due to the lack and cost of equipment required for the assessment of bone mineral density (BMD). Dual‐energy x‐ray absorptiometry (DEXA) ‐ also the gold standard evaluation, is too expensive for widespread implementation. In light of this, the current study evaluated an ultrasound bone densitometer (Sonost 3000 Co Ltd.) as a novel screening tool for BMD in a resource‐deprived setting such as South Africa. We screened the heel bones of 88 female and 38 male students (21‐23 years age) at Stellenbosch University by employing the Sonost 3000 that passes non‐radiating ultrasound through the calcaneus bone. Weight and height, together with age, gender and ethnicity were recorded to accurately determine bone health status. Similar degrees of osteopenia in male and female students (13% and 14%, respectively) were noted. In addition, age, broadband ultrasound attenuation (BUA – indicative of bone structure) and sun exposure did not differ between the two groups. However, male students displayed a significantly increased speed of sound (SOS; marker of bone density and elasticity), bone quality index (BQI), as well as T‐scores vs. females. Furthermore, males led a relatively active lifestyle (58% vs 41%) and lifted more weights daily (26% vs 10%) compared to females. This study demonstrates that male students displayed improved bone health status versus females, and that this is likely due to the pursuance of a more active lifestyle. Our findings also show that the Sonost 3000 offers early promise as a preliminary screening method to assess BMD in especially resource‐limited settings.