Bone Health in Sub-Saharan Africa

Bone Health in Sub-Saharan Africa

Bone health has been overlooked as a healthcare priority in sub-Saharan Africa, where the availability of dual energy X-ray absorptiometry (DEXA) equipment and other tools for bone assessment is limited. However, the impact of several risk factors can be changed by interventions – such as dietary calcium and vitamin D supplementation. Additionally, screening methods such as quantitative ultrasound scanning (QUS) and DXA can be cost-effective and accessible. Increasing urbanisation is another important factor, and the changing nutritional and social behaviour that comes with it can negatively affect BMD. Human immunodeficiency virus (HIV) also has a negative impact on bone health; although highly active antiretroviral therapy improves the prognosis for bone disease, BMD remains low in HIV-infected people.

The acquisition and maintenance of peak bone mass during childhood and young adulthood is crucial for prevention of future fragility fractures. Therefore, any change that affects this process may result in an increased fracture risk. During the reproductive years, the use of hormonal contraceptives that affect oestrogen levels can reduce the accrual of peak bone density and increase premenopausal bone loss. In addition, the glucocorticoid side effects of the injectable contraceptive depo medroxyprogesterone acetate (DMPA) are known to adversely affect bone health.

During the past century, healthcare systems in SSA have prioritised the provision of maternal and child health care as well as treatment of infectious diseases such as tuberculosis and human immunodeficiency virus (HIV). These priorities are now being challenged, and a new challenge is being presented: providing chronic care for an ageing population that has not been recognised in the past. The majority of older Africans, especially women, remain in the labour force and play critical economic, family and community roles.

In white populations, the detrimental effect of thyrotoxicosis on Bone Health South Africa is well established. In black South Africans, however, it has been shown that the skeleton is protected against the negative impact of other endocrinopathies, such as hyperparathyroidism.

Increased bone resorption is a well-described consequence of primary hyperparathyroidism (PHPT), and decreased BMD, vertebral fractures and osteitis fibrosa cystica have been reported in patients with PHPT after parathyroidectomy. The aim of this study was to compare skeletal, biochemical and clinical parameters in black patients with PHPT and matched controls. This was done to distinguish between the effect of GD and the influence of ethnicity on bone metabolism and density. The results demonstrate that black PHPT patients have significantly lower bone mineral density than their matched controls and this is mainly due to increased bone resorption. However, the rate of bone formation was similar between groups and the difference in BMD was not clinically significant. Thus, the skeletal phenotype of black patients with PHPT does not seem to be different from that of their white counterparts. This might be explained by the fact that their histomorphometric characteristics are relatively normal. However, the skeletal phenotype of GD is still unknown in the black South African population. Therefore, the authors recommend that future research in this area should focus on the evaluation of the skeletal outcomes of GD in a black population.