RESUMO
INTRODUCTION: We hypothesized that the prevalence of vertebral fractures would be low and that bone mineral density (BMD) would be less severely affected in a black South African (SA) population treated with glucocorticoids (GCs) than that reported in mainly white populations. METHODS: All children aged 5-17.9 years with chronic non-malignant illnesses who were on GCs (intravenous or oral) for greater than 3 months duration were evaluated. DXA scans were performed using a Hologic Discovery machine (Software version Apex 4.0.2) and the Hologic paediatric reference database. Whole body less head (WBLH) and lumbar spine (LS) bone mineral content (BMC) and density (BMD) Z-scores unadjusted and adjusted for height were calculated using the Zemel equation calculator. RESULTS: Seventy-two patients (49% with renal, 24% with rheumatic, 14% with neurological, 11% with hepatic and 3% with respiratory conditions; mean age 11.6 ± 3.3 years, 57% boys, 92% SA black) were enrolled. The mean duration of GC treatment was 34.1 (±25.1) months. Mean WBLH and LS height adjusted BMD Z-scores were -1.2 ± 1.5 and -0.9 ± 1.0 respectively. Eleven percent of patients had a LS height adjusted BMD Z-score ≤ -2. The prevalence of vertebral fractures on lateral vertebral fracture assessment (VFA) was 15% (11 of 72 patients). CONCLUSION: The prevalence of vertebral fractures (15%) in predominantly black children on GCs with chronic non-malignant illnesses is similar to that reported from North America suggesting that routine yearly DXA scans including VFA are warranted in this highly at-risk population.
RESUMO
OBJECTIVES: To investigate the pattern of clinical presentation in a series of South African subjects with X-linked hypophosphataemia (XLH) with particular reference to ethnic differences in presentation and inheritance, and to determine the perceptions and psychosocial problems associated with the disease. DESIGN AND SETTING: The clinical details of 50 subjects were collected from their records as well as from examining those currently attending the clinics held at Chris Hani Baragwanath Hospital and the National Health Laboratory Services in Johannesburg. There were 17 males and 33 females in the study. The psychosocial part of the study involved interviews with 20 parents and 7 subjects (aged 16 years or more). RESULTS: Thirty-one of the subjects were black, 17 white and 2 Indian. The mean age of clinical onset was 2.02 years (range 0.25 - 10 years). Fifty-four per cent of the cases were apparently sporadic. The prevalence of sporadic mutations was 64% among the black subjects and 41% among the white subjects. No differences were found in either clinical or biochemical presentation between genders or ethnic groups, despite an apparently higher sporadic presentation in the black children. The study also showed that this disorder had not only affected family life but also the lives of the subjects and their interpersonal relationships. The hereditary nature of the condition was not clear to most parents even after having attended the clinic for many years. CONCLUSIONS: South African subjects with XLH have similar features to those reported in other studies but there is a higher prevalence of sporadic mutations in the black subjects. Better counselling services are needed to improve the understanding of this condition among parents of affected children.
