Risk of fracture prevention in spina bifida patients: correlation between bone mineral density, vitamin D, and electrolyte values.

PURPOSE: The aim of our study was to investigate the relationship between bone mineral density (BMD), vitamin D, and electrolyte blood values in patients with spina bifida, to find a possible therapeutic regimen and an intervention to reduce the risk of fractures in this population. METHODS: BMD values were measured in 49 patients (32 females, 17 males; aged 14.1 ± 3.86 years; range 5-20 years) using dual-energy X-ray absorptiometry (DEXA) and were analyzed based on sex, the level of spinal involvement, vitamin D, and electrolyte values, physical activity, body mass index (BMI), and ambulatory status [patients were divided into three subgroups: full-time wheelchair (FTWC), limited ambulator (LA), and full-time ambulator (FTA)]. These data were analyzed considering sex-, age-, and BMD-matched values and compared with those of normal population. RESULTS: BMD was significantly lower in these patients compared with that in the general healthy population (Z-score: -1.2 ± 1.8); in particular, females had Z-score values significantly lower that of the males (Z-score: -2.43 ± 2.02; P < 0.0004). In FTWC subgroup, Z-score was lower than that of the other two subgroups (P < 0.009). Vitamin D values were significantly lower compared with those in the general healthy population (vitamin D spina bifida group: 14.6 ± 8.7 mg/dL; normal subjects: 35 ± 9.8 mg/dL; P < 0.001). Subjects with spina bifida showed hypophosphatemia (<3 mg/dL) because of the lower levels of vitamin D (3.1 ± 0.9 mg/dL; P < 0.001). CONCLUSIONS: Spina bifida patients showed lower BMD, vitamin D, and electrolyte values than the healthy population; hence, they have an increase risk of developing pathological fractures. Vitamin D supplementation for a longer time period could reduce this risk.