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.