Bone density and bone turnover markers in patients with epilepsy on chronic antiepileptic drug therapy

In this comparative, cross-sectional study, we evaluated 55 patients with epilepsy on chronic use of antiepileptic drugs (AED); [(38 females and 17 males, 35 ± 6 years (25 to 47)] and compared to 24 healthy subjects (17 females/7 males). Laboratorial evaluation of bone and mineral metabolism including measurements of bone specific alkaline phosphatase (BALP) and carboxyterminal telopeptide of type I collagen (CTX-I) were performed. Bone mineral density (BMD) was measured by DXA. BALP and CTX-I levels did not differ significantly between the groups. CTX-I levels were significantly higher in patients who were exposed to phenobarbital (P< 0.01) than those who were not. Patients presented BMD of both sites significantly lower than the controls (0.975 ± 0.13 vs. 1.058 ± 0.1 g/cm²; p= 0.03; 0.930 ± 0.1 vs. 0.988 ± 0.12 g/cm²; p= 0.02, respectively). Total hip BMD (0.890 ± 0.10 vs. 0.970 ± 0.08 g/cm²; p< 0.003) and femoral neck (0.830 ± 0.09 vs. 0.890 ± 0.09 g/cm²; p< 0.03) were significantly lower in patients who had been exposed to phenobarbital, in comparison to the non-phenobarbital users. In conclusion, patients on AED demonstrate reduced BMD. Among the AED, phenobarbital seems to be the main mediator of low BMD and increases in CTX-I.

Neste estudo comparativo, transversal, 55 pacientes com epilepsia [38 mulheres e 17 homens; 35 ± 6 anos (25 a 47anos)] foram comparados com 24 indivíduos normais (17 mulheres / 7 homens). Foi realizada uma avaliação laboratorial do metabolismo ósseo e mineral incluindo a dosagem de fosfatase alcalina específica óssea (BALP) e telopeptídeo carboxiterminal do colágeno tipo I (CTX-I). Densidade mineral óssea (DMO) da coluna lombar e do fêmur foi medida por DXA. BALP e CTX-I não foram diferentes entre os grupos. CTX-I foi significativamente mais elevado nos pacientes expostos ao fenobarbital do que os que não usaram essa medicação (p< 0,01). DMO de ambos os sítios foi menor no grupo de pacientes (0,975 ± 0,13 vs. 1,058 ± 0,1 g/cm²; p= 0,03; 0,930 ± 0,1 vs. 0,988 ± 0,12 g/cm²; p= 0,02, respectivamente). DMO do fêmur total (0,890 ± 0,10 vs. 0,970 ± 0,08 g/cm²; p< 0,003) e colo do fêmur (0,830 ± 0,09 vs. 0,890 ± 0,09 g/cm²; p< 0,03) foi significativamente menor nos pacientes que usaram fenobarbital. Em conclusão, pacientes portadores de epilepsia em uso crônico de drogas antiepilépticas (DAE) demonstraram uma redução da DMO. Entre as DAE, o fenobarbital parece ser o principal mediador da diminuição da DMO e do aumento do CTX-I.

Fracturas vertebrales, osteoporosis y vitamina D en la posmenopausia: Estudio en 555 mujeres en Chile / Vertebral fractures, osteoporosis and vitamin D levels in Chilean postmenopausal women

Background: Approximately one-third of vertebral fractures can be clinically diagnosed. Aim: To study the frequency of vertebral fractures in postmenopausal women. Patients and methods: We recruited 555 postmenopausal women from Santiago, Chile, aged 55-84 years, who manifested interest in their bone health. All were healthy by self-declaration and by general clinical and laboratory tests and had not taken any bone-active therapy. They all underwent a spine and femoral neck (FN) densitometry and a digital lateral spine X-ray from T4 to L4 was obtained. PTH, calcidiol, and other parameters of calcium metabolism were also measured. Results: Overall, 142 of 478 patients with a complete study (29.7 percent) had at least one vertebral fracture. The proportion of women with fractures increased with age. A T score below -2.5 in the spine and hip was found in 32 percent and 14 percent of women, respectively. The proportion of women with spinal opeoporosis doubled between ages 55-70 and remained constant afterwards. In contrast, at the femoral neck, this proportion increased progressively reaching 53.3 percent at age 80-85. However, 56 percent of patients with vertebral fractures did not have densitometric osteoporosis in any location. Calcidiol levels were 16.8±6.8 ng/mL. With a cutoff point of 17 ng/mL, 47.5 percent of the patients had hypovitaminosis D. There was no association between calcidiol levels and vertebral fractures or bone density at the spine or femoral neck. Patients with fractures differed from those without fractures in that they had significantly lower bone density at the spine and hip and were older (p <0.001). However they did not differ in weight, body mass index, or calcidiol levels. Conclusions: Thirty percent of postmenopausal women in this series had a vertebral fractures. Osteoporosis and vitamin D deficiency were also common. Most vertebral fractures were observed in women without osteoporosis by densitometric criteria.