[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%) 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% and 14% of women, respectively. The proportion of women with spinal osteoporosis doubled between ages 55-70 and remained constant afterwards. In contrast, at the femoral neck, this proportion increased progressively reaching 53.3% at age 80-85. However, 56% 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% 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.