Vertebral fracture risk factors in postmenopausal women over 50 in Valencia, Spain. A population-based cross-sectional study

Purpose: This study aims to estimate the prevalence of risk factors for osteoporotic vertebral fracture and analyze the possible associations between these factors and the presence of densitometric osteoporosis and prevalent morphometric vertebral fracture.

Methods: Data from a population-based cross-sectional sample of 804 postmenopausal women over the age of 50 years old living in the city of Valencia (Spain) were used. The women were interviewed to identify the prevalence of osteoporotic fracture risk factors and underwent a densitometry and a dorsolumbar spine X-ray.

Results: The most prevalent risk factors were densitometric osteoporosis (31.7%), history of parental hip fracture (19.4%), hypoestrogenism (19%), and body mass index (BMI) ≥ 30 kg/m(2) (35.2%). After adjusting for all covariables, densitometric osteoporosis was associated with increased age [odds ratio (OR)(65-69 years): 2.84, 95% confidence interval (CI): 1.75-4.61; OR(70-74 years): 4.01, 95% CI: 2.47-6.52; OR(75+years): 5.96, 95% CI: 3.27-10.87] and inversely associated with high BMI (OR(25.0-29.9): 0.51, 95% CI: 0.34-0.76; OR(≥ 30): 0.30, 95% CI: 0.19-0.46). Morphometric vertebral fracture was associated with age (OR(65-69 years): 2.04, 95% CI: 1.03-4.05; OR(70-74 years): 4.05, 95% CI: 2.11-7.77; OR(75+years): 8.43, 95% CI: 3.97-17.93), poor educational level (OR: 1.70, 95% CI: 1.06-2.72) and with densitometric osteoporosis and BMI ≥ 30 kg/m(2) (OR: 3.35, 95% CI: 1.85-6.07).

Conclusions: The most prevalent osteoporotic fracture risk factors were having a high BMI and the presence of densitometric osteoporosis. A higher risk of morphometric vertebral fracture in women with both low bone mineral density and high BMI was found. This association, if confirmed, has important implications for clinical practice and fracture risk tools. We also found a higher risk in women with a poor educational level. More attention should be addressed to these populations in order to control modifiable risk factors.