Prevalence of vertebral fracture in elderly men and women with osteopenia

Abstract

The objective of our cross-sectional, not population-based, observational study was to determine the prevalence of patients with osteopenia in relation to bone mineral density (BMD) and vertebral fractures and to identify risk factors for vertebral fractures above the osteoporotic BMD T-score threshold of -2.5. A total of 698 consecutive hospitalized and ambulatory white patients with T-scores between -1.0 and -2.5 were investigated in an academic medical center in Austria between January 2005 and June 2006. Measurements of BMD (T-score at spine and hip) by DXA, spinal X-ray, laboratory data of bone metabolism and vitamin D, and sex-specific data were assessed. A multivariate general linear model was used to calculate vertebral and non-vertebral fractures, age, BMI and lowest T-score at measured anatomic sites. Overall, 218 patients (31.2%) with a mean age of 72.2 years and mean BMI of 26.0 presented with vertebral fractures; in comparison, patients with non-vertebral fractures had a mean age of 62.6 years and BMI 24.6, and patients without fractures had a mean age of 61.3 years and BMI 24.0 (P < 0.001). Serum markers of bone resorption and formation had no influence on fracture occurrence but 73% of the patients had vitamin D deficiency (25.2 +/- 9.8 ng/ml). The lowest T-score in all fracture patients was found at the femoral neck. At this site 64.3% patients with vertebral fractures had a T-score within the range -1.0 to -2.0 (95% CI 57.3-70.8). The prevalence of vertebral fractures increased stepwise (P < 0.05) and at T-scores between -1.5 and -2.0 the increase was linear. We conclude that a significant proportion of non-osteoporotic elderly men and women with mean age 72 years, BMI 26.0 and a threshold T-score above -2.0 are susceptible to osteoporotic vertebral fractures. These patients are not adequately detected by BMD measurements based on WHO thresholds. Early assessment, prior to their first fracture, is important for identifying individuals with clinical risk factors.