Hip and Nonvertebral Fracture Prediction in Nursing Home Patients: Role of Bone Ultrasound and Bone Marker Measurements

Abstract

Absolute fracture risk in nursing home patients is the highest among the communities studied. Screening for high-risk patients in such an environment is usually difficult. The objective was to investigate whether quantitative bone ultrasound measurements and/or markers of bone turnover/metabolism help in predicting which patients will incur hip or nonvertebral fractures. In this prospective study, mobile teams enrolled 1664 female patients from 95 nursing homes in Austria. Calcaneal stiffness (n = 1117), radial speed of sound (SOS) (n = 1332), and phalangeal SOS (n = 1498) measurements were performed at baseline. Serum samples (n = 960) were analyzed for serum calcium and phosphate, 25 hydroxyvitamin D, PTH, osteocalcin, C-terminal telopeptide crosslinks, and osteoprotegerin (OPG). Patients were prospectively followed for hip and other nonvertebral fractures for 2 yr. A total of 117 hip fractures and 269 nonvertebral fractures developed during a mean observation period of 2 yr. Prevalence of vitamin D deficiency and secondary hyperparathyroidism was high. A history of a past fracture was significantly associated with a hazard ratio (HR) of 1.47 (95% confidence interval, 1.01-2.15) and 1.65 (1.26-2.16) for the development of hip and nonvertebral fractures, respectively. Cox regression analysis revealed a multivariate adjusted elevation in both hip [HR 1.30 (1.12-1.43)] and nonvertebral [HR 1.14 (1.02-1.25)] fracture risk for each sd decrease in calcaneal stiffness. Patients in the lowest quartile for calcaneal stiffness Z-score had 2.5 and 1.2 times higher rates of hip and nonvertebral fractures when compared with patients in the highest quartile. Fracture rates were not statistically associated with baseline radial or phalangeal SOS measurements or with serum osteocalcin, C-terminal telopeptide crosslinks, and OPG concentrations. When adjusted for bone mass, higher serum OPG levels were associated with fewer hip as well as nonvertebral fractures [HR 0.85 (0.73-0.99) and 0.89 (0.80-0.99) per increment of 1]. Higher serum phosphate levels indicated an increased hip [HR 1.54 (1.07-2.21)] and nonvertebral fracture risk [HR 1.40 (1.10-1.78) per increase of 1 mg/dl]. Body mass index was protective of hip fractures [HR 0.94 (0.90-0.98) per increase of 1] as well as medication with acetylsalicylic acid [HR 0.59 (0.36-0.95) for hip and 0.72 (0.52-0.99) for nonvertebral fractures]. In contrast, current use of glucocorticoids [HR 5.65 (1.77-18.0)] and opiates [HR 1.85 (1.18-2.92)] exerted a negative effect on prospective hip fracture risk. Calcaneal stiffness measurements proved to be useful in predicting hip fractures and to a lesser extent nonvertebral fractures in nursing home residents. Radial and phalangeal bone ultrasound measurements and baseline markers of bone turnover, however, were not indicative of future fracture risk in this population.