Long-term Risk of Incident Vertebral Fractures
- Jane A. Cauley, DrPH;
- Marc C. Hochberg, MD, MPH;
- Li-Yung Lui, MA, MS;
- Lisa Palermo, MS;
- Kristine E. Ensrud, MD, MPH;
- Teresa A. Hillier, MD, MS;
- Michael C. Nevitt, PhD, MPH;
- Steven R. Cummings, MD
- Author Affiliations: Department of Epidemiology, University of Pittsburgh, Pittsburgh, Pennsylvania (Dr Cauley); Department of Medicine, University of Maryland Medical Center, Baltimore (Dr Hochberg); San Francisco Coordinating Center, California Pacific Medical Center, San Francisco (Ms Lui and Dr Cummings); Department of Epidemiology and Biostatistics, University of California, San Francisco (Ms Palermo and Drs Nevitt and Cummings); Department of Medicine, Minneapolis VA Medical Center, Minneapolis, Minnesota (Dr Ensrud); and Kaiser Permanente Center for Health Research Northwest/Hawaii, Portland, Oregon (Dr Hillier).
- Corresponding Author: Jane A. Cauley, DrPH, University of Pittsburgh, 130 DeSoto St, Crabtree A524, Pittsburgh, PA 15261 (jcauley{at}edc.pitt.edu).
Abstract
Context Vertebral fractures are the most common osteoporotic fracture. Women with low bone mineral density (BMD) and prevalent vertebral fractures have a greater risk of incident vertebral fractures over the short-term, but their absolute risk of vertebral fracture over the long-term is uncertain.
Objective To examine the absolute risk of incident vertebral fracture by BMD and prevalent vertebral fracture status over 15 years.
Design, Setting, and Participants A total of 9704 white women were recruited at 4 US clinical centers and enrolled in the Study of Osteoporotic Fractures, a longitudinal cohort study. Of these, 2680 attended a clinic visit an average of 14.9 years after baseline; mean age of 68.8 years at entry and 83.8 years at follow-up.
Mean Outcome Measure Incident vertebral fractures identified from lateral spinal radiographs defined as a decrease of at least 20% and 4 mm at any vertebral level. Prevalent vertebral fractures were identified on the baseline radiographs using vertebral morphometry. Bone mineral density was measured at the total hip and lumbar spine using dual-energy x-ray absorptiometry.
Results Of the 2680 women, 487 (18.2%) had an incident vertebral fracture including 163 of the 394 (41.4%) with a prevalent vertebral fracture at baseline and 324 of the 2286 (14.2%) without a prevalent vertebral fracture at baseline (odds ratio, 4.21; 95% confidence interval, 3.33-5.34). Low BMD was associated with an increased risk of incident vertebral fracture (odds ratio per 1 SD decrease in total hip BMD, 1.78 [95% confidence interval, 1.58-2.00]). The absolute risk of vertebral fracture ranged from 56% among women with total hip BMD T score of −2.5 or less and a prevalent vertebral fracture to 9% in women with normal BMD and no prevalent vertebral fracture.
Conclusions Low BMD and prevalent vertebral fractures are independently related to new vertebral fractures over 15 years of follow-up. Women with a prevalent vertebral fracture have a substantially increased absolute risk of an incident fracture, especially if they have osteoporosis diagnosed by BMD.
- KEYWORDS:
- RISK FACTORS
- SPINAL FRACTURES
- SPINE
