Serum 25-hydroxyvitamin D and risk of major osteoporotic fractures in older U.S. adults
Journal of Bone and Mineral Research
Anne C. Looker Ph.D National Center for Health Statistics, Centers for Disease Control and Prevention, Hyattsville MD, Email: Anne C. Looker Ph.D (ALooker@cdc.gov)
Accepted manuscript online: 26 NOV 2012; Manuscript Accepted: 12 NOV 2012; Manuscript Revised: 26 OCT 2012; Manuscript Received: 31 AUG 2012
This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi: [10.1002/jbmr.1828].
The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention.
Results from previous prospective studies linking serum hydroxyvitamin D (25OHD) with fracture risk have been inconsistent. The present study examined the relationship between serum 25OHD and risk of incident major osteoporotic fracture (hip, spine, radius and humerus) in older US adults. The study used a pooled cohort of 4749 men and women ages 65 years and older from the third National Health and Nutrition Examination Survey (NHANES III, 1988-94) and NHANES 2000-2004. Incident fractures were identified using linked mortality and Medicare records that were obtained for participants from both surveys. Serum 25OHD values were measured by radioimmunoassay in both surveys. Cox proportional hazards models were used to estimate the relative risk (RR) of fracture by serum 25OHD level. There were 525 incident major osteoporotic fractures (287 hip fractures) in the sample.
Serum 25OHD was a significant linear predictor of major osteoporotic fracture and significant quadratic predictor of hip fracture in the total sample and among those with less than 10 years of follow-up, but it was not related to risk of either fracture type among those with > 10 years of follow-up.
Major osteoporotic fracture risk was increased by 26-27% for each SD decrease in serum 25OHD among those with less than 10 years of follow-up. Serum 25OHD was significantly related to risk of major osteoporotic fractures as a group and to hip fracture alone in this cohort of older US adults from NHANES III and NHANES 2000-2004. However, the predictive utility of serum 25OHD diminished after ten years. In addition, the relationship appeared to be linear when major osteoporotic fracture risk was considered but quadratic when hip fracture risk was assessed.
© 2012 American Society for Bone and Mineral Research.
The vitamin D levels change so much with the passage of time
It is difficult to make a prediction based on vitamin D levels more than 10 year previous.
This has been obeserved in many previous studies.