Older Men with either High or Low Serum 25-hydroxy Vitamin D levels have Significantly Increased Fracture Risk: Results from the Prospective CHAMP Study.
Category: Osteoporosis - Epidemiology
Oral Poster Session, Presentation Number: FR0349
Session: Oral Poster Session 3 (Clinical)
Friday, October 12, 2012 5:15 PM - 5:20 PM, Minneapolis Convention Center, Auditorium-Main
Plenary Sessions, Presentation Number: FR0349
Session: Welcome Reception and Plenary Poster Session
Friday, October 12, 2012 5:45 PM - 7:00 PM, Minneapolis Convention Center, Discovery Hall-Hall B
Poster Sessions, Presentation Number: SA0349
Session: Poster Session I and Poster Tours
Saturday, October 13, 2012 11:00 AM - 1:00 PM, Minneapolis Convention Center, Discovery Hall-Hall B
* , AUSTRALIA, , AUSTRALIA, Robert Cumming, School of Public Health, University of Sydney, Vasikaran Naganathan, Centre for Education and Research on Ageing, University of Sydney
Introduction: The relationship between serum 25-hydroxyvitamin D (25OHD) and fracture risk is unclear. The aim of this study was to investigate the relationship between serum 25OHD and incident fractures in a large population based cohort of older men.
Background: As the relationship between serum levels of 25OHD and fracture risk remains unclear, we investigated this question in a large population-based cohort of older men in Sydney, Australia.
Methods: In the CHAMP study, 1705 community-dwelling men aged 70-97 years were followed for a mean of 4.4 years, during which time data on radiologically verified fractures was collected prospectively. Serum 25OHD levels were measured using a radioimmunoassay detecting both D2 and D3 (DiaSorin). Information on potential confounders was collected at baseline using clinical measures and questionnaires. We accounted for bone mineral density (BMD), falls’ history, physical activity, sun exposure, season of blood draw, country of birth, in addition to anthropometric and lifestyle factors, medical history, muscle strength, balance, and serum biochemistry. The relationship between fractures and serum 25OHD levels was analyzed using Cox’s Proportional Hazard regression.
Results: There were 123 first incident fragility fractures in 1662 men with valid serum 25OHD measures. The relationship between baseline serum 25OHD and fracture risk was “U-shaped”, with an increased fracture risk in men with either low or high serum 25OHD levels. In multivariate analysis, the risk of fracture was greatest in men with serum 25OHD in the lowest quintile (25OHD ≤ 36 nmol/L (14.4 ng/mL); HR= 4.5, 95% CI:2.0,10.2) and in men in the highest quintile (25OHD ≥ 73nmol/L (29.2 ng/mL); HR=3.5, 95% CI:1.5, 8.0) compared to men in the 4th quintile (25OHD: 59 to 72 nmol/L (23.6-28.8 ng/mL)) (table 1).
Conclusion: In community-dwelling older men, fracture risk was significantly increased not only in vitamin D-deficient men, but also in men within the highest quintile of serum 25OHD. This effect was not explained by lower BMD, increased physical activity, falls’ risk or other lifestyle or anthropomorphic factors.
* Presenting Authors(s):