Serum 25-hydroxyvitamin D concentrations and risk for hip fractures.
BACKGROUND
The relationship between serum 25-hydroxyvitamin D [25(OH) vitamin D] concentration and hip fractures is unclear.


OBJECTIVE
To see whether low serum 25(OH) vitamin D concentrations are associated with hip fractures in community-dwelling women.


METHODS
Nested case-control study.


METHODS
40 clinical centers in the United States.


METHODS
400 case-patients with incident hip fracture and 400 control participants matched on the basis of age, race or ethnicity, and date of blood draw. Both groups were selected from 39 795 postmenopausal women who were not using estrogens or other bone-active therapies and who had not had a previous hip fracture.


METHODS
Serum 25(OH) vitamin D was measured and patients were followed for a median of 7.1 years (range, 0.7 to 9.3 years) to assess fractures.


RESULTS
Mean serum 25(OH) vitamin D concentrations were lower in case-patients than in control participants (55.95 nmol/L [SD, 20.28] vs. 59.60 nmol/L [SD, 18.05]; P = 0.007), and lower serum 25(OH) vitamin D concentrations increased hip fracture risk (adjusted odds ratio for each 25-nmol/L decrease, 1.33 [95% CI, 1.06 to 1.68]). Women with the lowest 25(OH) vitamin D concentrations (< or =47.5 nmol/L) had a higher fracture risk than did those with the highest concentrations (> or =70.7 nmol/L) (adjusted odds ratio, 1.71 [CI, 1.05 to 2.79]), and the risk increased statistically significantly across quartiles of serum 25(OH) vitamin D concentration (P for trend = 0.016). This association was independent of number of falls, physical function, frailty, renal function, and sex-steroid hormone levels and seemed to be partially mediated by bone resorption.


CONCLUSIONS
Few case-patients were nonwhite women. Bone mineral density and parathyroid hormone levels were not accounted for in the analysis.


CONCLUSIONS
Low serum 25(OH) vitamin D concentrations are associated with a higher risk for hip fracture.
Cauley
Jane A
JA
University of Pittsburgh, Department of Epidemiology, 130 DeSoto Street, Crabtree A524, Pittsburgh, PA 15261, USA. jcauley@edc.pitt.edu
Lacroix
Andrea Z
AZ
Wu
LieLing
L
Horwitz
Mara
M
Danielson
Michelle E
ME
Bauer
Doug C
DC
Lee
Jennifer S
JS
Jackson
Rebecca D
RD
Robbins
John A
JA
Wu
Chunyuan
C
Stanczyk
Frank Z
FZ
LeBoff
Meryl S
MS
Wactawski-Wende
Jean
J
Sarto
Gloria
G
Ockene
Judith
J
Cummings
Steven R
SR
D000058:Accidental Falls; D000305:Adrenal Cortex Hormones / Q000627:therapeutic use; D000368:Aged; D015992:Body Mass Index; D001862:Bone Resorption; D016022:Case-Control Studies; D005260:Female; D016330:Frail Elderly; D012739:Gonadal Steroid Hormones / Q000097:blood; D006304:Health Status; D006620:Hip Fractures / Q000097:blood* / Q000209:etiology*; D006801:Humans; D008875:Middle Aged; D016017:Odds Ratio; D010809:Physical Fitness; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
D000305:Adrenal Cortex Hormones; D012739:Gonadal Steroid Hormones; D014807:Vitamin D; C104450:25-hydroxyvitamin D