Circulating 25-hydroxyvitamin D levels and frailty status in older women.
BACKGROUND
Vitamin D deficiency and frailty are common with aging, but the association between these conditions is uncertain.


OBJECTIVE
To determine the association between 25-hydroxyvitamin D (25(OH)D) levels and prevalent and incident frailty status among older women.


METHODS
Cross-sectional and longitudinal analyses of a prospective cohort study.


METHODS
Four U.S. centers.


METHODS
6307 women aged≥69 years.


METHODS
Frailty status classified as robust, intermediate stage, or frail at baseline; and robust, intermediate stage, frail, or dead (all-cause mortality) at follow-up an average of 4.5 years later.


RESULTS
At baseline, there was a U-shaped association between 25(OH)D level and odds of frailty with the lowest risk among women with levels 20.0-29.9 ng/ml (referent group). Compared with this group, the odds of frailty were higher among those with levels<15.0 ng/ml [multivariable odds ratio (MOR) 1.47, 95% confidence interval (CI), 1.19-1.82], those with levels 15.0-19.9 ng/ml (MOR 1.24, 95% CI 0.99-1.54), and those with levels≥30 ng/ml (MOR 1.32, 95% CI 1.06-1.63). Among 4551 nonfrail women at baseline, the odds of frailty/death (vs. robust/intermediate) at follow-up appeared higher among those with levels 15.0-19.9 ng/ml (MOR 1.21, 95% CI 0.99-1.49), but the CI overlapped 1.0. The odds of death (vs. robust/intermediate/frail at follow-up) was higher among those with levels<15.0 ng/ml (MOR 1.40, 95% CI 1.04-1.88) and those with levels 15.0-19.9 ng/ml (MOR 1.30, 95% CI 0.97-1.75), although the latter association did not quite reach significance.


CONCLUSIONS
Lower (<20 ng/ml) and higher (≥30 ng/ml) levels of 25(OH)D among older women were moderately associated with a higher odds of frailty at baseline. Among nonfrail women at baseline, lower levels (<20 ng/ml) were modestly associated with an increased risk of incident frailty or death at follow-up.
Center for Chronic Disease Outcomes Research, VA Medical Center, and Department of Medicine, University of Minnesota, M.P.H., One Veterans Drive (111-0), Minneapolis, Minnesota 55417, USA. ensru001@umn.edu
Kristine E
KE
Ensrud
Susan K
SK
Ewing
Lisa
L
Fredman
Marc C
MC
Hochberg
Jane A
JA
Cauley
Teresa A
TA
Hillier
Steven R
SR
Cummings
Kristine
K
Yaffe
Peggy M
PM
Cawthon
D000368:Aged; D000428:Alcohol Drinking; D002136:Calcium, Dietary; D002762:Cholecalciferol / Q000097:blood; D003430:Cross-Sectional Studies; D004872:Ergocalciferols / Q000097:blood; D005260:Female; D005500:Follow-Up Studies; D016330:Frail Elderly / Q000706:statistics & numerical data*; D006304:Health Status; D006801:Humans; D008137:Longitudinal Studies; D016017:Odds Ratio; D015995:Prevalence; D018570:Risk Assessment; D012907:Smoking / Q000453:epidemiology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000150:complications
D002136:Calcium, Dietary; D004872:Ergocalciferols; D014807:Vitamin D; D002762:Cholecalciferol; C104450:25-hydroxyvitamin D