The prevalence and associated mortality of non-anaemic iron deficiency in older adults: a 14 year observational cohort study
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
Background: Iron is central to multiple biological pathways, and treatment of non-anaemic absolute iron deficiency (NAID) is beneficial in certain conditions. However, it is unknown if NAID is associated with increased mortality in older-adults.
Methods: A nationally representative sample of 4451 older-adults from the English Longitudinal Study of Ageing was used. NAID was defined as serum ferritin <30μg/L and haemoglobin ≥120g/L (women) or ≥130g/L (men). Cumulative mortality was estimated by Kaplan Meier method. Unadjusted and adjusted hazard ratios (HR) of mortality were calculated using Cox proportional hazards regression models.
Results: Baseline NAID prevalence was 8.8% (95%CI 8.0%-9.7%). 10.9% (95% CI of 9.7-12.3%) for women and 6.35% for men (95% CI 5.3%-7.5%). The HR for mortality for individuals with NAID compared with non-anaemic individuals without iron deficiency over 14-year follow-up was 1.58 (95% CI 1.29-1.93). This association was independent of all identified demographic, health-related and biological covariates, and robust in multiple sensitivity analyses.
Conclusions: In older-adults in England, NAID is common and associated with an increased mortality rate compared to non-anaemic individuals with normal serum ferritin. The association is principally driven by an excess mortality in women.
Methods: A nationally representative sample of 4451 older-adults from the English Longitudinal Study of Ageing was used. NAID was defined as serum ferritin <30μg/L and haemoglobin ≥120g/L (women) or ≥130g/L (men). Cumulative mortality was estimated by Kaplan Meier method. Unadjusted and adjusted hazard ratios (HR) of mortality were calculated using Cox proportional hazards regression models.
Results: Baseline NAID prevalence was 8.8% (95%CI 8.0%-9.7%). 10.9% (95% CI of 9.7-12.3%) for women and 6.35% for men (95% CI 5.3%-7.5%). The HR for mortality for individuals with NAID compared with non-anaemic individuals without iron deficiency over 14-year follow-up was 1.58 (95% CI 1.29-1.93). This association was independent of all identified demographic, health-related and biological covariates, and robust in multiple sensitivity analyses.
Conclusions: In older-adults in England, NAID is common and associated with an increased mortality rate compared to non-anaemic individuals with normal serum ferritin. The association is principally driven by an excess mortality in women.
Date Issued
2020-05
Date Acceptance
2019-11-21
Citation
British Journal of Haematology, 2020, 189 (3), pp.566-572
ISSN
0007-1048
Publisher
Wiley
Start Page
566
End Page
572
Journal / Book Title
British Journal of Haematology
Volume
189
Issue
3
Copyright Statement
© 2020 British Society for Haematology and John Wiley & Sons Ltd. This is the accepted version of the following article: Philip, K.E.J., Sadaka, A.S., Polkey, M.I., Hopkinson, N.S., Steptoe, A. and Fancourt, D. (2020), The prevalence and associated mortality of non‐anaemic iron deficiency in older adults: a 14 years observational cohort study. Br J Haematol, 189: 566-572, which has been published in final form at https://doi.org/10.1111/bjh.16409
Sponsor
National Institute of Health and Medical Research
Imperial College London
Identifier
https://onlinelibrary.wiley.com/doi/full/10.1111/bjh.16409
Grant Number
NIHR ACF in Respiratory Medicine
Subjects
Science & Technology
Life Sciences & Biomedicine
Hematology
iron deficiency
mortality
non-anaemic
older adults
CHRONIC HEART-FAILURE
SERUM FERRITIN
THERAPY
ANEMIA
IMPACT
iron deficiency
mortality
non-anaemic
older adults
Immunology
1102 Cardiorespiratory Medicine and Haematology
Publication Status
Published
Date Publish Online
2020-02-18