The EPIC-Norfolk Study
The Relation Between Thyroid Function and Anemia: A Pooled Analysis of Individual Participant Data.
The Journal of clinical endocrinology and metabolism 2018 ; 103: 3658-3667.
Wopereis DM, Du Puy RS, van Heemst D, Walsh JP, Bremner A, Bakker SJL, Bauer DC, Cappola AR, Ceresini G, Degryse J, Dullaart RPF, Feller M, Ferrucci L, Floriani C, Franco OH, Iacoviello M, Iervasi G, Imaizumi M, Jukema JW, Khaw KT, Luben RN, Molinaro S, Nauck M, Patel KV, Peeters RP, Psaty BM, Razvi S, Schindhelm RK, van Schoor NM, Stott DJ, Vaes B, Vanderpump MPJ, Völzke H, Westendorp RGJ, Rodondi N, Cobbaert CM, Gussekloo J, den Elzen WPJ, and Thyroid Studies Collaboration Thyroid Studies Collaboration
DOI : 10.1210/jc.2018-00481
PubMed ID : 30113667
PMCID : PMC6179176
URL : https://academic.oup.com/jcem/article/103/10/3658/5063492
Abstract
Anemia and thyroid dysfunction often co-occur, and both increase with age. Human data on relationships between thyroid disease and anemia are scarce.
To investigate the cross-sectional and longitudinal associations between clinical thyroid status and anemia.
Individual participant data meta-analysis.
Sixteen cohorts participating in the Thyroid Studies Collaboration (n = 42,162).
Primary outcome measure was anemia (hemoglobin <130 g/L in men and <120 g/L in women).
Cross-sectionally, participants with abnormal thyroid status had an increased risk of having anemia compared with euthyroid participants [overt hypothyroidism, pooled OR 1.84 (95% CI 1.35 to 2.50), subclinical hypothyroidism 1.21 (1.02 to 1.43), subclinical hyperthyroidism 1.27 (1.03 to 1.57), and overt hyperthyroidism 1.69 (1.00 to 2.87)]. Hemoglobin levels were lower in all groups compared with participants with euthyroidism. In the longitudinal analyses (n = 25,466 from 14 cohorts), the pooled hazard ratio for the risk of development of anemia was 1.38 (95% CI 0.86 to 2.20) for overt hypothyroidism, 1.18 (1.00 to 1.38) for subclinical hypothyroidism, 1.15 (0.94 to 1.42) for subclinical hyperthyroidism, and 1.47 (0.91 to 2.38) for overt hyperthyroidism. Sensitivity analyses excluding thyroid medication or high levels of C-reactive protein yielded similar results. No differences in mean annual change in hemoglobin levels were observed between the thyroid hormone status groups.
Higher odds of having anemia were observed in participants with both hypothyroid function and hyperthyroid function. In addition, reduced thyroid function at baseline showed a trend of increased risk of developing anemia during follow-up. It remains to be assessed in a randomized controlled trial whether treatment is effective in reducing anemia.