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Meta-Analysis
. 2016 Nov;101(11):4270-4282.
doi: 10.1210/jc.2016-2255. Epub 2016 Sep 7.

Thyroid Function Within the Reference Range and the Risk of Stroke: An Individual Participant Data Analysis

Affiliations
Meta-Analysis

Thyroid Function Within the Reference Range and the Risk of Stroke: An Individual Participant Data Analysis

Layal Chaker et al. J Clin Endocrinol Metab. 2016 Nov.

Abstract

Context: The currently applied reference ranges for thyroid function are under debate. Despite evidence that thyroid function within the reference range is related with several cardiovascular disorders, its association with the risk of stroke has not been evaluated previously.

Design and setting: We identified studies through a systematic literature search and the Thyroid Studies Collaboration, a collaboration of prospective cohort studies. Studies measuring baseline TSH, free T4, and stroke outcomes were included, and we collected individual participant data from each study, including thyroid function measurements and incident all stroke (combined fatal and nonfatal) and fatal stroke. The applied reference range for TSH levels was between 0.45 and 4.49 mIU/L.

Results: We collected individual participant data on 43 598 adults with TSH within the reference range from 17 cohorts, with a median follow-up of 11.6 years (interquartile range 5.1-13.9), including 449 908 person-years. Age- and sex-adjusted pooled hazard ratio for TSH was 0.78 (95% confidence interval [CI] 0.65-0.95 across the reference range of TSH) for all stroke and 0.83 (95% CI 0.62-1.09) for fatal stroke. For the free T4 analyses, the hazard ratio was 1.08 (95% CI 0.99-1.15 per SD increase) for all stroke and 1.10 (95% CI 1.04-1.19) for fatal stroke. This was independent of cardiovascular risk factors including systolic blood pressure, total cholesterol, smoking, and prevalent diabetes.

Conclusion: Higher levels of TSH within the reference range may decrease the risk of stroke, highlighting the need for further research focusing on the clinical consequences associated with differences within the reference range of thyroid function.

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Figures

Figure 1.
Figure 1.
The association between TSH and risk of all stroke (A) and fatal stroke (B). HRs and their 95% CIs are represented by squares and are across the range of TSH (0.45 and 4.49 mIU/L). Sizes of data markers are proportional to the inverse of the variance of the HRs. Data for all stroke were available in 12 studies. Three hundred ninety-three participants were excluded from the analysis of all stroke due to missing follow-up data. Data for fatal stroke were available in 17 studies. Two hundred sixty-five participants were excluded from the analysis of fatal stroke due to missing cause of death.
Figure 2.
Figure 2.
The association between standardized FT4 and risk of all stroke (A) and fatal stroke (B). HRs and their 95% CIs are represented by squares and are per one increase of 1 SD of FT4. Sizes of data markers are proportional to the inverse of the variance of the HRs. Data for all stroke were available in nine studies. Three hundred eighty-seven participants were excluded from the analysis of all stroke due to missing follow-up data. Data for fatal stroke were available in 13 studies. Twenty-seven participants were excluded from the analysis of fatal stroke due to missing cause of death.

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References

    1. Rodondi N, den Elzen WP, Bauer DC, et al. Subclinical hypothyroidism and the risk of coronary heart disease and mortality. JAMA. 2010;304:1365–1374. - PMC - PubMed
    1. Bauer DC, Ettinger B, Browner WS. Thyroid functions and serum lipids in older women: a population-based study. Am J Med. 1998;104:546–551. - PubMed
    1. Biondi B, Cooper DS. The clinical significance of subclinical thyroid dysfunction. Endocr Rev. 2008;29:76–131. - PubMed
    1. Collet TH, Gussekloo J, Bauer DC, et al. Subclinical hyperthyroidism and the risk of coronary heart disease and mortality. Arch Intern Med. 2012;172:799–809. - PMC - PubMed
    1. Surks MI, Boucai L. Age- and race-based serum thyrotropin reference limits. J Clin Endocrinol Metab. 2010;95:496–502. - PubMed

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