@article {6795, title = {Subclinical thyroid dysfunction and fracture risk: a meta-analysis.}, journal = {JAMA}, volume = {313}, year = {2015}, month = {2015 May 26}, pages = {2055-65}, abstract = {

IMPORTANCE: Associations between subclinical thyroid dysfunction and fractures are unclear and clinical trials are lacking.

OBJECTIVE: To assess the association of subclinical thyroid dysfunction with hip, nonspine, spine, or any fractures.

DATA SOURCES AND STUDY SELECTION: The databases of MEDLINE and EMBASE (inception to March 26, 2015) were searched without language restrictions for prospective cohort studies with thyroid function data and subsequent fractures.

DATA EXTRACTION: Individual participant data were obtained from 13 prospective cohorts in the United States, Europe, Australia, and Japan. Levels of thyroid function were defined as euthyroidism (thyroid-stimulating hormone [TSH], 0.45-4.49 mIU/L), subclinical hyperthyroidism (TSH <0.45 mIU/L), and subclinical hypothyroidism (TSH >=4.50-19.99 mIU/L) with normal thyroxine concentrations.

MAIN OUTCOME AND MEASURES: The primary outcome was hip fracture. Any fractures, nonspine fractures, and clinical spine fractures were secondary outcomes.

RESULTS: Among 70,298 participants, 4092 (5.8\%) had subclinical hypothyroidism and 2219 (3.2\%) had subclinical hyperthyroidism. During 762,401 person-years of follow-up, hip fracture occurred in 2975 participants (4.6\%; 12 studies), any fracture in 2528 participants (9.0\%; 8 studies), nonspine fracture in 2018 participants (8.4\%; 8 studies), and spine fracture in 296 participants (1.3\%; 6 studies). In age- and sex-adjusted analyses, the hazard ratio (HR) for subclinical hyperthyroidism vs euthyroidism was 1.36 for hip fracture (95\% CI, 1.13-1.64; 146 events in 2082 participants vs 2534 in 56,471); for any fracture, HR was 1.28 (95\% CI, 1.06-1.53; 121 events in 888 participants vs 2203 in 25,901); for nonspine fracture, HR was 1.16 (95\% CI, 0.95-1.41; 107 events in 946 participants vs 1745 in 21,722); and for spine fracture, HR was 1.51 (95\% CI, 0.93-2.45; 17 events in 732 participants vs 255 in 20,328). Lower TSH was associated with higher fracture rates: for TSH of less than 0.10 mIU/L, HR was 1.61 for hip fracture (95\% CI, 1.21-2.15; 47 events in 510 participants); for any fracture, HR was 1.98 (95\% CI, 1.41-2.78; 44 events in 212 participants); for nonspine fracture, HR was 1.61 (95\% CI, 0.96-2.71; 32 events in 185 participants); and for spine fracture, HR was 3.57 (95\% CI, 1.88-6.78; 8 events in 162 participants). Risks were similar after adjustment for other fracture risk factors. Endogenous subclinical hyperthyroidism (excluding thyroid medication users) was associated with HRs of 1.52 (95\% CI, 1.19-1.93) for hip fracture, 1.42 (95\% CI, 1.16-1.74) for any fracture, and 1.74 (95\% CI, 1.01-2.99) for spine fracture. No association was found between subclinical hypothyroidism and fracture risk.

CONCLUSIONS AND RELEVANCE: Subclinical hyperthyroidism was associated with an increased risk of hip and other fractures, particularly among those with TSH levels of less than 0.10 mIU/L and those with endogenous subclinical hyperthyroidism. Further study is needed to determine whether treating subclinical hyperthyroidism can prevent fractures.

}, keywords = {Adolescent, Adult, Aged, Aged, 80 and over, Female, Fractures, Bone, Hip Fractures, Humans, Hyperthyroidism, Hypothyroidism, Male, Middle Aged, Risk Factors, Spinal Fractures, Thyrotropin, Young Adult}, issn = {1538-3598}, doi = {10.1001/jama.2015.5161}, author = {Blum, Manuel R and Bauer, Douglas C and Collet, Tinh-Hai and Fink, Howard A and Cappola, Anne R and da Costa, Bruno R and Wirth, Christina D and Peeters, Robin P and Asvold, Bj{\o}rn O and den Elzen, Wendy P J and Luben, Robert N and Imaizumi, Misa and Bremner, Alexandra P and Gogakos, Apostolos and Eastell, Richard and Kearney, Patricia M and Strotmeyer, Elsa S and Wallace, Erin R and Hoff, Mari and Ceresini, Graziano and Rivadeneira, Fernando and Uitterlinden, Andr{\'e} G and Stott, David J and Westendorp, Rudi G J and Khaw, Kay-Tee and Langhammer, Arnuf and Ferrucci, Luigi and Gussekloo, Jacobijn and Williams, Graham R and Walsh, John P and J{\"u}ni, Peter and Aujesky, Drahomir and Rodondi, Nicolas} }