This Article Full Text Full Text (PDF) All Versions of this Article: 90/7/4019    most recent Author Manuscript (PDF) Submit a related Letter to the Editor Purchase Article View Shopping Cart Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Knudsen, N. Articles by Jørgensen, T. Search for Related Content PubMed PubMed Citation Articles by Knudsen, N. Articles by Jørgensen, T. Related Collections Thyroid Metabolism Obesity

Small Differences in Thyroid Function May Be Important for Body Mass Index and the Occurrence of Obesity in the Population

Endocrine Unit (N.K., H.P.), Medical Clinic I, Bispebjerg Hospital, 2400 Copenhagen, Denmark; Research Centre for Prevention and Health (N.K., T.J.), Copenhagen County, 2600 Glostrup, Denmark; Department of Endocrinology (P.L., I.B.), Aalborg Hospital, 9100 Aalborg, Denmark; Department of Nutrition (L.B.R.), Danish Institute for Food and Veterinary Research, 2860 Søborg, Denmark; The National Heart Foundation (L.O.), 1127 Copenhagen, Denmark; and The Danish Centre for Prevention of Thyroid Diseases, 2600 Glostrup, Denmark

Address all correspondence and requests for reprints to: Nils Knudsen, Erantishaven 108, DK-2765 Smoerum, Denmark. E-mail: nk01{at}bbh.hosp.dk.

Context: Increasing prevalence of overweight in the population is a major concern globally; and in the United States, nearly one third of adults were classified as obese at the end of the 20th century. Few data have been presented regarding an association between variations in thyroid function seen in the general population and body weight.

Objective: The aim of this study was to investigate the association between thyroid function and body mass index (BMI) or obesity in a normal population.

Design: A cross-sectional population study (The DanThyr Study) was conducted.

Participants: In all, 4649 participants were investigated, and 4082 were eligible for these analyses after exclusion of subjects with previous or present overt thyroid dysfunction.

Main Outcome Measures: The study examined the association between category of serum TSH or serum thyroid hormones and BMI or obesity in multivariate models, adjusting for possible confounding.

Results: We found a positive association between BMI and category of serum TSH (P < 0.001) and a negative association between BMI and category of serum free T₄ (P < 0.001). No association was found between BMI and serum free T₃ levels. The difference in BMI between the groups with the highest and lowest serum TSH levels was 1.9 kg/m², corresponding to a difference in body weight of 5.5 kg among women. Similarly, the category of serum TSH correlated positively with weight gain during 5 yr (P = 0.04), but no statistically significant association was found with weight gain during 6 months (P = 0.17). There was an association between obesity (BMI > 30 kg/m²) and serum TSH levels (P = 0.001).

Conclusions: Our results suggest that thyroid function (also within the normal range) could be one of several factors acting in concert to determine body weight in a population. Even slightly elevated serum TSH levels are associated with an increase in the occurrence of obesity.

This article has been cited by other articles:

				H. Volzke, D. M. Robinson, T. Spielhagen, M. Nauck, A. Obst, R. Ewert, B. Wolff, H. Wallaschofski, S. B. Felix, and M. Dorr Are serum thyrotropin levels within the reference range associated with endothelial function? Eur. Heart J., November 13, 2008; (2008) ehn508v1. [Abstract] [Full Text] [PDF]

				I. M. Stylianou, S. R. Langley, K. Walsh, Y. Chen, C. Revenu, and B. Paigen Differences in DBA/1J and DBA/2J reveal lipid QTL genes J. Lipid Res., November 1, 2008; 49(11): 2402 - 2413. [Abstract] [Full Text] [PDF]

				S. H. Choi, Y. J. Lee, Y. J. Park, K. W. Kim, E. J. Lee, S. Lim, D. J. Park, S. E. Kim, K. S. Park, H. C. Jang, et al. Retinol Binding Protein-4 Elevation Is Associated with Serum Thyroid-Stimulating Hormone Level Independently of Obesity in Elderly Subjects with Normal Glucose Tolerance J. Clin. Endocrinol. Metab., June 1, 2008; 93(6): 2313 - 2318. [Abstract] [Full Text] [PDF]

				B. O. Asvold, T. Bjoro, T. I. L. Nilsen, D. Gunnell, and L. J. Vatten Thyrotropin Levels and Risk of Fatal Coronary Heart Disease: The HUNT Study Arch Intern Med, April 28, 2008; 168(8): 855 - 860. [Abstract] [Full Text] [PDF]

				R. E. Weiss and R. L. Brown Doctor . . . Could It Be My Thyroid? Arch Intern Med, March 24, 2008; 168(6): 568 - 569. [Full Text] [PDF]

				C. S. Fox, M. J. Pencina, R. B. D'Agostino, J. M. Murabito, E. W. Seely, E. N. Pearce, and R. S. Vasan Relations of Thyroid Function to Body Weight: Cross-sectional and Longitudinal Observations in a Community-Based Sample Arch Intern Med, March 24, 2008; 168(6): 587 - 592. [Abstract] [Full Text] [PDF]

				B. Biondi and D. S. Cooper The Clinical Significance of Subclinical Thyroid Dysfunction Endocr. Rev., February 1, 2008; 29(1): 76 - 131. [Abstract] [Full Text] [PDF]

				B. O. Asvold, T. Bjoro, T. I. Nilsen, and L. J. Vatten Tobacco Smoking and Thyroid Function: Is Weight Gain a Confounder? Reply Arch Intern Med, January 14, 2008; 168(1): 114 - 114. [Full Text] [PDF]

				D C Ferguson, Z Caffall, and M Hoenig Obesity increases free thyroxine proportionally to nonesterified fatty acid concentrations in adult neutered female cats J. Endocrinol., August 1, 2007; 194(2): 267 - 273. [Abstract] [Full Text] [PDF]

				E. Ortega, N. Pannacciulli, C. Bogardus, and J. Krakoff Plasma concentrations of free triiodothyronine predict weight change in euthyroid persons Am. J. Clinical Nutrition, February 1, 2007; 85(2): 440 - 445. [Abstract] [Full Text] [PDF]

				R. P Peeters, W. M van der Deure, and T. J Visser Genetic variation in thyroid hormone pathway genes; polymorphisms in the TSH receptor and the iodothyronine deiodinases. Eur. J. Endocrinol., November 1, 2006; 155(5): 655 - 662. [Abstract] [Full Text] [PDF]

				P. Vejbjerg, N. Knudsen, H. Perrild, P. Laurberg, I. B. Pedersen, L. B Rasmussen, L. Ovesen, and T. Jorgensen The association between hypoechogenicity or irregular echo pattern at thyroid ultrasonography and thyroid function in the general population. Eur. J. Endocrinol., October 1, 2006; 155(4): 547 - 552. [Abstract] [Full Text] [PDF]

				J.-M. Fernandez-Real, A. Lopez-Bermejo, A. Castro, R. Casamitjana, and W. Ricart Thyroid Function Is Intrinsically Linked to Insulin Sensitivity and Endothelium-Dependent Vasodilation in Healthy Euthyroid Subjects J. Clin. Endocrinol. Metab., September 1, 2006; 91(9): 3337 - 3343. [Abstract] [Full Text] [PDF]

				P. Laurberg, T. Jorgensen, H. Perrild, L. Ovesen, N. Knudsen, I. B. Pedersen, L. B Rasmussen, A. Carle, and P. Vejbjerg The Danish investigation on iodine intake and thyroid disease, DanThyr: status and perspectives. Eur. J. Endocrinol., August 1, 2006; 155(2): 219 - 228. [Abstract] [Full Text] [PDF]

				T. Reinehr, G. de Sousa, and W. Andler Hyperthyrotropinemia in Obese Children Is Reversible after Weight Loss and Is Not Related to Lipids J. Clin. Endocrinol. Metab., August 1, 2006; 91(8): 3088 - 3091. [Abstract] [Full Text] [PDF]

				G Brabant, P Beck-Peccoz, B Jarzab, P Laurberg, J Orgiazzi, I Szabolcs, A P Weetman, and W M Wiersinga Is there a need to redefine the upper normal limit of TSH? Eur. J. Endocrinol., May 1, 2006; 154(5): 633 - 637. [Abstract] [Full Text] [PDF]