Thyroid Volume Predicts Body Mass Index 2 and 6 Years Later

Abstract

Background : Thyroid volume correlates positively with body mass index (BMI). This correlation holds true for both iodine-sufficient and mild/moderate iodine-deficient areas. We examined the association between thyroid volume and BMI and change in BMI over 4 years in middle-age adults recruited from the general population. Methods : A total of 2,495 subjects, for whom thyroid volume, FT4 and TSH were available (women aged 35 - 60 years and men aged 45 - 60 years), were derived from the Supplementation en Vitamines et Mineraux Antioxydants (SU.VI. MAX) cohort study conducted in France since baseline (1994). Weight and height were measured 2 and 6 years after inclusion. Linear univariate and multiple regression analyses were performed to evaluate correlations between thyroid volume and BMI at 2 and 6 years and BMI change from year 2 to 6. Results : Baseline thyroid volume was positively correlated with BMI at 2 years (men: beta = 0.09, P < 0.01; women: beta = 0.09, P < 0.01) and 6 years after inclusion (men: beta = 0.10, P < 0.01; women: beta = 0.09, P < 0.01). The correlation between thyroid volume and BMI at 2 and 6 years remained significant after adjusting for free T4, TSH, gender, age, smoking, alcohol consumption and TSH-thyroid volume interaction factor (beta = 0.11, P < 0.01). Baseline thyroid volume was not correlated with BMI change from year 2 to 6 in linear regression analysis. Conclusion : In French adults, thyroid volume predicted BMI at 2 and 6 years. Further studies are needed to explore the association between thyroid volume and BMI. J Endocrinol Metab. 2012;2(3):105-109 doi: https://doi.org/10.4021/jem99w