Association between serum TSH concentration within the normal range and adiposity

Abstract

Background: Overt hypothyroidism is clearly related to body weight gain and greater adiposity, but the range of hormonal change in serum TSH concentration associated with weight gain remains a focus of debate. Aim: The aim of this review was to assess studies that evaluated the relationship between anthropometric measures and serum TSH concentration in euthyroid subjects. Methods: Studies held on the Ovid MEDLINE database were searched and original articles published from 2000 to 2010 were included. The literature search was restricted to studies conducted in humans aged 18 years or older and written in English, Spanish, or Portuguese. Studies that evaluated the association between anthropometric measures and serum TSH within the normal range as the primary objective, as well as additional analysis, were included. Results: A total of 29 studies met the inclusion criteria. Of the 29 studies, 18 showed a positive relationship between measures of adiposity and serum TSH. Despite the plausibility of this association, only two studies reported longitudinal findings. The influence of smoking on the association between serum TSH and anthropometric measures was evaluated in only three studies and remains unclear. Conclusion: Thus, further longitudinal studies are needed to better understand the mechanisms by which TSH concentration might impact body weight.

Associations between thyroid hormone levels and regional fat accumulation in euthyroid men

“…Indeed, a great deal of research has been conducted to elucidate the association between thyroid function and obesity or BMI. However, data conflict with regard to whether mild hypothyroidism, subclinical hypothyroidism, or both are associated with obesity (18). Although the studies showing positive relationships mostly involved morbidly obese subjects (19,20,21,22,23), we were able to demonstrate a significant relationship between thyroid function and regional fat accumulation in nonobese, euthyroid men, in spite of a relatively small sample.…”

MECHANISMS IN ENDOCRINOLOGY: The crosstalk between thyroid gland and adipose tissue: signal integration in health and disease

“…A recent review of 29 studies assessed the relationship between serum TSH and BMI in euthyroid subjects (58). Eighteen of these studies showed a positive correlation between the measures of adiposity and serum TSH.…”

Thyroid Hormones and the Metabolic Syndrome

“…adipose and muscle tissue. Apart from overt dysfunction, changes in body weight also correlate with serum TSH concentrations even within the normal range [55], this cross-sectional, population-based study (included patients older than 40 years of age) describes a positive association of subclinical hypothyroidism with obesity. A study by Ittermann et al [56] found a positive correlation of TH status and BMI in adolescence, which was stronger in individuals exposed to smoke (either actively or passively).…”