Association of thyroid hormones with resting energy expenditure and complement C3 in normal weight high body fat women

Maryam Karkhaneh; Mostafa Qorbani; Asal Ataie-Jafari; Mohamad Reza Mohajeri-Tehrani; Hamid Asayesh; Saeed Hosseini

doi:10.1186/s13044-019-0070-4

Association of thyroid hormones with resting energy expenditure and complement C3 in normal weight high body fat women

Thyroid Res. 2019 Oct 25:12:9. doi: 10.1186/s13044-019-0070-4. eCollection 2019.

Authors

Maryam Karkhaneh¹, Mostafa Qorbani^{2

3}, Asal Ataie-Jafari⁴, Mohamad Reza Mohajeri-Tehrani⁵, Hamid Asayesh⁶, Saeed Hosseini^{5

7}

Affiliations

¹ 1Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran.
² 2Non-communicable Diseases Research Center, Alborz University of Medical Sciences, Karaj, Iran.
³ 3Chronic Diseases Research Center, Endocrinology and Metabolism Population Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
⁴ 4Department of Nutrition, Faculty of Medicine, Science and Research Branch, Islamic Azad University, Tehran, Iran.
⁵ 5Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
⁶ 6Department of Medical Emergencies, Qom University of Medical Sciences, Qom, Iran.
⁷ 7Department of Clinical Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Hojatdost street, Naderi street, Keshavarz Blv, Tehran, Iran.

Abstract

Background: A high body fat percentage has a specific effect on activation of the hypothalamic-pituitary-thyroid axis. On the other hand, a slight change in thyroid hormones can affect metabolism and body composition as well as immune function. This study aims to examine the relationship between adiposity, thyroid hormone levels and immunity by comparing resting energy expenditure (REE), serum thyroid hormone levels and complement C3 in normal-weight high body fat (normal weight obesity) women and normal-weight normal body fat women.

Methods: In this case-control study, 40 women with normal body weight (BMI < 24.9 kg/m2) and body fat mass (FM) ≥ 30% (normal-weight obesity (NWO) group), and 30 non-obese women (BMI < 24.9 kg/m2) and FM < 30% (non-normal weight obesity (non-NWO) group) were recruited from a sport club in Tehran. Body composition was analyzed using bioimpedance analyzer. Blood samples were collected and analyzed for fasting serum concentration of thyroid hormones (including total T3 and total T4), thyroid-stimulating hormone (TSH), and serum complement C3. REE was measured by an indirect calorimetry.

Results: Serum T3 and T4 and also complement C3 were higher in the NWO group than in the non-NWO group. Body fat percentages had significant positive correlation with T3 (r; 0.344, P < 0.05), T4 (r; 0.294, P < 0.05), and complement C3 (r; 0.417, P < 0.05). Serum T3 and T4 were also positively correlated with C3 concentration (r; 0.417, p < 0.001) and (r; 0.349, p < 0.05); respectively, but there was no significant correlation between TSH and C3. REE was not significantly different between the two groups. REE only had a significant positive correlation with fat-free mass (r; 0.421, P < 0.001).

Conclusion: An increase in body fat even in the presence of a normal body weight can be accompanied by the changes in thyroid function and inflammatory markers such as complement C3.

Keywords: Body fat mass; Complement C3; Normal Weight Obesity; Resting energy expenditure; Thyroxine; Triiodothyronine.