Chronic autoimmune thyroiditis (Hashimoto’s thyroiditis) is the most common cause of hypothyroidism which may associate weight increase and changes in serum lipid levels. There is still controversy over the link between obesity and autoimmune hypothyroidism. The paper aims to assess obesity and lipid metabolism in patients with Hashimoto’s thyroiditis, and to establish a correlation between TSH (thyroid-stimulating hormone), FT4 (free thyroxine) levels, and the titer of antithyroid antibodies.
Material and Methods
100 female and male patients diagnosed with Hashimoto’s thyroiditis were included. According to BMI (body mass index), the patients were divided into three subgroups: normal BMI, overweight and obese group.
31% of patients had normal BMI, 37% were overweight and 32% had obesity. TSH mean value was higher in the overweight (10.76 μUI/mL) and obesity groups (7.58 μUI/mL), as compared to normal BMI group (2.67 μUI/mL). Similar results were obtained for anti-TPOAb (antithyroid-peroxidase antibodies) mean value. Antithyroglobulin antibodies (anti-TgAb) had higher values in patients with normal body weight: 431.23 U/mL compared to 212.37 U/mL in overweight and 368.64 U/mL in obese patients. FT4 average value was lower in obese patients (1.15 ng/ mL compared to 1.68 ng/mL in the normal weight and 1.53 ng/mL in overweight patients. There were no statistically significant correlations between BMI and TSH (p = 0.2753), FT4 (p = 0.6156, anti-TPOAb (p = 0.3347) and anti TgAb levels (p = 0.154). The correlation between TSH and total serum cholesterol was statistically significant (p <0.05).
The presence of obesity in patients with Hashimoto’s thyroiditis is directly related to hypothyroidism associated to autoimmunity.Thyroid autoimmunity may have some effects on hyperlipidaemia and obesity, independently of thyroid function.
Key words: thyroid, obesity, autoimmune thyroiditis, leptin.
List of abbreviations
TSH= Thyroid Stimulating Hormone
FT4= free thyroxine
TPOAb=thyroid peroxidase antibody
TgAb= thyroglobulin antibody
BMI= body mass index
TC= total cholesterol
HDL- cholesterol=High Density Lipoprotein-cholesterol