Endocrine Abstracts

Background

Vitamin D deficiency is a global health problem. Nowadays is intensively studied the influence of vitamin D on the course of autoimmune diseases of the thyroid gland.

Objective

To study the relationship between vitamin D status and metabolic parameters in premenopausal women with autoimmune hypothyroidism.

Methods

146 premenopausal women with autoimmune hypothyroidism were examined. The mean age of patients was 46.8 ± 0.73 years. All women underwent anthropometric, general clinical, biochemical examinations, including determination of lipid and hydrocarbon metabolism, assessment of the functional state of the thyroid gland: TSH level, free thyroxine (FT4), free triiodothyronine (FT3), thyroid antibodies (TPOAb, TGAb). The collected data were statisstically analyzed using the Statistica 12 (р<0.05).

Results

The average level of TSH was 4.40 ± 0.21 uIU/ml; fТ3 –1.97 ± 0.09 pmol/l; fТ4 – 12.96 ± 0.37 pmol/l; TPOAb –112.87 ± 5.61 IU/ml; TGAb –152.25 ± 5.04 IU/ml, р<0.05. The mean level of 25 (OH) D in women with hypothyroidism was 16.42 ± 0.57 ng/ml, which corresponds to vitamin D deficiency (<20 ng/ml). Vitamin D deficiency was found in 78.8%, insufficiency in 17.1% of premenopausal women with hypothyroidism. There was a significantly strong (P <0.05) negative correlation between 25 (OH) D and TPOAb (r = -0.77), TSH (r = -0.72), TGAb (r = -0.33 ). Positive correlations of medium strength were found between 25 (OH) D and the level of fT3 (r = 0.46) and fT4 (r = 0.44), P <0.05. The body mass index averaged 29.4 ± 0.29 kg/m². The mean level of glucose 5.49 ± 0.06 mmol/l, basal insulin level 28.63 ± 0.88 mIU/l, HOMA-IR 3.31 ± 0.08 (р<0.01). Hypercholesterolemia averaged 6.1 ± 0.12 mmol/l, cholesterol LDL 3.72 ± 0.07 mmol/l, cholesterol HDL 1.37 ± 0.02 mmol/l, TG 3.73 ± 0.09 mmol/l, atherogenic coefficient (AC) >3 was observed in 64%, P <0.01. Analysis of the relationships of metabolic parameters showed a significantly strong (P<0.05) negative correlation between 25 (OH) D with BMI (r = -0.74), AC (r = -0.65), the level of cholesterol HDL (r = -0.72), cholesterol LDL (r = -0.58), TG (r = -0.46), HOMA resistance index (r = -0.57).

Conclusion

Low vitamin D status is significantly associated with autoimmune thyroid dysfunction and determines the degree of metabolic disorders and cardiovascular risk in premenopausal women with autoimmune hypothyroidism.