Endocrine Abstracts

Introduce: Subclinical hyperthyroidism (SH) affects 0.2 - 11.8% of world human population and is associated with important cardiovascular risk factors. It remains controversial whether or not to treat patients with low serum TSH levels. Between unwanted potential outcomes of treatment of SH there is an elevation of the level of serum triglycerides and cholesterol which may be responsible for higher risk of cardiac death.

Aim: To estimate an influence of cure of SH on the level of serum triglycerides and cholesterol fractions: total (Tchol), low density (LDL) and high density (HDL).

Method: 44 patients (37 women, 7 men) aged mean 45, with 13 month history of only autonomous endogenous SH (mean TSH=0.16 mIU/l) were examined twice: before and mean 6 months after TSH normalization (obtained mean TSH=1.32 mIU/l) with radioiodine treatment (mean 12.1 mCi). The average time between examinations was one year.

Results: The cure of SH caused statistically insignificant increase of serum triglycerides from 95.2 to 102.6 mg/dl (P=0.273) and Tchol from 204.6 to 211.1 mg/dl (P=0.11) but significant increase of LDL from 114.3 to 121.9 mg/dl (P=0.018) and HDL from 64.02 to 66.25 mg/dl (P=0.041).

Conclusions: 1 Cure of autonomous subclinical hyperthyroidism insignificantly increases levels of serum triglycerides and total cholesterol. 2. Potential deleterious effect of statistically significant increase of serum LDL could be abolished by significant increase of serum HDL. 3. Further investigations are needed.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector