Metabolic Changes after Radioiodine Correction of Grade 1 and Grade 2 Subclinical Hyperthyroidism

Lipoprotein alterations in endocrine disorders - a review of the recent developments in the field

Dyslipidemia is one of the most common disorders worldwide, which, if left untreated, results in a multitude of complications. Thus proper diagnostics, which includes identifying of secondary causes of dyslipidemia is crucial. Endocrine disorders are an important cause of secondary dyslipidemia. This paper aims to review the publications on lipoprotein alterations in endocrine disorders from the past two years and provide an overview of the recent discoveries in this dynamically developing and large field. Significant changes in lipoprotein serum concentrations are present in most endocrinological diseases and can be modified with proper treatment. Some lipoproteins have also been proposed as markers in some endocrine diseases, e.g., thyroid carcinoma. From the scope of endocrine disorders, the largest number of studies explored the lipoprotein changes in polycystic ovary syndrome and in women during the menopausal and peri-menopausal period. Even though the association of thyroid disorders with dyslipidemia is already well studied, new research has delivered some exciting findings about lipoprotein alterations in euthyroid patients with either positive antithyroid peroxidase antibodies or reduced sensitivity to thyroid hormones. The problem of the adverse metabolic profile, including dyslipidemia in hypoprolactinemia has been recognized. Moreover, this review describes other significant discoveries encompassing lipoprotein alterations in disorders of the adrenals, thyroid, parathyroid glands, pituitary, and gonads. The up-to-date knowledge of the influence of endocrine disorders and hormonal changes on serum lipoproteins is prudent as it can significantly impact therapeutic decisions.

Treatment of post-radioactive iodine relapse of hyperthyroidism: comparison of long-term methimazole and radioactive iodine treatment

BACKGROUND

This study aimed to compare the time to achieve euthyroidism and sustained control of hyperthyroidism after treatment with radioactive iodine (RAI) or long-term methimazole (LT-MMI) in patients with post-RAI relapsed hyperthyroidism.

METHODS

Sixty four patients with recurrence of hyperthyroidism after RAI treatment were randomly assigned to either RAI or LT-MMI treatment. Both groups were followed every 1-3 months in the first year and then every 6 months for a total of 60 months.

RESULTS

In RAI and LT-MMI groups, mean age was 49.0 ± 12.1 and 50.1 ± 14.6 years and time of relapse of hyperthyroidism after previous RAI treatment was 23.2 ± 18.8 and 20.8 ± 17.1 months, respectively. At the end of study, in the LT-MMI group, 31 (97%) and 1 (3%) were euthyroid and hypothyroid, respectively; in the RAI group, 8 (25%) patients were euthyroid, whereas 18 (56%), 3 (9.5%) and 3 (9.5%) had overt hypothyroidism, subclinical hypothyroidism and hyperthyroidism, respectively. Mean time to euthyroidism was 9.4 ± 5.0 months in the RAI group and 3.5 ± 2.8 months in the LT-MMI group (p < 0.001). Patients in the RAI group spent 77.7 ± 14.0 percent and those in the LT-MMI group spent 95.2 ± 5.9 percent of 60 months in the euthyroid state (p < 0.001).

CONCLUSION

In patients with post-RAI relapse of hyperthyroidism, LT-MMI treatment was superior to radioiodine because of faster achievement of euthyroidism and more sustained control of hyperthyroidism during 60 months of follow-up.