Antioxidant supplementation and serum lipids in patients with Graves' disease: Effect on LDL-cholesterol

Abstract

Graves' disease is an autoimmune disorder and the most common cause of hyperthyroidism. Graves' disease occurs more often in women with a female/male ratio of 5:1 and a population prevalence of 1 to 2 %. The disease is associated with circulating immunoglobulins that bind to and stimulate thyrotropin, the thyroid stimulating hormone (TSH) receptor, resulting in sustained thyroid overactivity (1). Through its hormones, The effect of supplementation with a fixed combination of antioxidants (beta-carotene, selenium, vitamins C and E) on serum lipids was monitored in patients with newly detected Graves' disease. Measurements were made prior to the commencement of therapy and after 30 and 60 days. Patients were randomized into two groups. Test group comprised patients who received antioxidant supplementation in addition to methimazole, while patients treated with methimazole only were in the control group. The concentration of total and HDL-cholesterol increased significantly in test and control groups (p < 0.05) but these groups did not differ significantly. Concentration of LDL-cholesterol increased significantly in the test group only (p < 0.005) and was significantly different from the control group 60 days after the commencement of therapy (p < 0.005). Significant increase in the LDL-cholesterol concentration in the test group requires further investigations.

Oxidative Stress in Graves Disease and Graves Orbitopathy

“…The effects of selenium on GH were investigated in a few clinical studies, which tested selenium either alone or within a mixture containing other antioxidant agents, in patients treated with ATD [41][42][43][44][45][46][47]. The hypothesis was that selenium deficiency, by worsening the counteracting response of the antioxidant machinery to ROS, could enhance oxidative stress in thyrotoxicosis.…”

Current and Future Treatments for Graves’ Disease and Graves’ Ophthalmopathy

“…Selenium The use of selenium in GD has been proposed given the presence of reactive oxygen species in the thyroid and the known antioxidant effect that selenium provides. While some studies with a mixture of antioxidants found beneficial results on biochemical parameters [50], studies looking directly at the benefit of adding selenium to MMI had mixed results [51][52][53][54]. One such study [53] showed a positive result in terms of biochemical control of hyperthyroidism while two RCTs did not show any benefit for improving hyperthyroidism in the short term [52] and response or recurrence rates in GD [54].…”

Mechanistic Pathways of Selenium in the Treatment of Graves’ Disease and Graves’ Orbitopathy

“…In these studies, patients were given selenium alone, or within a mixture of antioxidant compounds, as an adjuvant measure in addition to antithyroid medications [2,3,21,22,51,52]. Using a relatively low dose of selenium (60 μg/day), given within a mixture of antioxidants including β-carotene, Vitamin C, and Vitamin E and concomitantly with the administration of methimazole (MMI), Vrca et al found a better response to treatment in terms of increase in LDL-cholesterol levels compared with patients given MMI alone [51]. On the other hand, there was no apparent advantage in control of thyroid function [51].…”

“…Using a relatively low dose of selenium (60 μg/day), given within a mixture of antioxidants including β-carotene, Vitamin C, and Vitamin E and concomitantly with the administration of methimazole (MMI), Vrca et al found a better response to treatment in terms of increase in LDL-cholesterol levels compared with patients given MMI alone [51]. On the other hand, there was no apparent advantage in control of thyroid function [51]. In another study, Guerra et al treated patients with an antioxidant mixture containing a small amount of selenium (15 μg/day), still associated with MMI, and observed a better biochemical and clinical control of hyperthyroidism compared with MMI alone [21].…”