Treatment of Swedish Patients with Graves' Hyperthyroidism Is Associated with Changes in Acylcarnitine Levels.

Abstract

Hyperthyroidism is associated with alterations in metabolism that are currently only partially understood. The objective of the study was to investigate changes in metabolism associated with reinstatement of euthyroidism in Swedish patients. Eighty metabolites in plasma were profiled from 10 subjects with Graves' disease (GD) at baseline and after 9 and 15 months of treatment to reinstate euthyroidism. Thyroid parameters, thyrotropin (TSH), TSH receptor antibodies, free triiodothyronine, and free thyroxine were followed. Main findings were validated in plasma from 20 subjects with GD at baseline and at three, six, and nine months. The study was conducted at the endocrinology clinic in Malmö, Sweden. Euthyroidism was reinstated at three months, and thyroid status did not change further during the 15-month follow-up. This was paralleled by altered levels of 9/19 detected acylcarnitines (p < 0.05 after adjustment for multiple testing). Levels of short-chain acylcarnitines were decreased, intermediate-chain acylcarnitines elevated, and long-chain acylcarnitines unaltered. GD and treatment of the disease is associated with pronounced acyl chain length-dependent alterations in acylcarnitine levels. These changes may be impacted by ethnicity and or dietary differences.