Serum Lipid Levels in Thyroid Dysfunction with Special Reference to Transient Elevation During Treatment in Hyperthyroid Graves' Disease

Abstract

Lipid metabolism was examined in patients with hyper- or hypothyroidism. Compared with corresponding age and sex matched controls, serum total cholesterol (T-chol), low density lipoprotein cholesterol (LDL-chol), phospholipid (PL) and LDL levels were significantly low and free fatty acid (FFA) levels were high with apparently normal triglyceride (TG), very low density lipoprotein (VLDL) and high density lipoprotein cholesterol (HDL-chol) levels in 61 hyperthyroid patients, while T-chol, LDL-chol, TG, PL, VLDL and LDL levels were high with normal FFA and HDL-chol levels in 31 hypothyroid patients. Serum lipid levels were then repeatedly measured in 7 men and 7 women with hyperthyroid Graves' disease before treatment (stage I), just after the patients became euthyroid with anti-thyroid drug (stage II) and more than 2 months after the patients remained euthyroid (stage III). Serum T-chol, LDL-chol, PL and LDL levels were low at stage I, significantly elevated at stage II and then normalized at stage III. Transient but significant elevation of serum TG, VLDL and HDL-chol levels at stage II were also observed in men. Accelerated catabolism and anabolism of lipid has been reported in hyperthyroidism. Transient elevation of serum lipid levels suggests a more rapid improvement in catabolism than in anabolism of lipid in an early stage of the medical treatment for hyperthyroidism.

Relationships between plasma thyrotropin receptor antibodies and lipid or lipoprotein parameters in Graves' disease

“…Finally, our data show that the mean TC, LDL-C, apo-B and HDL-C levels are decreased in hyperthyroid patients positive for TSH-R-ab, in agreement with previous reports (9,10,(13)(14)(15). Furthermore, our results confirm that thyroid hormones are involved in cholesterol metabolism.…”

Lipid Abnormalities and Cardiometabolic Risk in Patients with Overt and Subclinical Thyroid Disease

“…Most of the existing studies support lower total and LDL cholesterol levels in patients with hyperthyroidism [3, 32, 39, 68–73], while only a few data support no change [21]. Lower triglycerides, HDL, apoA1, apoB, and Lp(a) levels have been found in patients with hyperthyroidism compared with euthyroid controls, which is questionable by other reports [21–23, 32, 68–72] (Table 2).…”

“…However, there are few trials where LDL did not significantly fall after treatment [29, 46, 51], especially if the pretreatment TSH levels were less than 10 mIU/L [49, 68]. Triglycerides, HDL, apoA1, apoB, and Lp(a) levels are less influenced by thyroxine treatment in the majority of studies in subclinical hypothyroidism [28–30, 38, 43–49, 52, 53, 58, 65, 66].…”

Crosstalk of thyroid hormone receptor and liver X receptor in lipid metabolism and beyond [Review]

“…In fact, the role of thyroid hormone and thyroid hormone receptors (TRs) in the regulation of cholesterol metabolism has been examined intensively [1,3,4]. However, it still remains unclear how thyroid hormone affects triglyceride metabolism [5][6][7][8][9].…”