Lipid Profile Change after Thyroidectomy

Abstract

Purpose: Thyroid diseases and lipid metabolic abnormalities have been reported to be correlated. In patients with thyroid cancer, thyroid stimulating hormone levels are suppressed to prevent recurrence. Many studies have reported dyslipidemia associated with thyroid function, although its extent before and after thyroidectomy remains to be studied. This study aimed to determine the lipid levels for administering accurate lipid treatment in thyroid cancer patients post thyroidectomy. Methods: In total, 1,203 patients with thyroid cancer who underwent thyroidectomy between June 1, 2016 and December 31, 2016 at the Thyroid Cancer Center, Gangnam Severance Hospital, Yonsei University, were enrolled in the study. Of these, patients aged <19 years and taking medication for dyslipidemia were excluded. Finally, we enrolled 295 thyroid cancer patients who underwent thyroidectomy and whose lipid profiles were confirmed pre-and post-operatively. Results: The total cholesterol levels in the lobectomy group without levothyroxine supplementation were significantly increased 1 year after surgery than those before surgery (168.17±29.19 mg/dL vs. 182.50±34.03 mg/dL, P=0.003). Additionally, the triglyceride (TG) levels were significantly decreased in the lobectomy with levothyroxine supplementation and total thyroidectomy groups, whereas cholesterol and low-density lipoprotein-cholesterol (LDL-C) levels showed no significant change. No significant changes in the levels of cholesterol, LDL-C, and TG were observed in all the 3 groups. Conclusion: Extent of surgery and levothyroxine supplementation had an insignificant impact on the levels of cholesterol, LDL-C, TG, and high-density lipoprotein-cholesterol compared pre-and post-operatively.

Dyslipidemia Risk in Thyroid Cancer Patients: A Nationwide Population-Based Cohort Study

“…In contrast, a recent systematic review and meta-analysis showed that dyslipidemia, including both hypercholesterolemia and hypertriglyceridemia, was not associated with TC (16). Further, Chu et al found no differences in the levels of cholesterol, LDL-C, triglyceride, and HDL-C before and after surgery in patients with TC, regardless of treatment modality (23). Nevertheless, most previous studies were conducted on a relatively small number of patients over a short period of time, whereas our study was based on a large cohort database with a follow-up period of over 7 years.…”

“…Further, Chu et al. found no differences in the levels of cholesterol, LDL-C, triglyceride, and HDL-C before and after surgery in patients with TC, regardless of treatment modality ( 23 ).…”

“…Moreover, opposite changes occur in conditions resulting from thyroid hormone deficiency (12)(13)(14). However, only few studies have investigated dyslipidemia risk in patients with TC, and these have yielded conflicting results (15)(16)(17)(18)(19)(20)(21)(22)(23)(24), possibly because of differences in the study population, sample size, and follow-up period.…”

Biochemical changes in patients during hypothyroid phase after thyroidectomy

“…Thyroid hormone increases cholesterol production in the liver by inducing 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity. Cholesterol production rises in hyperthyroidism, although total blood cholesterol and low-density lipoprotein cholesterol (LDL-C) concentrations drop due to enhanced LDL-C metabolism [ 3 ]. Numerous factors contribute to accelerated atherosclerosis in hypothyroid individuals, including insulin resistance, hypercholesterolemia, enhanced low-density lipoprotein (LDL) oxidation, hypercoagulable condition, and increased peripheral vascular resistance.…”