Hyperthyroidism is associated with higher plasma endothelin-1 concentrations.
The objective of this study was to determine the change of plasma endothelin (ET)-1 concentrations and insulin resistance index after therapy for hyperthyroidism. We studied 20 patients with hyperthyroidism (15 women and 5 men; age, 34.0 +/- 2.8 years), and 31 patients with euthyroid goiters as controls (27 women, 4 men; age, 37.0 +/- 2.4 years). All hyperthyroid patients were treated with antithyroid drugs. The patients received evaluations before and after normalization of thyroid function. The evaluations included body mass index (BMI), body fat, and measurement of circulating concentrations of thyroid hormones, glucose, insulin, and ET-1. Hyperthyroid subjects had higher plasma ET-1 concentrations than the control group (P < 0.001). No significant differences in serum glucose and insulin concentrations or insulin resistance index estimated by the R value of the homeostasis model assessment (HOMA-R) were noted between the groups. Plasma ET-1 concentrations decreased after correction of hyperthyroidism compared with pretreatment (P = 0.006). Serum glucose concentrations decreased after correction of hyperthyroidism (P = 0.005). Moreover, both body weight-adjusted insulin concentrations and the HOMA-R index were also decreased after correction of hyperthyroidism compared with pretreatment (P = 0.026 and P = 0.019, respectively). Pearson's correlation revealed that plasma ET-1 levels positively correlated with serum triiodothyronine (T3) and free thyroxine (FT4) levels. Serum insulin levels and the HOMA-R index positively correlated with BMI and body fat. The HOMA-R index also positively correlated with serum T3 and FT4 levels. Neither insulin levels nor the HOMA-R index correlated with ET-1 levels. Hyperthyroidism is associated with higher plasma ET-1 concentrations. In addition, correction of hyperthyroidism is also associated with a decrease of plasma ET-1 levels as well as the insulin resistance index calculated by HOMA-R.
Chu
Chih-Hsun
CH
Division of Endocrinology and Metabolism, Kaohsiung Veterans General Hospital, Taiwan.
Lee
Jenn-Kuen
JK
Keng
Hsiu-Man
HM
Chuang
Ming-Ju
MJ
Lu
Chih-Chen
CC
Wang
Mei-Chun
MC
Sun
Chun-Chin
CC
Wei
Mei-Chih
MC
Lam
Hing-Chung
HC
D000328:Adult; D013956:Antithyroid Agents / Q000627:therapeutic use; D016022:Case-Control Studies; D019332:Endothelin-1 / Q000097:blood*; D005260:Female; D006111:Graves Disease / Q000097:blood* / Q000188:drug therapy; D006801:Humans; D007333:Insulin Resistance; D008297:Male; D013974:Thyroxine / Q000097:blood; D016896:Treatment Outcome; D014284:Triiodothyronine / Q000097:blood
D013956:Antithyroid Agents; D019332:Endothelin-1; D014284:Triiodothyronine; D013974:Thyroxine