A Worthy Finding: Decrease in Total Cholesterol and Low-Density Lipoprotein Cholesterol in Treated Mild Subclinical Hypothyroidism.
Mild subclinical hypothyroidism (SCH) affects a large number of people and is known to be a risk factor for dyslipidemia. However, whether mild SCH patients should be treated with L-thyroxine to improve lipid profiles remains controversial. In addition, it is also unclear whether all mild SCH patients can benefit from L-thyroxine treatment, regardless of basal thyrotropin or lipid levels. This study aimed to assess the effects of L-thyroxine replacement therapy on the lipid profiles of mild SCH patients.



This open-label randomized controlled trial was performed in Ningyang County, Shandong Province, China. A total of 378 mild SCH patients with diagnoses confirmed by two thyroid function tests were randomly assigned to either the intervention group (L-thyroxine replacement therapy) or the control group (no treatment). The primary outcome was a change in serum total cholesterol (TC) concentration.



In all, 369 participants completed the 15-month follow-up period. Reduced TC concentrations were more prominent in the intervention group than they were in the control group (-0.41 mmol/L vs. -0.17 mmol/L; p = 0.012), and changes in low-density lipoprotein cholesterol levels exhibited the same trend. Subgroup analyses were performed to assess the effects of L-thyroxine in patients with different thyrotropin or TC levels. When the study population was stratified according to basal thyrotropin concentration, all patients who had received L-thyroxine showed reduced TC levels (p < 0.001). The treatment was similarly beneficial for all patients, regardless of basal TC level. Even for subjects with TC levels <5.18 mmol/L, serum TC concentrations remained unchanged in the intervention group (p = 0.936) but increased by 0.35 mmol/L in the control group (p = 0.004).



The findings suggest that mild SCH patients could benefit from L-thyroxine treatment to improve lipid profiles, regardless of basal thyrotropin or TC concentrations.
1 Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University , Jinan, China .|2 Shandong Clinical Medical Center of Endocrinology and Metabolism , Jinan, China .|3 Institute of Endocrinology and Metabolism , Shandong Academy of Clinical Medicine, Jinan, China .
Meng
M
Zhao
1 Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University , Jinan, China .|2 Shandong Clinical Medical Center of Endocrinology and Metabolism , Jinan, China .|3 Institute of Endocrinology and Metabolism , Shandong Academy of Clinical Medicine, Jinan, China .
Lu
L
Liu
4 School of Clinical Medicine, Ningxia Medical University , Yinchuan, China .
Fei
F
Wang
5 Department of Epidemiology and Biostatistics, School of Public Health, Shandong University , Jinan, China .
Zhongshang
Z
Yuan
1 Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University , Jinan, China .|2 Shandong Clinical Medical Center of Endocrinology and Metabolism , Jinan, China .|3 Institute of Endocrinology and Metabolism , Shandong Academy of Clinical Medicine, Jinan, China .
Xu
X
Zhang
1 Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University , Jinan, China .|2 Shandong Clinical Medical Center of Endocrinology and Metabolism , Jinan, China .|3 Institute of Endocrinology and Metabolism , Shandong Academy of Clinical Medicine, Jinan, China .
Chao
C
Xu
1 Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University , Jinan, China .|2 Shandong Clinical Medical Center of Endocrinology and Metabolism , Jinan, China .|3 Institute of Endocrinology and Metabolism , Shandong Academy of Clinical Medicine, Jinan, China .
Yongfeng
Y
Song
1 Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University , Jinan, China .|2 Shandong Clinical Medical Center of Endocrinology and Metabolism , Jinan, China .|3 Institute of Endocrinology and Metabolism , Shandong Academy of Clinical Medicine, Jinan, China .
Qingbo
Q
Guan
2 Shandong Clinical Medical Center of Endocrinology and Metabolism , Jinan, China .|3 Institute of Endocrinology and Metabolism , Shandong Academy of Clinical Medicine, Jinan, China .|6 Scientific Center, Shandong Provincial Hospital affiliated to Shandong University , Jinan, China .
Ling
L
Gao
7 Department of Endocrinology and Metabolism, The First Affiliated Hospital of China Medical University , Shenyang, China .
Zhongyan
Z
Shan
1 Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University , Jinan, China .|2 Shandong Clinical Medical Center of Endocrinology and Metabolism , Jinan, China .|3 Institute of Endocrinology and Metabolism , Shandong Academy of Clinical Medicine, Jinan, China .
Haiqing
H
Zhang
1 Department of Endocrinology, Shandong Provincial Hospital affiliated to Shandong University , Jinan, China .|2 Shandong Clinical Medical Center of Endocrinology and Metabolism , Jinan, China .|3 Institute of Endocrinology and Metabolism , Shandong Academy of Clinical Medicine, Jinan, China .
Jiajun
J
Zhao
D000368:Aged; D008076:Cholesterol, HDL / Q000097:blood*; D008078:Cholesterol, LDL / Q000097:blood*; D005260:Female; D020249:Hormone Replacement Therapy; D006801:Humans; D007037:Hypothyroidism / Q000097:blood* / Q000175:diagnosis / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D013960:Thyroid Function Tests; D013974:Thyroxine / Q000627:therapeutic use*; D016896:Treatment Outcome
D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D013974:Thyroxine