Lipotoxicity, a potential risk factor for the increasing prevalence of subclinical hypothyroidism?
BACKGROUND
Subclinical hypothyroidism (SCH) is an important public health problem worldwide for its increasing prevalence and potential deleterious effects, whereas its etiology has not been fully elucidated. Lipotoxicity exerts extensive and serious impact on human health, but so far, the potential effect of lipotoxicity on thyroid is unclear.


OBJECTIVE
The objective of the study was to assess the association between serum triglyceride levels and the risk for SCH.


METHODS
We conducted a population-based case-control study. A total of 24 100 subjects with similar and stable iodine nutrition status were recruited from China. Cases of 5033 SCH patients were identified and equal controls were matched by age, gender, and region. Conditional logistic regression was used to analyze the association between serum triglyceride levels and risk for SCH.


RESULTS
Hypertriglyceridemia was associated with an approximately 35% increased risk for SCH in both men (odds ratio 1.325; 95% confidence interval 1.002-1.753) and women (odds ratio 1.397; 95% confidence interval 1.217-1.604), even after adjustment for potential confounders. Notably, the risk for SCH increased progressively following the elevation of serum triglyceride levels. Compared with individuals with serum triglyceride levels less than 0.97 mmol/L, the risk for SCH increased approximately 1.9-fold in men and 1.4-fold in women, respectively, when triglyceride levels were greater than 1.99 mmol/L.


CONCLUSIONS
Our findings suggested that hypertriglyceridemia was positively associated with the risk for SCH.
Department of Endocrinology and Metabolism (M.Z., Q.G., S.S., Xu.Z., Y.S., H.Z., L.F., C.Y., Q.L., Xi.Z., C.X., J.Z.), Clinical Laboratory (B.Z., Z.L.), and Scientific Center (L.G.), Shandong Provincial Hospital affiliated to Shandong University, Institute of Endocrinology and Metabolic Diseases (M.Z., Q.G., S.S., Xu.Z., Y.S., H.Z., L.F., C.Y., Q.L., Xi.Z., L.G., C.X., J.Z.), Shandong Academy of Clinical Medicine, and Department of Epidemiology and Biostatistics (F.X., Z.Y.), Shandong University, Jinan, 250021 Shandong, China; School of Public Health, Shandong University, Jinan, 250012 Shandong, China; Department of Endocrinology (X.T.), The First Hospital of Lanzhou University, Lanzhou, 730000 Gansu, China; and Department of Endocrinology (T.Y.), The First Hospital affiliated to Nanjing Medical University, Nanjing, 210029 Jiangsu, China.
Meng
M
Zhao
Xulei
X
Tang
Tao
T
Yang
Bingchang
B
Zhang
Qingbo
Q
Guan
Shanshan
S
Shao
Fuzhong
F
Xue
Xu
X
Zhang
Zhanfeng
Z
Liu
Zhongshang
Z
Yuan
Yongfeng
Y
Song
Haiqing
H
Zhang
Li
L
Fang
Chunxiao
C
Yu
Qiu
Q
Li
Xiaohan
X
Zhang
Ling
L
Gao
Chao
C
Xu
Jiajun
J
Zhao
D000368:Aged; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D015228:Hypertriglyceridemia / Q000097:blood / Q000150:complications*; D007037:Hypothyroidism / Q000097:blood / Q000453:epidemiology* / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012307:Risk Factors; D012720:Severity of Illness Index; D014280:Triglycerides / Q000097:blood*
D014280:Triglycerides