Regular aerobic exercise training improves endothelium-dependent arterial dilation in patients with subclinical hypothyroidism.
OBJECTIVE
Impairment of flow-mediated endothelium-dependent arterial dilation (FMD) exists in patients with subclinical hypothyroidism (sHT). Several studies showed that exercise training can improve FMD in patients with type 1 and type 2 diabetes. Therefore, we hypothesized that exercise training can also improve FMD in subjects with sHT. The purpose of the study was to test this hypothesis.


METHODS
We selected 30 sedentary women with sHT and 27 sedentary healthy women with euthyroid. All individuals participated in an exercise training of 6 months. Before and after exercise training, high resolution ultrasound was used to measure FMD.


RESULTS
At baseline, FMD among subjects with sHT was 3.87%, which was significantly lower than that in controls (5.98%; P<0.001). After 6 months of exercise, there was a remarkable increase in FMD (31.3%) and VO(2) max (36.7%; P<0.01), and significant decreases in total cholesterol (20%), low-density lipoprotein cholesterol (LDL; 29%), triglycerides (TG; 47.6%), and C-reactive protein (CRP; 61.5%; P<0.05) were observed over the exercise in patients with sHT. The absolute changes in FMD showed significant correlation with changes in LDL (r=-0.596), TG (r=-0.532), and CRP (r=-0.511; P<0.01), and multiple regression analysis showed changes of LDL, TG, CRP were significant determinants of changes of FMD in sHT patients during exercise course.


CONCLUSIONS
Regular aerobic exercise improves FMD in sHT patients, and changes of lipids and inflammation during the exercise period may partially contribute to the improvement of endothelial function.
Xiang
Guang-da
GD
Department of Endocrinology, Wuhan General Hospital of Guangzhou Command, Wuluo Road 627, Wuhan 430070, Hubei Province, People's Republic of China. guangda64@hotmail.com
Pu
Jinhui
J
Sun
Huiling
H
Zhao
Linshuang
L
Yue
Ling
L
Hou
Jie
J
D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D001916:Brachial Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002097:C-Reactive Protein / Q000378:metabolism; D002784:Cholesterol / Q000097:blood; D004730:Endothelium, Vascular / Q000503:physiopathology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D007037:Hypothyroidism / Q000097:blood / Q000503:physiopathology* / Q000628:therapy*; D016014:Linear Models; D008875:Middle Aged; D010101:Oxygen Consumption / Q000502:physiology; D013974:Thyroxine / Q000097:blood; D014280:Triglycerides / Q000097:blood; D014284:Triiodothyronine / Q000097:blood; D014463:Ultrasonography; D014664:Vasodilation / Q000502:physiology
D001786:Blood Glucose; D014280:Triglycerides; D014284:Triiodothyronine; D002097:C-Reactive Protein; D002784:Cholesterol; D013974:Thyroxine