ObjectiveTo observe the changes of plasma homocysteine (Hcy) and brachial ankle pulse wave velocity (baPWV) in patients with subclinical hypothyroidism, and discuss the relationship between subclinical hypothyroidism and arterial stiffness. MethodSeventy-three patients with subclinical hypothyroidism who were not treated before were divided into two groups according to thyroid stimulating hormone (TSH) level between January 2013 and June 2014. There were 35 patients in group A (4 mU/L < TSH < 10 mU/L) and 38 in group B (TSH ≥ 10 mU/L). Another 30 healthy individuals were selected as controls. Hcy and baPWV were determined in all subjects. ResultsCompared with the controls, patients had significantly higher level of TSH, Hcy and baPWV in group A, and had significantly higher TSH, triacylglycerol (TG), low density lipoprotein cholesterol (LDL)-C, Hcy, and baPWV in group B (P<0.05). Compared with group A, TSH, TG, LDL-C, Hcy, and baPWV in group B patiens were significantly higher (P<0.05). Pearson correlation analysis showed that Hcy was positively correlated with TSH (r=0.353, P<0.01) and baPWV was positively correlated with TSH (r=0.416, P<0.01). ConclusionsHcy level and peripheric arterial stiffness increase in patients with subclinical hypothyroidism. Both of them are correlated positively with TSH.