Association of subclinical hypothyroidism with dyslipidemia and non-alcoholic fatty liver

Objective To investigate the prevalence of subclinical hypothyroidism and its relation to serum total cholesterol (TC),triglyceride (TG) levels and non-alcoholic fatty liver.Methods Serum levels of TC,TG, TSH,TT_3 and TT_4 were determined in 1 602 subjects which were divided into groups by sex and age (20-39,40- 59 and≥60 years).Fatty liver was diagnosed by type B ultrasonography.Restults ( 1 ) Prevalence of subclinical hypothyroidism was 6.6% in this population.(2) The mean levels of serum TC and TG in subclinical hypothyroidism group and normal group showed no significant difference ( both P＞0.05 ).(3) On the whole,the prevalences of subclinical hypothyroidism in hypercholesterolemia group and normal cholesterolemia group showed significant difference (P＜0.01 ).(4) In the three age groups of male and few.ale examinees,the prevalences of subclinical hypothyroidism in hypercholesterulemla group and normal cholesterolemia group showed no significant difference ( all P＞0.05 ).In the multiple regression analysis,TSH level was not related with raised TC level.(5) In the three age groups of male,there was no significant difference between the prevalences of subclinical hypothyroidism in hypertriglyceridemla group and normal triglyceridemia group ( all P＞0.05 ).In female,expect for the elderly group (＞60 years old ),the prevalence of subclinical hypothyroidism was higher in hypertriglyceridemia group than that in normal triglyceridemia.However,in the multiple regression analysis, increased TSH level was positively associated with increased serum TG level ( OR = 1.072,P=0.013 and OR = 1.102,P = 0.03 ).(6) The prevalence of subclinical hypothyroidism in non-alcobolic fatty liver group and normal group showed no significant difference ( P＞0.05 ).In the multiple regression analysis,TSH level was not the independent risk factor of non-alcoholic fatty liver (P＞0.05 ).Conclusion Subclinical hypothyroidism is not asseciated with serum TC level but positively associated with serum TG level.Subclinical hypothyroidism does not apparently increase the prevalence of non-alcoholic fatty liver.