关键词: 非酒精性脂肪性肝病, 甲状腺功能正常, 甲状腺功能减退症, 甲状腺激素类, 影响因素分析

Abstract: Background　Thyroid hormone is involved in the body's energy balance and lipid metabolism，which may be one of the potential mechanisms leading to the occurrence of non-alcoholic fatty liver disease（NAFLD）．Recently，the correlation between thyroid hormone and NAFLD is becoming a focus of clinical research，but no clear conclusion has been made.Objective　To investigate the correlation between thyroid hormone and NAFLD in patients with euthyroidism and hypothyroidism.Methods　A total of 382 inpatients from the Endocrine and Diabetes Center，Affiliated Hospital of Integrated Traditional Chinese and Western Medicine，Nanjing University of Chinese Medicine were enrolled from March 2015 to March 2018，including 268 with euthyroidism，114 with hypothyroidism；166 with NAFLD，and 216 without.Thyroid hormone indices were collected，and their correlations with NAFLD were explored by using Logistic regression and ROC analysis.Results　Of the 268 cases of euthyroidism，113 had NAFLD，and other 155 had not.NAFLD was associated with higher average levels of waist circumference（WC），total cholesterol（TC），low-density lipoprotein cholesterol（LDL-C），and fasting insulin（FINS），and higher average FT3/FT4 ratio，and homeostatic model assessment of insulin resistance index（HOMA-IR） in euthyroidism patients（P<0.05）．Among the 114 cases of hypothyroidism，53 had NAFLD，and other 61 had not.NAFLD was associated with higher average levels of WC，TSH，TC，LDL-C，and FINS，and higher average FT3/FT4 ratio，and HOMA-IR in hypothyroidism patients（P<0.05）．Multivariate Logistic regression analyses showed that WC〔OR=1.564，95%CI（1.125，2.174）〕，FT3/FT4 ratio〔OR=1.255，95%CI（1.067，1.477）〕and HOMA-IR〔OR=1.922，95%CI（1.194，3.095）〕 were influencing factors for NAFLD in all patients（P<0.05），and WC〔OR=1.233，95%CI（1.056，1.439）〕，FT3/FT4 ratio〔OR=1.628，95%CI（1.381，1.919）〕，TC〔OR=1.168，95%CI（1.014，1.345）〕and HOMA-IR〔OR=1.502，95%CI（1.053，2.142）〕 were influencing factors for NAFLD in patients with hypothyroidism（P<0.05）．ROC curve analysis found that，the AUC of FT3/FT4 ratio was 0.707〔95%CI（0.611，0.809）〕 for predicting the risk of NAFLD in patients with euthyroidism and hypothyroidism，the determined optimal cut-off point was 0.37，with corresponding sensitivity of 78.2%，and specificity of 58.5%.The AUC of FT3/FT4 ratio was 0.746〔95%CI（0.570，0.865） 〕 for predicting the risk of NAFLD in patients with hypothyroidism，the determined optimal cut-off point was 0.47，with corresponding sensitivity of 82.4%，and specificity of 61.2%.Conclusion　FT3/FT4 ratio，HOMA-IR and WC are the risk factors of NAFLD in those with euthyroidism and hypothyroidism.For those with hypothyroidism，TC is an additional independent risk factor for NAFLD.

Key words: Non-alcoholic fatty liver disease, Euthyroidism, Hypothyroidism, Thyroid hormones, Root cause analysis