探讨肥胖患者亚临床甲状腺功能减退（SCH）、血清维生素D水平和非酒精性脂肪肝（NAFLD）严重程度的相关性。

回顾性分析2021年11月1日至2022年3月31日在安徽医科大学第二附属医院减重代谢外科就诊的120例肥胖合并NAFLD患者的临床资料，根据是否存在SCH，将患者分为SCH组和对照组。进一步根据维生素D水平进行亚组分析：SCH-VD不足组、SCH-VD缺乏组、对照-VD不足组、对照-VD缺乏组。NAFLD的诊断采用肝脏超声检查，腹部定量CT用于评估肝脏脂肪含量，并使用肝脂肪指数（FLI）和FIB-4（fibrosis index based on the 4 factor）评分预测NALFD肝脂肪变性和肝纤维化程度。

SCH组患者的FLI、FIB-4和肝脏脂肪含量明显高于对照组（P<0.05），维生素D水平显著低于对照组（P<0.05），亚组分析显示SCH合并维生素D缺乏患者的FLI、FIB-4和肝脏脂肪含量更高（P<0.05）。相关性分析显示血清促甲状腺激素（TSH）与FLI、FIB-4和肝脏脂肪含量呈正相关（P=0.030，r=0.199；P<0.001，r=0.387；P=0.004，r=0.261），而维生素D水平与FLI、FIB-4和肝脏脂肪含量呈负相关（P=0.012，r=-0.229；P=0.249，r=-0.106；P<0.001，r=-0.363），维生素D水平与TSH的相关性分析显示二者呈负相关（P<0.001, r=-0.326）。此外，多元回归分析显示维生素D缺乏是重度NAFLD的独立危险因素（P=0.034，OR=0.615）。

SCH和维生素D缺乏与肥胖患者的NAFLD密切相关，而且维生素D缺乏是重度NAFLD的独立危险因素，因此对于肥胖伴NAFLD患者，建议完善甲状腺功能以及血清维生素D检查，以便即时干预。

To analyze the correlation between subclinical hypothyroidism (SCH), serum vitamin D levels, and the severity of non-alcoholic fatty liver disease (NAFLD) in patients with obesity.

Clinical data of 120 obese patients with NAFLD who visited the Department of Weight and Metabolism Surgery of the Second Affiliated Hospital of Anhui Medical University from November 1, 2021 to March 31, 2022, were retrospectively analyzed. Patients were divided into SCH group and control group based on the presence of SCH, and further subgroup analysis was performed based on the vitamin D levels: SCH-Vitamin D deficient group, SCH-Vitamin D insufficient group, control-Vitamin D deficient group, and control-Vitamin D insufficient group. Liver ultrasonography was used to diagnose NAFLD, QCT was used to evaluate liver fat content, and the Fatty Liver Index (FLI) and Fibrosis Index Based on the 4 Factor (FIB-4) score were used to predict NAFLD liver fat degeneration and liver fibrosis.

The FLI, FIB-4, and liver fat content were significantly higher in the SCH group compared to the control group (P<0.05), whereas vitamin D levels were lower in the SCH group (P<0.05). Subgroup analysis revealed that patients with both SCH and vitamin D deficiency had higher FLI, FIB-4, and liver fat content (P<0.05). Correlation analysis demonstrated a positive correlation between thyroid stimulating hormone (TSH) and FLI, FIB-4, as well as liver fat content (P=0.030, r=0.199; P<0.001, r=0.387; P=0.004, r=0.261), while vitamin D exhibited a negative correlation with FLI, FIB-4, and liver fat content (P=0.012, r=-0.229; P=0.249, r=-0.106; P<0.001, r=-0.363). Additionally, the correlation analysis between vitamin D levels and TSH demonstrated a negative correlation (P<0.001, r=-0.326). Furthermore, vitamin D (P=0.034, OR=0.615) was identified as an independent risk factor for severe NAFLD.

Our findings suggest a close association between SCH, vitamin D deficiency, and NAFLD in obese patients. Vitamin D deficiency emerges as an independent risk factor for severe NAFLD.Therefore, for obese patients with NAFLD, it is recommended to improve thyroid function and serum vitamin D levels to facilitate timely intervention.