Prevalence and impact of non-alcoholic fatty liver disease in patients with papillary thyroid carcinoma

Purpose Papillary thyroid carcinoma (PTC) is the most common thyroid cancer. Non-alcoholic Fatty Liver Disease (NAFLD) was possibly among the risk factors for thyroid carcinoma. It is uncertain whether NAFLD is associated with the aggressiveness of PTC. Methods We obtained data on patients with PTC who had undergone surgery at the First Affiliated Hospital of Wenzhou Medical University between January 2020 and February 2022. Pre-and post-operative data were obtained from electronic medical records and analyzed. Patients were split into two groups based on the NAFLD diagnostic criteria and compared using univariate and multivariate analysis through a logistic regression model. Results In all, 3468 patients with PTC were included in this study, of which 594 (17.1%) were diagnosed with NAFLD. NAFLD was found to be an independent risk factor for lymph node metastasis ( OR = 1.285 95% CI: 1.052–1.570), incidence of BRAF V600E mutation ( OR = 1.504, 95% CI: 1.148–1.972) and later tumor stage at diagnosis ( OR = 2.310, 95% CI: 1.700–3.139) in PTC. The association mentioned above remained significant in subgroups of patients with Hashimoto’s thyroiditis (HT), hypertension, diabetes (DM), high triglyceride (TG) levels, low levels of high-density lipoprotein-cholesterol (HDL-C), and high body mass index (BMI). In subgroup of female rather than male, NAFLD was an independent risk factor for lymph node metastasis ( OR = 1.638 95% CI: 1.264–2.123), incidence of BRAF V600E mutation ( OR = 1.973, 95% CI: 1.368–2.846) as well as later tumor stage ( OR = 2.825, 95% CI: 1.964–4.063) in PTC. However, NAFLD was not a risk factor for the larger tumor size (>1 cm), extra-thyroidal extension (ETE), or multifocality in PTC. Conclusion Our cross-sectional study indicated that there is a strong association of NAFLD with higher incidence of lymph node metastasis, higher incidence of BRAF V600E mutation and later TNM stage than non-NAFLD in females with PTC.