Objective To explore the effects of methimazole on endocrine function in patients with hyperthyroidism at different neuregulin 4(NRG4)levels.Methods A total of 60 patients with hyperthyroidism admitted to Huzhou First People's Hospital from January 2022 to January 2023 were selected.According to the level of NRG4,they were divided into case Ⅰ group(NRG4<80ng/ml,28 cases),case Ⅱ group(NRG4 80-120ng/ml,18 cases)and case Ⅲ group(NRG4>120ng/ml,14 cases).The clinical efficacy,thyroid hormone levels,glucose and lipid metabolism indexes and adverse reactions of three groups were compared.Results The difference of total effective rate among three groups was statistically significant(χ2=10.836,P<0.001).There were statistically significant differences in thyroid-stimulating hormone(TSH),free triiodothyronine(FT3),free thyroxine(FT4)between groups,time points and interactions among three groups(P<0.05).TSH levels increased and FT3 and FT4 levels decreased in all three groups after treatment(P<0.05).One month after treatment,the levels of fasting blood glucose,2h postprandial blood glucose,glycated hemoglobin,total cholesterol and low density lipoprotein cholesterol in three groups were significantly lower than before treatment(P<0.05),and the differences in above indicators among the three groups were statistically significant(P<0.05).There was no significant difference in total incidence of adverse reactions among three groups(χ2=5.349,P=0.069).After treatment,NRG4 levels in three groups decreased significantly over time(P<0.05).There were significant differences in NRG4 levels among the three groups at different time points(P<0.05),and case Ⅰ group