Effect Of Insulin Resistance On Thyroid Nodules In Patients With Obesity

Objective:Epidemiological surveys around the world have shown that the incidence of obesity and obesity complications is showing a grim upward trend,and the expenditure on its prevention and treatment has also increased significantly.Therefore,there are endless studies on obesity-related diseases,among which metabolic diseases have been widely explored,such as diabetes,fatty liver,polycystic ovary,etc.Studies believe that insulin resistance(IR)plays a role in promoting the occurrence and development of obesity-related diseases.Insulin,as a major regulator of carbohydrate metabolism,is also a growth factor that stimulates cell proliferation,and epidemiological evidence indicates that more than 80%of obese patients are complicated with IR.With the popularization of ultrasound imaging examination,the incidence of thyroid nodules(TN)has reached as high as 60%in the healthy population.There are many causes for the formation of TN,including genetics,iodine deficiency and goiter,and another possible factor is IR,but this has not been fully confirmed in obese patients.Therefore,this study compared the TN situation in obese patients with IR.Methods:Clinical data of 216 obese patients admitted to the Department of Gastrointestinal and Bariatric Metabolic Surgery,the Second Affiliated Hospital of Anhui Medical University from July 2021 to February 2022 were retrospectively analyzed.The patients were divided into two groups according to whether TN was present:TN group and NTN group;TN group was divided into TN-IR group and TN-NIR group according to insulin resistance.Then,the frequency of different characters of thyroid nodule and insulin resistance level in TN-IR group were compared.The risk factors of TN in obese patients were analyzed by Logistic regression.Finally,the changes of body indexes,TN and laboratory indexes before and after surgery were compared and analyzed in 31 patients who completed follow-up.Results:A total of 216 obese patients were enrolled in this study,including 65 males and 151 females,with an average BMI of 38.77kg/m~2.There were 133 patients in TN group and 83 patients in NTN group.Among them,81.95%(109/133)patients in TN group and 43.37%(36/83)patients in NTN group had IR,which was significantly lower than that in TN group(P<0.01).Similarly,the incidence of TN was 75.00%(108/144)in patients with IR,while only 34.72%(25/72)in patients without IR(P<0.01).Obese patients with TN had higher BMI,neck circumference(CC),waist-to-hip ratio(WHR),and homeostasis model assessment of insulin resistance(HOMA-IR)(P<0.01).In the TN-IR group,the incidence of thyroid nodule traits was higher in large nodules than in small nodules,multiple nodules than single nodules,bilateral nodules than unilateral nodules(P<0.01),and larger,taller,and with significant blood flow signals had higher HOMA-IR levels(P<0.01).Multivariate logistic regression analysis showed that fasting insulin(FI),fasting blood glucose(FG),HOMA-IR and waist-hip ratio were risk factors for TN.The 3-month follow-up data showed that the obese patients had significant weight loss(P<0.01),and IR decreased(P<0.01),TN diameter decreased(P<0.01).Conclusion:IR in obese patients is an independent risk factor for thyroid nodule occurrence and can affect the morphology and structure of thyroid nodule.Bariatric surgery may reduce the nodule diameter by improving IR.