Relationship between body mass index and the incidence risk and severity of papillary thyroid microcarcinoma / 国际外科学杂志

ABSTRACT

Objectives To evaluate the relationship between body mass index (BMI) and the incidence risk of papillary thyroid microcarcinoma (PTMC).Methods This retrospective study included 1210 PTMC patients who underwent surgery between November 2013 and October 2014 in Peking Union Medical College Hospital,China Academy of Medical Science.A population-based 1∶1 matched case-control study was conducted,and each PTMC patients was matched with one who received thyroid function and ultrasonic to confirm that there was no disease in the thyroid.The clinical profiles of these patients were collected.According to Guidelines for Prevention and Control of Overweight and Obesity in Chinese Adults,all subjects were divided into three groupsunderweight (BMI ≤ 18.5 kg/m2),normal(18.5 kg/m2 ＜ BMI ≤ 23.9 kg/m2),overweight (24.0 kg/m2 ＜ BMI ＜ 27.9 kg/m2) and obese group(BMI≥28.0 kg/m2).The relationship between BMI and PTMC incidence risk was analyzed by casecontrol study.Univariate and multivariate logistic regression analysis was applied to analyze the relationship between BMI and PTMC severity.Results The BMI of PTMC patients was significant higher than in normal control [(24.30 ±3.33) kg/m2 vs (23.31 ± 3.50) kg/m2,P ＜ 0.0001].Compared with BMI normal group,the incidence risk of PTMC in underweight group was significantly lower (OR =0.449,95 ％ CI0.270-0.747),which is higher in overweight and obese group (OR =1.559,95％ CI1.261-1.928;OR =2.059,95％ CI1.501-2.823).Histopathological review of 1210 PTMC patients with surgical resection revealed.The proportions of underweight,normal,overweight and obese group of the patients with extrathyroid extension (3.1％,48.0％,36.7％,12.2％) have significant differences with those in the patients whose tumor are limited to the thyroid (0.7％,45.2％,36.0％,18.1％) (P =0.0090).The proportions of 4 group of the patients with multiple lesions (3.2％,49.0％,35.6％,12.2％) were significantly differences to those in the patients with single lesion (0.8％,43.3％,38.7％,17.2％) (P =0.0050).Multivariate analysis showed that underweight is a protective factor of extrathyroidal extension (OR =0.219,95 ％ CI0.051-0.932;OR =0.279,95 ％ CI0.085-0.935) and mulifocality,and obese is an independent risk factors(OR =1.556,95％CI1.047-2.312;OR =1.764,95％CI1.204-2.584).Conclusions This study identified that the incidence risk of PTMC is positive related with BMI.In PTMC patients,obesity increases the risk of mulifocality and extrathyroidal extension.Attention should be paid to the effect of obesity on the incidence risk of PTMC and the diagnosis and treatment in clinical practice.