As an important incentive for cardiovascular disease, cancer, diabetes and other chronic diseases, obesity after cardiovascular disease and cancer has been listed as the third largest threat to human health by World Health Organization. Recent research has shown that obesity is associated with colorectal cancer, esophageal cancer, kidney cancer, endometrial cancer, however, it has not been fully disclosed that the mechanism could lead to an increased risk of tumors. Leptin and adiponectin are a kind of hormone secreted by adipose tissue, which involve in the energy metabolism, and play an increasing significant role in the tumors' affecting factors.

Objective:To investigate the association of body mass index (BMI), blood lipid, serum leptin, adiponectin with papillary thyroid carcinoma.Methods:A total of 120 patients including 40 cases of papillary thyroid carcinoma (papillary thyroid carcinoma group), 40 cases of nodular goiter (nodular goiter group) and 40 cases diagnosed without thyroid diseases or other metabolic diseases during the corresponding period (the control group) in Inner Mongolia People's Hospital from April 2015 to January 2016 were enrolled. The BMI of all subjects was calculated. The levels of blood lipid, serum leptin and adiponectin were detected.Results:The number of females was more than that of males in nodular goiter group and papillary thyroid carcinoma group, and the difference in gender distribution of three groups was statistically significant (χ 2 = 19.024, P < 0.01). The level of BMI, leptin, triglyceride and total cholesterol of papillary thyroid carcinoma group was higher than that of the control group [(24.86±3.26) kg/m 2 vs. (20.79±2.15) kg/m 2, (0.68±0.07) ng/ml vs. (0.61±0.39) ng/ml, (1.42±0.53) mmol/L vs. (1.05±0.36) mmol/L, (4.76±0.57) mmol/L vs.(4.28±0.46) mmol/L], and the differences were statistically significant ( t values were 4.302, 3.296, 1.993 and 2.177, respectively, all P < 0.05). The level of total cholesterol and low-density lipoprotein [(4.97±0.55) mmol/L, (2.72±0.58) mmol/L] in the nodular goiter group was higher than that in the control group [(4.28±0.46) mmol/L, (2.18±0.69) mmol/L], and the differences were statistically significant ( t values were 2.954 and 2.148, respectively; all P < 0.05). The level of adiponectin [(4.21±0.34) ng/ml, (4.30±0.27) ng/ml] in papillary thyroid carcinoma and nodular goiter group was lower than that in the control group [(4.87±0.27) ng/ml], and the differences were statistically significant ( t values were 7.631 and 7.416, respectively; all P < 0.05). Conclusion:The increase of BMI, triglyceride, total cholesterol, serum leptin and the decrease of serum adiponectin may be related to the occurrence of papillary thyroid carcinoma.