title: Overweight, obesity and thyroid cancer risk: a meta-analysis of cohort studies.
abstract: OBJECTIVE
  This meta-analysis examined the relationship between excess body weight or body mass index (BMI) and risk of thyroid cancer.
  
  
  METHODS
  PubMed(®), MEDLINE(®), EMBASE™ and Academic Search™ Premier databases were searched to identify cohort  studies examining the effect of being overweight or obese on the risk of thyroid cancer.
  
  
  RESULTS
  The inclusion criteria were met by seven cohort studies (total number of thyroid cancer cases, 5154). The pooled relative risk (RR) of thyroid cancer was 1.13 (95% confidence interval [CI] 1.04,  1.22) for overweight. Obesity was also linked with increased thyroid cancer risk in males and females, the strength of the association increasing with increasing BMI. The combined RR of thyroid cancer was 1.18 (95% CI 1.11, 1.25) for excess body weight (overweight and obesity combined). Being  overweight was associated with a significant increase in thyroid cancer risk among non-Asians, but not among Asians. Overweight, obesity and excess body weight were all associated with papillary thyroid carcinoma risk.
  
  
  CONCLUSIONS
  The association between overweight/obesity/excess body weight  and thyroid cancer risk was confirmed.
authors: Third Department of Surgery, Baotou Tumour Hospital, Baotou, Inner Mongolia Autonomous Region, China.
authors: Z G
authors: ZG
authors: Zhao
authors: X G
authors: XG
authors: Guo
authors: C X
authors: CX
authors: Ba
authors: W
authors: W
authors: Wang
authors: Y Y
authors: YY
authors: Yang
authors: J
authors: J
authors: Wang
authors: H Y
authors: HY
authors: Cao
mesh_terms: D015992:Body Mass Index; D001835:Body Weight; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008297:Male; D009765:Obesity / Q000453:epidemiology*; D012307:Risk Factors; D013964:Thyroid Neoplasms / Q000453:epidemiology*