Obesity is associated with increased risk of thyroid cancer, according to a review published in Obesity Reviews.
Daniela Schmid, Ph.D., from the University of Regensburg in Germany, and colleagues performed a meta-analysis of adiposity measures and thyroid cancer using 21 articles which included data on 12,199 thyroid cancer cases.
The researchers found that, compared with normal-weight individuals, the risk of thyroid cancer was significantly greater for overweight and obese individuals (25 and 55 percent increased risk, respectively).
The risks of thyroid cancer were increased 30, 5, 5, and 14 percent, respectively, with each 5-unit increase in body mass index (BMI), 5 kg increase in weight, 5 cm increase in waist or hip circumference, and 0.1-unit increase in waist-to-hip ratio.
Obesity was significantly positively associated with papillary, follicular, and anaplastic thyroid cancer in analysis by histologic type; an inverse association was seen for obesity with medullary thyroid cancer.
“Our findings imply that maintaining normal weight represents an important strategy for decreasing thyroid cancer risk in both men and women,” the authors write.
“More epidemiologic research is needed to discern potential variation in the effects of BMI across thyroid cancer histologic subtypes.”