Does the Risk of Metabolic Syndrome Increase in Thyroid Cancer Survivors?

BACKGROUND: The steep rise in thyroid cancer observed in recent decades has caused an increase in the population of long-term thyroid cancer survivors. Other than recurrences of cancer, the long-term health consequences of surviving thyroid cancer, particularly metabolic syndrome, have not yet been determined. The aim of this study was to estimate the risk of metabolic syndrome in thyroid cancer survivors.

MATERIALS AND METHODS: Population-based data from the Korean National Health and Nutrition Examination Survey (KNHANES) were used for the analysis. The data of KNHANES IV-VI from 2007-2014 were obtained. After excluding subjects who were under 19 years old, whose fasting interval was less than 8 hours, and whose data for predefined variables including metabolic syndrome components were incomplete, 34,347 subjects were analyzed. The incidence of metabolic syndrome and its components were evaluated in three groups: subjects with no history of thyroid cancer, subjects diagnosed with thyroid cancer within 3 years of the survey date, and subjects diagnosed more than 3 years before the survey date.

RESULTS: Thyroid cancer diagnoses were made within 3 years of the survey date for 95 subjects (group 1, short-term survivors) and more than 3 years earlier than the survey date for 60 subjects (group 2, long-term survivors). Metabolic syndrome was frequently observed with clinical significance (odds ratio [OR] 1.986 [95% confidence interval [CI] 1.0-3.70], p = 0.030) in short-term survivors compared with subjects with no thyroid cancer history. Risks for having high blood pressure and high fasting glucose were estimated to be higher in the short-term survivor group (OR 2.115 [CI 1.23-3.64], p = 0.006 and OR 1.792 [CI 1.03-3.11], p = 0.038, respectively). No significant associations were noticed in the long-term survivor group when compared with the group with no thyroid cancer history.

CONCLUSION: Risks for metabolic syndrome, especially high blood pressure and high fasting glucose, were increased in short-term survivors of thyroid cancer but not in long-term survivors when compared with subjects with no history of thyroid cancer.