Association between Thyroid Cancer and Weight Change: A Longitudinal Follow-Up Study

Background: The purpose of this study was to evaluate body mass index (BMI) and systolic blood pressure (SBP)/diastolic blood pressure (DBP) between Korean adults who underwent thyroidectomy and comparison groups. Methods: Data were included from the Korean National Health Insurance Service-Health Screening Cohort (2002–2015). BMI and SBP/DBP were measured before thyroidectomy, 1 and 2 years after thyroidectomy (n = 1995 in study I, n = 2162 in study II), comparing 1:4 matched participants (n = 7980 in study I, n = 8648 in study II). The paired t-test and linear mixed model were used to identify the differences between groups. Results: DBP in both thyroid cancer II and comparison II group were significantly lower after thyroidectomy than before thyroidectomy. However, the interaction effect of thyroidectomy in study I and study II did not reach statistical significance. Conclusion: BMI, SBP and DBP were not significantly different between the thyroidectomy group and the matched comparison group.