Introduction: Patients with differentiated thyroid cancer (DTC) often have complained of fatigue, weight changes or decreased quality of life (QOL) after thyroidectomy. The aim of this study was to identify whether there exist changes of resting metabolic rate, body composition, or muscle strength after thyroidectomy in female patients with DTC, and whether those are associated with QOL changes.
Methods: In this prospective study, we recruited 36 middle-aged female DTC patients scheduled for thyroidectomy. Among them, 18 subjects received radioactive iodine treatment (RAI), while 18 did not. Resting metabolic rate (RMR), muscle strength (knee extension), or body composition (DEXA) were measured at baseline, postoperative 7 and 12 months. Questionnaire for QOL (SF36), physical activity (IPAQ), and dietary records of 24 hour recall were also obtained.
Results: Baseline TSH values were 1.74 ± 1.34 μIU/mL and those of postoperative 7 and 12months were 0.23 ± 0.41 μIU/mL and 0.34 ± 0.82 μIU/mL. The % body fat was decreased at postoperative 12 months compared to individual baseline (37.3 ± 5.1 vs. 35.8 ± 4.7, p < 0.001), although energy intake or physical activity was not changed in total 36 subjects. There were no significant changes in weight, BMI, RMR and total scores of SF-36. When we evaluated postoperative changes according to RAI treatment, the % body fat was significantly decreased at postoperative 7 and 12 months (37.4 ± 5.5 vs 34.6 ± 5.5 vs. 35.0 ± 5.4, p<0.001) only in no RAI group. On the other hands, muscle strength significantly increased at postoperative 12 months (Extension, peak torque: 76.0 ± 21.3 vs. 86.6 ± 16.7 nm, p=0.024) only in RAI group.
Conclusions: Our study demonstrated that body composition, muscle strength or QOL was not deteriorated after thyroidectomy in DTC patients.