Endocrine Abstracts

Introduction: It is currently unclear how hyperthyroidism and its treatment impact on the weight trajectory of an individual. Anticipated weight gain with the treatment of hyperthyroidism is one of the main concerns of patients.

Methods: We prospectively examined the BMI changes that occurred with hyperthyroidism and its therapy and sought risk factors for treatment-related weight gain. An established institutional protocol for the management of hyperthyroidism was followed; patients with BMI≥25 kg/m² were verbally advised to visit a dietitian. Descriptive statistics are given as means (SD) and median (IQR) for parametric and non-parametric variables, respectively. Paired t-test, t-test, Wilcoxon two-sample signed rank test and Pearson’s correlation were employed.

Results: 33 patients with hyperthyroidism were recruited; mean age was 45.1 years (15.27) and 54.5% were females. The self-reported mean weight loss was 6.6 kg (5.15) and BMI reduction was 2.5 kg/m² (0.73–3.85) over a median duration of 12 weeks (IQR 4–24). The mean baseline weight was 72.42 kg (15.93) and BMI was 25.77 (5.04) kg/m². The final recorded mean weight and BMI increase were 6.52 kg (3.79) and 1.72 kg/m² (1.27), respectively, over a mean follow-up time of 24 weeks. The self-reported weight loss was only correlated with male gender (P=0.037). The baseline BMI was only correlated with the baseline TSH (P=0.018). The BMI post-therapy was significantly higher from as early as 6 weeks after therapy (P=0.01) and remained so at three and six months (P<0.0001). Overall there was no significant difference between the weight lost at presentation to that gained following treatment (P=0.981 and P=0.279, respectively). None of the patients elected to see a dietitian.

Conclusion: Overall, in this prospective pilot study the patients seemed to have recovered their pre-morbid weight status following treatment. Notwithstanding, many patients moved further away from their ideal weight range following hyperthyroidism therapy and this bears further investigation.