12569 Improvement Of Life Quality In Mexican Patients With Primary Hypothyroidism And Residual Symptoms On Combination Therapy With LT4/LT3

Abstract Disclosure: S.H. Aguilar Maciel: None. I.O. Calderón-Lojero: None. R. Álvarez-Hernández: None. M.A. Mejía-Blanquel: None. O.P. González-Guzmán: None. N.G. Nieto-Velázquez: None. K. Sanchez-Pozos: Other; Self; We thank Productos Medix, S.A. de C.V. for liothyronine. Introduction: Despite achieving “biochemical euthyroidism” (TSH of 0.5-4.5 mIU/L) with levothyroxine replacement (LT4), the 10-15% of patients with primary hypothyroidism persist with residual symptoms, which deteriorates their quality of life (QoL). This has led to the introduction of the LT4 and liothyronine (LT3) combination therapy. Objective: This study aims to assess the effectiveness of combined therapy with LT4/LT3 on the QoL of Mexican patients with primary hypothyroidism and residual symptoms. Methods: This is a longitudinal observational study that included adult patients aged 18-60 years diagnosed with primary hypothyroidism and residual symptoms under LT4 monotherapy. The evaluation of QoL was performed with the validated Spanish version of ThyPRO. Patients completed the ThyPRO questionnaire before initiating combined therapy and at six months post-treatment. Anthropometric measurements were recorded, and blood samples were collected for biochemical and hormonal analysis before initiating combined therapy, at three and, six months post-treatment. ANOVA or Kruskal-Wallis tests were employed to compare anthropometric, biochemical, and hormonal variables over time. Results: We recruited 45 patients with primary hypothyroidism and residual symptoms (44 women and 1 man). The causes of primary hypothyroidism were autoimmunity (45.5%), thyroidectomy (25.0%), idiopathic hypothyroidism (20.5%), radioactive iodine therapy (6.7%), and thyroid dysgenesis (2.3%). All patients presented biochemical euthyroidism at the beginning of the study. Achilles reflex absence was observed in 40% of patients, 82.2% reported weight gain, and 95.6% experiencing fatigue, while 57.8% reported memory loss. Three months of combined therapy reduced Achilles reflex absence (14.3%), weight gain (37.1%), fatigue (51.4%) and memory loss (40.0%). At six months post-treament weight gain (22.2%) and fatigue (33.3%) remained reduced. Also, insomnia improved with combined therapy, from 60.0% prior to therapy to 31.4% at three months and 41.2% at six months post-treatment. After 24 weeks of combined therapy, ThyPRO scores indicated improvements in hyperthyroidism, eye symptoms, anxiety, depression, emotional susceptibility, impaired social and daily life, and cosmetic complaints (p < 0.05). Notably, 65% of patients reported symptom improvement without any reported side effects. There were no significant differences in biochemical parameters or bone mineral density at six months compared to baseline. Conclusions: This study, the first of its kind in the Mexican population, demonstrates that combined therapy significantly improves the QoL of patients with primary hypothyroidism and residual symptoms without adverse biochemical effects. Thus, combined therapy may be considered an alternative for patients with residual symptoms, although larger studies are warranted. Presentation: 6/3/2024