RESUMEN
INTRODUCTION: Euthyroid patients show decreased TSH level following sleeve gastrectomy. However, studies of levothyroxine absorption after bariatric surgery reported contradictory results and data on levothyroxine dose adjustment according to weight are sparse. The aim of this study was to evaluate levothyroxine dose adjustment during weight loss following sleeve surgery. METHOD: This retrospective study assessed change in levothyroxine dose in patients undergoing sleeve gastrectomy at the university hospital center of Nîmes (France) between January 2010 and March 2016. Patients were receiving standard bariatric surgery follow-up with levothyroxine therapy for hypothyroidism. RESULTS: Fifty-two of the 271 patients who underwent sleeve gastrectomy (19.2%) were being treated with levothyroxine. Among these patients, 31 were followed up for 12 months, including 12 who were followed up for 24 months. Mean weight loss was 35±11kg at 12 months and 41.8±10.2 kg at 24 months. Daily levothyroxine dose decreased from 108 [88-144] µg/day to 94 [63-125] µg/day at 12 months and 69 [44-134] µg/day at 24 months, with positive correlation between dose and weight loss at 12 months (P=0.03). Weight-adjusted dose was 1.04 [0.81-1.24] µg/kg/day at baseline, 1.14 [0.85-1.66] µg/kg/day at 12 months, and 0.85 [0.53-2.10] µg/kg/day at 24 months, showing no correlation with weight loss. Median TSH level dropped to 1.30 [0.63-2.27] mIU/l at 12 months and 1.48 [1.08-2.42] mIU/l at 24 months. CONCLUSION: Despite a decrease in daily levothyroxine dose correlating with weight loss at 12 months, the absence of correlation with weight-adjusted dose suggests the involvement of confounding factors such as poor levothyroxine absorption or altered thyroid function. Further studies are required to elucidate the absorption of levothyroxine.
Asunto(s)
Gastrectomía/efectos adversos , Hipotiroidismo/tratamiento farmacológico , Síndromes de Malabsorción , Obesidad Mórbida/cirugía , Tiroxina/administración & dosificación , Pérdida de Peso/fisiología , Adulto , Cirugía Bariátrica/efectos adversos , Relación Dosis-Respuesta a Droga , Cálculo de Dosificación de Drogas , Femenino , Francia , Humanos , Hipotiroidismo/sangre , Hipotiroidismo/complicaciones , Hipotiroidismo/cirugía , Síndromes de Malabsorción/sangre , Síndromes de Malabsorción/tratamiento farmacológico , Síndromes de Malabsorción/etiología , Masculino , Persona de Mediana Edad , Obesidad Mórbida/sangre , Obesidad Mórbida/complicaciones , Obesidad Mórbida/tratamiento farmacológico , Complicaciones Posoperatorias/sangre , Complicaciones Posoperatorias/tratamiento farmacológico , Periodo Posoperatorio , Estudios Retrospectivos , Hormonas Tiroideas/sangre , Tirotropina/sangreRESUMEN
OBJECTIVE: L-Thyroxine-suppressive therapy benefits high-risk differentiated thyroid cancer patients by decreasing recurrence rates and cancer-related mortality. However, fully suppressed serum thyroid-stimulating hormone (TSH) implies a state of subclinical hyperthyroidism (SCH) with associated adverse cardiac effects. Because left ventricular (LV) diastolic dysfunction may be the first manifestation of more severe LV failure, and to balance the risks from thyroid cancer recurrence with risks of cardiac failure, the purpose of this study was to analyse new parameters of LV function in asymptomatic patients with exogenous SCH. DESIGN: Case-control study with 24 patients on TSH-suppressive therapy of short duration (≤ 4 years) after thyroid ablative therapy for differentiated thyroid carcinoma and 20 age- and sex-matched subjects. MEASUREMENTS: LV function [LV global strain and strain rate (SR) curves] was assessed by speckle tracking imaging echocardiography in each subject. RESULTS: Patients and controls do not differ in body mass index, systolic blood pressure and heart rate. No significant differences were observed in LV morphology (LV mass and relative wall thickness), cardiac output and parameters of LV systolic function between patients on suppressive therapy and controls. When compared with controls, patients with exogenous SCH had a significantly impaired longitudinal protodiastolic strain, SR and strain diastolic index but preserved radial strain and SR function. CONCLUSIONS: In subjects with SCH at the early phase of TSH-suppressive therapy, evidence of isolated longitudinal LV diastolic dysfunction was observed, despite a normal LV morphology. Further prospective studies to clarify the prognosis of picking-up early diastolic dysfunction in asymptomatic patients are needed before serial measurements could be recommended.