Severity of Fatigue and Its Relationship with TSH before and after Levothyroxine Replacement Therapy in Patients with Primary Hypothyroidism
María Guadalupe Ruíz-Pacheco,
Irma Hernández,
Guadalupe Hernández-Estrella,
Lourdes Basurto,
Guadalupe Vargas-Ortega,
Baldomero González-Virla,
Mario Molina-Ayala,
Alex Francisco Hernández-Martínez,
Rosamaría Luengas-Mondragón,
Angel Alejandro Hernández-Allende,
Victoria Mendoza-Zubieta,
Lourdes Balcázar-Hernández
Affiliations
María Guadalupe Ruíz-Pacheco
Centro Médico Nacional Siglo XXI, Department of Endocrinology, Hospital de Especialidades, Instituto Mexicano del Seguro Social, Mexico City 06720, Mexico
Irma Hernández
Centro Médico Nacional Siglo XXI, Department of Endocrinology, Hospital de Especialidades, Instituto Mexicano del Seguro Social, Mexico City 06720, Mexico
Guadalupe Hernández-Estrella
Unidad de Medicina Familiar No. 69, Department of Family Medicine, Instituto Mexicano del Seguro Social, Calle José María Morelos 210-232, Centro, Texcoco 56100, Mexico
Lourdes Basurto
Endocrine Diseases Research Unit, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Mexico City 06720, Mexico
Guadalupe Vargas-Ortega
Centro Médico Nacional Siglo XXI, Department of Endocrinology, Hospital de Especialidades, Instituto Mexicano del Seguro Social, Mexico City 06720, Mexico
Baldomero González-Virla
Centro Médico Nacional Siglo XXI, Department of Endocrinology, Hospital de Especialidades, Instituto Mexicano del Seguro Social, Mexico City 06720, Mexico
Mario Molina-Ayala
Centro Médico Nacional Siglo XXI, Department of Endocrinology, Hospital de Especialidades, Instituto Mexicano del Seguro Social, Mexico City 06720, Mexico
Alex Francisco Hernández-Martínez
Centro Médico Nacional Siglo XXI, Department of Endocrinology, Hospital de Especialidades, Instituto Mexicano del Seguro Social, Mexico City 06720, Mexico
Rosamaría Luengas-Mondragón
Faculty of Medicine, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
Angel Alejandro Hernández-Allende
Faculty of Medicine, Universidad Nacional Autónoma de México, Mexico City 04510, Mexico
Victoria Mendoza-Zubieta
Centro Médico Nacional Siglo XXI, Department of Endocrinology, Hospital de Especialidades, Instituto Mexicano del Seguro Social, Mexico City 06720, Mexico
Lourdes Balcázar-Hernández
Centro Médico Nacional Siglo XXI, Department of Endocrinology, Hospital de Especialidades, Instituto Mexicano del Seguro Social, Mexico City 06720, Mexico
Background: Fatigue is a common symptom in hypothyroidism; however, the effect of levothyroxine on fatigue has been little studied. The aim of this study was to evaluate the effect of levothyroxine on fatigue in Latino patients with primary hypothyroidism, as well as the association of TSH and free T4 (FT4) with the severity and persistence of fatigue. Methods: A prospective study was performed in 92 patients with primary hypothyroidism. Fatigue severity scale (FSS) scores and clinical and biochemical characteristics before and at 6 months of levothyroxine were evaluated. Results: After 6 months of levothyroxine, a reduction in FSS (53 (47–57) vs. 36 (16–38); p = 0.001) and fatigue frequency (45.7% vs. 26.1%; p = 0.008) was evident. Both before and after 6 months of levothyroxine, there was a positive correlation of the FSS score with TSH and a negative correlation with FT4. Persistent fatigue was associated with a pretreatment FSS score (r = 0.75; p = 0.001) and diabetes (r = 0.40; p = 0.001). An FSS > 34 (RR 3.9 (95% CI 1.43–10.73; p = 0.008)), an FSS > 36 (RR 3.23 (95% CI 1.21–8.6; p = 0.019)), and diabetes (RR 5.7 (95% CI 1.25–9.6; p = 0.024)) before treatment were risk factors for persistent fatigue. Conclusions: Levothyroxine improved fatigue in most patients. Diabetes and an FSS score >34 or >36 before treatment were risk factors for persistent fatigue.
