Effects of subclinical hypothyroidism treatment on psychiatric symptoms, muscular complaints, and quality of life.

OBJECTIVES To evaluate the impact of subclinical hypothyroidism (sHT) treatment on health-related quality of life (QoL), psychiatric symptoms, clinical score, and muscle function. MATERIALS AND METHODS In this randomized double-blind study, patients were assigned either to treatment (n = 35) or placebo (n = 36). Clinical and psychiatric symptoms were assessed by the Zulewski, Hamilton and Beck scales. QoL was assessed by the SF-36 questionnaire. Assessments of quadriceps (QS) and inspiratory muscle (IS) strength were performed by a chair dynamometer and a manuvacuometer. RESULTS Treatment improved IS (+11.5 ± 17.2; p = 0.041), as did QoL domains "Pain" and "Role Physical" (+19.7 ± 15.2, 0.039 and +22.1 ± 47.5, p = 0.054; respectively). Clinical and psychiatric symptoms showed similar responses to both interventions. CONCLUSIONS sHT treatment improved IS and physical aspects of QoL, despite no impact in other muscle parameters. Clinical score, psychiatric symptoms, and SF-36 domains, based on mental dimensions of QoL may be more susceptible to "placebo effect" in patients with sHT.