[Primary hypothyroidism with obstructive sleep apnea syndrome].

The relationship between severity of hypothyroidism and OSA syndrome before and after treatment was analyzed and discussed. All patients had typical clinical features of primary hypothyroidism and were diagnosed by thyroid hormonal investigations. They were treated with conventional desiccated thyroid. Polysomnography and blood oxygen saturation % (SaO2%) were performed during sleep before and after substitutive treatment. In this series of 21 patients taking respiratory functional tests, 11 were consistent with OSA (42.4%). The serum values of TT4, FT4I, TT3 and TSH after treatment were markedly different from the initial values in 9 cases who were followed up after treatment (P < 0.001, respectively). The respiratory parameters including maximum apnea time, mean apnea time, respiratory disturbances index and the lowest oxygen saturation % were also markedly different in patients before and after treatment (P < 0.001-0.02, respectively). The serum levels of TT4 and FT4I were significantly correlated with the values of maximum and mean apnea time and the highest oxygen saturation % after substitution (r = 0.64-0.98, P < 0.01-0.05, respectively). We conclude that OSA in hypothyroidism showed the most satisfactory response to non-surgical treatment, and OSA syndrome could be cured as soon as hypothyroidism was controlled by desiccated thyroid.