Two cases of sleep apnea syndrome caused by primary hypothyroidism

Two cases of sleep apnea syndrome caused by primary hypothyroidism are reported. The first patient was a 66-year-old man who complained of sleep apnea; his apnea-hypopnea index (AHI) was 50.8, as assessed by all-night monitoring. Hypothyroidism was subsequently suspected when he showed delayed recovery from general anesthesia following surgery involving uvulopalatopharyngoplasty. Hypothyroidism was diagnosed on the basis of blood tests. His snoring and apnea improved after 2 months of levothyroxine sodium administration and the AHI fell from 50.8 to 13.0. The second patient was a 73-year-old man with an AHI of 41.3, as assessed by all-night monitoring. Hypothyroidism was diagnosed on the basis of blood tests and was suspected because of his slow speech. He was similarly treated with levothyroxine sodium. The AHI did not decrease after 4 months of treatment. His desaturation rate (rate of O-2 saturation < 90%) improved however, from 56.6% to 31.9%, and the symptoms of hypothyroidism also improved markedly. In both patients, elevated creatine phosphokinase, a dull facial expression, peripheral edema and slow speech were recognized, and these symptoms were suggestive of hypothyroidism. The type of sleep apnea was mainly obstructive in both patients.