ASSOCIATION OF HYPOTHYROIDISM AND OBSTRUCTIVE SLEEP-APNEA

Obstructive sleep apnea (OSA) and hypothyroidism are relatively common disorders that have similar clinical features and are thought to be c ausally linked. We sought to determine the prevalence of previously un recognized hypothyroidism in a series of patients evaluated for OSA an d whether an association between hypothyroidism and OSA was present. C hart review was used to obtain information on thyroid function status, polysomnography results, levothyroxine use, and clinical signs and sy mptoms in 336 consecutive adult patients who underwent polysomnography for suspected OSA. In addition, levothyroxine use was determined in a ge- and sex-matched control subjects for the purposes of a case-contro l study. Among the patients without prior history of hypothyroidism wh o underwent polysomnography and thyroid function testing, four new cas es or 1.41% (95% CI 0.04-2.78) were found to have subclinical hypothyr oidism. Our findings do not support routine thyroid screening by speci alists in patients referred for polysomnography. The odds ratio of the association of prior history of hypothyroidism to OSA was 1.47 (95% C I 0.8-2.8). Limitations in study design may have limited our ability t o detect a statistically significant association between OSA and hypot hyroidism.