SLEEP AND NEUROMUSCULAR DISEASE - FREQUENCY OF SLEEP-DISORDERED BREATHING IN A NEUROMUSCULAR DISEASE CLINIC POPULATION

We investigated 60 adult and pediatric patients (33 male, 27 female) w ith various neuromuscular disorders for sleep-disordered breathing in a clinic population at a local altitude of 1,500 m. Measurements inclu ded a questionnaire concerning symptoms of sleep and daytime function, a disability index, and pulmonary function tests. We used an EdenTrac e monitor for 1 night to evaluate breathing during sleep and calculate d mean and minimum oxygen saturation (SpO(2)), total apneas, hypopneas , and respiratory disturbance index (RDI). We had validated the EdenTr ace II monitor prior to the study. The majority of the patients had sy mptoms of daytime dysfunction. The frequency of sleep-disordered breat hing in this population was much higher (42% with RDI > 15) than frequ encies indicated in recent population-based surveys. Spirometry reveal ed no positional effect in this population. Statistical analysis compa ring RDI with disability index, pulmonary function tests, age, sex, bo dy mass index, and Epworth Sleepiness Scales identified no strong corr elates that could be used as predictors of sleep-disordered breathing in this population. Sleep studies using ambulatory equipment such as t he EdenTrace II are an easy and effective means of identifying sleep-d isordered breathing in patients with neuromuscular disorders and, give n the high frequency of sleep-disordered breathing in our sample, shou ld be performed on most patients with neuromuscular disorders if sleep -disordered breathing is to be identified early.