No abstract

OSA severity was independently associated with cholesterol and TG concentrations.

In recent AASM practice, parameter actimetry is cited to measure total sleep time in obstructive sleep apnoea patients, when polysomnography is not available. An actigraph was therefore compared to polysomnographic data in 28 subjects with known sleep disordered breathing. Total sleep time (TST), sleep period time (SPT), sleep efficiency (SE), sustained sleep efficiency (SSE), sleep onset latency (SL) and sleep/wake pattern were compared to gold standard polysomnography. The results of an epoch-by-epoch comparison of sleep/wake from actigraphy to sleep stages from polysomnography gave a sensitivity of 90.2%, a specificity of 95.2% and an overall accuracy of 85.9%. Correlations were moderately strong for SE (0.71, p < 0.001) and SSE (0.65, p < 0.001) and high for TST (0.89, p < 0.001), SPT (0.91, p < 0.001) and SL (0.89, p < 0.001). It was concluded that actigraphy is not identical with PSG recording but gives good results in sleep/wake patterns and predicting TST, SPT, SSE, SE and SL also in sleep apnoea patients not suffering from other sleep disorders. The difficult detection of correct sleep onset causes SSE and SL to be less predictable. Therefore a 15-epoch criterion was introduced and resulted in high correlation of 0.89 for sleep latency, but has to be tested on a bigger population.

An actigraph extended with electroencephalography (EEG), electroocculography (EOG) and electromyography (EMG) was compared to polysomnography in two studies on patients suffering from sleep disordered breathing. Study A with 30 subjects used a single lead EEG, and study B with 20 subjects used EOG and EMG in addition. Sleep was scored according to Rechtschaffen and Kales rules. Total sleep time (TST), sleep period time (SPT), sleep efficiency (SE), sustained sleep efficiency (SSE), sleep-onset latency (SL), and sleep stages were compared. For study A an epoch-by-epoch comparison of sleep stages revealed an overall agreement of 74.2%. Correlations were high for SE (0.98, p < 0.001), SSE (0.98, p < 0.001), TST (0.99, p < 0.001), SPT (0.99, p < 0.001), and SL (0.98, p < 0.001). Regarding the sleep stages, correlations were high for rapid eye movement (REM) (0.83, p < 0.001), light-sleep (0.78, p < 0.001), and deep sleep (0.73, p < 0.001). For study B, results of an epoch-by-epoch comparison of sleep stages showed an overall agreement of 75.5%. Correlations were high for SE (0.98, p < 0.001), SSE (0.98, p < 0.001), TST (0.87, p < 0.001), SL (0.98, p < 0.001), SPT (0.94, p < 0.001), and for rapid eye movement (REM) (0.91, p < 0.001), light-sleep (0.74, p < 0.001), and deep sleep (0.89, p < 0.001). In summary the study revealed high agreement between polysomnography and single lead EEG in sleep apnea patients. Deviations for REM were slightly higher for the single lead EEG compared to single lead EEG plus EOG/EMG. Both simplified systems proved to be reliable for comfortable out-patient sleep recording.