Gastrointestinal motility and sleep patterns assessed by ambulatory tracking of telemetric capsules combined with polysomnography

Introduction Due to the inaccessibility of the gastrointestinal (GI) tract and lack of proper measurement techniques clinical studies describing gastrointestinal function during sleep are sparse. In the present pilot study we aimed at introducing a novel ambulatory telemetric capsule system (3D-Transit) in conjunction with polysomnography (PSG). Materials and methods 3D-Transit (Motilis Medica SA) consists of ingestible electronic capsules, an extracorporeal portable detector containing 4 magnetic field sensors, and visualization software. The electromagnetic field emitted by each capsule is converted into space–time coordinates defining the distance and angular orientation of each capsule in relation to the detector. Changes in position and orientation of the capsules reflect GI contractile activity and progression. Nine healthy subjects (5 females, age 24–52) ingested a capsule in the morning at 08:00 a.m and another in the evening at 06:30 p.m. Polysomnography was carried out as an unattended portable sleep study with the electrodes placed just before bedtime. Standard placement of electrodes was used (EEG scalp sites: F3/F4, C3/C4, O1/O2, References M1/M2, EOG: E1/E2, EMG: Chin, ECG). The hypnograms were scored using 30- seconds epochs and were synchronized with 3D-Transit recordings. During sleep the first capsule was located in the colon and the second was initially in the stomach but moved to the small intestine (SI) within approximately 4h (range 2–5.5h). Propagating movements (PM) were defined as ⩾ 3cm anterograde displacement of the capsule with a velocity of either ⩾ 15cm/min (fast movements) or ⩾ 1.5cm/min (slow movement). Basic colonic activity was defined as the mean standard deviation of the position of capsules during displacement of 3cm. Results Median sleep time was 6.6h (range 5.1–7.5h) with a median arousal index of 7.6 per hour sleep (range 4.9–16.9) and a median WASO of 26min (range 7–84). From a total of 140 PM observed (85% in the SI and 15% in the colon), 12 (9%) occurred within 30 s after an arousal, 10 (7%) during wake periods and (84%) during stable sleep. There was no association between the sleep stages and the occurrence of PM (REM median 0.5 PM/h (range 0 – 6.9), N1 0 PM/h (0–2.7), N2 1.2PM/h (0.3–5.7) and N3 2.2 PM/h (0–7.0). The speed of progression through the SI did not change with depth of sleep or between REM and NREM sleep. Basic colonic activity was significantly lower during N3 ( p =0.02) than during N2 and also lower during NREM sleep than during REM sleep ( p =0.02). There was no difference between basic colonic activity during REM sleep and wake periods ( p =0.87). Conclusion The novel ambulatory capsule technique (3D-Transit) in combination with PSG allows easy, minor invasive and completely ambulatory investigation of associations between sleep patterns and gastrointestinal motility. This pilot study supports previous findings of deep sleep having an inhibitory effect on colonic activity.