OSA Common in Veterans With Chronic Pain Syndrome

Abstract

SESSION TITLE: Sleep Disorders 2 SESSION TYPE: Original Investigation Poster PRESENTED ON: Wednesday, October 26, 2016 at 01:30 PM - 02:30 PM PURPOSE: Obstructive Sleep Apnea (OSA) and Chronic Pain Syndrome (CPS) are both very common conditions and may occur frequently by chance alone. We studied the interaction between these disorders. METHODS: Veterans with CPS admitted to a referral pain rehabilitation center underwent polysomnography on presentation. Three groups of patients were compared: patients with CPS taking either opiates (O group), tramadol (T group) or none of these agents (C group). Demographics, Epworth Sleepiness Score (ESS) and sleep parameters were recorded and compared among these groups for statistical significance. RESULTS: Twenty-nine patients were studied and 90% of them had OSA with AHI >5; 48% were sleepy (ESS > 10) and 45% had OSA syndrome. Forty five percent of all patients were obese (BMI>30). Severe OSA was more common in the C group (7/14) than in the O group (3/12). The three patients in the T group had moderate or severe OSA. Obese patients in the O group had a lower AHI (11.4+/- 6.7) than obese patients in the C group (28.5 +/- 13.7), p 0.04. REM latency was longer in the T group (215 +/- 76 mins) than in the O group (105 +/- 74 mins; p 0.04). There was a trend towards a shorter REM latency in alert patients (ESS <11) in the C group (47 +/- 28 mins) compared to alert patients in the O group (99 +/- 51 mins), p 0.07. Sleepy patients in the C group tended to have a higher REM latency (170 +/- 128 mins) than alert patients (47+/- 28 mins), p 0.06. Obese sleepy patients in the C group had a shorter REM latency (59.3 +/- 9.5 min) than non-obese sleepy patients (192+/- 98 min), p 0.03. Obese sleepy patients in the C group tended to have less N3 sleep (15.4+/- 5.6%) than non-obese sleepy patients (24.4 +/-6.5%), p 0.06. Obese sleepy patients in the O group had a lower arousal index (9.7 +/- 0.8 events/hr) than non-obese sleepy patients (21.9+/- 2.3), p 0.001. Only one patient from all groups, who was taking opiates, had clinically significant central sleep apnea (central apnea index > obstructive apnea index > 5 events/hr). CONCLUSIONS: OSA is very common in veterans with CPS. Weight may modify the severity of OSA in this condition in an inverse fashion. Patients with CPS not treated with opiates may have a shorter REM latency, particularly if they are obese and alert. Somnolent patients with CPS may lose N3 sleep if they gain weight. However, if obese patients with CPS take opiates, they may have a lower arousal index than their non-obese counterparts. CLINICAL IMPLICATIONS: Veterans with CPS should be screened for OSA. The sleep architecture of patients with CPS and the natural history of OSA and CPS should be explored further. DISCLOSURE: The following authors have nothing to disclose: Karel Calero, Steven Sanders, Zachary Stachura, William Anderson No Product/Research Disclosure Information