What Is the Prevalence of Symptomatic Obstructive Sleep Apnea Syndrome in Chronic Spinal Pain Patients? An Assessment of the Correlation of OSAS with Chronic Opioid Therapy, Obesity, and Smoking.

Background In modern medicine, obstructive sleep apnea syndrome (OSAS) is a commonly described sleep disorder with airway obstruction, disrupted sleep, and excessive daytime sleepiness. Since its description in 1976 by Guilleminault et al, numerous epidemiologic studies and systematic reviews, with multiple comorbidities related to cardiovascular sequelae, altered cognitive function, and multiple other potential complications have been described. Multiple risk factors have been identified included obesity, smoking, alcohol consumption, and other factors. Chronic pain and chronic opioid therapy also have been described to contribute to a large proportion of patients with OSAS. Chronic pain, obesity, smoking, and chronic opioid therapy are often found together, yet there is a paucity of literature describing OSAS in chronic pain patients. Objectives To assess the prevalence of symptomatic OSAS in chronic spinal pain patients receiving chronic opioid therapy and determine the association of OSAS with multiple risk factors and comorbidities. Study design A retrospective assessment of patients who attend a single interventional pain management practice from January 1, 2010to December 31, 2014. Setting A private interventional pain management practice in the United States. Methods The data were collected from 4,036 consecutive patients presenting for assessment to a pain management center from January 1, 2010 to December 31, 2014. All assessments were comprehensive and performed by 2 physicians. The comprehensive assessment included a complete history, a physical examination, and a review of records. Results The prevalence of OSAS in patients with chronic spinal pain was 13.8%. The results showed a higher prevalence in males compared to females (15.1% versus 12.8%), a higher prevalence in those aged 45 or older compared to those 25-45 years and those 18-25 years (16.3% versus 10.7% or 2.5%), higher prevalence in Hispanics and Asians compared to African Americans and whites (23.7% versus 16.2% versus 13.4%), higher prevalence in patients with combined back and neck pain compared to patients with thoracic pain only or back pain only (16.3% versus 8.2% to 11%). Prevalence also varied by body mass index (BMI): 32.4% in morbidly obese patients, 20.3% in severely obese patients, 15.7% in obese patients, 9.2% in those who were overweight, and only 5.7% in those with normal weight. A significant correlation with OSAS was also observed in patients smoking more than 40 pack years and multiple respiratory symptoms except for chronic bronchitis and multiple cardiovascular ailments. Limitations The retrospective nature of the assessment. Conclusion This retrospective assessment of over 4,000 patients suffering from chronic pain and receiving chronic opioid therapy indicated a prevalence of sleep apnea syndrome as 13.8%. Multiple risk factors including obesity, chronic obstructive pulmonary disease (COPD), chronic sinus and nasal discharge, and multiple comorbidities including cardiovascular and related ailments have been identified. Key words Obstructive sleep apnea syndrome, chronic pain, chronic spinal pain, chronic opioid therapy, obesity, smoking, cardiovascular risk factors, pulmonary risk factors.