Factors associated with sleep apnea in men with spinal cord injury: a population-based case-control study

Abstract

Objective: To characterize a population of spinal cord injury (SCI) patients with sleep apnea, and to determine associated factors and comorbidities Study Design: Population-based retrospective case-control study. Subjects: 584 male patients served by a Veterans Aairs SCI service. Measures: Medical records were reviewed for sleep apnea diagnosis, demographic information, neurologic characteristics, and treatments received. Sleep study reports were not available to determine the nature of abnormal respiratory events (ie central, obstructive, hypoventilation). For each case with tetraplegia, a control tetraplegic subject without sleep apnea diagnosis was selected. Results: We identi®ed 53 subjects with diagnosed sleep apnea: 42 tetraplegic, 11 paraplegic. This represented 14.9% of all tetraplegic and 3.7% of all paraplegic patients in the population (P50.0001 for comparison of tetraplegic and paraplegic proportions). In tetraplegic subjects, sleep apnea was associated with obesity and more rostral motor level, but not with ASIA Impairment Scale. Medical comorbidities associated with sleep apnea in non-SCI patients, such as hypertension, were more common in case subjects. Less than half of case subjects were receiving some form of treatment. For motor-complete tetraplegics, long-term positive airway pressure treatment was less common with motor level C5 and above compared to C6 and below. Conclusion: In this population, sleep apnea has been frequently diagnosed, particularly in tetraplegic subjects. The true prevalence is likely to be considerably higher, since this study considered only previously diagnosed cases. Sleep apnea was associated with obesity and higher neurologic level, but not ASIA Impairment Scale. Medical comorbidities were more frequent in this group, and treatment acceptance was poor with higher level motor-complete injuries. Since the type of sleep apnea (central or obstructive) was not distinguished, we cannot comment on the prevalence and associations based on speci®c types of sleep apnea. Spinal Cord (2001) 39, 15 ± 22

Quality of sleep in individuals with spinal cord injury: a comparison between patients with and without pain

“…In patients with tetraplegia, apnoeas -especially the obstructive kind -have been found to be a significant problem (prevalence between 15 and 48%), interfering negatively with the quality of sleep. [26][27][28] Unfortunately, apnoeas cannot be verified by subjective reports. Apnoeas can be associated with, among other things, obesity (a high body-mass index) and the use of antispastic medication.…”

Clinical Assessment and Management of Obesity in Individuals With Spinal Cord Injury: A Review

“…Case study reports suggest that compared with other individuals with similar levels of injury, obese individuals with SCI have more difficulties with transfers, have poorer functional outcomes, and require special equipment and additional staff time for transfers and personal care (33). Obesity in SCI has also been implicated in carpel tunnel syndrome, pulmonary embolism, and obstructive sleep apnea (34)(35)(36)(37)(38)(39). In people with SCI, obesity is commonly cited as one of the major risk factors for the higher prevalence of CVD in this population (40).…”

“…For example, the link between obesity and CVD risk factors and sleep apnea has been variable (48)(49)(50)(51). Akin to the general population, obesity may be a leading risk factor for sleep apnea in individuals with paraplegia, but it may not be strongest or the most common risk factor in individuals with tetraplegia (38). Because obesity predisposes individuals to sleep apnea by excessive fat deposition in the upper pharyngeal area, Burns and colleagues suggest that total body fat may be a better marker of sleep apnea in individuals with SCI (38).…”

“…Akin to the general population, obesity may be a leading risk factor for sleep apnea in individuals with paraplegia, but it may not be strongest or the most common risk factor in individuals with tetraplegia (38). Because obesity predisposes individuals to sleep apnea by excessive fat deposition in the upper pharyngeal area, Burns and colleagues suggest that total body fat may be a better marker of sleep apnea in individuals with SCI (38). In the case of CVD risk factors and obesity, Buchholz and colleagues in a comprehensive review on this topic suggest that measurement error and insensitivity of body weight and BMI to measure actual fat mass and fat distribution in people with SCI may account for inconsistencies in this relationship (49).…”

Baclofen Pump Intervention for Spasticity Affecting Pulmonary Function

“…Sleep apnea is often present after SCI, but the exact prevalence is not known. Burns et al reports sleep apnea in up to 40% of individuals with SCI (21,22). Flavell et al (23) diagnosed severe nocturnal hypoxic episodes in 3 of 10 individuals with tetraplegia, and Cahan et al (24) reported on 6 of 16 patients with tetraplegia who had normal oxygen saturations during the day and demonstrated desaturation at night.…”