Towards an understanding of disturbed sleep phenotypes after traumatic spinal cord injury.

OBJECTIVE

Examine the Spinal Cord Injury-Pressure Injury Resource (SCI-PIR) database to assess the prevalence and identify relationships among sleep disorders and cardiometabolic risk after spinal cord injury.

DESIGN

Retrospective observational cohort study using the Department of Veterans Affair SCI-PIR database.

SUBJECTS/PATIENTS: 18,894 Veterans living with spinal cord injury.

METHODS

The SCI-PIR database was queried for ICD9 codes related to cardiovascular, metabolic, psychological, and sleep conditions to identify subgroups of spinal cord injury individuals with sleep disorders and associated clustering of cardiometabolic risk factors and sleep diagnoses. Multiple correspondence analysis probed the underlying associations. Cramer V statistics confirmed and quantified the associations.

RESULTS

Sleep apnoea (6.7%) and insomnia (4.3%) were the most common sleep diagnoses. Multiple correspondence analysis demonstrated 2 phenotypic clusters: Cluster A showed robust links between sleep apnoea, hypersomnia, heart failure, and arrhythmias, and secondary associations with coronary artery disease, chronic kidney disease, obesity, diabetes, and hyperlipidaemia. Cluster B showed strong relationships between insomnia, anxiety, and post-traumatic stress disorder.

CONCLUSION

2 distinct sleep clusters were identified for persons with spinal cord injury. This analysis supports previous findings that sleep disorders associate with overall health in individuals with spinal cord injury, and particularly cardiovascular health. ICD9 coding may under-report sleep diagnoses. Data-driven statistical analysis can uncover insights into the complex interplay between spinal cord injury and secondary health conditions.