Blood Pressure Variability in Daily Life: Comparing Individuals with Cervical and Upper-Thoracic Spinal Cord Injury to Non-Injured Controls

BackgroundSpinal cord injury (SCI) above the sixth thoracic spinal cord segment can disrupt autonomic cardiovascular control, leading to increased BP variability (BPV). This study compared BPV, nocturnal dipping patterns, and blood pressure (BP) fluctuations among individuals with cervical SCI (C-SCI), upper-thoracic SCI (UT-SCI), and non-injured controls (NI-C). MethodsUsing 24-hour ambulatory blood pressure monitoring, we analyzed BPV (via standard deviation [SD], coefficient of variation [CoV], average real variability [ARV], and variability independent of the mean [VIM]), nocturnal dipping, and systolic/diastolic BP fluctuations. Nocturnal dipping percentages were calculated and patterns classified. Hypotensive (SBP <100mmHg, DBP <70mmHg) and hypertensive (SBP >150mmHg per clinical guideline thresholds) events were identified. BP distribution was analyzed using skewness and kurtosis. ResultsEighty participants (44 C-SCI, 19 UT-SCI, 17 NI-C) had 66 {+/-} 18 measurements taken and are included in the analysis. The C-SCI group exhibited significantly higher systolic BPV metrics across SD, CoV, ARV, and VIM compared to the UT-SCI and NI-C groups (P < 0.01). C-SCI nocturnal BP dips were reduced, and reverse dipping patterns were more prevalent (P < 0.001). Hypotensive events occurred more frequently in C-SCI and UT-SCI compared to NI-C (both P < 0.001). SCI groups, particularly those with C-SCI, showed significantly more right-skewed SBP distributions and a higher proportion of non-Gaussian BP profiles, suggesting increased BP lability. ConclusionIndividuals with C-SCI showed significantly increased BPV and impaired nocturnal dipping, while both C-SCI and UT-SCI demonstrated heightened susceptibility to hypotensive events. These findings highlight the need for targeted cardiovascular monitoring and interventions in individuals with C-SCI and UT-SCI to mitigate the known risks associated with BP dysregulation.