Heart rate and blood pressure response improve the prediction of orthostatic cardiovascular dysregulation in persons with chronic spinal cord injury.

Unstable blood pressure after spinal cord injury (SCI) is not routinely examined but rather predicted by level and completeness of injury (i.e., American Spinal Injury Association Impairment Scale AIS classification). Our aim was to investigate hemodynamic response to a sit-up test in a large cohort of individuals with chronic SCI to better understand cardiovascular function in this population. Continuous blood pressure and ECG were recorded from individuals with SCI (n = 159) and non-injured individuals (n = 48). We found orthostatic hypotension occurred within each level and AIS classification (n = 36). Moreover, 45 individuals with chronic SCI experienced a drop in blood pressure that did not meet the criteria for orthostatic hypotension, but was accompanied by dramatic increases in heart rate, reflecting orthostatic intolerance. A cluster analysis of hemodynamic response to a seated position identified eight distinct patterns of interaction between blood pressure and heart rate during orthostatic stress indicating varied autonomic responses. Algorithmic cluster analysis of heart rate and blood pressure is more sensitive to diagnosing orthostatic cardiovascular dysregulation. This indicates blood pressure instability cannot be predicted by level and completeness of SCI, and the consensus statement definition of orthostatic hypotension is insufficient to characterize the variability of blood pressure and heart rate responses during orthostatic stress. Both blood pressure and heart rate responses are needed to characterize autonomic function after SCI.

Fenofibrate therapy to lower serum triglyceride concentrations in persons with spinal cord injury: A preliminary analysis of its safety profile.

Context: Fenofibrate is used to treat elevated serum triglyceride (TG) concentrations (e.g. ≥150 mg/dl). The lipoprotein profile of most individuals with spinal cord injury (SCI) would not satisfy conventional criteria to initiate lipid-lowering therapies. Serum TG concentrations of 115 and 137 mg/dl were recently identified as potential intervention thresholds for persons with a SCI proximal to the 4th and below the 5th thoracic vertebrae, respectively. Fenofibrate therapy has not been tested for safety in persons with SCI. Methods: An open-label trial was performed in 15 persons with SCI to determine the safety profile of 4 months of once-daily fenofibrate (145 mg tablet) treatment when initiated using modified intervention thresholds. Fasting blood tests and a review of systems were performed monthly to determine changes in liver and kidney function, as well as overall health status. Results: Fifteen subjects participated and 4 had an adverse event (e.g. 2 with gastrointestinal distress; 2 with elevated liver enzymes). Three subjects discontinued the trial within the first month and one participant remained in the trial with no further adverse events. Two participants were discontinued from fenofibrate after 2 months after not responding to treatment, as per protocol, and 10 participants completed the 4-month trial without experiencing an adverse event. Conclusion: In persons with SCI, 4 months of fenofibrate therapy initiated at lower threshold serum TG concentrations did not result in an increased incidence of adverse events compared to that reported in the general population. Fenofibrate therapy appears to be well tolerated in persons with SCI.

Relationships between T-scores at the hip and bone mineral density at the distal femur and proximal tibia in persons with spinal cord injury.

Objective: To identify T-score values at the total hip (TH) and femoral neck (FN) that correspond to the cutoff value of <0.60 g/cm2 for heightened risk of fracture at the distal femur (DF) and proximal tibia (PT).Design: Retrospective analysis of data in a research center's database. Setting: Community-based individuals with spinal cord injury (SCI). Participants: 105 unique individuals with SCI. Outcome Measurements: DXA derived areal BMD (aBMD) and T-score of the DF, PT, TH, and FN. Results: The aBMD at the DF and PT regions were predictors of T-scores at the TH (R2 = 0.63, P < 0.001 and R2 = 0.65, P < 0.001) and FN (R2 = 0.55, P < 0.001 and R2 = 0.58, P < 0.001). Using the DF and PT aBMD of 0.60 g/cm2 as a value below which fractures were more likely to occur, the predicted T-score was -3.1 and -3.5 at the TH and -2.6 and -2.9 at the FN, respectively. However, when the predicted and observed T-score values disagree outside the 95% limit of agreement, the predicted T-score values are lower than the measured T-score values, overestimating the measured values between -2.0 and -4.0 SD. Conclusion: The DF and PT cutoff value for aBMD of 0.60 g/cm2 was a moderate predictor of T-score values at the TH and FN, with considerable inaccuracies outside the clinically acceptable limits of agreement. As such, the direct measurement of knee aBMD in persons with SCI should be performed, whenever possible, prior to prescribing weight bearing upright activities, such as robotic exoskeletal-assisted walking.

A Four Month Randomized Controlled Trial on the Efficacy of Once-daily Fenofibrate Monotherapy in Persons with Spinal Cord Injury.

An open-label, randomized clinical trial of once-daily fenofibrate monotherapy administered for 2- (Mo2) and 4- (Mo4) months using modified intervention thresholds for triglyceride (TG) was performed in persons with chronic spinal cord injury (SCI). Fenofibrate (145 mg tablet) was self-administered daily in 10 persons with SCI for 4 months with monthly blood testing to quantify the lipoprotein profile (e.g., serum TG, LDL-C, and HDL-C concentrations). Eight SCI participants were control subjects. In comparison to the control group, the treatment group at Mo2 had a 40% (±12%; p < 0.05) reduction in serum TG concentration, a 28% (±21%; p < 0.05) increase in HDL-C and 14% (±20%; p < 0.05) decline in LDL-C. In the same comparison at Mo4, the treatment group maintained a 40% (±20%; p < 0.05) reduction in serum TG concentration, had an 18% in reduction in LDL-C (±12%; p < 0.05) and a 23% (±23%; p < 0.05) increase in HDL-C. Fenofibrate monotherapy for Mo2 and Mo4 initiated in persons with SCI resulted in a robust and favorable change in the serum lipoprotein profile and ratios, suggesting reduced risk for cardiovascular disease.