Claire Trotter: Reduced resting beat-to-beat blood pressure variability in multiple sclerosis

Multiple Sclerosis (MS) is an autoimmune disease associated with increased cardiovascular risk. Greater resting beat-to-beat blood pressure variability (BPV) is a known predictor of cardiovascular risk. Therefore, we hypothesized that resting beat-to-beat BPV is increased in individuals with MS compared to matched healthy controls. In 7 patients with relapsing-remitting MS (2 males) and 7 sex-, age-, and weight-matched healthy controls, beat-to-beat blood pressure (Finometer) was recorded during 10 minutes of quiet supine rest. Individuals with MS had similar resting mean blood pressure (BP) compared to healthy controls (P= 0.736), however the BP standard deviation (SD) and coefficient of variation (CV) was less in MS (BP SD; MS: 3.2 +/- 0.2 vs. CON: 4.0 +/- 0.2, P=0.022 and BP CV; MS: 3.8 +/- 0.3 vs. CON: 4.7 +/- 0.2, P=0.025 ). Similarly, mean resting systolic blood pressure (SBP) was not different between MS and healthy controls (P=0.207) but the SBP SD and CV was less in MS (SBP SD; MS: 4.7 +/- 0.4 vs. CON: 6.6 +/- 0.5, P=0.013 and SBP CV; MS: 4.3 +/- 0.4 vs. CON: 5.8 +/- 0.4, P=0.033). In contrast, there was no difference in the DBP SD or CV between the two groups (P= 0.321 and P=0.295; respectively). Contrary to our hypothesis, individuals with MS exhibited reduced resting beat-to-beat BPV compared to healthy controls which may be related to altered autonomic function.