Objective To examine the relationship between visit-to-visit systolic blood pressure (SBP) variability and patient-reported outcome measure of disability in multiple sclerosis (MS) patients.
Design A retrospective cohort study of individuals with MS who completed a patient-determined disease steps (PDDS) scale between 2011 and 2015 at an MS specialty clinic.
Participants Individuals with MS for whom both a completed PDDS scale and ≥3 SBP measures within the prior 12 months of the survey were available.
Main outcome measure Participants were grouped into three classes of disability (no or mild (PDDS 0–1), moderate (2–3), severe (4–7)). SBP variability was calculated as within-subject SD using all SBP measures taken during the past 12 months. SBP variability was analysed by Tertile groups.
Results Ninety-two subjects were included in this analysis. Mean PDDS score was 2.22±1.89. Compared with subjects in Tertile 1 (lowest variability), the odds of being in a higher disability group was 3.5 times higher (OR=3.48; 95% CI: 1.08 to 11.25; p=0.037) in Tertile 2 and 5.2 times higher (OR=5.19; 95% CI: 1.53 to 17.61; p=0.008) in Tertile 3 (highest variability), independent of mean SBP, age, sex, race/ethnicity, body mass index and comorbidities (p for trend=0.008). Mean PDDS scores were 1.52±1.18 in Tertile 1, 2.73±1.02 in Tertile 2 and 2.42±0.89 in Tertile 3 after adjusting for the same covariates.
Conclusions Our results show a significant gradient relationship between SBP variability and MS-related disability. More research is needed to determine the underlying pathophysiological relationship between SBP variability and MS disability progression.
- multiple sclerosis
- disability progression
- blood pressure variability
- cardiovascular comorbidities
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Contributors MDG: study concept and design, acquisition of data, analysis and interpretation of data and drafting/revising the manuscript. SM: acquisition of data, drafting/revising the manuscript. JML: diagram creation, drafting/revising the manuscript. M-WS: study concept and design, analysis and interpretation of data, statistical analysis and drafting/revising the manuscript.
Funding This work was supported by philanthropic funds provided by the ziMS Foundation.
Competing interests MDG has served as a consultant for ADAMAS, Celgene, EMD Serono, Novartis Pharmaceuticals, Sanofi Genzyme, Teva Pharmaceuticals. She has received research funding from Biogen Idec, Novartis Pharmaceuticals, National MS Society, MedDay Pharmaceuticals and PCORI.
Patient consent for publication Not required.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement Data are available upon reasonable request. Anonymized data not published within this article are available from the corresponding author (MDG) on reasonable request.
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