title: Biological correlates of blood pressure variability in elderly at high risk of cardiovascular disease.
abstract: BACKGROUND
  Visit-to-visit variability in blood pressure is an independent predictor of cardiovascular disease. This study investigates biological correlates of intra-individual variability in blood pressure in older persons.
  
  
  METHODS
  Nested observational study within the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER) among 3,794 male and female participants (range 70-82 years) with a history of, or risk factors for cardiovascular disease. Individual visit-to-visit variability in systolic and diastolic blood pressure and pulse pressure (expressed as 1 SD in mm Hg) was assessed using nine measurements over 2 years. Correlates of higher visit-to-visit variability were examined at baseline, including markers of inflammation, endothelial function, renal function and glucose homeostasis.
  
  
  RESULTS
  Over the first 2 years, the mean intra-individual variability (1 SD) was 14.4mm Hg for systolic blood pressure, 7.7mm Hg for diastolic blood pressure, and 12.6mm Hg for pulse pressure. After multivariate adjustment a higher level of interleukin-6 at baseline was consistently associated with higher intra-individual variability of blood pressure, including systolic, diastolic, and pulse pressure. Markers of endothelial function (Von Willebrand factor, tissue plasminogen activator), renal function (glomerular filtration rate) and glucose homeostasis (blood glucose, homeostatic model assessment index) were not or to a minor extent associated with blood pressure variability.
  
  
  CONCLUSIONS
  In an elderly population at risk of cardiovascular disease, inflammation (as evidenced by higher levels of interleukin-6) is associated with higher intra-individual variability in systolic, diastolic, and pulse pressure.
authors.affiliation: Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, The Netherlands; r.k.e.poortvliet@lumc.nl.
authors.forename: Rosalinde K E
authors.initials: RK
authors.lastname: Poortvliet
authors.affiliation: Robertson Centre for Biostatistics, University of Glasgow, Glasgow, UK;
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: Lloyd
authors.affiliation: Robertson Centre for Biostatistics, University of Glasgow, Glasgow, UK;
authors.forename: Ian
authors.initials: I
authors.lastname: Ford
authors.affiliation: British Heart Foundation, Glasgow Cardiovascular Research Centre, University of Glasgow, Glasgow, UK;
authors.forename: Naveed
authors.initials: N
authors.lastname: Sattar
authors.affiliation: Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, The Netherlands;
authors.forename: Anton J M
authors.initials: AJ
authors.lastname: de Craen
authors.affiliation: Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, The Netherlands; Netherlands Consortium for Healthy Ageing, Leiden, The Netherlands;
authors.forename: Liselotte W
authors.initials: LW
authors.lastname: Wijsman
authors.affiliation: Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, The Netherlands; Netherlands Consortium for Healthy Ageing, Leiden, The Netherlands; Institute for Evidence-Based Medicine in Old Age, Leiden, The Netherlands;
authors.forename: Simon P
authors.initials: SP
authors.lastname: Mooijaart
authors.affiliation: Netherlands Consortium for Healthy Ageing, Leiden, The Netherlands;
authors.forename: Rudi G J
authors.initials: RG
authors.lastname: Westendorp
authors.affiliation: Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands;
authors.forename: J Wouter
authors.initials: JW
authors.lastname: Jukema
authors.affiliation: Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, The Netherlands;
authors.forename: Wouter
authors.initials: W
authors.lastname: de Ruijter
authors.affiliation: Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, The Netherlands;
authors.forename: Jacobijn
authors.initials: J
authors.lastname: Gussekloo
authors.affiliation: Academic Section of Geriatric Medicine, University of Glasgow-Faculty of Medicine, Glasgow Royal Infirmary, Glasgow, UK.
authors.forename: David J
authors.initials: DJ
authors.lastname: Stott
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D008297:Male; D000367:Age Factors; D015415:Biomarkers / Q000097:blood; D001794:Blood Pressure; D002318:Cardiovascular Diseases / Q000097:blood / Q000175:diagnosis / Q000503:physiopathology; D005060:Europe; D018836:Inflammation Mediators / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D016014:Linear Models; D015999:Multivariate Analysis; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors
chemical_list: D015415:Biomarkers; C508600:IL6 protein, human; D018836:Inflammation Mediators; D015850:Interleukin-6
keywords: blood pressure; cardiovascular risk; correlates; hypertension; mortality; old age; variability.