title: Cerebral Microbleeds and White Matter Hyperintensities in Cognitively Healthy Elderly: A Cross-Sectional Cohort Study Evaluating the Effect of Arterial Stiffness.
abstract: BACKGROUND
  Arterial stiffness reflects the ageing processes in the vascular system, and studies have shown an association between reduced cognitive function and cerebral small vessel disease. Small vessel disease can be visualized as white matter hyperintensities (WMH) and lacunar infarcts but also as cerebral microbleeds on brain magnetic resonance imaging (MRI). We aimed to investigate if arterial stiffness influences the presence of microbleeds, WMH and cognitive function in a population of cognitively healthy elderly.
  
  
  METHODS
  The study population is part of the Swedish BioFinder study and consisted of 208 individuals without any symptoms of cognitive impairment, who scored >27 points on the Mini-Mental State Examination. The participants (mean age, 72 years; 59% women) underwent MRI of the brain with visual rating of microbleeds and WMH. Arterial stiffness was measured with carotid-femoral pulse wave velocity (cfPWV). Eight cognitive tests covering different cognitive domains were performed.
  
  
  RESULTS
  Microbleeds were detected in 12% and WMH in 31% of the participants. Mean (±standard deviation, SD) cfPWV was 10.0 (±2.0) m/s. There was no association between the presence of microbleeds and arterial stiffness. There was a positive association between arterial stiffness and WMH independent of age or sex (odds ratio, 1.58; 95% confidence interval, 1.04-2.40, p < 0.05), but the effect was attenuated when further adjustments for several cardiovascular risk factors were performed (p > 0.05). Cognitive performance was not associated with microbleeds, but individuals with WMH performed slightly worse than those without WMH on the Symbol Digit Modalities Test (mean ± SD, 35 ± 7.8 vs. 39 ± 8.1, p < 0.05). Linear regression revealed no direct associations between arterial stiffness and the results of the cognitive tests.
  
  
  CONCLUSIONS
  Arterial stiffness was not associated with the presence of cerebral microbleeds or cognitive function in cognitively healthy elderly. However, arterial stiffness was related to the presence of WMH, but the association was attenuated when multiple adjustments were made. There was a weak negative association between WMH and performance in one specific test of attention. Longitudinal follow-up studies are needed to further assess the associations.
authors.affiliation: Memory Clinic, Skåne University Hospital, Sweden ; Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Sweden.
authors.forename: Anna-Märta
authors.initials: AM
authors.lastname: Gustavsson
authors.affiliation: Memory Clinic, Skåne University Hospital, Sweden ; Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Sweden.
authors.forename: Erik
authors.initials: E
authors.lastname: Stomrud
authors.affiliation: Medical Radiology Unit, Department of Clinical Sciences Malmö, Sweden.
authors.forename: Kasim
authors.initials: K
authors.lastname: Abul-Kasim
authors.affiliation: Memory Clinic, Skåne University Hospital, Sweden ; Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Sweden.
authors.forename: Lennart
authors.initials: L
authors.lastname: Minthon
authors.affiliation: Department of Clinical Sciences Malmö, Lund University, Malmö, Sweden.
authors.forename: Peter M
authors.initials: PM
authors.lastname: Nilsson
authors.affiliation: Memory Clinic, Skåne University Hospital, Sweden ; Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Sweden.
authors.forename: Oskar
authors.initials: O
authors.lastname: Hansson
authors.affiliation: Memory Clinic, Skåne University Hospital, Sweden ; Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Sweden.
authors.forename: Katarina
authors.initials: K
authors.lastname: Nägga
keywords: Arterial stiffness; Cerebral microbleeds; Cognitive function; Healthy elderly; Pulse wave velocity; White matter hyperintensities