title: African Caribbeans have greater subclinical cerebrovascular disease than Europeans: this is associated with both their elevated resting and ambulatory blood pressure and their hyperglycaemia.
abstract: OBJECTIVE
  Stroke is elevated in people of black African descent, but evidence for excess subclinical cerebrovascular disease is conflicting, and the role of risk factors in determining any ethnic differences observed unexplored.
  
  
  METHODS
  We compared prevalence of brain infarcts, and severe white matter hyperintensities (WMHs) on cerebral MRI, in a community-based sample of men and women aged 58-86 of African Caribbean (214) and European (605) descent, in London, UK. Resting, central and ambulatory blood pressure (BP) were measured; diabetes was assessed by blood testing and questionnaire.
  
  
  RESULTS
  Mean age was 70. Multiple (≥4) brain infarcts and severe WMH occurred more frequently in African Caribbeans (18/43%), than Europeans (7/33%, P=0.05/0.008). Separately, clinic and night-time ambulatory BP were significantly associated with severe WMH in both ethnic groups; when both were entered into the model, the association for clinic SBP was attenuated and lost statistical significance [1.00 (0.98-1.02) P=0.9 in Europeans, 1.00 (0.97-1.04) P=0.9 in African Caribbeans], whereas the association for night-time SBP was retained [1.04 (1.02-1.07) P<0.001 in Europeans, 1.08 (1.03-1.12), P=0.001 in African Caribbeans]. The greater age-adjusted and sex-adjusted risk of severe WMH in African Caribbeans compared with Europeans [2.08 (1.15-3.76) P=0.02], was attenuated to 1.45 [(0.74-2.83) P=0.3] on adjustment for clinic and night-time systolic pressure, antihypertensive medication use and glycated haemoglobin.
  
  
  CONCLUSIONS
  African Caribbeans have a greater burden of subclinical cerebrovascular disease than Europeans. This excess is related to elevated clinic and ambulatory BP, and to hyperglycaemia.
authors.affiliation: aDepartment of Radiology, University of Washington Medical Centre, Seattle, Washington, USA bNational Heart & Lung Institute, Imperial College London cDepartment of Radiology, St Mary's Hospital, Imperial College NHS Healthcare Trust, London, UK.
authors.forename: Dean
authors.initials: D
authors.lastname: Shibata
authors.forename: Therese
authors.initials: T
authors.lastname: Tillin
authors.forename: Norman
authors.initials: N
authors.lastname: Beauchamp
authors.forename: John
authors.initials: J
authors.lastname: Heasman
authors.forename: Alun D
authors.initials: AD
authors.lastname: Hughes
authors.forename: Chloe
authors.initials: C
authors.lastname: Park
authors.forename: Wady
authors.initials: W
authors.lastname: Gedroyc
authors.forename: Nish
authors.initials: N
authors.lastname: Chaturvedi
mesh_terms: D000368:Aged; D044383:Black People; D001794:Blood Pressure; D005260:Female; D006801:Humans; D006943:Hyperglycemia / Q000150:complications*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D020521:Stroke / Q000150:complications* / Q000453:epidemiology; D014900:West Indies; D044465:White People
references.citation: Hypertension. 2005 Apr;45(4):766-72
references.pmid: 15699471
references.citation: Stroke. 1994 Nov;25(11):2120-5
references.pmid: 7974531
references.citation: J Hypertens. 2012 Mar;30(3):445-8
references.pmid: 22278144
references.citation: Neurology. 2001 Oct 9;57(7):1222-9
references.pmid: 11591840
references.citation: Diabetes Care. 2006 Sep;29(9):2127-9
references.pmid: 16936166
references.citation: J Hypertens. 1992 Aug;10(8):875-8
references.pmid: 1325522
references.citation: Am J Med Sci. 1995 Dec;310 Suppl 1:S86-90
references.pmid: 7503132
references.citation: J Neurol Neurosurg Psychiatry. 2002 Feb;72(2):211-6
references.pmid: 11796771
references.citation: Hypertens Res. 2001 May;24(3):195-201
references.pmid: 11409640
references.citation: Diabetes Care. 1998 Dec;21(12):2191-2
references.pmid: 9839117
references.citation: Stroke. 2003 Oct;34(10):2471-4
references.pmid: 14500939
references.citation: Stroke. 1996 Aug;27(8):1274-82
references.pmid: 8711786
references.citation: J Hypertens Suppl. 1986 Dec;4(5):S293-6
references.pmid: 3471909
references.citation: AJNR Am J Neuroradiol. 1999 Aug;20(7):1273-80
references.pmid: 10472985
references.citation: Eur Heart J. 2013 Jul;34(28):2159-219
references.pmid: 23771844
references.citation: Hypertension. 1993 Jul;22(1):90-6
references.pmid: 8319998
references.citation: AJNR Am J Neuroradiol. 1994 Oct;15(9):1625-33
references.pmid: 7847205
references.citation: Stroke. 1999 Apr;30(4):736-43
references.pmid: 10187871
references.citation: J Public Health (Oxf). 2007 Jun;29(2):191-8
references.pmid: 17456532
references.citation: Stroke. 2003 May;34(5):1126-9
references.pmid: 12690219
references.citation: Arch Intern Med. 2001 Oct 22;161(19):2343-50
references.pmid: 11606150
references.citation: Int J Epidemiol. 2012 Feb;41(1):33-42
references.pmid: 21044979
references.citation: Arch Neurol. 1998 Sep;55(9):1217-25
references.pmid: 9740116
references.citation: Stroke. 2004 Feb;35(2):426-31
references.pmid: 14757893
references.citation: J Neurosurg. 1993 Oct;79(4):483-9
references.pmid: 8410214
references.citation: Stroke. 2008 Aug;39(8):2204-10
references.pmid: 18535279
references.citation: Hypertension. 2013 May;61(5):1014-20
references.pmid: 23478098
references.citation: Am J Hypertens. 2000 Dec;13(12):1250-5
references.pmid: 11130767
references.citation: J Hypertens. 2005 Apr;23(4):697-701
references.pmid: 15775768
references.citation: Arch Neurol. 1998 Feb;55(2):201-6
references.pmid: 9482362
references.citation: Neuroepidemiology. 1997;16(3):149-62
references.pmid: 9159770
references.citation: Neurology. 2008 Feb 5;70(6):425-30
references.pmid: 17898325
references.citation: Hypertension. 2009 Mar;53(3):480-6
references.pmid: 19204180