title: Should Blood Pressure Targets After Lacunar Stroke Vary by Body Size? The SPS3 Trial.
abstract: BACKGROUND
  It is unknown whether the physiological impact of a given blood pressure (BP) varies by body size. We explored interactions between higher vs. lower systolic BP (SBP) targets and anthropometric measures (body mass index (BMI), body surface area (BSA), height, weight) and recurrent stroke and death in the Secondary Prevention of Small Subcortical Strokes (SPS3) Trial.
  
  
  METHODS
  Patients with recent magnetic resonance imaging-proven lacunar infarcts were randomized to 2 BP targets (130-149 mm Hg vs. <130) in a prospective, open-label, blinded end-point design. Time to outcome was evaluated with Cox proportional hazard models and compared between targets. We examined multiplicative interactions between each anthropometric measure and target and mean difference in achieved BP 1 year after randomization between BP groups by quartile. We also computed rates of recurrent stroke and death by quartiles of anthropometrics.
  
  
  RESULTS
  Three thousand and twenty patients were followed over a mean of 3.7 (SD 2.0) years. Mean age was 63; 63% were male. Mean height was 167 (SD 11) cm, weight 81 (18) kg, BMI 29 (5.9) kg/m(2), and BSA 1.9 (0.25) m(2). Achieved BP at 1 year was comparable between quartiles for each anthropometric measurement. We found no consistent interactions between BP target and anthropometrics for either outcome, nor were there any significant associations between hazard of stroke or death when assessed by BMI, BSA, height, or weight.
  
  
  CONCLUSIONS
  We found no interactions between BP target groups and quartiles of anthropometrics for rates of stroke and death in SPS3. There is no evidence at this time supporting body size-based modifications to current BP targets for secondary prevention after lacunar stroke.
  
  
  BACKGROUND
  Trial Number NCT00059306.
authors.affiliation: Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada; thalia.field@ubc.ca.
authors.forename: Thalia S
authors.initials: TS
authors.lastname: Field
authors.affiliation: Department of Biostatistics, University of Alabama at Birmingham, Birmingham, Alabama;
authors.forename: Leslie A
authors.initials: LA
authors.lastname: McClure
authors.affiliation: University of Texas Health Sciences Center at San Antonio, San Antonio, Texas;
authors.forename: Carole L
authors.initials: CL
authors.lastname: White
authors.affiliation: University of Texas Health Sciences Center at San Antonio, San Antonio, Texas;
authors.forename: Pablo E
authors.initials: PE
authors.lastname: Pergola
authors.affiliation: Population Health Research Institute, McMaster University, Hamilton, Ontario, Canada;
authors.forename: Robert G
authors.initials: RG
authors.lastname: Hart
authors.affiliation: Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada;
authors.forename: Oscar R
authors.initials: OR
authors.lastname: Benavente
authors.affiliation: Hotchkiss Brain Center, Department of Neurosciences, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Hill
mesh_terms: D000368:Aged; D000959:Antihypertensive Agents / Q000627:therapeutic use; D001795:Blood Pressure Determination / Q000379:methods; D015992:Body Mass Index; D049628:Body Size; D001830:Body Surface Area; D004359:Drug Therapy, Combination; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications / Q000175:diagnosis / Q000188:drug therapy; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016016:Proportional Hazards Models; D012008:Recurrence; D055502:Secondary Prevention; D013223:Statistics as Topic; D059409:Stroke, Lacunar / Q000175:diagnosis / Q000209:etiology / Q000517:prevention & control
chemical_list: D000959:Antihypertensive Agents
keywords: BMI; BSA; blood pressure; body size; height; hypertension; lacunar stroke; prognosis; secondary prevention; weight.