Impact of age on the importance of systolic and diastolic blood pressures for stroke risk: The MOnica, Risk, Genetics, Archiving, and Monograph (MORGAM) Project
Cardiovascular Research Unit, Cardiovascular Department of Internal Medicine, Denmark; Research Centre for Prevention and Health, Glostrup University Hospital, Building 84-85, Nordre Ringvej 57, 2600 Glostrup, Denmark; Division of Cardiology, Holbk University Hospital, Holbk, Denmark; Department of Cardiovascular Epidemiology and Prevention, Cardinal Stefan Wyszynski Institute of Cardiology, Warsaw, Poland; Cerebro and Cardiovascular Epidemiology Unit, National Centre of Epidemiology, Surveillance, and Promotion of Health, National Institute of Health, Rome, Italy; United Kingdom Clinical Research Collaboration Centre of Excellence for Public Health Research, Queen's University of Belfast, Belfast, United Kingdom; Clinica Medica e Istituto Auxologico Italiano, Milan, Italy; Research Centre on Chronic Degenerative Diseases Osp. S. Gerardo, Monza, Italy; National Institute for Health and Welfare, Helsinki, Finland; Institute of Health Studies, Department of Health, Barcelona, Spain; Department of Endocrinology, Odense University Hospital, Odense, Denmark; Hypertension in Africa Research Team, North-West University, Potchefstroom, South Africa
This study investigates age-related shifts in the relative importance of systolic (SBP) and diastolic (DBP) blood pressures as predictors of stroke and whether these relations are influenced by other cardiovascular risk factors. Using 34 European cohorts from the MOnica, Risk, Genetics, Archiving, and Monograph (MORGAM) Project with baseline between 1982 and 1997, 68 551 subjects aged 19 to 78 years, without cardiovascular disease and not receiving antihypertensive treatment, were included. During a mean of 13.2 years of follow-up, stroke incidence was 2.8%. Stroke risk was analyzed using hazard ratios per 10-mm Hg/5-mm Hg increase in SBP/DBP by multivariate-adjusted Cox regressions, including SBP and DBP simultaneously. Because of nonlinearity, DBP was analyzed separately for DBP <71 mm Hg and DBP <71 mm Hg. Stroke risk was associated positively with SBP and DBP <71 mm Hg (SBP/DBP <71 mm Hg; hazard ratios: 1.15/1.06 [95% CI: 1.12-1.18/1.03-1.09]) and negatively with DBP <71 mm Hg (0.88[0.79-0.98]). The hazard ratio for DBP decreased with age (P<0.001) and was not influenced by other cardiovascular risk factors. Taking into account the age×DBP interaction, both SBP and DBP <71 mm Hg were significantly associated with stroke risk until age 62 years, but in subjects older than 46 years the superiority of SBP for stroke risk exceeded that of DBP <71 mm Hg and remained significant until age 78 years. DBP <71 mm Hg became significant at age 50 years with an inverse relation to stroke risk. In Europeans, stroke risk should be assessed by both SBP and DBP until age 62 years with increased focus on SBP from age 47 years. From age 62 years, emphasis should be on SBP without neglecting the potential harm of very low DBP. © 2012 American Heart Association, Inc.
cholesterol; adult; age; aged; antihypertensive therapy; article; body mass; cardiovascular risk; cerebrovascular accident; cholesterol blood level; cohort analysis; controlled study; diastolic blood pressure; Europe; female; follow up; hazard ratio; human; incidence; major clinical study; male; mean arterial pressure; prediction; priority journal; proportional hazards model; pulse pressure; risk assessment; systolic blood pressure; Adult; Age Factors; Aged; Blood Pressure; Cohort Studies; Europe; Female; Humans; Incidence; Male; Middle Aged; Multivariate Analysis; Proportional Hazards Models; Risk Assessment; Risk Factors; Stroke; Young Adult