Risk stratification by self-measured home blood pressure across categories of conventional blood pressure: a participant-level meta-analysis.
BACKGROUND
The Global Burden of Diseases Study 2010 reported that hypertension is worldwide the leading risk factor for cardiovascular disease, causing 9.4 million deaths annually. We examined to what extent self-measurement of home blood pressure (HBP) refines risk stratification across increasing categories of conventional blood pressure (CBP).


RESULTS
This meta-analysis included 5,008 individuals randomly recruited from five populations (56.6% women; mean age, 57.1 y). All were not treated with antihypertensive drugs. In multivariable analyses, hazard ratios (HRs) associated with 10-mm Hg increases in systolic HBP were computed across CBP categories, using the following systolic/diastolic CBP thresholds (in mm Hg): optimal, <120/<80; normal, 120-129/80-84; high-normal, 130-139/85-89; mild hypertension, 140-159/90-99; and severe hypertension, ≥160/≥100. Over 8.3 y, 522 participants died, and 414, 225, and 194 had cardiovascular, cardiac, and cerebrovascular events, respectively. In participants with optimal or normal CBP, HRs for a composite cardiovascular end point associated with a 10-mm Hg higher systolic HBP were 1.28 (1.01-1.62) and 1.22 (1.00-1.49), respectively. At high-normal CBP and in mild hypertension, the HRs were 1.24 (1.03-1.49) and 1.20 (1.06-1.37), respectively, for all cardiovascular events and 1.33 (1.07-1.65) and 1.30 (1.09-1.56), respectively, for stroke. In severe hypertension, the HRs were not significant (p≥0.20). Among people with optimal, normal, and high-normal CBP, 67 (5.0%), 187 (18.4%), and 315 (30.3%), respectively, had masked hypertension (HBP≥130 mm Hg systolic or ≥85 mm Hg diastolic). Compared to true optimal CBP, masked hypertension was associated with a 2.3-fold (1.5-3.5) higher cardiovascular risk. A limitation was few data from low- and middle-income countries.


CONCLUSIONS
HBP substantially refines risk stratification at CBP levels assumed to carry no or only mildly increased risk, in particular in the presence of masked hypertension. Randomized trials could help determine the best use of CBP vs. HBP in guiding BP management. Our study identified a novel indication for HBP, which, in view of its low cost and the increased availability of electronic communication, might be globally applicable, even in remote areas or in low-resource settings.
Studies Coordinating Centre, Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium ; Tohoku University Graduate School of Pharmaceutical Sciences, Sendai, Japan.
Kei
K
Asayama
Studies Coordinating Centre, Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium.
Lutgarde
L
Thijs
Division of Hypertension, Department of Internal Medicine, University Medical Centre Ljubljana, Ljubljana, Slovenia.
Jana
J
Brguljan-Hitij
Population Studies Unit, Department of Chronic Disease Prevention, National Institute for Health and Welfare, Turku, Finland ; Department of Medicine, Turku University Hospital, Turku, Finland.
Teemu J
TJ
Niiranen
Department of Preventive Medicine and Epidemiology, Tohoku Medical Megabank Organization, Tohoku University, Sendai, Japan.
Atsushi
A
Hozawa
Centro de Nefrología and Departamento de Fisiopatología, Hospital de Clínicas, Universidad de la República, Montevideo, Uruguay.
José
J
Boggia
Studies Coordinating Centre, Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium ; Sección Hipertensión Arterial, Servicio de Clínica Médica, Hospital Italiano de Buenos Aires, Buenos Aires, Argentina.
Lucas S
LS
Aparicio
Studies Coordinating Centre, Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium.
Azusa
A
Hara
Population Studies Unit, Department of Chronic Disease Prevention, National Institute for Health and Welfare, Turku, Finland.
Jouni K
JK
Johansson
Department of Hygiene and Public Health, Teikyo University School of Medicine, Tokyo, Japan.
Takayoshi
T
Ohkubo
Inserm U708, University Bordeaux Segalen, Bordeaux, France.
Christophe
C
Tzourio
Hypertension Center, Third Department of Medicine, University of Athens, Sotiria Hospital, Athens, Greece.
George S
GS
Stergiou
Asociación Española Primera de Socorros Mutuos, Montevideo, Uruguay.
Edgardo
E
Sandoya
Department of Public Health, Tohoku University Graduate School of Medicine, Sendai, Japan.
Ichiro
I
Tsuji
Population Studies Unit, Department of Chronic Disease Prevention, National Institute for Health and Welfare, Turku, Finland.
Antti M
AM
Jula
Tohoku University Graduate School of Pharmaceutical Sciences, Sendai, Japan.
Yutaka
Y
Imai
Studies Coordinating Centre, Research Unit Hypertension and Cardiovascular Epidemiology, KU Leuven Department of Cardiovascular Sciences, University of Leuven, Leuven, Belgium ; Department of Epidemiology, Maastricht University, Maastricht, The Netherlands.
Jan A
JA
Staessen
D000328:Adult; D000368:Aged; D001794:Blood Pressure; D018660:Blood Pressure Monitoring, Ambulatory / Q000706:statistics & numerical data*; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000453:epidemiology*; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011446:Prospective Studies; D018570:Risk Assessment / Q000379:methods; D057566:Self Report; D014583:Uruguay / Q000453:epidemiology; D055815:Young Adult