CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 1, February 2012
44
AFRICA
Review Article
The prevalence and heterogeneity of prehypertension:
a meta-analysis and meta-regression of published
literature worldwide
X GUO, L ZHENG, X ZHANG, L ZOU, J LI, Z SUN, J HU, Y SUN
Abstract
Objective:
Prehypertension appears to be a precursor of
hypertension and has been recognised as a major risk factor
for cardiovascular disease (CVD). Recognition of prehy-
pertension provides important opportunities for preventing
hypertension and CVD. We aimed to investigate the world-
wide prevalence and heterogeneity of prehypertension.
Methods:
We performed a meta-analysis of cross-sectional
studies worldwide that reported the prevalence of prehyper-
tension. We searched for publications between January 1966
and November 2010, using PubMed, Ovid and the Cochrane
Library, with the keyword ‘prehypertension’, supplemented
by a manual search of references from recent reviews
and relevant published original studies. Pooled prevalence
of prehypertension was calculated using random-effects
models. Heterogeneity was investigated by subgroup analysis
and meta-regression. Twenty-two articles met our inclusion
criteria, with a total sample of 242 322 individuals.
Results:
The overall pooled prevalence of prehypertension
was 38%. Significant heterogeneity across estimates of preva-
lence was observed (
p
=
0.000,
I
2
=
99.9%). The prevalence
rose as the sample size increased, and was higher among
men than women (41 vs 34%). The non-Asian population
was more likely to be prehypertensive than Asian individuals
(42 vs 36%). A high prevalence of 47% was observed among
the blackAfrican population in the non-Asian subgroup. The
inception year of the surveys was the only source of heteroge-
neity we found by meta-regressional analysis (
p
=
0.06).
Conclusion:
These results indicate that the prevalence of
prehypertension was relatively high, particularly among
males. Although more attention has been paid to this
segment of the population since 2003, additional practical
and reasonable steps should be taken to prevent and treat
prehypertension.
Keywords:
epidemiology, meta-analysis, meta-regression,
prehypertension, prevalence
Submitted 17/3/11, accepted 15/9/11
Cardiovasc J Afr
2012;
23
: 44–50
DOI: 10.5830/CVJA-2011-058
High blood pressure (BP) has always been recognised as a major
risk factor for cardiovascular disease (CVD).
1,2
In 2003, the
Joint National Committee on Prevention, Detection, Evaluation,
and Treatment of High Blood Pressure first introduced the
blood pressure category ‘prehypertension’, replacing former
categories of ‘high normal’ and ‘above-optimal’ blood pressure.
3
Individuals with systolic blood pressure (SBP) between 120 and
139 mmHg or diastolic blood pressure (DBP) between 80 and
89 mmHg were categorised as having prehypertension. This
evidence-based definition was established to focus clinical and
public health attention on the population who are at higher-than-
normal CVD risk, since prehypertension has been noticed to be
associated with carotid artery stenosis, myocardial infarction,
coronary artery disease and many other adverse consequences.
4-6
Effective strategies on prevention for this segment of the
population would be of value. Because screening and treatment
would be based on the new classification, it is important to know
the prevalence of this new blood pressure category. However,
the prevalence varies considerably worldwide. Therefore, we
performed this study, aiming to systematically review the find-
ings of all available studies and estimate the overall prevalence
of prehypertension. In addition, we aimed to explore potential
sources of heterogeneity.
Methods
We performed a systematic search for publications between
January 1966 and November 2010 in which the prevalence of
Department of Cardiology, First Affiliated Hospital of China
Medical University, Shenyang, People’s Republic of China
X GUO, MD
X ZHANG, MD
J HU, MD
Y SUN, MD, PhD,
Department of Clinical Epidemiology, Library, Shengjing
Hospital of China Medical University, Shenyang, People’s
Republic of China
L ZHENG, MD
Department of Preventive Medicine, Tongji University,
Shanghai, People’s Republic of China
L ZOU, MD
Heart, Lung and Blood Vessel Centre, Tongji University,
Shanghai, People’s Republic of China
J LI, MD
Department of Cardiology, Shengjing Hospital of China
Medical University, Shenyang, People’s Republic of China
Z SUN, MD
