CARDIOVASCULAR JOURNAL OF AFRICA • Vol 21, No 4, July/August 2010
200
AFRICA
Prevalence of microalbuminuria in hypertensive patients
and its associated cardiovascular risk in clinical cardiology:
Moroccan results of the global i-SEARCH survey –
a sub-analysis of a survey with 21 050 patients in
26 countries worldwide
R HABBAL, AR SEKHRI, M VOLPE, i-SEARCH INVESTIGATORS
Summary
Objectives:
To determine the prevalence of microalbuminuria
(MAU) in hypertensive outpatients visiting a cardiologist’s
office or clinic and to describe the relationship between MAU
and cardiovascular risk factors.
Methods:
This was an international, observational, cross-
sectional study of 22 282 patients, with 457 subjects from
Morocco in 40 cardiology centres. Inclusion criteria were:
male and female outpatients aged
≥
18 years with currently
treated or newly diagnosed hypertension (
≥
140/90 mmHg
at rest on the day of the study visit) and no reason for false
positive microalbuminuria dipstick tests.
Outcome measures:
Prevalence of microalbuminuria assessed
using a dipstick test, co-morbid cardiovascular risk factors
or disease and their relationship with the presence of MAU,
and role of pharmacotherapy in modulating the prevalence
of MAU.
Results:
The prevalence of microalbuminuria in hyperten-
sive patients in Morocco (67.8%) was high compared to
the worldwide prevalence (58.3%). Despite the fact that all
physicians regarded MAU as important for risk assessment
and therapeutic decisions, routine MAU measurement was
performed in only 35% of the practices. In clinical cardiol-
ogy, MAU is highly correlated with a wide variety of cardio-
vascular risk factors and cardiovascular disease.
While angiotensin receptor blockers (ARBs) appeared to
be associated with the lowest risk of MAU, calcium channel
blockers (CCBs) were more often used in this patient group.
Conclusions:
Hypertensive, high-risk cardiovascular patients
are common in clinical cardiology. Given the high prevalence
detected, screening of MAU in addition to more aggressive
multi-factorial treatment to reduce blood pressure as well as
other cardiovascular risk factors is required.
Keywords:
microalbuminuria, prevalence, cardiology, hyperten-
sion, irbesartan, risk factors
Submitted 17/10/09, accepted 10/3/10
Cardiovasc J Afr
2010;
21
: 200–205
The presence of albumin in the urine indicates a disturbance in
the barrier function of the endothelial glomerular cells (podo-
cytes).
1,2
This parameter is measured in mg per 24 hours or
µ
g/
ml urine. Excretion of albumin into the urine must be detected
as early as possible, because once pathological thresholds are
reached, progression to advanced renal disease may result. The
range of 30–300 mg/24 hours, termed microalbuminuria (MAU),
is accompanied by an increased incidence of clinical proteinuria,
an increase in serum creatinine, and more frequent development
of terminal renal insufficiency, in addition to increased cardio-
vascular risk.
3
Albuminuria is frequently regarded as a disease of the
kidneys. However, there is often a simultaneous secretion of
albumin into the retinal bed (cotton wool spots).
4
Moreover,
pre-clinical studies have shown that, using labelled albumin, this
disorder is also present in the whole vascular system including
the myocardium
5
and brain.
6-8
From a cardiologist’s standpoint, therefore, albuminuria is
of critical importance to determine the prognosis of patients
with cardiovascular disease. Patients with myocardial infarction,
for example, have a worse prognosis if albuminuria is present
compared to no albuminuria.
9-11
Furthermore, in patients with
normal coronary arteries on angiography, the extent of endothe-
lial dysfunction has been shown to correlate with the degree of
albumin excretion.
12
Overall it has been shown that MAU is more
important than many established cardiovascular risk factors for
the prediction of the further course and outcome.
13
The International Survey Evaluating microAlbuminu-
ria Routinely by Cardiologists in patients with Hypertension
(i-SEARCH) was undertaken in 26 countries around the world
in a total of 1 750 sites to provide epidemiological data on the
prevalence of MAU and its associations with established cardio-
vascular risk markers and disease. This article reports the data
for Morocco, worldwide results having been published recently.
14
Methods
This was an international, observational, cross-sectional study
in which subjects were evaluated during a single visit (methods
have been published previously
14
). It had a two-step epide-
miological design. In the first step, prior to patient recruitment,
Cardiology Department, Ibn Rochd University Hospital,
Casablanca, Morocco
R HABBAL, MD
Medical Affairs Department, sanofi-aventis, Casablanca,
Morocco
AR SEKHRI, MD,
University of Roma ‘La Sapienza’, 2nd Faculty of Medicine,
S Andrea Hospital, Rome and IRCCS, Neuromed, Italy
M VOLPE, MD
i-SEARCH INVESTIGATORS
