| E.H.S.
EXECUTIVE BOARD:
President
:M. M. Ibrahim, MD
Vice President : H. E. Attia, MD
Secretary : H. Rizk, MD
Treasurer :W. El Aroussy, MD
Members :
A. M. Hassaballa, MD
M.S.Mokhtar, MD
S. EI-Tobgy, MD
O. Khashaab, MD |
EDITORAL
COMMITTEE: Editor
: M. Hamed, MD
Assistant Editors :
A.M. EI-Keiy, MD
A. EI-Etriby, MD
M. El Ramly, MD
H. Gobran, MD
W.El Naggar, MD
Z. Ashour, MD
M. M. Gomaa, MD |
PRESIDENT'S
MESSAGE:
EPIDEMIOLOGIC
SURVEYS IN HYPERTENSION IN SEARCH OF HYPERTENSION
RISK FACTORS
Epidemiolgic
research in the past three decades provided us with
information about a number of demographic and environmental
factors that increase the risk of developing hypertension.
Identification of these hypertension risk factors
will help answer the question why an individual,
group of individuals, a community or an entire nation
is at increased risk of high blood pressure. Furthermore,
the recognition and possible modification of these
risk factors should eventually reduce the incidence
of hypertension and its cardiovascular sequelae
namely strokes, heart attacks, cardiac and renal
failure.
A
number of epidemiologic approaches can be used to
identify hypertension risk factors. These include:
First, population studies, which are of two types:
a)
lnterpopulation studies:- we compare the prevalence
of hypertension and risk factors between different
countries.
b)
Intrapopulation studies:- we examine the prevalence
of these factors in different regions, groups or
sections of the same population. The question is
to find why people of the same ethnic and genetic
background have differences in the prevalence of
the disease and what is special about these individuals
who develop hypertension that makes them different
from normotensives. A second type of study are immigration
studies in these studies we follow the same individuals
when they move from one place (environment) to another.
The
risk of developing hypertension increases when people
migrate from rural to urban areas. The last type
are prospective controlled studies, i.e., following
a cohort or group of individuals over a period of
time and observing who develops the disease and
how he differs from others without the disease.
An example of an interpopulation and intrapopulation
study is the INTERSALT where the prevalence of hypertension
and 24-hour urinary sodium excretion were examined
in 52 different populations in 32 countries.
An
interesting finding in the Egyptian National Hypertension
Project (NHP), was the significant regional differences
in hypertension prevalence. Cairo area has a rate
of 31 %, while the frontier areas have a rate of
19.9%. In this interpopulatior study, the question
is why Egyptians living in Cairo have higher prevalence
rates than those living in the oasis ? Another example
of intrapopulation study is comparing prevalence
rates and risk factors between urban and rural Egyptians
Hypertension was more prevalent in urban areas (32%)
in comparison with rural areas (25%) This difference
in hypertension prevalence between urban and rural
communities has been repeatedly demonstrated in
a number of studies. An important study in Africa
compared demographic, social habits and environmental
characteristics between urban and rural Zulu.
Urban
Zulu were more obese, less physically active than
Zulu who walk for long distances. Furthermore, anxiety
indices, insomnia and alcohol intake were more prevalent
in the urban community. Immigration studies showed
that hypertension was more common in immigrants,
particularly when they moved from rural to urban
communities. The following factors were identified
in migration studies and were associated with early
development of hypertension: Weight gain, higher
pulse rate, possibly secondary to increased sympathetic
activities due to stress. and thirdly increased
sodium/potassium excretion rates indicating changes
in dietary habits, eating more salt and less potassium.
Results
from these different epidemiologic studies provide
us with clues to a number of hypertension risk factors
that will help answer the question why some people
develop hypertension and others remain normotensive.
Established modifiable risk factors are obesity,
androgenic body fat distribution, alcohol excess,
salt intake, psychosocial stress and the use of
oral contraceptives.
Modifiable
but possible risk factors include deficiency in
potassium, calcium and magnesium, hyperinsulinism,
sedentary life style, environmental pollution, e.g.,
excess noise and lead, soft drinking water, schistosomiasis
and the use of potentially hypertensive drugs. Aging
and positive family history of hypertension are
important non-modifiable risk factors. There is
no doubt that hypertension runs in families and
there is a definite familial aggregation of high
blood pressure.
It
has been proposed that 30% of variance in blood
pressure is genetically determined and 50% is due
to environmental factors. 30-40% of the offspring
of hypertensive patients are at risk of developing
hypertension.
Data
from the Egyptian NHP confirmed the higher prevalence
of hypertension in all age decades till age 75 years
in individuals with positive family history of hypertension
in comparison with those of a negative family history.
Aging constitutes possibly the most important non-modifiable
hypertension risk factor. Data from NHP shows the
progressive increase in hypertension prevalence
with aging in different age groups.
Furthermore,
there are lower prevalence rates of hypertension
in women compared to men before the age of 45 and
the reversal of these rates in old age. This increase
in hypertension prevalence with aging has been demonstrated
in almost all epidemiologic surveys except those
in some isolated communities, where hypertension
does not exist.
Identification
of hypertension risk factors and correcting modifiable
ones such as obesity, excess salt and alcohol intake
will help decrease the incidence of hypertension.
The recent data from the DASH study presented at
the American Heart Association Meeting in November
- 1996, held in New Orleans. provided evidence that
dietary modification through increasing fruits and
vegetable intake and limiting fat in diet can decrease
blood pressure.
The
change in blood pressure was possible without limiting
salt intake or reducing weight. Continued epidemiologic,
clinical and experimental research is needed in
order to unravel the mystery of essential hypertension.
M.
Mohsen Ibrahim, MD
Professor
and chairman of the Cardiology
Department-Cairo University.
Principal Investigator the Egyptian National
Hypertension Project
Editorial
MOLECULAR
BIOLOGY OF THE RENIN ANGIOTENSIN SYSTEM
By
HELMY M. SIRAGY,
M.D.
Professor of Medicine
University of Virginia, Charlottesville Virginia,
USA
The
developments in molecular biology of the past
decade have created a powerful technology with
important, if not revolutionary, clinical applications.
This technology helped a great deal in the study
of both normal physiology and pathophysiology,
especially when it is applied to heart diseases
and hypertension in general and the renin-angiotension
system in particular Although the existence of
the renin-angiotensin system has been known for
over two decades, recent advances in cell and
molecular biology as well as renal physiology
have opened the doors for a greater understanding
of the role of the system in normal and diseased
states.
Already
the angiotensin converting enzyme and the angiotensinogen
genes have been implicated in myocardial infarction
and hypertension. Exciting new concepts, such
as molecular cloning of genes for renin angiotensinogen,
angiotensin- converting enzyme and the angliotensin
AT1 receptor, have been derived from recent studies.
New
angiotensin peptides with unique actions have
been identified, and the role of angiotensins
as cell-to-cell mediators (i.e. paracrine substances)
has recently been appreciated Human renin genes
have been cloned and sequenced. A single locus
is found in the human gene, which contains10 exons
and 9 interons. A renin mRNA is formed from pro-renin
mRNA affer interon splicing in the nucleus. The
mRNA of the renin gene is translated into the
protein preprorenin.
In
the endoplasmic reticulum, prepro-renin is cleaved
into pro-renin, which is enzymatically inactive
Pro-renin is packaged into secretory granules
at the Gorgi apparatus, where it is further processed
into active renin.
Active
renin is released by an exosetic process Renin
acts on angiotensinogen, a high molecular weight
protein that is synthesized by the liver and kidney
tubules. to form an inactive decapeptide, angiotensin
I Angiotensin I is hydrolized to the octapeptide,
angiotensin II, by angiotensin converting enzymes.
Angiotensin II acts at a specific receptor. and
this interaction can be blocked by a variety of
peptide or non-peptide angiotensin II antagonists.
At
least two distinct angiotensin II receptor subtypes
are defined, on the basis of their differential
pharnacological and biochemical properties. They
are designated as type I (AT1) and type II (AT2)
receptors. Recent cloning studies have revealed
that the AT1 type belongs to a 7-transmembrane,
g-protein coupled receptor superfamily. To date,
the evidence indicates that almost all of the
known effects of angiotensin II in adult tissues
are attributable to the AT1 receptor.
Much
less is known about the function of the AT2 receptor.
Defining the functions of the ATi and AT2 receptor
subtypes in cardiovascular regulation will help
elucidate the normal physiology and pathophysiology
of cardiovascular diseases and the discovery of
new drugs.
Ongoing
Research
To
date there is no published data about the degree
of fundus involvement in hypertensive Egyptians
The NHP data base provides this information Research
into this field not only aims at establishing how
many Egyptian hypertensives have fundus changes
but also how these changes relate to other target
organ damage.
A
total of 662 normotensives and 1322 hypertensives
were examined. The amount of persons suffering from
fundus changes is shown in the figure below. Looking
at graded fund us changes of the normo-and hypertensive
population revealed the following percentages among
patients with abnormal fund. While grade I abnormality
was more common in the normotensives with fundus
changes all other grades were more common in hypertensives.
Establishment of correlates of these changes is
still being looked into.
Abstracts
of Local Literature
PREVALENCE
OF ABNORMAL SIGNAL AVERAGED ELEECTROGRAM IN PATIENTS
WITH SYSTEMIC HYPERTENSION
Y.Salah, H. Kholeif,
H. Fraig, A. Rozza, S. El Hawary and E.. Elsawy
Cardiology Department, Al Azhar University and El
Matariah Teaching Hospital, Cairo, Egypt
The
prevalence of abnormal SAECG in pts. with systemic
hypertension is variable ranging from 1% to 39%.
The prevalence and predictors of SAECG were, therefore.,
studied in 95 pts. with systemic hypertension. Fifty-nine
pts were males., their age ranged between 23 and
84 years (mean 53.6±13.7 years). Patients with schemic
heart disease or history of chest pain were excluded
from the study.
The
prevalence of +ve SAECG ranged between 3% and 7%
according to the criteria of SAECG which is used.
SAECG was considered +ve whenever two of the following
criteria existed:
(1)
RMS less than 25 uV.
(2) HFLA more than 38 ms.
(3) QRS duration more than or equal 120 ms.
Positive
SAECG was found in 5 Pts. (5%) with systemic hypertension.
None of the hypertensive Pts. without left ventricular
hypertrophy in ECG and normal left ventricular mass
by M-mode echo had +ve SAECG. Age (more or less
than 50 years). sex , left ventricular hypertrophy
by ECG, left ventricular mass by M-mode echo. EF
(> or <50%), reversed EIA ratio by Doppler
flow across the mitral valve and the degree of hypertension
(borderline., mild, moderate or severe) are not
predictors of SAECG in our Pt. population.
Ventricular
fibrillation was induced in the only Pt with +ve
SAECG in whom the study was done. The clinical significance
of +ve SAECG in Pts. with systemic hypertension
remained to be determined by follow-up of those
Pts.
BHJ
48' 191 June. 1996
BIOCHEMICAL
INDICATORS OF ATHEROSCLEROTIC RISKS IN HYPERTENSIVE
PATIENTS
By
Noor EI-Deen A. El-Hefny,
Hassan A. Hassanein*, Ali M Kassam*, Madeha M. Zakhary**
Soad M. Abdel-Ghany** and Enas A.R EI-Kareemy
Department of Internal Medicine, Assiut and Sohag*
Faculty of Medicine and Department of Biochemistry**9
Assiut Faculty of Medicine
Because
of the importance of glycosaminoglycans and glycoproteins
in the pathogenesis of atherosclerosis, the hexosamines,
which are important constituents of the previous
compounds were determined in plasma of 49 hypertensive
patients together with 18 healthy controls. The
study revealed significantly increased levels of
total and protein bound hexosamines in hypertensive
patients (p<0.001).
Free
hexosamines showed non significant decrease while
free/bound hexosamine ratio was significantly decreased
(p<0.001). The levels of total and protein bound
hexosamines correlated significantly with diastolic
blood pressure levels. These changes indicate that
there is shedding of endothelia cells into the vascular
lumen and changes in the proteoglycosaminoglycans
of basement membrane which are believed to be important
early events in atherogenesis.
The
study also revealed significantly increased levels
of homocystein in hypertensive patients compared
with controls (p<0.05). This aminoacid could
cause endothelial loss and endothelemia leading
to increased loss of heparan sulfate, hyaluronic
acid and glycoproteins with concomitant increase
in plasma hexosamine levels. Furthermore this amino
acid increased sulfation of heparan sulfate delaying
their metabolic breakdown and increasing their plasma
levels in hypertensive subjects.
In
conclusion, the prominent quantitative changes in
hexosamine levels in plasma of hypertensive patients
accompanied by significantly increased cholesterol
levels suggest increased atherosclerotic risks in
these patients.
EHJ
Feb.'96, 48:29
CAN
EXERCISE-INDUCED RISE IN BLOOD PRESSURE DISCRIMINATE
BETWEEN HYPERTENSIVES WITH SIMILAR OFFICE BLOOD
PRESSURE MEASUREMENTS
Ashour ZA, Rizk HH,
Ibrahim MM.
Department of Cardiology, Cairo University Hospitals,
Cairo Egypt
Background:
Exaggerated hypertensive response to exercise is
present in some pts with mild hypertension (HT).
The 24 hours (hrs) BP profile of these pts might
be different from other Hts.
Objective:
To determine whether exaggerated exercise-induced
BP rise can predict ambulatory 24 hrs BP (ABP) levels.
Design
and Methods: We studied 66 hypertensives, 39
males and 27 females with an age of 47.8±12.05 years
(mean±SD), a SBP of 160.1±16.2 mmHg and a DBP of
100.7±10.1 mmHg by means of office BP, ABP recording
(using Accutracker II ABP monitors) and exercise
testing by Bruce Protocol.
Results:
33 pts (gp A) showed exaggerated BP rise to exercise
(>200/110 mmHg) while 33 pts (gp B) did not.
The two gps showed the following significant (p<0.05)
differences:
| |
Gp
A n=33 |
Gp
B n=33 |
| mean
24 hour SBP(mmHg) |
144.3+17.2 |
136+14.3 |
| %
of readings> 140/90 mmHg |
57.6+25.5 |
42.3+24.1 |
| mean
day SBP (mmHg) |
149.8+17.2 |
140.2+14 |
There
was no significant difference between the 2 grps
in age, office SBP, DBP or mean diastolic ABP.
Conclusion:
Hypertensives with exaggerated exercise induced
BP rise had higher ambulatory mean 24 hrs and daytime
systolic readings than other hypertensives.
EHJ
June'96 45:259
Abstracts
of World Literature
BLOOD
PRESSURE AS A CARDIOVASCULAR RISK FACTOR
Prevention
and Treatment William B. Kannel, MD
Objective.-To
examine the prevalence, incidence, predisposing
factors for hypertension, its hazards as an ingredient
of the cardiovascular risk profile, and the implications
of this information for prevention and treatment.
Methods.-
Prospective longitudinal analysis of 36- year follow-up
data from the Framingham study of the relation of
antecedent blood pressure to occurrence of subsequent
cardiovascular morbidity and mortality depending
on the metabolically linked burden of associated
risk factors.
Results.-Hypertension
is one of the most prevalent and powerful contributors
to cardiovascular diseases, the leading cause of
death in the United States. There is, on average,
a 20 mmHg systolic and 10 mmHg diastolic increment
increase in blood pressure from age 30 to 65 years.
Isolated systolic hypertension is the dominant variety.
There
is no evidence of a decline in the prevalence of
hypertension over 4 decades despite improvements
in its detection and treatment. Hypertension contributes
to all of the major atherosclerotic cardiovascular
disease out-comes increasing risk, on average, 2-to
3-fold. Coronary disease, the most lethal and common
sequela, deserves highest priority.
Hypertension
clusters with dyslipdemia, insulin resistance, glucose
intolerance, and obesity. occurring in isolation
in less than 20%. The hazard depends on the number
of these associated metabolically linked risk factors
present. Coexistent overt cardiovascular disease
also influences the hazard and choice of therapy.
Conclusion.-The
absence of a decline in the prevalence of hypertension
indicates an urgent need for primary prevention
by weight control exercise, and reduced salt and
alcohol intake. The urgency and choice of therapy
of existing hypertension should be based on the
multivariate cardiovascular risk profile that more
appropriately targets hypertensive persons for treatment
and prevention of cardiovascular sequelae.
(JAMA.
1996;275:1571-1576)
NONINVASIVE
AMBULATORY 24-HOUR BLOOD PRESSURE IN PATIENTS WITH
HIGH NORMAL BLOOD PRESSURE AND EXAGGERATED SYSTOLIC
PRESSURE RESPONSE TO EXERCISE
Eliudem G Lima, Nelson
Spritzer, Fernando L.Herkenhoff, Ambrosina Bermudes,
Elisardo C. Vasquez
Few
studies have investigated the significance of abnormal
increases in systolic pressure during exercise in
patients with high normal blood pressure and its
correlation with 24-hour ambulatory blood pressure
monitoring and left ventricular structure. This
study was performed in 30 sedentary subjects (42±4
years old) with high normal blood pressure.
Fifteen
subjects presenting >/=220 mmHg systolic pressure
during ergometric exercise were compared with 15
others with systolic pressure >/=220 mmHg. Average
24-hour (systolic,127±5 versus 142±4 mmHg, P<01;
diastolic 82±4 versus 92±3 mmHg. P<.01), daytime
(systolic 130±6 versus 14414 mmHg, P<.01; diastolic
84±4 versus 92±4 mmHg, P<.0l), and nighttime
(systolic, 116±7 versus 132±6 mmHg, P<.01; diastolic,
72±6 versus 85±6 mmHg, P<.01) ambulatory blood
pressure monitoring values were significantly higher
in subjects with an exaggerated blood pressure response
to exercise.
No
significant differences were observed in left ventricular
morphology. These findings indicate that subjects
presenting high normal blood pressure and exaggerated
systolic pressure during exercise show significantly
high ambulatory blood pressure monitoring values
that are not associated with left ventricular hypertrophy.
(Hypertension.
1 995;26 [part 2]: 1121-1124.)
DIETARY
PROTEIN AND BLOOD PRESSURE
Eva Ibarzanek, PhD,
Paul A. Velletri, PhD; Jeffrey A.Culter, MD
Objective.-
To review published and presented data on the relationship
between dietary protein and blood pressure in humans
and animals.
Data
Sources.- Bibliographies from review articles
and books on diet and blood pressure that had references
to dietary protein. The bibliographies were supplemented
with computerized MEDLINE search restricted to English
language and abstracts presented at epidemiologic
meetings.
Study
Selection.- Observational and intervention studies
in humans and experimental studies in animals.
Data
Extraction.- In human studies, systolic or diastolic
blood pressure were outcome measures, and dietary
protein was measured by dietary assessment methods
or by urine collections. In animal studies, blood
pressure and related physiological effects were
outcome measures, and experimental treatment included
protein or amino acids.
Data
Synthesis.-Historically, dietary protein has
been thought to raise blood pressure; however, studies
conducted in Japan raised the possibility of an
inverse relationship. Data analyses from subsequent
observational studies in the United States and elsewhere
have provided evidence of an inverse relationship
between protein and blood pressure. However. intervention
studies have mostly found no significant effects
of protein on blood pressure. Few animal studies
have specifically examined the effects of increased
dietary protein on blood pressure.
Conclusions.-
Because of insufficient data and limitations in
previous investigations, better controlled and adequately
powered human studies are needed to assess the effect
of dietary protein on blood pressure. In addition,
more research using animal models, in which experimental
conditions are highly controlled and detailed mechanistic
studies can be performed, is needed to help provide
experimental support for or against the protein-blood
pressure hypothesis.
(JAMA.
1 996;275: 1598-1603)
Forthcoming
Research
RELATIONSHIP
BETWEEN BLOOD PRESSURE LEVEL, SERUM AND URINARY
ELECTROLYTES.
Wafaa EI-Aroussy,
MD, M. Mobsen Ibrahim, MD, Amal Rizk, MD.
Background:
*
Early cross-cultural epidemiological studies described
a positive correlation between dietary sodium
intake and prevalence of hypertension.
*
Most within population studies have found NO CLEAR
relationship between Na intake or excretion and
BP in unselected normal subjects and patients
with essential HTN.
In
Contrast:
- Interpopulation studies have found a highly
significant relationship.
Objectives:
1.
To investigate the relationship between BP level
and Na, K and Mg in both serum and urine in a
random sample of hypertensive Egyptians and their
control group of normotensive subjects.
2. To demonstrate geographic, demographic and
environmental factors that affect salt intake.
EHS
NEWS
*
The first continuing medical education course on
hypertension for 1997 is due to take place on January
the 5 th 1997 and will deal with the definition,
diagnosis, measurement and management of the disease.
The course coordinator is Prof. Adel Zaky, Prof.
of Cardiology, Cairo University.
The
course is intended for young general practitioners
and physicians and will include
1- Lectures on the definition, diagnosis and treatment
of hypertension.
2- A workshop on how to measure blood pressure.
3- A whip round session to guage assimilation of
knowledge.
4- A prize of LE 500 for the best physician or practitioner
all round the course.
*
The EHS meeting which was scheduled to be held in
Fayed on October the 17th l996 has been changed
as far as the meeting venue and will be held in
Port Said on the same date. The theme of the meeting
will be discussion of hypertension in special groups
and is intended to be run in 3 sessions as follows.
Session
1- Hypertension in. the elderly.
Session 2- Hypertension in women and adolescents.
Session 3- White coat and neurogenic hypertension.
A
Luncheon panel discussion on resistant hypertension
is due to take place in between session 2 and 3.
*
The Second Annual Meeting of the Egyptian Hypertension
Society is due to take place on the 18-20th of December
1996 at the Marriot Hotel., Cairo. The Chairman
of the Organizing Committee is Prof. Khairy Abdel
Dayem, Vice Dean of Faculty of Medicine, Ain Shams
University. The meeting will include symposia, state
of the art lecturers, panel discussions, controversies,
original communications and satellite symposia all
of which will tackle the problem of hypertension
from its different aspects.
*
A booklet on the development, goals, activities
and Board of Directors of the Society (1995-1996)
has been issued by the EHS Executive board in both
the Arabic and English Language, and has been distributed
to all members of the medical profession, scientific
societies as well as the Ministry of Public Health
and Medical Syndicate. It is intended to give an
idea of the Society in order to recruit memberships,
funds and sponsoring of scientific research.
*
The Aswan Meeting of the working group on "Guidelines
for the management of hypertension" that took
place in Aswan from the 11-15 of January 1996 has
crystallized out into a very neat booklet entitled"'
Short Review of Hypertension and Guidelines for,
its management in Egypt".
The
report represents the first attempt to outline a
National policy and consensus advocated by the EHS
without any governmental or drug industries bias
it provides some basic, elementary, and practical
knowledge which is required for every-day practice.
The
working group was headed by Prof. M brahim President
of the EHS and its members were the following doctors
(titles reserved) Samir Abdel kader, Omar Awaad,
Wagdy Ayad, Wafaa El-Aroussy, Fawzia EI-Demerdash,
Oma Knashaeb, Sherif El-Tobgy, Mokhtar Gomaa, Ibtihag,
Hamdy, Alaa Hamed, Mohamed Hamed, Hossaam Kandill,
Hassan Khalil, Fathy Maklady, Sherif Mokhtar and
Hussein Rizk.
*
A Layman's booklet on "'Blood Pressure and
what you Must Know About It "'was published
recently by the Egyptian Society of Hypertension
in the Arabic Language. The booklet includes:
a)
The definition of high blood pressure.
b) Dangers of high blood pressure
c) Causes of high blood pressure.
d) Essential hypertension.
e) Prevention of high blood pressure.
f) Treatment of high blood pressure.
g) Low blood pressure.
CALENDAR
| Year |
Month |
Days |
Meeting |
Venue |
Correspondence |
| 1996 |
October |
2-4 |
European
Conference on Tobacco or Health. |
Helsinki
Finland |
TSG-Congress
Ltd. Kaisaniermenkatu 3 B 31 00100
Heisink, Finland |
| 1996 |
November |
6-9 |
5th
Conference of the Scientific Section of the
German Hypertension |
Aachen
Germany |
PD
Dr. med. B. Heintz Medizinische Kllnik 11. RWtH
Aachen Pauweisstrasse 30.52057 Aachen
Germany |
| 1996 |
November |
15-16 |
5
th Congress of the Polish Society of Hypertension. |
Warsaw
Poland |
Prof.
S.L. Rywik National Institute of Cardiology
Dept. CVD Epidemiology and Prevention Alpejska
Str. 42.04-628 Warsaw. Poland |
