VOLUME 8 NUMBER 3 • SEPTEMBER 2011
137
SA JOURNAL OF DIABETES & VASCULAR DISEASE
JOURNAL UPDATE
Journal Update
Cardiovascular protection in African patients, from the world literature
Hypertension: a risk factor in
vascular surgery
The aim of this study was to determine risk
factors associated with intermediate and
long-term mortality in South African vascu-
lar surgical patients. Two risk factors identi-
fied in the South African National Burden of
Disease study were associated with mortal-
ity: a ‘western lifestyle’ and the presence of
associated risk factors such as hypertension
and diabetes. This is in contrast to European
and American populations where hyperten-
sion and diabetes are not important risk fac-
tors. In this study, hypertension was the only
predictor of intermediate and long-term sur-
vival following vascular surgery in the South
African setting.
A cohort of 283 vascular surgical patients
over the age of 39 years, admitted for both
elective and emergency vascular surgery at
Inkosi Albert Luthuli Central Hospital, were
included in this study. All patients survived
the surgical procedure and were discharged
from hospital. Subsequent hospital clinic
visits or hospital admissions were identified;
and for those patients not returning, con-
tact was made with the patient and/or next
of kin.
Demographic data associated with peri-
operative cardiac risk, as well as intra-hos-
pital and all-cause mortality were extracted
for all patients. Data collection on clinical
risk factors included: history of ischaemic
heart disease, history of congestive heart
failure, diabetes, serum creatinine > 180
μmol/l, history of cerebrovascular accident,
age, gender, history of smoking, and history
of hypertension.
Determination of predictors of interme-
diate and long-term survival are important,
as these may identify patients who require
further aggressive risk-factor modification,
therapy and increased surveillance postop-
eratively. The prevalence of clinical risk pre-
dictors in South African vascular patients
was similar to or higher than those reported
in European vascular patients.
In contrast to developed-world obser-
vations, peri-operative clinical risk indices
were not associated with intermediate and
long-term survival in South African vascular
surgical patients. Hypertension was the only
predictor of intermediate and long-term sur-
vival. It appears that traditional public health
issues are more predictive of mortality for
South African vascular surgical patients.
Source: Biccard BM, Nepaul S. Risk factors associated
with intermediate and long-term mortality following vas-
cular surgery in South African patients.
Cardiovasc J Afr
2010;
21
(5): 263–267. PubMed PMID: 20972514.
A hidden burden of sub-clinical
heart disease in obese urban African
females
This study seeks to quantify the burden of
clinically overt and sub-clinical heart disease
and cardiovascular risk factors relative to
other conditions in urban Africans seeking pri-
mary healthcare. Considering the large pool
of hypertensives and latent diabetics in the
Soweto population, the identification of at-
risk patients is being overlooked in the prima-
ry-care model. Risk factor profiling and referral
for advanced investigation reveal a hidden
burden of sub-clinical heart disease; the vul-
nerable patient being the African female,
obese, with hypertension and latent diabetes.
Data were collected on 1 311 consecu-
tive patients attending two primary-care
clinics in Soweto over a six-month period.
A standardised programme of participant
assessment included: self-reported cultural
and socio-demographic profiling, risk factor
profiling (family history of diabetes and
heart disease, smoking, random blood glu-
cose levels) and anthropometric profiles.
Clinical assessment encompassed aver-
age seated systolic and diastolic blood pres-
sure, heart rate and a physical examination
for signs and symptoms of potential heart
disease. A 12-lead ECG was performed.
Prior and current diagnoses and pharmaco-
logical therapy for prevention or treatment
of cardiovascular disease were recorded.
The contribution of diagnosed forms of
heart disease on case burden was small, at
fewer than one in 100 patients (even though
one in three were hypertensive). When sus-
picious cases were deferred for more defini-
tive assessment, the case burden rose to
three in 100 patients.
Cardiovascular disease was evident in
4.9% of cases, in which gender bias for
risk factors was evident. Females were more
likely to have a history of hypertension, be
obese and display symptoms suggestive of
heart disease. Males were more likely to
smoke and exhibit higher blood pressure in
hypertension.
The prevalence of diagnosed type 2 diabe-
tes was relatively low at 3.4%; however, 9.8%
of patients had random blood glucose levels >
7.0 mmol/l, placing them at risk of metabolic
disorders. Obese women were 2.0-fold more
likely to record high blood glucose and systolic
blood pressure than obese males. Males were
2.6-fold more likely to have an ECG abnor-
mality than females. African women with high
levels of obesity, hypertension and potentially
latent diabetes were found to be particularly
vulnerable to heart disease.
This study highlights the central impor-
tance of assessment of cardiovascular risk
and the implementation of proactive pre-
vention and treatment campaigns to reduce
non-communicable forms of disease in
urban areas. Enhanced primary-care preven-
tion may truncate the potential epidemic of
heart disease related to hypertension and
metabolic disorders.
Source: Stewart S, Carrington MJ, Pretorius S, Ogah
OS, Blauwet L, Antras-Ferry J, Sliwa K. Elevated risk fac-
tors but low burden of heart disease in urban African
primary care patients: A fundamental role for primary
prevention.
Int J Cardiol 2011
, Feb 23. [Epub ahead of
print] PubMed PMID: 21353319.
Legacy of foetal and infant under-
nutrition in Nigerian adults:
increased hypertension and
impaired glucose tolerance
A growing body of evidence suggests that
increased susceptibility to chronic diseases in
adulthood has a developmental basis originat-
ing in foetal life. Epidemiological studies from
high-income countries have linked under-nu-
trition in foetal life with increased burden of
non-communicable diseases in later life.
This study examined the risks for hyperten-
sion, glucose intolerance and overweight 40
years after foetal exposure to famine during
the Nigerian civil war (1967–1970) and
found that adults exposed to foetal–infant
famine are at greater risk of hypertension
and impaired glucose tolerance/diabetes,
contributing to cardiovascular disease.
This observational study was based on the
findings from a cohort of 1 339 ethnic Igbo,
born before, during and after the Biafran
famine. Participant selection was restricted
