CARDIOVASCULAR JOURNAL OF AFRICA • Vol 23, No 1, February 2012
52
AFRICA
and other clinical and biological param-
eters were assessed.
Participants with gastrectomy had
higher systolic blood pressure, and
lower HbA
1c
and LDL cholesterol levels,
compared to those without gastrectomy.
Other clinical characteristics were similar
between the two groups. Mean carot-
id IMT was significantly lower in the
gastrectomised group than in those with-
out gastrectomy (
p
=
0.04). This differ-
ence persisted in some subgroup analyses
(smokers, patients with hypertension), but
not in all. Subgroup analyses however,
were based on small numbers.
The authors concluded that in addition
to the known beneficial effects of gastrec-
tomy on glucose tolerance, this procedure
may also have a favourable effect on
the progression of atherosclerosis. The
study, as recognised by the investigators,
was cross-sectional and based on a small
sample size.
Sagittal abdominal diameter a
better predictor of arterial stiff-
ening than waist circumference
Ostgren and his collaborators from
Linkoping University in Sweden demon-
strated a finding suggesting that sagit-
tal abdominal diameter (SAD) was a
better predictor of arterial stiffening than
waist circumference (WC) in people with
diabetes. This was based on 255 partici-
pants with type 2 diabetes, members of
the CARDIPP cohort (CArdiovascular
Risk factors in people with Diabetes – a
Prospective study in Primary care).
Arterial stiffness was measured by
pulse wave velocity (PWV) and partici-
pants were followed for four years
between 2006 and 2010. They had accept-
able metabolic control both at baseline
and during follow up.
In multivariable linear regression
analysis, they found that SAD, not WC
or body mass index (BMI) was signifi-
cantly associated with PWV at baseline.
Likewise, during follow up, change in
SAD and BMI, but not WC were associ-
ated with four-year change in PWV.
In general, SAD is much easier to
measure than WC and may show less
variability across populations than WC.
Raised adiponectin in orthostatic
hypotension in diabetes
Othostatic hypotension (OH), a frequent
complication of diabetes mellitus, is asso-
ciated with increased risk of mortality.
Related mechanisms are still ill under-
stood. This exploratory study was under-
taken by Terasawa and co-workers from
Dokkyo Medical University Koshigaya
in Japan.
They hypothesised that serum high-
molecular weight (HMW) adiponectin
(the most commonly occurring adipokine,
and a determinant of cardiovascular
disease and mortality) might be elevated
in patients with type 2 diabetes and ortho-
static hypotension. They also investigated
the associations of orthostatic hypotension
with variables of coagulation⁄fibrinolysis
and with arterial stiffness
They recruited a group of 105 type 2
diabetes patients (30 with OH), in whom
the quantified HMW adiponectin level
and many other clinical and biological
parameters were assessed. Serum total
and HMW adiponectin levels were higher
in patients with OH than in those without.
They also had worse renal function and
a lower haematocrit, which may possibly
be explained, at least in part, by the high
levels of adiponectin.
In multivariable linear regression
analysis, systolic blood pressure, HDL
cholesterol, haematocrit, prothrombin and
brachial pulse-wave velocity were the
main determinants of HMW adiponec-
tin. The study was cross-sectional and
therefore precluded speculation about
causal relationship. The authors howev-
er suggested that the presence of OH
is probably an indicator of a clustering
of cardiovascular risk factors including
HMW adiponectin.
Vascular stiffening response in
type 2 diabetes
This study by Penno and co-workers from
Azienda Ospedaliero Universitaria Pisana
in Italy focused on the single and joint
effects of diabetes mellitus and hyperten-
sion on carotid and peripheral vascular
stiffness. They recruited 114 subjects,
including 14 normotensive non-diabetics,
37 hypertensive non-diabetics, 20 non-
hypertensive diabetics and 39 hyperten-
sive diabetics.
Pulse wave velocity (PWV) was meas-
ured by applanation tonometry, and carot-
id IMT and lumen diameter were assessed
by ultrasonography. Peripheral PWV was
similar between the four groups, while
aortic PWV, carotid stiffness index, carot-
id IMT and lumen diameter differed and
were higher in participants with diabetes
or hypertension, compared with their non-
diabetic or normotensive counterparts.
In mutually adjusted regression analy-
sis, both hypertension and diabetes were
associated with high aortic PWV. In addi-
tion, diabetes was associated with high
IMT, while hypertension was associated
with high carotid stiffness and diameter.
The authors concluded that type 2
diabetes and hypertension are character-
ised by discrete differences in the vascu-
lature stiffening response. This, however,
was based on a very small number in a
cross-sectional analysis.
ADVANCE model better predic-
tor of cardiovascular risk in
diabetes
The use of global cardiovascular risk
models is increasingly recommended as
an appropriate basis for initiation and
intensification of cardiovascular risk-
reduction therapies in people with diabe-
tes. However, those models specific to
people with diabetes and developed only
recently have not been extensively tested.
In the last presentation in this series,
Dr Kengne, on behalf of the ADVANCE
investigators, shared their validation
studies of the ADVANCE risk model.
ADVANCE is the largest global trial of
cardiovascular prevention in people with
diabetes. Dr Kengne and his colleagues
used the four to five years’ follow-up data
of the trial to develop a model for predict-
ing major cardiovascular disease based on
10 predictors.
They subsequently applied their model
to participants from the DIABHYCAR
study, a trial of ramipril for the prevention
of kidney disease in people with diabetes,
conducted in 16 countries around the
Mediterranean. The model had an accept-
able performance with a
c
-statistic of 0.69,
equivalent to what was obtained when
the model was tested on the ADVANCE
cohort (internal validation).
The ADVANCE model also largely
did better than two popular Framingham
equations. Based on a four-year risk
threshold of
≥
8% (equivalent to a 10-year
risk of 20%), the ADVANCE model iden-
tified the 39% of the DIABHYCAR
participants in whom 66% cardiovascular
disease events were recorded.
Based on this performance, the inves-
tigators concluded that the ADVANCE
risk model is appropriate for cardiovas-
