Page 41 - SAJDVD 9.1

VOLUME 9 NUMBER 1 • MARCH 2012 39
SA JOURNAL OF DIABETES & VASCULAR DISEASE REPORT
Arterial stiffness was measured by pulse
wave velocity (PWV) and participants were
followed for four years between 2006
and 2010. They had acceptable metabolic
control both at baseline and during follow
up.
In multivariate linear regression analy-
sis, they found that SAD, not WC or body
mass index (BMI) was significantly asso-
ciated with PWV at baseline. Likewise,
during follow up, change in SAD and BMI,
but not WC were associated with four-year
change in PWV.
In general, SAD is much easier to meas-
ure 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 understood.
This exploratory study was undertaken 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 orthostatic hypo-
tension. They also investigated the asso-
ciations 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 param-
eters 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 hae-
matocrit, which may possibly be explained,
at least in part, by the high levels of adi-
ponectin.
In multivariate linear regression analysis,
systolic blood pressure, HDL cholesterol,
haematocrit, prothrombin and brachial
pulse-wave velocity were the main deter-
minants of HMW adiponectin. The study
was cross-sectional and therefore pre-
cluded speculation about causal relation-
ship. The authors however 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 hypertension on
carotid and peripheral vascular stiffness.
They recruited 114 subjects, including 14
normotensive non-diabetics, 37 hyperten-
sive non-diabetics, 20 non-hypertensive
diabetics and 39 hypertensive diabetics.
Pulse wave velocity (PWV) was meas-
ured by applanation tonometry, and carotid
IMT and lumen diameter were assessed by
ultrasonography. Peripheral PWV was simi-
lar between the four groups, while aortic
PWV, carotid stiffness index, carotid 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 analysis,
both hypertension and diabetes were asso-
ciated with high aortic PWV. In addition,
diabetes was associated with high IMT,
while hypertension was associated with
high carotid stiffness and diameter.
The authors concluded that type 2 dia-
betes and hypertension are characterised
by discrete differences in the vasculature
stiffening response. This, however, was
based on a very small number in a cross-
sectional analysis.
ADVANCE model better predictor
of cardiovascular risk in diabetes
The use of global cardiovascular risk models
is increasingly recommended as an appro-
priate basis for initiation and intensification
of cardiovascular risk-reduction therapies
in people with diabetes. 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 inves-
tigators, shared their validation studies of
the ADVANCE risk model. ADVANCE is the
largest global trial of cardiovascular pre-
vention 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 predicting 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 thresh-
old of ≥ 8% (equivalent to a 10-year risk
of 20%), the ADVANCE model identified
the 39% of the DIABHYCAR participants in
whom 66% cardiovascular disease events
were recorded.
Based on this performance, the investi-
gators concluded that the ADVANCE risk
model is appropriate for cardiovascular risk
stratification in contemporary populations
with diabetes who are already receiving
many risk-reducing therapies. It would be
interesting if this acceptable performance
was demonstrated in other validation stud-
ies, and that the uptake of the model be
shown to improve decision making and the
outcomes of care.
Further results from global
A1chieveTM study of insulin usage
in type 2 diabetes
J Aalbers, Special Assignments Editor
The A1chieveTM study was the largest-ever
observational study on the use of insulin
therapy in patients with type 2 diabetes.
The baseline data involving almost 70 000
patients were presented for the first time
at the 2011 American Diabetes Association
(ADA) meeting in June last year.
The study was a non-interventional
24-week observational study of type 2 dia-
betes patients, including both insulin users
and non-insulin users, who were started
on insulin detemir (Levemir®), insulin aspart
(NovoRapid®) or biphasic insulin aspart 30
(NovoMix 30®) in 28 countries across four
continents.
Of importance to our region is that the
study concentrated on less well-resourced
and newly developed countries. It could
well be the pivotal study of insulin manage-
ment in type 2 diabetes, providing unique
data that are more applicable to Africa
than that from other studies such as the
UKPDS.
The highlights of data presented at the
IDF is summarised in this report and will be
extensively covered in future issues of the
South African Journal of Diabetes and Vas-
cular Disease.