128
VOLUME 9 NUMBER 3 • SEPTEMBER 2012
ADA WATCH
SA JOURNAL OF DIABETES & VASCULAR DISEASE
TABLE OF CONTENTS
CLINICAL REVIEW
Hypoglycaemia and cardiovascular risk................ 128
Differentiating between GLP-1 receptor agonists... 128
Differentiating between GLP-1 receptor agonists...128
Focus on basal insulin.......................................... 129
New bolus insulins............................................... 130
Preserving beta-cells............................................ 130
Bariatric surgery: gastric bypass........................... 130
Islet cell transplantation: numbers still small,
but some success.............................................. 130
FOCUS ON QUALITY OF CARE
How to improve diabetes outcomes: a systematic
review of strategies that work, presented as
part of the ADA/
Lancet
symposium.................. 131
NHANES casts spotlight on risk of diabetes from
exposure to tobacco smoke (passive smoking).. 131
Baroreflex sensitivity (BRS) in type 2 diabetes
improves on statin therapy (low-dose
atorvastatin)..................................................... 131
Global survey finds one in four type 2 diabetes
patients do not take basal insulin as prescribed
and more than a third suffer from
hypoglycaemia................................................. 131
ORIGIN trial shows safety and efficacy of insulin
glargine: no adverse cardiovascular outcomes
after a 6.2-year follow up of early insulin use.... 131
‘
Real-world’ study of liraglutide versus twice-daily
exenatide and DPP-4 inhibitors......................... 132
BARI 2D study adds insights on glycaemic control
strategies and peripheral neuropathy................ 132
SYMPOSIUM ON SLEEP DISORDERS AND DIABETES
Sleep duration and quality and diabetes risk........ 132
Sleep apnoea and diabetes risk............................ 132
Mechanisms of insulin resistance in sleep apnoea.. 132
SYMPOSIUM ON THE EFFECTS OF BARIATRIC SUR-
GERY ON MATERNAL AND OFFSPRING OUTCOMES
Effects of restrictive and malabsorptive bariatric
surgery on reproductive-age women: fertility,
metabolic effects and contraception................. 132
Approach to managing the post-bariatric patient
during pregnancy, including impact on pre-
gestational and gestational diabetes and
hypertension.................................................... 132
New lessons in hypertension and diabetes:
an update on clinical trials and clinical guidelines.. 133
Alternative markers of glycaemia in the ARIC study. 133
2012
UPDATE FROM PHILADELPHIA, USA
American Diabetes Association Congress
8–12
June 2012
Contributors:
Dr L Lombard, Dr D Jivan, J Aalbers
SUMMARIES
ADA WATCH
CLINICAL REVIEW
Hypoglycaemia and cardiovascular
risk
Simon Heller elaborated on the possible
mechanisms of increased cardiovascular
risk caused by hypoglycaemia. Data were
shown that hypoglycaemia caused a pro-
longed QT, therefore increasing the risk
of ventricular rhythm disturbances as well
as increased platelet aggregation for sev-
eral hours after the hypoglycaemic event.
It also decreased spontaneous thromboly-
sis after a serious hypoglycaemic event
(
this effect has been shown to last up to
seven days). Hypoglycaemia has also been
strongly linked to bradydysrhythmias, with
an increased relative risk of nearly nine-fold
for bradycardia. It therefore also increases
the risk of sudden death.
Exenatide twice daily versus
glimepiride
In an ADA
/
Lancet
symposium, Prof Guntram
Schernthaner presented the EUREXA study,
comparing exenatide twice daily versus
glimepiride for prevention of glycaemic
deterioration in patients with type 2 diabe-
tes who failed metformin therapy. This was
an open-label, randomised, controlled trial
comparing 10 µg bid of exenatide versus
glimepiride in a titration dose.
Failure was diagnosed as an HbA
1
c
level
> 7% on two consecutive occasions, or an
HbA
1
c
level > 9% on one occasion. Patients
(515)
were randomised to the exenatide
group, of whom 203 achieved failure of
this treatment, while in 514 patients in the
glimepiride group, 262 reached the end-
point of failure of this therapy. Exenatide
was therefore shown to be non-inferior
to glimepiride for the time-to-treatment
failure.
The groups were well matched, although
there was quite a large dropout percent-
age during the study. At baseline, the
HbA
1
c
level was 7.43% on average. At 24
weeks, the Kaplan-Meier curves diverted
in favour of exenatide. At the end of the
study, 41.4% of the patients on exenatide
failed the treatment, while 53.8% of those
on glimepiride failed.
If the starting HbA
1
c
level was ≤ 7.3%,
exenatide and glimepride showed the same
results, but when the HbA
1
c
level was above
7.3%,
the exenatide was superior; 44.8%
of the patients on exenatide could achieve
an HbA
1
c
level of < 7%, compared to 30.8%
on glimepiride at the end of the study.
A 5.4-kg weight difference was shown
over the follow-up period of three years
in this study, favouring exenatide. The
exenatide group lost an average of 3.9 kg,
while the glimepiride group gained 1.5 kg.
Incidents of hypoglycaemia were much
more common in the glimepiride group,
as could be expected. The glimepiride
group had 5.3 hypoglycaemic incidents per
patient years, compared to 1.52 hypogly-
caemic events per patient years in the
exenatide group.
The only criticism of the trial was that
glimepiride was not titrated to full strength
in many of the patients, which could have
optimised HbA
1
c
levels in some of these
patients.
Differentiating between GLP-1
receptor agonists
In a session on incretin-based therapies,
Philip Knop gave a talk on GLP-1 receptor
agonists, asking whether they are all the
same. All the molecules were discussed and
the differences were pointed out.
Exenatide in a twice-daily dose (known
in South Africa as Byetta) has a half-life of
2.5
hours. The peak after injection is about
two hours. It mainly gets excreted via the
kidneys and gives a better postprandial
