These findings contrast with those reported recently
by the US National Heart Lung and Blood Institute (NHLBI), suggesting
that intensive glucose lowering had increased the death rate among
patients with diabetes recruited to the Action to Control
Cardiovascular Risk in Diabetes (ACCORD) trial. The ACCORD trial has
been stopped prematurely because of a higher rate of mortality in the
patients in the intensive arm. ACCORD is an NHLBI-sponsored study of
around 10,000 patients with Type 2 diabetes and either heart disease or
two risk factors for heart disease. The glycaemic control part of the
trial was testing whether an intensive strategy that targets an HbA1c
level of <6.0% reduces the rate of cardiovascular events more than a
standard strategy that targets an HbA1c of 7.0% to 7.9%. Patients were
then assigned to two other parts of the trial depending on their blood
pressure and cholesterol levels, testing the combination of a fibrate
and a statin or statin monotherapy, and these arms will continue.
A
separate study, Steno-2, reported this month showing that in high-risk
Type 2 diabetes patients, early intensive intervention with multiple
drug combinations and behaviour modification leads to reduced rates of
death and cardiovascular disorders.
1
ADVANCE was designed to
answer two questions in patients with Type 2 diabetes: first, does
intensive treatment to lower blood pressure improve outcome; and
second, does intensive treatment to reduce blood glucose improve
outcome.
In September 2007, the ADVANCE Collaborative Group
published evidence in The Lancet showing that the blood
pressure-lowering treatment had reduced the death rate among
participants. In January 2008, the part of the study designed to assess
the effects of the intensive treatment to reduce blood glucose was
completed. As in ACCORD, this intensive treatment programme was
designed to lower blood glucose to levels below those usually
recommended by clinical guidelines.
2
Chairman of the ADVANCE
Data Monitoring and Safety Committee, Professor Rory Collins from the
University of Oxford, said: The interim results from ADVANCE provide
no confirmation of the adverse mortality trend reported from the ACCORD
study. He also noted that the ADVANCE interim results were based on
more than twice as much data and similar levels of glucose control as
in ACCORD.
The members of the Data Monitoring and Safety
Committee are the only members of ADVANCE study team with access to the
study results.
In ADVANCE, the intensive blood glucose lowering
programme aimed to reduce levels of HbA1c to below 6.5%. This treatment
regimen included a sulphonylurea drug for all patients and a range of
other drugs for those not reaching target blood glucose levels. ADVANCE
began in July 2001 and patients were treated and followed-up for an
average of five years. The Data Monitoring and Safety Committee, made
up of a panel of independent experts in the field, met every six months
to review the study data for any safety issues or other concerns. Blood
pressure treatment included the ACE inhibitor, perindopril, and the
diuretic, indapamide. This treatment was shown to reduce mortality in
patients with diabetes.
2
Steno-2 reported a 20% absolute risk
reduction in the primary end point all-cause mortality after a
total of 13.3 years of follow-up. Similarly, the absolute risk
reduction for cardiovascular death was 13.0% in high-risk Type 2
diabetes patients.
1
Professor Anthony Barnett, Professor of
Medicine/Honorary Consultant Physician at the University of Birmingham,
told the NOF that these new trials may have provided conflicting
evidence by chance or may in time illuminate new mechanisms that
explain the findings. Furthermore, says Professor Barnett, Steno-2 and
ACCORD studied very different patient populations and this may explain
the different outcomes.
Patients in Steno-2 were younger, had
had diabetes on average six years, and were deemed high risk by the
presence of microalbuminuria rather than having heart disease or two
known risk factors for heart disease as in ACCORD.
1. Gaede P,
Lund-Anderson H, Parving HH, et al. Effect of a multifactorial
intervention on mortality in type 2 diabetes. NEJM. 2008;358:580-591
http://content.nejm.org/cgi/content/abstract/358/6/580
2.
ADVANCE Collaborative Group; Patel A, MacMahon S, Chalmers J, Neal B,
et al. Effects of a fixed combination of perindopril and indapamide on
macrovascular and microvascular outcomes in patients with type 2
diabetes mellitus (the ADVANCE trial): a randomised controlled trial.
Lancet 2007;370:829-40
http://www.thelancet.com/journals/lancet/article/PIIS0140673607613038/abstract