Patients with type 2 diabetes are at an increased
risk for developing cardiovascular disease. Diabetes can affect blood flow to
the heart, resulting in angina and heart attack. It could also cause heart failure. Besides, diabetes could also
affect the blood supply to the brain, leading to transient ischemic attacks and
Controlling blood sugar in diabetes helps to reduce the risk of
individuals suffering from these complications. However, it is unclear whether
an intensive control of blood glucose will be more effective than standard
therapy in reducing the incidence of cardiovascular events.
completed study (the ACCORD or Action to Control Cardiovascular Risk in
Diabetes trial) investigated whether intensive control of blood glucose would
reduce the risk for developing serious cardiovascular events
. The study was conducted in
middle-aged and elderly diabetics between 40 and 79 years of age from the
United States and Canada. These patients were suffering from diabetes over a
prolonged period. They had a cardiovascular risk factor or previous
cardiovascular disease and had glycated hemoglobin levels equal or greater than
7.5%. Glycated hemoglobin levels indicate the level of diabetes control. A person with a glycated
hemoglobin level of more than 6% is said to be suffering from diabetes.
The patients enrolled in the study were randomized
into two groups. One group was the intensive therapy group. This group was
treated to reduce glycated hemoglobin level below 6%. The other group was the
standard treatment group where the target glycated hemoglobin level was between
7 and 7.9%.
found that intensive blood glucose lowering did not result in a significant
decrease in cardiovascular events. In fact, at the end of 3.5 years, the
intensive therapy had to be terminated due to increased mortality in this
study was further continued for up to 5 years wherein the intensive therapy was
stopped and the standard therapy was adopted for all patients.
Though the deaths are not attributed to the lower
blood sugar levels and not all were related to the cardiovascular system, the
exact reason for these deaths was unclear. In fact, the patients in the
intensive treatment group had a reduced incidence of non-fatal heart attacks. However, due to the increased number of
deaths in this subgroup, the authors do not recommend intensive diabetes
therapy for high - risk patients with advanced type 2 diabetes.
Long-Term Effects of
Intensive Glucose Lowering on Cardiovascular Outcomes.
The ACCORD Study Group. N Engl J Med 2011; 364:818-828