Evidence-base - International Diabetes Federation

The Australian guidelines recommend using the Framingham risk equation unless
the person with diabetes is in a high risk category which include previous CVD event;
age > 60 years; microalbuminuria; moderate or severe chronic kidney disease (CKD)
(persistent proteinuria or eGFR < 45); extreme level of a single risk factor [6] .
The New Zealand guideline recommends annual risk assessment in people
with diabetes from the time of diagnosis and calculation of CVD risk using
the New Zealand Cardiovascular Risk Charts. People with diabetes with
microalbuminuria, diabetes duration of 10 or more years or with HbA 1c
consistently ≥ 8% / 64 mmol/mol are moved up one risk category [7] .
The Canadian guidelines consider the following with diabetes at high CVD risk:
men aged ≥ 45 years, women aged ≥ 50 years; men < 45 years and women < 50
years with ≥ 1 of the following: macrovascular disease; microvascular disease;
multiple additional risk factors; extreme level of a single risk factor; duration
of diabetes > 15 years with age > 30 years [8] . A risk calculator is not used to
assess CVD risk.
The Scottish SIGN guideline considers all people with diabetes over the age of
40 years to be at high risk and do not require a risk assessment with a scoring
system [9] .
WHO recommends decisions about whether to initiate specific CVD preventive
action, and with what degree of intensity, should be guided by estimation of the
risk of vascular events using risk prediction charts. Individuals who do not need
risk stratification because they are already at high CVD risk include those who
have already experienced a CVD event or have very high levels of individual risk
factors which includes people with 2 diabetes with overt nephropathy or other
significant renal disease [10] .
Ultimately the choice of risk assessment strategy must be made at a country
level taking into account country-specific CVD and risk factor epidemiological
data, availability and cost of CVD preventive treatments, and resource
implications of the size of the population identified at high risk and requiring
intervention.
There is an evidence-base for integrated multiple risk factor intensive
intervention, particularly in high-risk people with type 2 diabetes with
microalbuminuria, showing powerful absolute and relative risk reductions in
the Steno-2 study [11] and in its subsequent 5.5 years follow-up which showed a
further benefit in the reduction of mortality rates [12] .
People with diabetes identified at increased CVD risk require interventions
to reduce risk. High risk individuals should be encouraged to modify lifestyle
(see Chapter 5: Lifestyle management), smokers should cease smoking,
the overweight should reduce weight and blood glucose control should be
optimised. These individuals should also be treated with blood pressure
lowering medications (see Chapter 10: Blood pressure control) and statins,
unless contraindicated, not tolerated or clinically inappropriate. The wide
availability of low cost generic statins is likely to make them cost effective in
most parts of the world.
There is strong and consistent evidence that statins reduce the risk of death
or CVD events irrespective of age and gender, and across a wide range of
cholesterol levels [13-18] .
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