As type 2 diabetics are exposed to an increased risk of cardiovascular events, careful assessment of the level of risk is essential. It is necessary both to guide the essential complementary investigations and to determine the objectives of the treatment.
It is essential to assess the overall cardiovascular risk in each type 2 diabetic, given their increased risk of cardiovascular events. In theory, this is done simply by noting, one by one, the risk factors associated with elevated chronic blood sugar: smoking, elevated blood cholesterol, lack of physical exercise, stress, diet low in fruit and vegetables, male sex, age, family history of cardiovascular disease, excessive alcohol consumption…
But for diabetologists, the low cardiovascular risk does not exist in type 2 diabetics. Some patients have a moderate risk, but most of the time, the real challenge is to distinguish patients at very high risk from those who are just high risk. And this is where we must go further without harming the sick and weighing down the social security accounts.
High and very high risk
The very high risk is of course the patient who has already had a cardiovascular accident or the one who has proven kidney damage with a high level of albumin in the urine or kidney failure. If nothing is done, these patients are exposed to more frequent and earlier cardiovascular accidents: stroke, myocardial infarction, obstructive arteritis of the lower limbs, etc.
The patient at high risk is the diabetic who has other associated risk factors but no complications. The problem is that some diabetics who have no history of cardiovascular disease or kidney failure are also at very high risk of accidents, events that can occur very quickly. The challenge is therefore to identify the latter using other markers that are neither too expensive, nor too difficult, nor too dangerous.
Identify very high but “hidden” risks
Microalbuminuria, which testifies to damage to the blood vessels, is not a very high risk marker, but albuminuria becomes one (macroalbuminuria) because the latter testifies to kidney damage, but it is a marker bit late. Cholesterol or family history are rather associated risk factors that testify to a high level of impairment.
Searching for these very high-risk patients by functional examinations is of course possible, but if it is clearly possible to diagnose silent myocardial ischemia via a stress test or a myocardial stress scintigraphy, we cannot however subject these patients to examinations to all patients.
The calcium score to sort the sick
We therefore need a simple marker that allows sorting. And that’s the whole point of the calcium score, a very quick and inexpensive test that automatically detects and counts calcified atheroma plaques in the coronary arteries.
It has been demonstrated that in the event of a high calcium score, there is a major risk of coronary accident and it is therefore legitimate to consider a functional test: stress test or stress myocardial scintigraphy, which are more costly and riskier. The integration of this calcium score in the recommendations is in progress.
A fundamental initial assessment
This initial risk assessment time is therefore fundamental since it directs the level and cost of explorations, and ultimately, it guides the therapeutic objectives.
The objectives for lowering blood pressure in type 2 diabetics have been revised downwards but are identical in both cases: it is now necessary to reach 13/8, with a systolic between 120 and 129 mm Hg and a diastolic less than 90 mm Hg. In addition, these objectives must be achieved as quickly as possible, i.e. by immediately establishing a dual treatment (dual therapy) associating a renin system blocker and a diuretic or a calcium channel blocker .
On the other hand, for cholesterol, the objective of the level of LDL-cholesterol in the blood is less than 1 gram per liter in the event of high risk and less than 0.7 gram per liter in the event of very high risk for example.
For blood sugar, age must also be taken into account, because in patients who have had diabetes for a very long time, it is now clear that lowering them below 7% glycated hemoglobin puts them at risk of accident. and we will be less demanding from a certain age. Risk assessment will also impact the choice of therapies. For example, in the case of low HDL-cholesterol and high triglycerides, it will be possible to consider using a fibrate in combination with statins. For hypoglycaemics, it has been demonstrated that certain GLP1 analogues such as liraglutide and semaglutide give very interesting results in reducing cardiovascular accidents, which may make them indicated as first-line treatment in the event of very high risk.
5 risk factors to control
Beyond the balance of diabetes and the normalization of blood sugar levels, if we control each risk factor, this will result in a drastic reduction in risk: the cardiovascular risk at 10 years drops significantly below by 10%. According to a study published in the New England Journal of Medicinea well-adapted treatment and the absence of smoking can significantly reduce the aggravated risk of cardiovascular disease inherent in type 2 diabetes. In some cases, the excess risk could even disappear.
These risk factors associated with glycaemia, which are crucial to control, are blood pressure, lipid status (cholesterol, fractions of cholesterol and triglycerides in the blood), kidney function and smoking. Smoking is the most important risk factor for premature death, while high blood sugar is the most dangerous factor for heart attacks and strokes.
In diabetes, it is now a real paradigm shift, improving cardiovascular prognosis requires a more detailed assessment of risk levels which will make it possible to very significantly reduce the risk of accidents in order to better adjust control of all the risk factors associated with diabetes.
Perspectives: the interview with Pr Paul Valensi (Bobigny) on the management of cardiovascular risk in all its dimensions in type 2 diabetics
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