Metabolic syndrome (MetS) is a cluster of factors increasing the risk of atherosclerotic diseases and diabetes.
The risk of vascular disease within 5-10 years is twice as high as in people without MetS; the lifetime risk ratio is probably even higher.
The risk of diabetes is five-fold.
MetS consists of central obesity, hypertension, dyslipidaemia (high plasma triglyceride levels and low HDL cholesterol levels) and impaired glucose metabolism.
In addition to what constitutes MetS by definition, it is often associated with hyperuricaemia and a prothrombotic and proinflammatory state and insulin resistance, which are not routinely measured.
It is not categoric classification (MetS or no MetS) that is important but active examination and treatment of all associated factors if MetS is suspected.
A diagnosis of MetS is not a substitute for the assessment of total risk of arterial diseases using an appropriate risk calculator because the diagnosis of MetS does not consider age, gender, smoking or total and LDL cholesterol levels.
Definition
MetS is diagnosed in a patient with at least three of the following five criteria:
increased waist circumference by country-specific and ethnic limits (see below)
triglycerides ≥ 1.70 mmol/l or specific treatment for this lipid abnormality
HDL-cholesterol < 1.0 mmol/l in men or < 1.3 mmol/l in women or specific treatment for this lipid abnormality
blood pressure ≥ 130 / ≥ 85 mmHg or specific treatment for hypertension
fasting glucose ≥ 5.6 mmol/l or specific treatment affecting fasting glucose levels.
Waist circumference
In various definitions, two limits are specified for waist circumference for Europid people, both men and women:
men 94 cm, women 80 cm
men 102 cm, women 88 cm.
The interpretation is that if the lower limits are exceeded, the risks of vascular disease and diabetes start increasing (any worsening of the situation should be prevented, at least), and if the upper limits are exceeded, the risk is considerably increased (weight loss necessary).
For practical purposes, we can round off the action limits for men to 100 cm and for women to 90 cm.
Prevalence
The prevalence of MetS in a Finnish population sample aged 24 to 75 years (FINRISKI 2007) was 35%.
In a Northern Finnish group of elderly people (average age 72 years), the prevalence of MetS was, according to different definitions, 25 to 37% in men and 21 to 48% in women.
Diagnosis
Detection of any component of MetS should lead to examining the other components.
Waist circumference
Blood pressure
Plasma lipids
2-hour glucose tolerance test, unless the patient has been diagnosed with diabetes
Performing a glucose tolerance test increases new diagnoses of diabetes in patients at risk by one third compared to fasting glucose tests alone.
The following should be assessed in patients with MetS:
the total risk of arterial diseases (using appropriate risk calculator) and
After an intensive lifestyle intervention, the criteria for MetS cease to exist in twice the number of subjects compared to controls.
Weight loss is essential and has positive effects on all components of MetS and diseases associated with it.
The first aim is to permanently lose 5 to 10% of weight in one year; this is sufficient to achieve clear metabolic and other advantages.
Subsequent continued weight loss toward normal weight will have favourable effects.
It is most important for the quality of the diet to eat plenty of fruit and vegetables, soft (fish and vegetable) fats instead of hard (animal) fat, and whole grain products instead of sugar and refined grains, to limit salt intake, and to consume no more than moderate amounts of alcohol Dietary Advice for the Prevention of Type 2 Diabetes Mellitus in Adults.
In a controlled study, an intervention based on a healthy diet and exercise reduced the risk of diabetes in prediabetic patients by 58%, and similar results can be achieved in primary health care practice.
Due to their metabolic drawbacks, thiazide diuretics and beta blockers should be avoided as first-line medication but particularly small doses of thiazide diuretics or similar other diuretics or vasodilating beta blockers can be used in drug combinations.
The treatment of dyslipidaemia targets mainly LDL-cholesterol, aiming at levels of < 3 mmol/l, <2.6 mmol/l, < 1.8 mmol/l or < 1.4 mmol/l, depending on the assessed risk of arterial diseases Treatment of Dyslipidaemias.
A PCSK9 inhibitor can also be used, although reimbursement of such drug may not be available to all patients.
Smoking cessation is essential for reducing the risk of arterial diseases.
If the glucose metabolism disorder is at the diabetes level, the principles for the treatment of diabetes should be followed.
References
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