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Editors

SanniSöderlund
MikkoSyvänne

Metabolic Syndrome

Essentials

  • 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.
  • MetS is associated with accumulation of fat in the liver (non-alcoholic fatty liver disease, NAFLD Non-Alcoholic Fatty Liver Disease (NAFLD) and Non-Alcoholic Steatohepatitis (NASH)), skeletal muscle, myocardium and pancreas.
  • 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 HASH(0x2fcaf98) 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 HASH(0x2fcaf98) 130 / HASH(0x2fcaf98) 85 mmHg or specific treatment for hypertension
    • fasting glucose HASH(0x2fcaf98) 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
    • the risk of diabetes.
  • Patients with MetS commonly have fatty liver, and it is one of the most common causes of increased liver enzyme (ALT) concentrations. ALT is, however, an insensitive test, and routine screening is not recommended. See also the articles on assessing a patient with an abnormal liver function test result Assessing a Patient with an Abnormal Liver Function Test Result and on NAFLD/NASH Non-Alcoholic Fatty Liver Disease (NAFLD) and Non-Alcoholic Steatohepatitis (NASH).
  • Other disorders associated with MetS that should be considered include:

TreatmentPrevention of Type 2 Diabetes in Persons at Increased Risk for the Development of T2d

  • The treatment of MetS is based on lifestyle modification Interventions for Reversing Metabolic Syndrome.
    • 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.
  • Regular exercise will support weight management and significantly improve the components of MetS Exercise and Diet for Preventing Type 2 Diabetes Mellitus.
  • 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.
  • Hypertension is treated by lifestyle changes and, if needed, by medication Hypertension: Investigations, Treatment Initiation and Non-Pharmacological Treatment Drug Treatment for Hypertension, with the aim of reducing blood pressure to an average of < 140/< 90 mmHg as measured by a professional, which is equivalent to an average of < 135/< 85 mmHg measured at home. For persons with diabetes, the target level of diastolic pressure is < 80 mmHg.
  • 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.
  • 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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