Alternative names for Metabolic Syndrome

Syndrome X, Insulin Resistance syndrome, MetS

What is Metabolic Syndrome?

Metabolic Syndrome (MetS), is a group of conditions which are risk factors of cardiovascular disease (CVD) which increase the chance of having a heart attack. They include an increased risk of developing other metabolic diseases such as diabetes or non-diabetic hyperglycaemia (prediabetes). People with metabolic syndrome are five times more likely to develop type 2 diabetes mellitus. The conditions include individuals who have central obesity, high blood pressure, high blood sugar, and abnormal blood cholesterol.  

What causes Metabolic Syndrome?

A variety of factors contribute to the development of MetS. Early research has suggested that chronic, high concentrations of insulin (hyperinsulinemia), is an underlying cause and precedes the development of other symptoms such as hypertension, hypertriglyceridemia, and the development of type 2 diabetes (T2D). In addition, lifestyle factors such as diet and physical activity levels can contribute to the development of Metabolic Syndrome. Other risk factors include genetics, age, ethnicity (South-Asian/Hispanic) and increased weight.

What are the signs and symptoms of Metabolic Syndrome?

There are a number of symptoms which characterise MetS. These include elevated fasting blood glucose levels (diabetes/non-diabetic hyperglycaemia), excess body fat around the abdomen (abdominal obesity), high cholesterol and high blood pressure. The criteria for diagnosis are mentioned below. Some people may have signs of insulin resistance like darkened, thickened skin areas on the neck, armpits or in other folds and creases.

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Figure 1: Complications of metabolic syndrome

How common is Metabolic Syndrome?

The prevalence of metabolic syndrome commonly mirrors that of obesity and type 2 diabetes, which are outcomes of MetS. It is believed that MetS is about three times higher than diabetes and can be estimated to be a quarter of the world’s population, however, because the criteria of MetS differs between organisations, it is difficult to know the true number of individuals with MetS. According to the NHS in the UK, metabolic syndrome is very common affecting one in four individuals, and one in three individuals aged over 50 years.

Is Metabolic Syndrome inherited?

Genetics plays a significant role in metabolic syndrome, and up to 50% of all cases appear to be inherited. However, lifestyle factors are a major contributor too.

How is Metabolic Syndrome diagnosed?

Metabolic syndrome is a series of conditions which all have their own clinical diagnosis based on their clinical criteria. The criteria for MetS differs slightly, the most common criteria which are used are defined by organisations such as the World Health Organisation (WHO), International Diabetes Federation (IDF) and National Cholesterol Education Program (NCEP).

The International Diabetes Federation diagnose metabolic syndrome by patients having a waist circumference of ≥94 cm (in men) or >80 cm (in women) (≥ 90cm and ≥ 80cm for South and East Asian men and women, respectively) along with the presence of two or more of the following:

1. Fasting blood glucose greater than or equal to (≥) 5.6 mmol/L (100 mg/dl) or diagnosed with diabetes mellitus.
2. High density lipoprotein cholesterol (HDL-C) levels of <1.0 mmol/L (40 mg/dl) in men, <1.3 mmol/L (50 mg/dl) in women or drug treatment for low HDL-C.
3. Blood triglycerides ≥ 1.7 mmol/L (150 mg/dl) or drug treatment for elevated triglycerides.
4. Blood pressure ≥ 130/85 mmHg or drug treatment for hypertension.
   How is Metabolic Syndrome treated? 
   No single drug is used to treat MetS as it is comprised of multiple symptoms outlined above however, certain medications can be prescribed to treat individual symptoms.

Lifestyle interventions such as exercise play an important role in the treatment of patients with MetS. Increasing cardiorespiratory fitness through exercise training has been shown to reduce the risk of mortality and can also improve other aspects of mental and physical health such as increasing insulin sensitivity and improving glucose control, reducing blood pressure and increase cardiorespiratory capacity. At least 150 minutes of moderate to intense exercise a week, spread over four to five days. Reducing physical inactivity should be encouraged.

It can also be treated by changes in your food habits, either the types or quantity of food you consume which can improve blood glucose control, as well as reduce blood pressure and low-density lipoprotein (LDL) cholesterol levels. A diet high in fruits, vegetables, nuts, whole grains, and reduced saturated fat can be beneficial. Various diets can be helpful and should be individualised.

The goal is to reduce weight, reduce risk factors for heart disease like smoking, treat underlying conditions, and improve the quality of life.

Are there any side-effects to the treatment?

There are no side effects to the changes in diet or exercise interventions, however you should consult your GP before undertaking any extreme diet changes or rigorous exercise training regime to ensure that it’s safe for your current health status. There may be side-effects associated with medications being used for the underlying conditions and they should be discussed with healthcare professionals.

What are the longer-term implications of Metabolic Syndrome?

The range of complications which are related to MetS can have long term implications including the increased risk of cardiovascular disease (CVD) and chances of heart attack and stroke. Elevated blood glucose levels which are a result of insulin resistance and increased body fat (obesity) can lead to the development of Diabetes Mellitus which has a number of associated complications. It may also lead to build-up of fat in the liver (metabolic-dysfunction associated steatotic liver disease), deposits of uric acid in the joints (gout) and pain and stiffness of joints (osteoarthritis), and cancers (Figure 1).