Metabolic Syndrome

The increase in prevalence of individuals who are obese or develop metabolic complications like cardiovascular disease, diabetes and non-alcoholic fatty liver disease (NAFLD) is increasing. The development of these diseases is a result of a several of symptoms which are collectively known as metabolic syndrome.

Alternative names for Metabolic Syndrome

Syndrome X, Insulin Resistance, MetS

What is Metabolic Syndrome?

Metabolic Syndrome (MetS), is a series of complications which are risk factors of cardiovascular disease (CVD) which increase the chance of having a heart attack. The symptoms include other metabolic diseases such as diabetes or prediabetes of which people with metabolic syndrome are 5 times more likely to become diabetic.

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.

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/pre-diabetes), excess body fat around the abdomen (abdominal obesity), high cholesterol and high blood pressure.

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 three times higher than diabetes and can be estimated to be a quarter of the world’s population, however because 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 1 in 3 individuals aged over 50.

Is Metabolic Syndrome inherited?

Although research has shown that there are some genes which are linked to obesity and MetS, the rate in prevalence of individual who MetS mean that genetics potentially plays only a small part in the development of MetS.

How is Metabolic Syndrome diagnosed? 

Metabolic syndrome is a series of symptoms which all have their own clinical diagnosed 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 IDF, diagnose metabolic syndrome by patients having a waist circumference of >94 cm (men) or >80 cm (women) along with the presence of two or more of the following:

1. Blood glucose greater than 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 medication 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.

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.

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 rigorous exercise training regime to ensure that it’s safe for your current health status.

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. 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.

Useful external resources

National Health Service (NHS)
International Diabetes Federation 
Saklayen M. G. (2018). The Global Epidemic of the Metabolic Syndrome. Current hypertension reports, 20(2), 12
Roberts, C. K., Hevener, A. L., & Barnard, R. J. (2013). Metabolic syndrome and insulin resistance: underlying causes and modification by exercise training. Comprehensive Physiology, 3(1), 1–58. 

Last reviewed: Aug 2020