Metabolic Syndrome

Metabolic syndrome is thought to affect one in four adults in the UK. it is the name given to a mix of risk factors that can increase the risk of developing diseases of the heart and blood vessels such as heart attacks, strokes and diabetes.

These risk factors are:

  • high blood pressure
  • insulin resistance (where insulin is less effective in keeping the level of sugar in the blood at a normal healthy levels)
  • overweight or obesity – especially around the waistline
  • unhealthy levels of blood fats – usually high triglyceride levels and low HDL levels.

This group of risk factors has been known for many years and was first called “metabolic syndrome” back in 1988. Having 3 or more of these risk factors usually suggests a person has metabolic syndrome.

Insulin resistance

Insulin is a hormone that is made in the pancreas. It helps to control the amount of sugar in the blood. In insulin resistance our bodies don’t respond properly to the insulin we make. So our bodies make more and more insulin to cope with the build-up of sugar in the blood.

Over time the pancreas is put under more and more pressure to product more insulin. Eventually the strain can becomes too much. When this happens the pancreas will not be able to produce enough insulin or the insulin producing cells become exhausted. This makes the level of sugar in the blood rise and stay high. This problem is called type 2 diabetes. Doctors have special guidelines for diagnosing diabetes. This usually involves having a sugar tolerance test, to see how the body copes with a known amount of sugar over a known period of time.

Insulin resistance is more common in people who are obese, especially if they are carrying the excess fat around their waistline. Excess fat can get stuck inside the pancreas where is can cause problems with blood sugar control. People from certain ethnic backgrounds are more prone to metabolic syndrome. For example those with a South Asian or black Afro-Caribbean background.

High blood pressure

Blood pressure is a measure of the Blood pressure is a measure of the force that your heart uses to push blood around your body. It is recorded as two numbers:

  • systolic - this records the pressure when your heart beats
  • diastolic - this records the pressure when the heart is at rest (between the beats)

Both numbers are important. Blood pressure is extremely variable and may easily be raised by stress, emotional state, physical activity and even “a visit to the doctors”.

What is normal blood pressure?

Normal blood pressure is considered to be a systolic between 110 and 130 and a diastolic between 60 and 85. Blood pressure is measured in millimetres of mercury, which is written down as: mmHg. High blood pressure, or hypertension, is diagnosed when several readings (taken on at least 3 separate occasions) show your systolic pressure is 140 or above, or your diastolic is 90 or above, or both.

Why is high blood pressure (hypertension) dangerous?

Poorly controlled hypertension increases the risk of heart attacks and stroke as well as kidney and eye damage. If your blood pressure is too high your GP will prescribe medication and review this regularly. However simple changes to your diet and lifestyle can also be a very effective part of your treatment too.


Obesity is the name used for someone who has gained enough excess weight to put their health at risk. Central obesity – where excess fat is stored mainly around the waistline - can increase risk of developing diabetes and metabolic syndrome.

Measuring your waistline is a good way of identifying your risk. To do this use a flexible tape measure and wrap this around your waistline. For many people this will be at your widest point – roughly around where your tummy button is. Use the table below to check your risk:

  Increased health risk Serious health risk
Women 80 cm (32 inches) or above 88 cm (35 inches) or above
Men 94 cm (37 inches) or above 102 cm (40 inches) or above
Asian men 90 com (36 inches) or above 101 cm (39 inches) or above

Too much fat in the blood

Doctors now recognise that there is a particular pattern of raised blood fats that put people at risk of metabolic syndrome. They sometimes refer to this as dyslipidaemia.

These high levels of fat result when the body has more difficulty then normal coping with the fats and sugars from the food we eat. People with dyslipidaemia are often very overweight.

The main type of fat that is higher than normal is triglyceride. These high levels of triglycerides often go hand in hand with low amounts of a kind of cholesterol called HDL cholesterol. Some doctors refer to this as “good cholesterol”.

Normal levels of these blood fats are:

In the UK blood fats are measured in millimoles per litre (mmol/L). Some countries measure blood fats in milligrams per decilitre (mg/dl). Here we give the normal figures in mmol/L.

  • HDL cholesterol should be above 1mmol/L in men and 1.2mmol/L in women
  • Triglycerides should be below 1.7mmol/L (or less than 2.3mmol/L if you ate normally before the test)