What is metabolic syndrome?
Metabolic syndrome is a cluster of conditions — all of which increase the risk of heart disease — occurring together in one individual. People with metabolic syndrome not only have an increased risk of heart disease, but their risk of stroke and diabetes is also higher than average. Metabolic syndrome (also known as syndrome X and the insulin resistance syndrome) affects about 20-30 per cent of the adult population in Australia.
Five major international organisations recently developed a unified definition for metabolic syndrome. To have metabolic syndrome, a person must have at least 3 of the following 5 abnormal findings:
- central obesity (body fat that’s concentrated around the waist);
- a raised triglyceride level (a type of fat in the blood);
- a low level of HDL-cholesterol (‘good’ cholesterol);
- high blood pressure; or
- an increased blood sugar level after a period of fasting, or previously diagnosed type 2 diabetes.
If you had high blood pressure which is now normal because it’s controlled by medicine, then for the purposes of diagnosing metabolic syndrome you are still classed as having high blood pressure. Similarly, if your HDL-cholesterol or triglyceride results are normal but you’re taking medicine to make them that way, then you are still classed as having those risk factors.
The International Diabetes Federation defines central obesity in people of European descent as a waist circumference of 94 cm or more in men and 80 cm or more in women. But these values are not appropriate for all ethnic groups because of the differences in body proportions in different populations. For South and South-East Asian people, the corresponding values are 90 cm for men but remain at 80 cm for women.
Who gets metabolic syndrome?
Factors that may put you at a higher risk than other people of developing metabolic syndrome include:
- increasing age;
- a diet that’s high in kilojoules and saturated fat;
- lack of exercise and physical activity;
- a family history of diabetes;
- a history of gestational diabetes (diabetes during pregnancy);
- a history of polycystic ovary syndrome (a metabolic disorder that affects a woman’s hormones and reproductive system); and
- being of Asian descent.
Although metabolic syndrome generally affects older people, it is possible, with increasing childhood obesity, for metabolic syndrome to affect young adults and even adolescents and children.
What causes metabolic syndrome?
It is thought that the underlying causes of metabolic syndrome are central obesity (weight that is carried mainly around the waist) and resistance to insulin (a hormone made by the pancreas that helps control your blood sugar levels).
People who have insulin resistance tend to have higher than normal levels of insulin and sugar in their blood, increasing the risk of diabetes. In addition, high levels of insulin can contribute to the development of high blood pressure and help raise triglyceride levels.
The cause of insulin resistance is not yet properly understood, but both genetic and environmental factors, including being overweight and physically inactive, are thought to play a major role.
Why is metabolic syndrome a health concern?
All of the individual components of metabolic syndrome are risk factors for atherosclerosis (hardening and narrowing of the arteries). Atherosclerosis causes coronary heart disease (the disease that’s responsible for angina and heart attacks) and strokes. People with metabolic syndrome, who have a combination of several of these risk factors rolled into one, are at even higher risk of these problems. Having metabolic syndrome doubles your risk of having cardiovascular disease, such as heart attack or stroke, compared with people who don’t have this syndrome.
Insulin resistance and central obesity also put you at high risk of developing diabetes — people with metabolic syndrome have 5 times the risk of developing type 2 diabetes.
Is there any treatment?
Lifestyle interventions are the first step in treating metabolic syndrome. By changing your lifestyle, you can help delay or even prevent the complications of metabolic syndrome (heart disease, stroke and diabetes) from developing.
Even a small amount of weight loss can help improve insulin resistance, lower your blood pressure and correct your cholesterol levels. Try to restrict your calorie intake to achieve a 5-10 per cent reduction in your body weight within 12 months.
Eat a healthy diet
A healthy diet is one that’s low in kilojoules, fat and salt, and high in whole grains, fruits and vegetables. Reducing the amount of fats, especially saturated fats and trans fats, in your diet not only helps with weight loss, but also improves cholesterol levels. A healthy diet can also reduce your risk of developing diabetes, and by reducing your salt intake and eating healthily you can reduce your blood pressure.
Try to fit in 30-60 minutes of moderately strenuous activity (such as a brisk walk) on most days of the week. Increasing your level of physical activity will help you lose weight, lower your blood pressure and improve your blood glucose and cholesterol levels. But remember, if you don’t usually get much physical activity, it’s best to check with your doctor before starting an exercise programme.
Smoking worsens the health problems associated with metabolic syndrome. By quitting smoking you can help reduce your risk of heart disease and diabetes.
It’s important to have regular check-ups with your doctor to measure your weight, waist circumference, cholesterol levels, blood pressure and blood sugar levels. Your doctor can also provide support and help you stay motivated to keep up with your new, healthier habits.
What about medicines?
When lifestyle modifications alone aren't enough, medicines can be used to lower blood pressure and correct cholesterol and triglyceride levels. Medicines that control blood sugar levels can be used to treat people who already have type 2 diabetes, and also those with insulin resistance and elevated blood sugar levels, to delay or prevent the onset of full-blown diabetes.
There are also medicines available that can help with weight loss, which may be effective for some people when used in combination with a balanced diet and exercise. Medicines for weight loss are generally only tried if diet and exercise alone have not been successful.
Your doctor may also recommend you take low-dose aspirin, which has been found to reduce the risk of heart attack and stroke when taken on a daily basis.
Last Reviewed: 05/02/2010
1. Alberti KGMM, Eckel RH, Grundy SM, et al. Harmonizing the metabolic syndrome: A Joint Interim Statement of the International Diabetes Federation Task Force on Epidemiology and Prevention; National Heart, Lung, and Blood Institute; American Heart Association; World Heart Federation; International Atherosclerosis Society; and International Association for the Study of Obesity. Circulation 2009; 120: 1640-45. 2. Eckel RH, Alberti KGMM, Grundy SM, Zimmett PZ. The metabolic syndrome. Lancet 2010; 375: 181-83. 3. National Heart Lung and Blood Institute. What is the metabolic syndrome? [Website; revised January 2010]. http://www.nhlbi.nih.gov/health/dci/Diseases/ms/ms_whatis.html (accessed February 2010). 4. American Heart Association. Statistical fact sheet risk factors. Metabolic syndrome statistics [Updated 2010]. Available from: http://www.americanheart.org/downloadable/heart/1136819875357META06.pdf (accessed February 2010).
Video: Metabolic syndrome
What is metabolic syndrome?
Metabolic syndrome, also known as syndrome X or insulin resistance syndrome, is a collection of conditions that together increases the risk of developing heart disease or type 2 diabetes. These conditions include an increased waistline, hypertension (high blood pressure), increased blood sugar levels, high amounts of triglycerides and low levels of high density lipoprotein (HDL), also known as 'good' cholesterol, in the blood.
Metabolic syndrome is common in Australia, with around one in five people meeting the criteria for diagnosis1. Metabolic syndrome can affect both men and women and becomes more common as people get older.
The cause of metabolic syndrome is generally lifestyle related, including eating an unhealthy diet and lack of exercise. In some cases, genetic factors can also play a part.
Risk factors for metabolic syndrome include:
- Being overweight or obese;
- Being physically inactive;
- Eating a diet high in sugar or saturated fat;
- Older age;
- Menopause, and;
- Having a family history of metabolic syndrome or diabetes.
Limiting the amount of foods in your diet that contain saturated fat can help to prevent metabolic syndrome.
Signs and symptoms
Obesity is the main obvious sign of metabolic syndrome. The other conditions generally do not show specific signs and symptoms, even when at dangerous levels. If you have consistently high blood sugar levels, you may experience an increase in thirst. Hypertension can cause dull headaches, dizzy spells or nosebleeds if it has reached a dangerously high level for an extended period of time.
Methods for diagnosis
Metabolic syndrome can be diagnosed by your doctor using a physical examination and blood tests to assess for each of the conditions that are associated with the disorder. A diagnosis is made if you are obese and any two of either a high blood sugar level, a high triglyceride level, hypertension or low HDL cholesterol level. Tests include:
- A measurement of waist circumference. As a general guide, if your waist measurement is more than 94-102cm for men and 80cm for women, you have an increased risk of metabolic syndrome;
- A blood pressure test where a reading higher than 130/85 indicates you have hypertension;
- A blood test to check the level of fasting blood sugar, which can be taken before breakfast. A result greater than 5.6 mmol/L indicates a high level of blood sugar;
- A blood test to check the levels of triglycerides - a result higher than 1.7 mmol/L indicates a high level of triglycerides, and;
- A blood test to check the level of high density lipoprotein (HDL). A result of less than 1 mmol/L for men and 1.3 mmol/L for women indicates a low level of HDL.
A blood test can be used to check sugar and lipid levels in the blood.
Types of treatment
Treatment of metabolic syndrome involves lifestyle changes to become healthier. These include:
- Weight loss;
- Regular exercise. A good goal is to do at least 30 minutes of exercise on most days of the week;
- Eating less by reducing the portion sizes of main meals and avoiding snacking throughout the day;
- Eating healthily, which includes plenty of fruits and vegetables, lean meats and dairy products (mostly reduced fat);
- Limiting refined sugar found in sweets and sugary drinks;
- Drinking plenty of water - at least 6-8 glasses a day for adults;
- Reducing saturated fats by limiting fatty or processed foods;
- Improving cholesterol levels by eating nuts, fish and other foods that contain omega-3 fatty acids;
- Reducing stress;
- Not smoking, and;
- Reducing alcohol intake.
In some cases, diet and lifestyle changes are not enough and medication may be required to lower blood pressure or reduce the amount of triglycerides in the blood. Your doctor will be able to recommend which medication is needed to treat the various features of metabolic syndrome.
Exercise can help to reduce the risk of, as well as treat, metabolic syndrome.
The long-term complications of metabolic syndrome are heart disease and type 2 diabetes.
Heart disease, also known as cardiovascular disease, includes coronary artery disease, which is the formation of fat deposits inside the blood vessels of the heart. Heart disease can lead to angina, heart attack and death.
Type 2 diabetes
Type 2 diabetes is a chronic condition that affects the ability of your body to control the level of sugar in the blood. The condition can be effectively managed, but has complications including heart disease, nerve damage and kidney disease.
The outlook for people with metabolic syndrome is good if action is taken to address each feature of the syndrome to reach the recommended healthy targets.
Metabolic syndrome is almost always preventable. Prevention involves maintaining a healthy weight, eating nutritious food, limiting fatty or sugar-filled foods and exercising regularly. It is also important to have regular health checks to monitor blood pressure, blood sugar and blood triglyceride levels. This will allow your doctor to identify any abnormal results and suggest a treatment plan to bring your results into a healthy range.
Eating a wide variety of healthy foods can help to prevent metabolic syndrome.
Polycystic ovary syndrome
Polycystic ovary syndrome (PCOS) is a condition that affects females in their reproductive years. It may cause irregular periods, excess hair growth and cysts on the ovaries.
Red wine health benefits for type 2 diabetes
A glass of red wine with dinner for people with type 2 diabetes can reduce heart disease risk and improve blood sugar profiles.
Video: Cushing's syndrome
Cushing's syndrome is a rare condition in which the body has too much of the hormone cortisol. This hormone has many important roles in the human body. However, an excess of it can have unwanted effects such as weight gain, high blood pressure (hypertension) and bruising easily.
Video: Polycystic ovary syndrome
Polycystic ovary syndrome (PCOS) is a long-term condition in women causing an imbalance in sex hormones. Symptoms include weight gain, acne, and increase in facial or body hair, which can all affect self-esteem. There are a range of treatments available to help manage the condition.