To Colin, these symptoms alone did not seem very serious. He did not realize that added together, they greatly increase his risk of cardiovascular (heart and blood vessel) disease and type 2 diabetes. Both diseases are the result of metabolic syndrome, which he has probably had for years.

What is metabolic syndrome?

Metabolic syndrome represents a group of major heart disease risk factors. They include being overweight, having high insulin levels, high blood pressure, and abnormal blood fats. The blood fats combine high triglycerides with low HDL (good) cholesterol, and abnormal size and quality of LDL (bad) cholesterol. Metabolic syndrome is also called insulin resistance syndrome, or syndrome X (as first described in 1988). It is not a distinct disease but helps identify people, especially women, at higher risk of heart attack, stroke and type 2 diabetes. Cardiometabolic risk is another name for the same syndrome.

What causes metabolic syndrome?

Insulin resistance is believed to be the basic cause of metabolic syndrome. Insulin is a hormone the body needs to use glucose (sugar) as fuel. When someone develops insulin resistance, the body cells that normally respond to insulin no longer do so efficiently. These cells are then said to be ‘resistant’ to insulin. The body tries to make up for this poor response by making more insulin. This puts high levels of insulin into the bloodstream. Steady high levels of insulin in the bloodstream are thought to lead to metabolic syndrome.

High levels of insulin (hyperinsulinemia) may affect the sodium (salt) balance in the body, leading to high blood pressure.
The way in which the body stores and mobilizes fat is very sensitive to insulin. In insulin resistance, more fat is stored in the body. At the same time more body fat is broken down, resulting in high levels of triglycerides and lowered levels of HDL (good) cholesterol.
In people with type 2 diabetes, high blood glucose levels (hyperglycemia) occur when the body cannot make enough insulin to control the level of glucose in the blood.

Insulin resistance is very common, and can be inherited (genetic) or acquired. Those with a genetic tendency for insulin resistance include Aboriginal North Americans, people of South Asian heritage and African Americans. Excess weight gain, especially around the waist, is the most common reason for developing insulin resistance. Fat tissue is now known to be an active organ that makes a number of substances, such as growth factors, hormones, cytokines, and enzymes. Many affect sugar and fat metabolism (the process of breaking down and using the sugar and fat you eat). Several also affect the action of insulin. As you gain weight, you have more fat tissue and so produce more of these substances. Insulin's action is reduced, resulting in insulin resistance.

How common is metabolic syndrome?

According to two large studies in the U.S., one in four adults has metabolic syndrome. This includes both men and women. Traditionally, health professionals closely watch people with risk factors for heart disease. These risk factors include high blood LDL (bad) cholesterol, diabetes, high blood pressure, and family history of heart disease.

Although those with metabolic syndrome are at higher risk of heart disease, they often have normal or only slightly high levels of LDL cholesterol. This means they may not be identified as being at high risk. In fact, half of the people who suffer heart attacks and strokes have fairly normal LDL cholesterol levels. Increased awareness and diagnosis of metabolic syndrome will helps prevent and treat heart disease before it is established.

How can I assess my risk?

No single test is able to diagnose metabolic syndrome. However, these certain signs indicate a risk. Some can be checked at home or you may already know that you have them. Take a look at Table 1 to see whether you have any risks of metabolic syndrome.

Risk factors

Your waist girth (circumference) - to measure your waist circumference, place a tape measure around your bare waist at the level of your belly button. Be sure that the tape is snug, but does not press on your skin. It should be parallel to the floor. Relax; breathe out, and measure your waist.
High fasting blood glucose levels - fasting glucose levels instead of insulin levels are used for diagnosis.
Abnormal lipid values – a combination of high blood triglycerides and low HDL (good) cholesterol. Blood tests ordered by your doctor can find these values.
High blood pressure – also called hypertension.

Some of these can be checked at home or you may already know that you have them. Compare your values to those presented in Table 1.

Table 1. Diagnosing Metabolic Syndrome or Cardiometabolic Risk
People with any three of the following risk factors are said to have metabolic syndrome.
Large waist girth	Greater than 94 cm (37 inches) for men and greater than 80 cm (35 inches) for women. In men of South Asian, Japanese, Chinese or South and Central American ancestry, a measurement greater than 90 cm (35 inches).
High blood triglycerides	Greater than or equal to 1.7 mmol/L. (Normal is less than 1.5 mmol/L.)
Low HDL cholesterol	Less than 1 mmol/L for men, less than 1.3 mmol/L for women. (Normal is greater than 1.1 mmol/L for men and 1.3 mmol/L for women.)
Fasting plasma glucose	5.6 mmol/L or greater.
High blood pressure	Blood pressure greater than or equal to 130/85 mm Hg. (Normal is less than 120/80 mm Hg.)
Joint statement from the International Diabetes Federation, American Heart Association and the International Association for the Study of Obesity.

Additional risk factors for metabolic syndrome include:

Your body weight - people who are obese (body mass index or BMI of 30 kg/m2 or more) are at least twice as likely to have several of the risk factors for metabolic syndrome.
Family history of type 2 diabetes.
History of pre-diabetes (impaired glucose tolerance, where the blood glucose level is between normal and diabetes).
History of gestational diabetes in women (diabetes during pregnancy).
Acanthosis nigricans – a dark thickening of skin, especially at the neck and body folds. This indicates insulin resistance. These skin changes may be seen in dark as well as light-skinned people, so you can watch for them yourself.
Polycystic ovary syndrome – an increasingly common condition in which an imbalance in women’s sex hormones can lead to weight gain, diabetes and insulin resistance.

If you have one risk factor, ask to be checked for others, since they often occur together. For instance, if your doctor tells you that you have high blood pressure, be sure to get your lipid and fasting blood glucose levels tested.

Is metabolic syndrome preventable?

Yes. Two large studies have shown that lifestyle changes can be even more effective than medication in preventing diabetes and cardiovascular risk factors. In the studies, the lifestyle changes included eating a healthier diet with fewer calories, and increasing regular physical activity. Even though the average amount of weight lost during the three to four years of studies was only 3.5 to 5.5 kilograms (eight to 13 pounds), the risk of disease was still greatly reduced.

The message is that you can reduce your risk of metabolic syndrome by losing five to 10 per cent of body weight and being physically active for at least 30 minutes a day. Clinical studies have proven that the risk of diabetes can be cut by 60 per cent if you lose two pounds a year for four straight years. So every pound matters!

Why do lifestyle changes help?

Health behaviour changes are the best way to improve insulin resistance, which is believed to be the underlying cause of metabolic syndrome. In general, the more overweight you are, the greater your insulin resistance. As you become more insulin resistant, your pancreas (where insulin is made) pumps more insulin into your bloodstream. You are more likely to develop metabolic syndrome with higher insulin levels.

Losing weight and being more physically active improves your body's ability to use insulin. Physical activity helps by increasing your body’s sensitivity to insulin, so it is less likely to produce too much. Losing weight and increasing your activity level also lowers insulin levels in your blood stream. Lowered insulin levels put you at less risk of metabolic syndrome and the associated risks of heart disease and stroke.

The best way to change your lifestyle is to work with a team of health professionals. Many doctors have teamed up with nurses, dietitians, pharmacists, psychologists, and fitness experts to design programs best suited for their patients. Remember to check with your doctor before beginning any new nutrition or activity program.

When is drug therapy needed?

Sometimes changes in lifestyle are not enough. Work with your health care team to develop target values, such as levels for blood glucose, cholesterol and blood pressure. If target values are not met after changing your lifestyle for three to six months, then medication may be recommended.

No single drug can tackle metabolic syndrome. Separate medications may be needed to help lower your blood glucose, cholesterol, triglycerides, blood pressure, and even body weight. Your doctor or health professional can help decide when and what medications will be best. Ask your pharmacist if you have questions or if you are concerned about possible interactions between medications.

What should you do if you have type 2 diabetes?

Most people with type 2 diabetes also have metabolic syndrome. Both conditions are linked to higher risk of cardiovascular disease. If you have type 2 diabetes, you may already have early signs of cardiovascular disease. Find out if you have high blood pressure or dyslipidemia (high triglycerides along with low HDL cholesterol).

The same lifestyle changes used to treat diabetes, including better nutrition, more physical activity and weight loss, also manage cardiovascular disease. Work with your doctor and other health professionals (such as dietitians and pharmacists). Set appropriate target levels not only for blood glucose levels, but also blood pressure and blood fat levels. If these targets cannot be met through lifestyle changes, your doctor may prescribe medication.

For more information about metabolic syndrome:

www.ncbi.nlm.nih.govpubmedhealth/PMH0004546

It is not at all uncommon for someone with diabetes to require one or more types of medication to:

lower blood glucose levels to 6-10 mmol/L
control high blood pressure to less than 130/80
control abnormal blood fat and cholesterol levels, and protect against heart disease (bad cholesterol to 2 mmol/L or less).

Sometimes ASA (e.g. Aspirin™), is also recommended as a blood thinner.

Achieving treatment goals to manage metabolic syndrome is critically important in maintaining optimal health. Remember, every pound shed and inch lost from your waist will greatly improve your health. This lowers the risk of heart attack, stroke, diabetes and even cancer!

Metabolic Syndrome One in every four adults has it - do you?