The Metabolic Syndrome is a combination of medical disorders that increase the risk of developing cardiovascular disease (heart disease and stroke) and diabetes mellitus.
Metabolic Syndrome is also known as syndrome X, metabolic syndrome X and insulin resistance syndrome.
Metabolic Syndrome is also defined as a grouping of cardiac risk factors that result from insulin resistance (where the body’s tissues do not respond normally to insulin).
‘Metabolic’ refers to the biochemical processes involved in the body’s normal functioning.
‘Risk factors’ are behaviours or conditions that increase the chances of developing a disease.
The term ‘Metabolic Syndrome’ dates back to at least the late 1950’s. It only came into relatively common usage in the late 1970’s to describe various associations of risk factors with diabetes that had been noted as early as the 1920’s. Other authors at this time also developed the concept of risk factors for myocardial infarction or heart attacks, and used such terms as ‘constellation of abnormalities’.
In 1988, in his Banting lecture, Gerald M. Reaven proposed insulin resistance as the underlying factor and named the constellation of abnormalities Syndrome X. Reaven did not include abdominal obesity as part of the condition. Abdominal obesity is now recognised as an integral part of the Metabolic Syndrome.
Signs and Symptoms
The five conditions listed below are metabolic risk factors for heart disease. A person can develop any one of these risk factors by itself, but they do tend to occur together. Metabolic Syndrome is diagnosed when a person has at least three of these heart disease risk factors.
· Central obesity. This means overweight with fat deposits mainly around the waist, a large waistline. This is also called abdominal obesity.
· Elevated triglycerides (a type of fat found in the blood).
· High blood pressure.
· Decreased HDL cholesterol (high-density lipoprotein cholesterol). HDL is considered ‘good’ cholesterol as it lowers the chance of heart disease.
· Fasting hyperglycaemia (elevated blood glucose or blood sugar levels). Other names for this are diabetes mellitus type 2, impaired glucose tolerance or insulin resistance.
Three or more of these five factors result in a greater chance of developing heart disease, diabetes, or a stroke. In general, a person with Metabolic Syndrome is twice as likely to develop heart disease, and five times as likely to develop diabetes, when compared to someone without Metabolic Syndrome.
Associated diseases and symptoms include elevated uric acid levels, fatty liver, polycystic ovarian syndrome, hormonal disturbances, haemochromatosis (iron overload), fatigue, depression, sleep apnoea and disturbed memory.
A high level of LDL cholesterol (low-density lipoprotein cholesterol, considered ‘bad’ cholesterol) and smoking, for example, are key risk factors in heart disease, but they are not components of Metabolic Syndrome.
The chance of developing Metabolic Syndrome is closely linked to being overweight or obese and to lack of physical activity.
The following is an overview of the criteria levels in establishing Metabolic Syndrome as suggested by such groups as the World Health Organisation and the American Heart Association:
· Elevated waist circumference: for men, equal to or greater than 102cm (40 inches), for women equal to or greater than 89cm (35 inches)
· Elevated triglycerides: equal to or greater than 1.7 mmol/L (150 mg/dL)
· Elevated blood pressure: equal to or greater than 130/85 mm Hg: or use of medication for hypertension
· Reduced HDL cholesterol: for men, less than 1.04 mmol/L (40 mg/dL), for women less than 1.29 mmol/L (50 mg/dL)
· Elevated fasting glucose: equal to or greater than 5.6 mmol/L (100mg/dL).
The cause of Metabolic Syndrome is unknown. The pathophysiology is extremely complex. Most patients are older, obese, sedentary, and have a degree of insulin resistance. The most important factors in order are:
· Genetics. Metabolic Syndrome tends to run in families, along with the propensity for type 2 diabetes. Hispanics and Asians seem to be at greater risk.
· Lifestyle, especially a lifestyle of low physical activity and excess caloric/kilojoule intake.
There is debate regarding whether obesity or insulin resistance is the cause of the Metabolic Syndrome or if they are both consequences of a more far-reaching metabolic derangement. However, Metabolic Syndrome is not observed in the absence of insulin resistance, while obesity is not present in all individuals who present with Metabolic Syndrome. It would seem that the primary problem in Metabolic Syndrome is insulin resistance.
Insulin resistance is caused by unbalanced glucose and insulin levels, resulting from cells that have been desensitised to insulin. This insensitivity to insulin prevents the efficient conversion of glucose, or blood sugar, through the cell wall into energy. Instead, free-floating glucose remains in the blood stream where it causes elevated blood glucose levels. The glucose is sent to the liver where it is converted into fat and then stored throughout the body. The end result can be weight gain and obesity.
The first line of treatment is change in lifestyle:
· Restriction of energy (food) intake.
· Increased physical activity.
However, drug treatment is frequently required. When this is so, generally the individual disorders that comprise the Metabolic Syndrome are treated separately. The drug managements of hypertension, the dyslipidaemias (high triglycerides and low HDL cholesterol) and diabetes are not the purpose of this newsletter.
Essential lifestyle changes in the treatment of Metabolic Syndrome are:
· Exercise Daily
It is recommended that 20-30 minutes of moderate intensity exercise, such as brisk walking, be undertaken each day.
Of course, any exercise plan must be matched to the level of the individual’s aerobic fitness. Medical advice, or advice from a professional trainer, may be necessary before beginning an exercise program. The majority of those with Metabolic Syndrome have a very sedentary lifestyle with minimal physical activity.
One useful guideline to acceptable physical activity is the number steps taken in the day. Pedometers are cheap and readily available. Pedometers count the number of steps and the more complex ones calculate things such as distance covered or calories consumed. The minimum number of steps each day should be 5,000, aiming for 10,000 or more. This would represent a distance or some 4 km to 8 km per day.
Regular daily physical activity is the ideal and is preferable to a heavy workout once every week or so.
· Lose weight
Losing as little as 5 to 10 percent of body weight can reduce insulin levels and blood pressure and decrease the risk of diabetes. My June 2008 newsletter ‘Health Benefits of Weight Reduction and Exercise - The Cuban Experience’ sets out the benefits of a small reduction in weight (5-7 kg) with increased physical activity in reducing death rates from diabetes, heart attacks and strokes.
Those with Metabolic Syndrome should make every attempt to reduce their body weight to a Body Mass Index (BMI) of between 20 and 25. The BMI is the weight in kilograms divided by the height in metres squared. The more weight loss, the better. If obese (BMI 30 or greater), initially aim to be only overweight (BMI 25 to 30), and if overweight, aim to have a BMI less than 25.
Be thin, be very thin.
· Eat Healthily
Not only will this help achieve weight loss, but a diet which is dominantly plant based, low in fat, and high in fruit and vegetables, has been found to have other important health benefits. (See the homepage for my book ‘How to live to 100+ Years Free from Symptoms and Disease, The Dietary Guidelines’). This type of eating plan is an especially important part of the management of Metabolic Syndrome.
It is important to eat fibre-rich foods. Dietary fibre can lower insulin levels. Dietary fibre can be insoluble, as in wheat bran, or soluble. Psyllium husk powder and pectin are examples of soluble fibre. Oats have both soluble and insoluble fibre. Soluble fibre benefits individuals with Metabolic Syndrome through its effects on appetite, body weight and blood cholesterol levels. For example, beta-glucans, fractions of oat soluble fibre, have been shown to effectively lower blood cholesterol, reduce postprandial blood glucose, induce satiety and suppress appetite.
· Stop Smoking
As already mentioned, smoking is a risk factor in heart disease. Although it is not one of the five conditions listed above relative to the diagnosis of Metabolic Syndrome, cigarette smoking increases insulin resistance and worsens the health consequences of Metabolic Syndrome.
Drugs as Treatment
The benefits of the above lifestyle changes must be monitored.
Human nature (and human metabolism) being what it is, many individuals with Metabolic Syndrome have trouble accomplishing these goals. In these cases, each risk factor needs to be treated individually.
This would mean drug therapy. Unfortunately, drugs tend to be the first line of treatment, the ‘quick fix‘. It takes time to ‘sell’ lifestyle change, with constant encouragement and follow up to help ‘make it happen’
The ideal is always to treat the cause, rather than take the easy way of the quick fix, namely drug therapy, so encouraged by the pharmaceutical industry. After all, lipid lowering drugs (statins), and antihypertensive drugs are in the Top 10 drugs prescribed each year (see my June 2006, February 2007 and January 2008 newsletters ‘Drugs – the Top 10').
Whether you have one, two or none of the components of Metabolic Syndrome, as can be clearly seen from the above the following lifestyle changes will reduce your risk of heart disease, diabetes and stroke:
· Commit to a healthy diet as outlined above.
· Get moving, with plenty of regular exercise and physical activity.
· Schedule regular checkups for blood pressure, cholesterol, triglyceride and blood sugar measurements.
The Western world is experiencing an epidemic of overweight and obesity. Well in excess of 50% of Australians are now overweight or obese, and the percentage is increasing every year, especially in younger people and children.
The Metabolic Syndrome affects a great number of people, and as we have seen, the prevalence increases with age. Some studies estimate the prevalence of Metabolic Syndrome in the USA to be up to 25% of the population. Comparable figures are not available in Australia. However, as of June 2008, Australians are slightly ahead of Americans in obesity, 26% to 25%. Extrapolating from this fact, it would be fair to say that some 25% of Australians would have Metabolic Syndrome.
Metabolic Syndrome is a condition that is readily treatable. Essential to this treatment is a lifestyle change as set out above. It requires commitment and an ongoing disciplined approach to make it happen, and keep on happening throughout life. Key to success in preventing the complications of Metabolic Syndrome, namely heart attacks, strokes and diabetes, is to lose weight (be thin, be very thin), to eat a healthy plant-based, low fat diet, and to be physically active. No-one can exercise for you. It is only you who puts the food into your mouth.
Even if you do not have Metabolic Syndrome, remember that it is possible to prevent or delay Metabolic Syndrome, mainly by lifestyle changes.
A healthy lifestyle is a lifetime commitment. Carpe diem.
* Copyright 2008: The Huntly Centre.
Disclaimer: All material on the huntlycentre.com.au website is provided for informational or educational purposes only. Consult a health professional regarding the applicability of any opinions or recommendations expressed herein, with respect to your symptoms or medical condition.
Back to the list Print friendly version