Syndrome X: The silent killer

If you’ve never heard the term Syndrome X, you’re not alone. This little-publicized syndrome is rarely discussed outside medical circles. Actually, the threat goes by several names: Syndrome X, the Deadly Quartet, Dysmetabolic Syndrome, Insulin Resistance Syndrome, or the Metabolic Syndrome. Whatever you call it though, it is emerging as a major risk factor for cardiovascular disease (CVD) — the No. 1 killer of Filipinos today. Indeed, recent data from our National Health Survey have shown that as much as one out of every five adult Filipinos suffers from Syndrome X.

Many Names, Same Problems

Metabolic syndrome is actually a jigsaw puzzle of problems, and the pieces have only recently begun to fit together. The shorthand term Syndrome X was coined by Gerald Reaven, MD, an emeritus professor of medicine at Stanford University. Experts have identified four attributes that characterize the syndrome in most people, the so-called deadly quartet: Obesity, diabetes or insulin resistance (the body’s inefficient use of insulin), abnormal lipids and high blood pressure.

Obesity: The typical profile of a person with Syndrome X includes obesity, particularly central or abdominal obesity. These patients have an increased waist to hip ratio. "When I see a patient who is overweight and has central obesity – the ‘apple’ shape rather than the ‘pear’ – I strongly suspect that the patient is insulin-resistant," notes Angela Inzerillo, MD, an endocrinologist at the Mount Sinai School of Medicine in New York. However, being overweight or obese isn’t required. "Slim people may be insulin-resistant, while an overweight person may not," she adds.

Insulin resistance: Also known as insulin insensitivity, it is the central feature of Syndrome X. This refers to the inability to deliver fuel – in the form of glucose (blood sugar) – to body cells, primarily muscle and fat tissue. "We’re seeing more and more insulin-resistant people," says Dr. Inzerillo. "It’s largely due to increase in obesity and lack of exercise."

The insulin hormone secreted by the pancreas, shepherds glucose into the cells. It acts as a molecular "key" to unlock cells, allowing glucose to enter. Insulin is released into the blood after a meal as food is converted into glucose.

"People with insulin resistance have plenty of hormone available, but they are unable to utilize it properly," Dr. Inzerillo explains. In response, the pancreas pours out more and more insulin. This elevates the amount of insulin in the blood, a condition called hyperinsulimia.

Abnormal lipids: Lipids are fatty substances that circulate in the blood. The most well-known types are cholesterol and triglycerides. The "lipid profile" of an individual – the concentration of various lipids in the blood – can indicate a high risk for insulin resistance. The two chief signs are high levels of triglycerides and low levels of "good" HDL cholesterol. "These are indications that a person is probably insulin-resistant," says Dr. Inzerillo.

Hypertension. High blood pressure completes the quartet of major risk factors for Syndrome X. It may be related to the high insulin levels in the blood associated with insulin resistance. It is estimated that 50 percent of people with high blood pressure are insulin-resistant.

What Is Your Risk For Syndrome X?

Not all people with Syndrome X are the same. But here are some of the important risk factors:

• Obesity (more than 20 percent over ideal body weight)

• Sedentary lifestyle

• Hypertension (high blood pressure)

• A close relative with diabetes

• High triglycerides and low HDL ("good") cholesterol

• A history of abnormalities in glucose metabolism

• Fat accumulated around the abdomen, even if you are not overweight

• A history of gestational diabetes (diabetes during pregnancy)

Do You Have It?

The consequences of Syndrome X are serious enough to warrant action on your part. The main concern among doctors today is the increased risk for heart disease associated with insulin resistance as well as type 2 diabetes. Unfortunately, there’s no single test that shows you have insulin resistance. Your doctor may choose to perform certain examinations, such as:

• Glucose tests: Several blood examinations can determine if your insulin metabolism is abnormal. "The easiest screening test is to have your doctor measure your levels of glucose after an eight- to twelve-hour fast and to give you a two-hour glucose tolerance test," Dr. Inzerillo says. These blood exams are usually performed to check for diabetes. A finding of 110 to 125 mg/dL in your fasting glucose test is a strong indication of insulin resistance. This state is called impaired glucose tolerance, and it means your insulin is not performing as well as it should. In the two-hour glucose tolerance test, a finding between 126 and 140 is also indicative of an impaired glucose tolerance.

• Lipid profiling: Your doctor may also measure the lipids in your blood. Levels of HDL cholesterol under 35 mg/dL and triglyceride levels over 200 mg/dL indicate Syndrome X and a greater risk for heart disease.

• Blood pressure: People with systolic blood pressure of 140 or diastolic pressure of 90 mm Hg or higher have hypertension. This is a risk factor for Syndrome X, especially when combined with obesity and lack of regular exercise.

• Abdominal obesity: Another way to assess risk for Syndrome X is by measuring the ratio of your hip-to-waist circumference. The wider you are in the abdomen compared to the hips, the higher the ratio. A waist-to-hip ratio of 1.0 or higher in men or 0.8 or higher in women is a risk factor for insulin resistance.

What Can You Do About It?

So you’ve considered the risk factors, consulted your doctor, and appear to have Syndrome X. What should you do? The solution mostly comes down to changing your diet and getting more exercise. Your goal should be to improve your body’s sensitivity to insulin and to control the health conditions associated with insulin insensitivity, such as high blood pressure, obesity and abnormal lipids.

Although weight loss, regular exercise, and dietary changes (cut fat and increase fiber) are always the preferred therapy, your doctor may recommend medications to address the various health conditions associated with obesity and Syndrome X. Drugs that target the underlying problem of insulin resistance have become available. For example, medications such as metformin (Glucophage, Fornidd) or the gliazones – pioglitazone (Actos) and rosiglitazone (Avandia) – can improve insulin sensitivity.

Orlistat (Xenical), a fat-blocker medication that works locally in the gut to prevent dietary fat absorption by about 30 percent has also been found to be effective in treating Syndrome X by improving total cholesterol level and blood sugar level, reducing waist circumference, and by significantly diminishing the risk of developing type 2 diabetes.

"Aggressive management of lipids and blood pressure is also of central importance," Dr. Inzerillo adds.

Take Charge

Indeed, if you turn out to have insulin resistance, your doctor will urge you to be aggressive in implementing your treatment.

Weight loss and exercise are key steps in reducing insulin resistance and improving the abnormalities that characterize metabolic syndrome. Exercise actually improves insulin sensitivity, especially in muscle cells, and even a small weight loss can make a difference. In the ongoing Framingham Study, a weight loss of only four or five pounds produced dramatic benefits in people with Syndrome X.

The take-home message is this: At the first sign of problem, take steps to reduce your risks. It is increasingly clear that your life may depend on it.