What is the metabolic syndrome?
The metabolic syndrome is a group of risk factors that increases your risk of developing diabetes, heart disease, and stroke. People with metabolic syndrome have twice the risk of having heart disease or stroke and 5 times the risk of developing type 2 diabetes compared with people who do not have it. The metabolic syndrome is more common in women than in men, affecting 1 in every 3 women in the US.
A person is diagnosed with the metabolic syndrome if they have at least 3 of the following 5 risk factors: higher-than-normal blood sugar, blood pressure, or triglyceride levels; a large waistline; and low HDL (good) cholesterol. The metabolic syndrome does not usually have any immediate symptoms—the medical problems it causes develop gradually over time. Your doctor can diagnose the metabolic syndrome with a physical exam and simple blood tests.
Do I have the metabolic syndrome?
You are considered to have the metabolic syndrome if you have 3 or more components of the syndrome, outlined in the table below.
|Criteria for Metabolic Syndrome Diagnosis (Any 3 of 5)|
|Large waistline†||Waist larger than 35 inches in women (40 inches in men)|
|Elevated triglycerides*||150 mg/dL or higher|
|Low HDL (“good”) cholesterol||Less than 50 mg/dL in women (40 mg/dL in men)|
|Elevated blood pressure*||130 mm Hg or higher (top number)
85 mm Hg or higher (bottom number)
|Elevated blood sugar||Fasting blood sugar 100 mg/dL or higher|
|†In Asian Americans, the cutoff is 31 inches or more in women (35 inches in men). Some people of non-Asian origin (white, black, Hispanic) with slightly high waist circumference (31 to 35 inches in women, 37 to 39 inches in men) also benefit from lifestyle changes to reduce abdominal obesity.
*or if you are on medication for this risk factor
How common is the metabolic syndrome?
One in 3 women in the US have the metabolic syndrome. African-American women are 57% more likely to have the metabolic syndrome than African-American men, and Mexican-American women are 26% more likely to have the metabolic syndrome than Mexican-American men. There is no gender difference for white men and women. The chances of developing the metabolic syndrome increase as you get older; more than half of women older than 60 years have this syndrome.
US Prevalence of the Metabolic Syndrome
*Statistically significant gender difference
What causes the metabolic syndrome?
No single cause of metabolic syndrome has been identified, and it is possible that there are different causes in different people. The underlying factors that contribute to developing metabolic syndrome are being overweight or obese especially around the waist not getting enough exercise, and genetic factors that make you susceptible.
What is the connection between blood sugar and the metabolic syndrome?
In many people, the metabolic syndrome seems to be related to a disorder called insulin resistance. Insulin is a hormone released by the pancreas that helps sugar (glucose) enter your body’s cells. Insulin resistance is when your body cannot use insulin efficiently, causing an increased amount of sugar in your blood. This high blood sugar can lead to type 2 diabetes.
Metabolic syndrome usually happens when your blood sugar is higher than normal, but not high enough to be classified as diabetes. Exactly how this happens is not known, and some people with the metabolic syndrome do not have insulin resistance. Insulin resistance increases the levels of cholesterol and triglycerides in your blood, causing damage to your arteries, and may interfere with your kidney’s ability to process salt, raising your blood pressure.
Who is at risk for insulin resistance?
Some people are more likely than others to develop insulin resistance. Often this is due to genetic factors, such as a family history of diabetes. Women with a history of polycystic ovary syndrome (when the body produces too many male hormones) are more likely to develop insulin resistance, as are women who have had diabetes during pregnancy (gestational diabetes). In people with a predisposition to insulin resistance, being overweight and not getting enough exercise may trigger the metabolic syndrome.
Metabolic Syndrome and Stroke Prevention
How does the metabolic syndrome affect stroke risk?
Metabolic syndrome increases the risk of stroke in all ethnic groups and both sexes. Having the metabolic syndrome approximately doubles your risk of having a stroke compared with healthy persons, and the syndrome is estimated to account for 30% of all blocked-vessel (ischemic) strokes in women. Nearly half of all strokes occur in people who have the metabolic syndrome.
Each component of the metabolic syndrome increases your risk of a first or repeat blocked-vessel stroke. The more of these components you have, the higher your risk of developing stroke. High blood pressure, high cholesterol, and low HDL (good) cholesterol are all individual risk factors for atherosclerosis, meaning they can cause fatty deposits (plaque) to build up on the walls of your blood vessels and reduce blood flow to the brain. In a study of 1895 adults (59% were women), the metabolic syndrome increased by 36% the risk of developing plaque in the carotid arteries in the neck. Another study, of 1588 adults (37% were women), found that the metabolic syndrome increased the risk of developing atherosclerosis in the carotid arteries more in women than in men.
How can the metabolic syndrome be prevented?
Even if you already have 1 or 2 of the risk factors that are part of the metabolic syndrome, you can take steps to prevent getting the syndrome and the serious risks that come with it, including stroke.
The safest and most effective way to do this is by making heart-healthy lifestyle changes.
- Weight control: If you are overweight or obese, particularly if you have excess fat around the waist, you are at increased risk for developing metabolic syndrome.
- Exercise: As little as 30 minutes a day of moderate exercise can help you lose weight, lower your insulin levels, blood pressure, and LDL (bad) cholesterol, and increase HDL (good) cholesterol
- Diet: Eating a heart-healthy diet will help you lose weight and reduce your risk of developing stroke, heart disease, or diabetes.
Sometimes lifestyle changes are not enough to fully control your risk factors. You may need medications to improve some risk factors such as high blood pressure and high cholesterol and lipids.
How is the metabolic syndrome treated?
The goal of treating the metabolic syndrome is to prevent type 2 diabetes, heart disease, heart attack, and stroke. The same lifestyle changes that help prevent the metabolic syndrome (weight control, changing your diet, getting more exercise, and quitting smoking) also help if you are diagnosed with the metabolic syndrome. Improving your diet and exercising regularly can delay or prevent the metabolic syndrome from progressing to type 2 diabetes, a major risk factor for stroke.
If healthy lifestyle changes are not enough, your doctor may prescribe medications to treat the individual risk factors of the metabolic syndrome, such as high blood pressure, high blood sugar, and high cholesterol. You may also receive low-dose aspirin to help reduce your risk of blood clots. There is no one medication that treats the metabolic syndrome as a whole.
Does treating the metabolic syndrome prevent stroke?
The treatment of the risk factors that make up the metabolic syndrome reduces your chances of having a first or repeat blocked-vessel stroke. As a set of risk factors that occur together, the metabolic syndrome helps doctors identify people who are at an increased but potentially manageable risk for diabetes, heart disease, and stroke. Treatment and other preventive measures can then be taken to reverse or reduce the risk of developing any of these diseases in people who perhaps would not be treated as early or at all.