Metabolic syndrome, also known as insulin resistance syndrome or syndrome X, happens when you have a group of health conditions that put you at a greater risk of developing heart disease, stroke, and type 2 diabetes.
Although the first formal definition of metabolic syndrome entered medical textbooks not so long ago (1998), metabolic syndrome is widespread. As many as 93 million American adults have metabolic syndrome, or about 1 in 3 adults.
The syndrome runs in families and is more common among African-American, Hispanic, Asian, and Native American people. The risk of developing metabolic syndrome increases as you age. It’s also more common in people with lower socioeconomic status and less education.
Though a great number of people meet the criteria for metabolic syndrome, not all doctors agree that it’s a helpful way of looking at someone’s health.
What Is Metabolic Syndrome?
Metabolic syndrome is not a disease in itself. Instead, it's a group of risk factors for heart disease, stroke, and type 2 diabetes — high blood pressure, high blood sugar, unhealthy cholesterol levels, high triglycerides, and excess abdominal fat.
Specifically, metabolic syndrome can lead to atherosclerosis, a process in which a substance called plaque — made up of fats, cholesterol, and other substances — builds up on the sides of the arteries. The arteries then become clogged and stiff, limiting blood flow. Plaque may rupture, or break apart, leading to blood clots that can cut off the flow of blood. That can trigger a heart attack or stroke.
Obviously, having any one of these risk factors isn't good. But when they're combined, they set the stage for serious problems. These risk factors double your risk of blood vessel, or vascular, diseases and heart disease, which can lead to heart attacks and strokes. They increase your risk of diabetes by five times.
The good news is that metabolic syndrome can be controlled, largely with changes to your lifestyle.
Metabolic Syndrome Criteria
According to the American Heart Association and the National Heart, Lung, and Blood Institute, there are five risk factors that make up metabolic syndrome.
| For men: 40 inches or larger |
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150 mg/dL or higher
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For men: Less than 40 mg/dL
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Having blood pressure of 130/80 or greater
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Blood Sugar: High Fasting Glucose Level | 100 mg/dL or higher |
To be diagnosed with metabolic syndrome, you would have at least three of these risk factors.
Metabolic Syndrome Causes
Experts aren't sure why metabolic syndrome develops. It's a collection of risk factors, not a single disease. So it probably has many causes. Some risk factors are:
Insulin is a hormone made by the pancreas. It helps get glucose — a sugar made from the food you eat — into cells in your muscles, liver, and fat, where it’s used for energy or stored for later. When insulin resistance develops, those cells require more than normal amount of insulin to take in the glucose they need. If your pancreas does not make enough insulin, the glucose will remain in your bloodstream, elevating your blood sugar (or blood glucose) level. Eventually, this can lead to diabetes. Insulin resistance is closely connected to having excess weight in the belly. Some experts believe that insulin resistance plays the biggest role in metabolic syndrome.
Obesity, especially abdominal obesity, is an important risk factor. That’s because increasing amounts of fat boost your level of chemicals called free fatty acids. And as these accumulate, your risk of insulin resistance rises as well. Free fatty acids and insulin resistance also raise your LDL (or “bad”) cholesterol and lower your HDL (or “good”) cholesterol, as well as boost your blood pressure and your triglycerides. Fat cells also contribute to inflammation, which can lead to plaque buildup in your arteries and add to your risk of insulin resistance, high blood pressure, heart disease, and blood vessel disease.
Experts say that metabolic syndrome is becoming more common because of rising obesity rates.
Unhealthy lifestyle
Eating a diet high in unhealthy processed foods and not getting enough physical activity contributes to the development of metabolic syndrome.
Hormonal imbalance
Hormones may play a role. The sex hormone estrogen, for example, declines after menopause. When that happens, the risk of insulin resistance begins to rise. Low levels of the sex hormone testosterone also may increase the risk of insulin resistance.
Certain conditions involving hormones also increase the risk. For instance, polycystic ovary syndrome (PCOS), a condition that affects fertility, is related to hormonal imbalance and metabolic syndrome.
Smoking
Smoking contributes to several of the risk factors for metabolic syndrome. It lowers your HDL (“good”) cholesterol and raises your blood pressure. Smokers also have higher levels of triglycerides than nonsmokers. Keep in mind: Vaping also puts your health at risk. Research links it to high triglycerides, high blood pressure, and low HDL (“good”) cholesterol, and it may contribute to obesity and prediabetes as well.
Genetics
Certain gene mutations inherited from your parents can raise your risk of developing one or more of the five conditions that make up metabolic syndrome. For example, an estimated 250 different genes have been linked to obesity. Genes also play a part in insulin resistance and high blood pressure. And you can inherit genetic conditions that affect your cholesterol and triglyceride levels. The most common is familial combined hyperlipidemia, which causes high levels of LDL (“bad”) cholesterol, low levels of HDL (“good”) cholesterol, and high triglycerides. It has been linked with metabolic syndrome.
However, lifestyle factors, such as what you eat, and your environment also play a role. They can affect how your genes work. Some research suggests that high-calorie, high-fat diets affect genes involved in both metabolism and in appetite control. Poor nutrition early in life may alter your genes, making you more likely to develop obesity, diabetes, high blood pressure, and high cholesterol.
Use of certain medications
A number of different types of medications may trigger insulin resistance, weight gain, high triglycerides, or low HDL (“good”) cholesterol. They include:
- Corticosteroids
- Some blood pressure medications, such as beta-blockers and thiazide diuretics
- A type of diabetes drug called thiazolidinediones (TZDs)
- Oral contraceptives
- Some HIV medications
- Some antipsychotic drugs
- Some antidepressants
Sleep disorders
Experts don’t yet fully understand the relationship between sleep and metabolic syndrome. However, studies show that poor sleep does increase your risk of both the syndrome and the different conditions that contribute to it. For example, your risk of metabolic syndrome goes up if you get too little or too much sleep each night. Both also raise your risk of obesity and high blood pressure. Too little sleep also comes with a risk of elevated blood sugar. At least one common sleep disorder, obstructive sleep apnea, has been tied to all five components of metabolic syndrome: obesity, high blood pressure, high triglycerides, high blood sugar, and low HDL (“good”) cholesterol.
Metabolic Syndrome Diagnosis
Your doctor can determine if you have metabolic syndrome with a discussion of your health history, family history, your diet and exercise habits, and any risk factors and symptoms you may have. You also will undergo a few tests. These are:
Waist circumference. Your doctor will measure your waist to help determine if you have abdominal obesity. For men and people assigned male at birth (AMAB), this is more than 40 inches. For women and people assigned female at birth (AFAB), this is more than 35 inches.
Blood pressure. If your blood pressure measures more than 130/85, you may have high blood pressure.
High blood sugar. A fasting blood glucose test that measures 100-125 mg/dL or higher means you may have prediabetes or, if it’s above 125 mg/dL, diabetes.
High triglycerides. This will be measured as part of a blood test called a lipid panel. You may have high triglycerides if your triglycerides are 150 mg/dL or higher.
Low HDL (“good”) cholesterol. This will be measured as part of a blood test called a lipid panel. Low HDL is 40 mg/dL in men and people AMAB or less than 50 mg/dL in women and people AFAB.
Your doctor will diagnose you with metabolic syndrome if you have three or more of the above conditions.
Diet for Metabolic Syndrome
A heart-healthy diet can help you lose weight, improve your cholesterol and triglyceride levels, manage your blood sugar, and lower your blood pressure. There’s no specific diet for metabolic syndrome, but two eating plans stand out: the Mediterranean diet and the Dietary Approaches to Stop Hypertension (DASH) diet. Both emphasize fruits, vegetables, and whole grains, while limiting unhealthy fats like saturated fats. The DASH diet has fewer restrictions on meat and dairy, while the Mediterranean diet recommends using olive oil on a regular basis. Both diets limit added sugar, salt (sodium), and highly processed foods. Your doctor can refer you to a dietitian for guidance on the most appropriate eating plan for you. Don’t start a highly restrictive diet without first discussing it with your doctor. Such diets, including certain high-protein or low-carb diets, because they may not provide important nutrients that support your overall health.
Lifestyle Changes for Metabolic Syndrome
Along with a healthy eating plan, there’s plenty more that you can do to take care of yourself if you have metabolic syndrome.
Exercise regularly
Physical activity can improve insulin resistance, support heart health, and help with weight loss. Talk to your doctor before you get started to determine the safest and most effective exercise program for you.
Quit smoking and vaping
Both smoking and vaping can raise your blood pressure and triglycerides, lower your HDL (“good”) cholesterol, and otherwise harm your health. The American Lung Association can help.
Achieve and maintain a healthy weight
If you’re overweight or have obesity, even small amounts of weight loss bring significant benefits. For example, losing 7% of your body weight can improve your blood pressure and insulin resistance, and lower your risk of diabetes.
Manage your stress
Regular exercise, yoga, mindfulness meditation, breathing exercises, and other relaxation techniques can reduce your stress. Doing so can lower your cortisol, a hormone released during times of stress. Over time, higher than normal cortisol can lead to high blood pressure, high triglycerides, and high blood sugar.
Sleep well
Good quality sleep lowers your risk of metabolic syndrome or keeps it from getting worse. If you struggle to get 7 to 9 hours of good sleep each night, talk to your doctor to see if you have sleep apnea or another sleep disorder. Treatments and lifestyle adjustments can improve your sleep.
Metabolic Syndrome Treatment
The goal of treatment is to lower your risk of developing heart disease and type 2 diabetes. It will involve lifestyle changes and, if necessary, medications and surgery.
Metabolic syndrome medications
Medications may be prescribed to treat the individual components of metabolic syndrome, including:
- Cholesterol-lowering medications such as statins
- High blood pressure medications such as thiazide diuretics, ACE inhibitors, and calcium channel blockers
- Diabetes medications such as metformin
Weight loss surgery
Also called bariatric surgery, this major surgery makes your stomach smaller so that you eat less. It’s usually recommended only if you haven’t been able to lose weight by other means. Your doctor also may advise surgery if your obesity puts your health at greater risk than the potential complications of surgery, such as damage to your digestive system and a reduced ability to absorb the nutrients in the foods you eat.
Can Your Reverse Metabolic Syndrome?
Yes! Through lifestyle changes — and medications if you need them — you can get the different components of metabolic syndrome under control and lower your risk of diabetes, heart disease, and stroke. The most important things you can do: lose weight and exercise. Doing so will lower your blood pressure and cholesterol and improve your insulin resistance.
Takeaways
If you've just been diagnosed with metabolic syndrome, think of it as a wake-up call. It's time to get serious about improving your health. Making simple lasting changes to your habits, starting now, may not be easy, but doing so can prevent serious illness in the future. Talk to your doctor about starting an exercise program and a healthy eating plan, two key components of reversing metabolic syndrome. Also discuss any other contributing health issues, like poor sleep, chronic stress, and smoking.
Metabolic Syndrome FAQs
Why is metabolic syndrome called syndrome X?
Syndrome X was the original name, coined in 1988 by researcher Gerald Reaven, of the grouping of risk factors for heart disease and diabetes. In 1998, the World Health Organization defined the criteria of the syndrome and called it metabolic syndrome. It’s sometimes still referred to as syndrome X, as well as metabolic syndrome X, insulin resistance syndrome, and dysmetabolic syndrome.
What are the five signs of metabolic syndrome?
To be diagnosed with metabolic syndrome, you must have three of the five criteria, which are:
- High blood pressure
- High triglycerides
- High blood sugar
- Low HDL (“good”) cholesterol
- Abdominal obesity
What are metabolic diseases?
Metabolism is the process by which your body converts food and drink into energy. A metabolic disease is a disease, or disorder, that affects this process. Diabetes is one common example of a metabolic disease.
What is the best exercise for metabolic syndrome?
Follow a program that combines aerobic exercises, like walking, running, and swimming, and weight training. Aim for a minimum of 150 minutes of aerobic exercise per week and weight training twice a week. Talk to your doctor before you start to be sure your program will be safe and effective for you.
What foods are bad for metabolic syndrome?
Your doctor likely will advise you to limit foods with lots of carbs, as well as red meat, processed foods, and foods that contain unhealthy fats, added sugars, and high levels of salt.
What organs are affected by metabolic syndrome?
Your cardiovascular system, which includes your heart and blood vessels, as well as your pancreas and liver are among the prime targets of metabolic syndrome.
