Metabolic Syndrome

Metabolic syndrome is the result of a group of co-occurring conditions that increase your risk for type 2 diabetes, stroke, and heart disease. Criteria for metabolic syndrome include high triglyceride levels, excess body fat around the waist, abnormal cholesterol, high blood sugar and high blood pressure. 

Metabolic syndrome has several causes, and each affects the other. You can control some of these causes, such as your diet and physical activity levels. Other causes, such as your age and your genes, cannot be controlled.

A person’s weight is a major cause of metabolic syndrome. Fat cells, especially in your abdomen, can raise your levels of chemicals called free fatty acids. Free fatty acids can raise your levels of other chemicals and hormones that affect the way your body controls your blood sugar levels. Your body may not respond well to insulin, which is a hormone that controls how much sugar your muscles and organs absorb from your blood. This is called insulin resistance.

Free fatty acids and insulin resistance can raise your “bad” LDL cholesterol and lower your “good” HDL cholesterol. Insulin resistance can also raise your blood pressure and blood triglyceride levels.

Also, cells from your immune system can cause your extra fat cells to make chemicals that increase inflammation in your body. This inflammation can cause plaque, a waxy substance, to build up inside your blood vessels. Plaque can break off and block your blood vessels. Inflammation itself also causes insulin resistance, high blood pressure, and heart and blood vessel diseases.

You may have metabolic syndrome if you have three or more of the following conditions:

• A large waistline: This is also called abdominal obesity or "having an apple shape." Extra fat in your stomach area is a bigger risk factor for heart disease than extra fat in other parts of your body.
• High blood pressure: If your blood pressure rises and stays high for a long time, it can damage your heart and blood vessels. High blood pressure can also cause plaque, a waxy substance, to build up in your arteries. Plaque can cause heart and blood vessel diseases such as heart attack or stroke.
• High blood sugar levels: This can damage your blood vessels and raise your risk of getting blood clots. Blood clots can cause heart and blood vessel diseases.
• High blood triglycerides: Triglycerides are a type of fat found in your blood. High levels of triglycerides can raise your levels of LDL cholesterol, sometimes called bad cholesterol. This raises your risk of heart disease.
• Low HDL cholesterol, sometimes called good cholesterol: Blood cholesterol levels are important for heart health. “Good” HDL cholesterol can help remove “bad” LDL cholesterol from your blood vessels. “Bad” LDL cholesterol can cause plaque buildup in your blood vessels.

Your risk of metabolic syndrome is affected by some things you can control, such as your lifestyle habits, and some that you cannot control, such as your age or family history.

Risk factors you can control, like lifestyle habits, can raise your risk of metabolic syndrome:

• Being inactive
• Eating an unhealthy diet and large portion sizes
• Not getting enough good-quality sleep, which helps control how your body absorbs nutrients from the food you eat
• Smoking and drinking a lot of alcohol during pregnancy: These habits can raise your child’s risk of metabolic syndrome later in life.
• Occupation: Shift workers have a higher risk of metabolic syndrome because they often have circadian clocks that are not aligned with the environment. This can cause problems with how your body absorbs nutrients from food.

There are also some risk factors you may not be able to control that lead to a diagnosis of metabolic syndrome:

• Age: Your risk of metabolic syndrome increases as you get older.
• Environment: Low socioeconomic status can lead to an unhealthy diet and an inactive lifestyle, and can cause you not to get enough sleep (sleep deprivation).
• Family history and genetics: Your genes can affect your weight or how your body responds to insulin. You have a higher risk of metabolic syndrome if others in your family have had diabetes, metabolic syndrome or any of its risk factors.
• Other medical conditions: The following medical conditions can raise your risk of metabolic syndrome.
  • Overweight and obesity are the main risk factors for metabolic syndrome because they can raise “bad” LDL cholesterol, blood triglycerides and blood pressure, and lower “good” HDL cholesterol. Overweight and obesity during pregnancy can raise your child’s risk of metabolic syndrome. In infants, a low birth weight and rapid weight gain after birth can raise the risk of metabolic syndrome later in life.
  • Polycystic ovary syndrome (PCOS) is a condition that causes fluid-filled sacs called cysts to grow on the ovaries. The hormone changes that cause PCOS can also cause you to have a large waistline, high blood sugar levels, high triglyceride levels and low levels of “good” HDL cholesterol.
  • Problems with your immune system can cause some skin diseases such as psoriasis, which raise your risk. Certain cancer treatments that affect your immune system also can raise your risk.
  • Sleep problems, including not getting enough sleep (sleep deprivation), circadian rhythm disorders and sleep apnea, can raise your risk.
  • Some medicines used to treat allergies, bipolar disorder, depression, HIV and schizophrenia also raise your risk.
• Gender: In older adults, women have a higher risk of metabolic syndrome than men. This is because changes in hormone levels after menopause can raise the risk of a large waistline, high blood sugar levels and low levels of “good” HDL cholesterol.

The following risk factors may lead to a metabolic syndrome diagnosis:

• A large waistline: This is also called abdominal obesity or "having an apple shape." Extra fat in your stomach area is a bigger risk factor for heart disease than extra fat in other parts of your body.
• High blood pressure: If your blood pressure rises and stays high for a long time, it can damage your heart and blood vessels. High blood pressure can also cause plaque, a waxy substance, to build up in your arteries. Plaque can cause heart and blood vessel diseases such as heart attack or stroke.
• High blood sugar levels: This can damage your blood vessels and raise your risk of getting blood clots. Blood clots can cause heart and blood vessel diseases.
• High blood triglycerides: Triglycerides are a type of fat found in your blood. High levels of triglycerides can raise your levels of LDL cholesterol, sometimes called bad cholesterol. This raises your risk of heart disease.
• Low HDL cholesterol, sometimes called good cholesterol: Blood cholesterol levels are important for heart health. “Good” HDL cholesterol can help remove “bad” LDL cholesterol from your blood vessels. “Bad” LDL cholesterol can cause plaque buildup in your blood vessels.

The following steps can help you prevent metabolic syndrome:

• Maintain a healthy weight.
• Make heart-healthy lifestyle changes such as eating a healthy diet, getting regular exercise and quitting smoking.
• Schedule routine healthcare provider visits to keep track of your cholesterol, triglyceride, blood pressure and blood sugar levels.

If you have any risk factors for metabolic syndrome, your healthcare provider will do blood tests to screen for this condition. They may screen for the conditions that make up metabolic syndrome during a routine checkup. Your provider may also measure your waist size, weight and blood pressure.

Your provider will diagnose metabolic syndrome based on your medical and family history, a physical exam and diagnostic tests. They may also order heart tests to see how well your heart is working. This will help your provider find out whether you have complications from metabolic syndrome.

To diagnose metabolic syndrome, your provider will check your blood pressure and do blood tests to measure your blood sugar, cholesterol and triglyceride levels.

• Blood pressure: For most adults, a healthy blood pressure is less than 120/80 mm Hg (millimeters of mercury—the units used to measure blood pressure). You may have high blood pressure, one of the conditions of metabolic syndrome, if your blood pressure is consistently 130/85 mm Hg or higher.
• Blood sugar: A healthy blood sugar level for adults after 8 to 12 hours of fasting (not eating) is between 70 and 99 mg/dL (milligrams per deciliter—the units used to measure blood sugar, triglycerides and cholesterol). If your fasting blood sugar level is between 100 and 125 mg/dL, you have high blood sugar levels or prediabetes. If your fasting blood sugar level is 126 mg/dL or higher, you may have diabetes, a condition of metabolic syndrome. Also, you may have metabolic syndrome if you are taking medicines to treat high blood sugar or diabetes.
• Cholesterol: HDL cholesterol, or “good” cholesterol, levels of 60 mg/dL and above can help lower your risk of heart disease. You may have high blood cholesterol, one of the conditions of metabolic syndrome, if your HDL cholesterol levels are lower than 50 mg/dL for women and lower than 40 mg/dL for men.
• Triglyceride levels: Healthy blood triglyceride levels are less than 150 mg/dL for adults. You may have high blood triglycerides, one of the conditions of metabolic syndrome, if your triglyceride levels are consistently more than 150 mg/dL.

Children who have metabolic syndrome can also have these conditions. Your child’s provider will determine the measures and cutoff numbers for your child.

If you have metabolic syndrome, your symptoms will depend on which of the five conditions you have. Some symptoms can be seen, while others are not as obvious. For example, you or your healthcare provider may notice that you have a large waistline. However, high blood pressure, high blood triglycerides and low HDL cholesterol (“good” cholesterol) usually do not cause any symptoms.

High blood sugar may cause the following symptoms:

• Blurred vision
• Increased thirst
• Increased urination, especially at night
• Tiredness and weakness

Your provider may tell you that you have metabolic syndrome based on tests, such as blood pressure readings and blood tests, that you would get as part of a routine medical visit. Learn more about tests you can expect to help your provider diagnose metabolic syndrome.

If you have any risk factors for metabolic syndrome, your healthcare provider will do blood tests to screen for this condition. They may screen for the conditions that make up metabolic syndrome during a routine checkup. Your provider may also measure your waist size, weight and blood pressure.

Your provider will diagnose metabolic syndrome based on your medical and family history, a physical exam and diagnostic tests. They may also order heart tests to see how well your heart is working. This will help your provider find out whether you have complications from metabolic syndrome.

To diagnose metabolic syndrome, your provider will ask whether you or others in your family have any symptoms or risk factors. They may also ask you about your diet and whether you exercise regularly.

During your physical exam, your provider will measure your waist. You may have abdominal obesity, one of the conditions of metabolic syndrome, if your waist measures more than 40 inches for men and 35 inches for women. Your provider may use different measurement values for diagnosis, depending on your race and ethnicity.

To diagnose metabolic syndrome, your provider will check your blood pressure and do blood tests to measure your blood sugar, cholesterol and triglyceride levels.

For most adults, a healthy blood pressure is less than 120/80 mm Hg (millimeters of mercury—the units used to measure blood pressure). You may have high blood pressure, one of the conditions of metabolic syndrome, if your blood pressure is consistently 130/85 mm Hg or higher.

A healthy blood sugar level for adults after 8 to 12 hours of fasting (not eating) is between 70 and 99 mg/dL (milligrams per deciliter—the units used to measure blood sugar, triglycerides and cholesterol).

• If your fasting blood sugar level is between 100 and 125 mg/dL, you have high blood sugar levels or prediabetes.
• If your fasting blood sugar level is 126 mg/dL or higher, you may have diabetes, a condition of metabolic syndrome.

Also, you may have metabolic syndrome if you are taking medicines to treat high blood sugar or diabetes.

HDL cholesterol, or “good” cholesterol, levels of 60 mg/dL and above can help lower your risk of heart disease. You may have high blood cholesterol, one of the conditions of metabolic syndrome, if your HDL cholesterol levels are lower than 50 mg/dL for women and lower than 40 mg/dL for men.

Healthy blood triglyceride levels are less than 150 mg/dL for adults. You may have high blood triglycerides, one of the conditions of metabolic syndrome, if your triglyceride levels are consistently more than 150 mg/dL.

The main goals of treating metabolic syndrome are to lower your risk of heart disease and to prevent type 2 diabetes if it hasn’t already developed. If you already have type 2 diabetes, treatment can lower your risk of heart disease by controlling all your risk factors.

Heart-healthy lifestyle changes are the first line of treatment for metabolic syndrome. You may have to see a dietitian and a physical therapist to help find a diet and exercise plan that works for you. If healthy lifestyle changes do not work, you may need medicines or weight-loss surgery.

You may also need treatment for other health conditions that cause your metabolic syndrome or can make it worse.

The heart-healthy lifestyle changes listed below can help you control your risk factors and prevent complications.

If healthy lifestyle changes alone do not work for you, you may need certain types of medicines. These medicines are often used together with healthy lifestyle changes.

These include ACE inhibitors, angiotensin receptor blockers, diuretics and beta blockers. Some diuretics and beta blockers can raise the risk of type 2 diabetes in people who have metabolic syndrome. Learn more about treating high blood pressure.

Medicines such as statins and niacin can help lower triglyceride and “bad” LDL cholesterol levels. They can also help raise your levels of “good” HDL cholesterol. You may need to take more than one of these medicines. These medicines can cause digestive problems. Some statins can raise the risk of type 2 diabetes in people who have metabolic syndrome. Omega fatty acids, which are commonly found in fish oils, also can help lower blood triglycerides. Learn more about controlling your blood cholesterol and triglyceride levels.

Insulin sensitizers such as thiazolidinediones can help treat high blood sugar levels. These medicines can cause liver damage, anemia, heart failure and blood sugar levels that are too low or too high. You may also need medicines to prevent or treat complications such as diabetes, heart disease, kidney disease or stroke.

If you have obesity and complications from metabolic syndrome, you may need weight-loss medicines or surgery to help you lose weight.

Weight-loss medicines can help you lose weight by making you feel less hungry. They can also reduce how much fat your body absorbs from your food.

Weight-loss surgery reduces the size of your stomach to help you eat less. Complications from this surgery include damage to your stomach or intestines and problems absorbing nutrients from your food. Weight-loss surgery is not often used to treat metabolic syndrome in children and teens.

If you have been diagnosed with metabolic syndrome, it is important that you follow your treatment plan. You will need regular follow-up care to manage your condition and prevent complications.

What health problems can metabolic syndrome cause?

Metabolic syndrome can cause plaque buildup (atherosclerosis) and blood clots in your blood vessels. This can slow down or block blood flow to your organs. Also, high blood sugar levels can damage your blood vessels. Having damaged or blocked blood vessels raises your risk of the following heart and blood vessel diseases and other serious conditions:

• Coronary heart disease
• Erectile dysfunction
• Heart failure
• Long-term inflammation and problems with your immune system, which can raise your risk of having serious complications from infections such as COVID-19
• Organ damage, especially damage to your pancreas, liver, gallbladder and kidneys
• Polycystic ovary syndrome (PCOS)
• Pregnancy complications such as preeclampsia, eclampsia and gestational diabetes
• Problems with thinking and memory
• Sleep apnea
• Certain cancers
• Stroke
• Type 2 diabetes

Sometimes, the link between two health conditions can be complex. For example, polycystic ovary syndrome and sleep apnea can raise your risk of metabolic syndrome, and metabolic syndrome also raises your risk of sleep apnea and polycystic ovary syndrome. Current and future research will help doctors better understand the connections between metabolic syndrome and these two conditions.

As part of your treatment plan, your provider will ask you to make lifelong heart-healthy lifestyle changes. These can help prevent complications.

When you begin to make healthy lifestyle changes, make realistic short- and long-term goals for yourself. Work closely with your provider and seek regular medical care. Seeing a counselor also can help you make long-term changes to your lifestyle habits.

If you have metabolic syndrome, it’s important to get ongoing care.

• Monitor your condition. You may need to check your weight and measure your blood pressure regularly. You may also need routine blood tests to monitor your triglyceride and cholesterol levels.
• Keep all your healthcare appointments. Your provider may use heart and blood tests to check for complications, and you may need treatment for your complications.
• Get ongoing care after weight-loss surgery. If you have weight-loss surgery, you will need regular follow-up care to help prevent complications. You may also need counseling to help you learn and stick to new eating habits.
• Take your medicines as directed. Tell your provider if you have side effects from your medicines.