Metabolic Syndrome: What It Is and Why It Matters
Metabolic Syndrome: What It Is and Why It Matters
If you've ever thought or even said, "I don't have diabetes, so I'm doing okay," you're not alone.
Or maybe you've been told you have high blood pressure, but you've had it for years and think of it as "normal for me."
Maybe your cholesterol is a little high, but your blood sugar is fine.
Or your blood sugar is creeping up, but everything else looks okay.
We tend to think about these things separately. High blood pressure is one issue. Cholesterol is another. Blood sugar is something to worry about if you have diabetes.
But our bodies don't always work in separate categories.
That's one reason we have the concept of metabolic syndrome.
Metabolic syndrome isn't a single disease. It's a collection of health factors that tend to occur together and are associated with a higher risk of cardiovascular disease, type 2 diabetes, and other health problems. It gives healthcare professionals a way to consider several related risk factors together rather than each one in isolation.
That matters because overall metabolic health involves much more than weight alone.
What is metabolic syndrome?
Metabolic syndrome is generally identified when a person has three or more of five risk factors:
An elevated waist circumference
Elevated blood pressure
Elevated fasting blood glucose
Elevated triglycerides
Low HDL cholesterol
Specific criteria and waist-circumference cutoffs can vary somewhat depending on the guideline used and a person's population or ethnic background. Current criteria use population-specific waist-circumference measurements and consider three of the five risk factors sufficient for diagnosis.
And here is something important to note: Diabetes is NOT one of the five criteria.
A person can have metabolic syndrome without having diabetes.
In fact, that's part of why this concept is useful. These risk factors can develop before someone meets the criteria for a specific disease.
Where did the idea of metabolic syndrome come from?
The idea isn't really new.
Researchers have long recognized that certain health problems tend to occur together. Researchers have observed high blood pressure, abnormal blood fats, elevated blood glucose, and excess abdominal fat together in various combinations for much of the 20th century.
In 1988, physician and researcher Gerald Reaven brought particular attention to this clustering in his Banting Lecture. He called it Syndrome X and proposed that insulin resistance was an important underlying factor connecting several of these abnormalities.
Over time, the terminology evolved. You may see terms such as Syndrome X, insulin resistance syndrome, dysmetabolic syndrome, and metabolic syndrome used in the scientific literature.
The World Health Organization developed one of the first formal definitions in 1998. The National Cholesterol Education Program's Adult Treatment Panel III then introduced another widely used clinical definition in 2001. In 2009, several major organizations worked toward a coordinated definition based on the presence of three of five risk factors.
In other words, researchers didn't suddenly invent a new disease.
They were trying to better describe a pattern they had been seeing repeatedly.
The five pieces of metabolic syndrome
Let's look at each risk factor individually.
1. Waist circumference
Waist circumference is one way of estimating abdominal fat, which is associated with metabolic risk.
Commonly used U.S. cutoffs are more than 40 inches for men and more than 35 inches for women, although appropriate cutoffs can vary by ancestry and the guideline used.
This is one reason I don't think it's helpful to use body weight or BMI as a stand-in for metabolic health.
Two people can have the same weight and very different health profiles.
And two people at different weights can have similar metabolic risk factors.
2. Blood pressure
Blood pressure is another part of the equation.
For metabolic syndrome, elevated blood pressure is generally defined as a systolic pressure of at least 130 mm Hg or a diastolic pressure of at least 85 mm Hg, or the use of medication to treat elevated blood pressure.
And this is where the phrase "that's just normal for me" can become problematic.
If your blood pressure has been elevated for years, that doesn't make the elevation harmless.
Your body may be accustomed to it, but your cardiovascular system still has to deal with that pressure.
3. Blood glucose
Fasting blood glucose is another factor.
A fasting glucose of at least 100 mg/dL is one of the commonly used metabolic syndrome criteria, with medication treatment for elevated glucose also counting in the coordinated definition.
Again, this isn't the same as having diabetes.
A blood glucose level can be elevated without meeting the diagnostic criteria for diabetes.
That's one reason regular healthcare visits and appropriate screening are important.
4. Triglycerides
Triglycerides are a type of fat found in your blood.
A level of 150 mg/dL or higher is one of the metabolic syndrome criteria, as is treatment for elevated triglycerides. Some people don’t make that connection. Their triglycerides may be at a good level, but that is because they are already being treated for it, and that is why they are in an appropriate range.
Triglycerides are part of the standard lipid panel, so this is another piece of information that may already be available when you have routine blood work.
5. HDL cholesterol
HDL is often called the "good" cholesterol because higher levels are generally associated with lower cardiovascular risk.
For metabolic syndrome, low HDL is defined as less than 40 mg/dL in men or less than 50 mg/dL in women, with treatment for low HDL also considered in the coordinated definition.
Metabolic syndrome isn't simply about "having high cholesterol."
The individual components of a lipid panel are considered, so total cholesterol is only one part of the larger metabolic picture.
Why looking at the whole picture matters
This is probably the part of metabolic syndrome that I find most important to point out.
We often think about health risks in isolation.
"I don't have diabetes."
"My cholesterol is only a little high."
"My blood pressure has always been like that."
"My doctor isn't worried about my weight."
Each statement may be true.
But they don't necessarily tell you the whole story.
What happens when you put the information together?
Someone might have elevated blood pressure, elevated triglycerides, and elevated fasting glucose without having diabetes.
Another person might have low HDL, elevated blood pressure, and an elevated waist circumference.
Those combinations tell us something that any one measurement alone may not.
This is not about labeling yourself or assuming that one abnormal lab value means something is seriously wrong.
It's about paying attention to patterns.
Metabolic health is more than your weight
I want to make another important point.
Metabolic syndrome is not a synonym for obesity.
And metabolic health should not be reduced to body size.
Weight can be one factor associated with metabolic risk, but it does not tell us everything about a person's blood pressure, blood glucose, triglycerides, HDL cholesterol, physical activity, eating pattern, genetics, sleep, or other aspects of health.
That's why I don't want metabolic health to automatically become a discussion about weight loss.
You can care about your blood pressure without making shrinking your body the goal.
You can work on your blood glucose without going on a restrictive diet.
You can improve your eating pattern, become more physically active, get better sleep, or take medication when appropriate without treating your body as a problem that needs to be fixed.
Metabolic health is more than a number on the scale.
What should you do with this information?
First, don't diagnose yourself based on a blog post. Or what you find on the internet alone.
If you've been told that you have high blood pressure, elevated blood glucose, abnormal cholesterol or triglycerides, or other cardiometabolic risk factors, talk with your healthcare provider about what those numbers mean for you.
Second, don't focus on only one number.
Ask questions.
What do my blood pressure readings look like over time?
How are my triglycerides and HDL?
What is my fasting glucose or A1C?
Are there other risk factors I should know about?
And most importantly, how do these pieces fit together?
That's the key to understanding metabolic syndrome.
It's not about finding another health label to worry or obsess about.
It's about recognizing and acknowledging that our health doesn't exist in separate boxes.
Blood pressure, blood glucose, blood lipids, abdominal fat, genetics, lifestyle, age, medications, and many other factors can interact.
Looking at the whole picture gives us a much better starting point for making informed health decisions.
