What is the metabolic syndrome?
Back in the 1960s, Gerald Reaven and his colleagues at Stanford University noticed that heart attack patients often exhibited the same suite of conditions. They included high blood glucose, high triglycerides, high blood pressure, and abdominal obesity. In the 1980’s, Reaven termed this suite of conditions as Syndrome X, now known as the Metabolic Syndrome.
Researchers often use the following five conditions to characterize the metabolic syndrome:
1) High fasting blood glucose (more than 110 mg/dL)
2) High triglycerides (more than 150 mg/dL)
3) High blood pressure (more than 130 mm Hg systolic, more than 85 mm Hg diastolic)
4) Low HDL-cholesterol (less than 40 mg/dL in men and 50 mg/dL in women)
5) Central obesity (waist circumference more than 40 inches in men, more than 35 inches in women)
Commonly, researchers classify patients as having the metabolic syndrome if they have at least three of these five characteristics. Sometimes the cut point are slightly different, such as blood glucose greater than 100 mg/dL.
Why is the metabolic syndrome important?
Persons with the metabolic syndrome have considerably higher risk for a host of chronic diseases including cardiovascular disease (heart attack, heart failure, stroke), type 2 diabetes, nonalcoholic fatty liver disease, high blood pressure, obesity, and increased risk of premature death. You don’t want any of these conditions.
How prevalent is the metabolic syndrome in the US?
Researchers estimated the change in the prevalence of the metabolic syndrome in the US between 2011 and 2018. Data came from 8,183 participants over 20 years of age (average age 48) in the National Health and Nutrition Examination Survey. The metabolic syndrome was defined as the presence of at least three of the following: 1) elevated fasting blood glucose (more than 100 ml/dL or taking glucose lowering medication), 2) elevated triglycerides (more than 150 mg/dL), 3) elevated blood pressure (more than 130 mm Hg systolic and more than 85 mm Hg diastolic or taking anti-hypertensive medication), 4) reduced HDL-cholesterol (less than 40 mg/dL in men and less than 50 mg/dL in women), and 5) central obesity (more than 36 inches in women and 40 inches in men).
The prevalence of the metabolic syndrome increased significantly from 37.6 percent in 2011 to 41.8 percent in 2018. With respect to participant characteristics, those with Mexican-American ethnicity and less than 11th grade education showed significant increases in the metabolic syndrome from 2011 to 2018. Of the five criteria for the metabolic syndrome, the prevalence of elevated fasting blood glucose increased from 48.9 percent in 2011 to 64.7 percent in 2018. The prevalence of the other four criteria did not change significantly. In 2018, an estimated 93 million Americans had the metabolic syndrome. We Americans have a long ways to go to improve our metabolic health
Optimal metabolic health
Do most Americans have optimal metabolic health? Researchers at Tufts University answered this question with data from a nationally representative sample of 55,081 participants in the National Health and Nutrition Examination Surveys from 1999-2000 to 2017-2018. Optimal cardiometabolic health was defined in terms of 1) body fat (BMI < 25 and waist circumference < 35/40 inches for women/men), 2) blood glucose (fasting blood glucose < 100 mg/dL and HbA1c < 5.7%, 3) blood lipids (total cholesterol/HDL-cholesterol < 3.5 with no medications), 4) blood pressure (<120 mm Hg systolic and < 80 mm Hg diastolic with no medications), and 5) no history of cardiovascular disease.
During the 20-year study period, the proportion of participants with optimal cardiometabolic health declined to 6.8 percent. Declines in optimal cardiometabolic health were greater for participants with low education, male sex, greater age, and non-White race/ethnicity. For participants age 65 and older, only 4 out of every 1,000 participants had optimal cardiometabolic health. These results bode ill for the ability of the US medical care system to handle the influx of metabolically ill baby boomers.
What to do
You absolutely don’t want the metabolic syndrome. You can gauge your status by comparing your health measures (blood pressure, fasting blood glucose, triglycerides, HDL-cholesterol, ratio of total cholesterol / HDL-cholesterol, waist circumference) to those listed above. If any of your measures exceed the metabolic syndrome criteria above, take steps to correct the situation. The primary ways to avoid the metabolic syndrome include Keep Moving and Eat Better. More specifically, aim to get at least 150 minutes of moderate to strenuous physical activity each week. More is better and strenuous is better that moderate intensity. Emphasize the usual healthy foods in your daily eating. Ramp up vegetables, fruits, legumes (lentils, beans), nuts, and seeds. Steer clear of sugary drinks and other ultra-processed foods.
