A person is diagnosed with metabolic syndrome when they have three or more risk factors for the condition, such as abdominal obesity, high blood pressure and high cholesterol.
Metabolic syndrome occurs when an individual has three or more risk factors that raise the likelihood of cardiovascular illness and mortality. These risk factors include abdominal obesity, high triglyceride level, high cholesterol, high blood pressure and high fasting glucose level.
According to the National Heart, Lung and Blood Institute, people with metabolic syndrome are twice as likely to develop heart disease and five times as likely to develop diabetes as those without the condition.
Previous data from the 1999-2006 National Health and Nutrition Examination Survey (NHANES) revealed that around 34% of adults in the US have metabolic syndrome.
In this latest study, Dr. Robert J. Wong, of the Division of Gastroenterology and Hepatology at the Alameda Health System-Highland Hospital in Oakland, CA, and colleagues sought to get an updated estimate of metabolic syndrome prevalence in the US.
"Understanding updated prevalence trends may be important given the potential effect of the metabolic syndrome and its associated health complications on the aging US population," note the authors.
Dr. Wong and colleagues used NHANES data from 2003-04 to 2011-12 to estimate overall prevalence of metabolic syndrome among US adults aged 20 and older.
Prevalence of the condition was also assessed over three age groups (20-39, 40-59 and 60 and older), as well as by sex and race/ethnicity.
High prevalence of metabolic syndrome among seniors a 'concerning observation'
The team found that overall prevalence of metabolic syndrome increased from 32.9% in 2003-04 to 34.7% in 2011-12.
Between 2007-08 and 2011-12, however, overall metabolic syndrome rates remained stable. They also remained stable among men and all race/ethnic groups, and even reduced among women, from 39.4% in 2007-08 to 36.6% in 2011-12.
- The more risk factors a person has for metabolic syndrome, the more likely they are to develop associated conditions
- Overweight and obesity, physical inactivity and genetic factors are just some of the underlying causes of metabolic syndrome
- Lifestyle changes - such as quitting smoking and adopting a healthy diet - are the best way to prevent or treat metabolic syndrome.
The team says the stabilizing of metabolic syndrome prevalence may be down to greater awareness of the condition and its health implications, leading to an uptake in treatment for high blood pressure and other risk factors.
"Furthermore," the authors add, "recent NHANES data demonstrate that obesity prevalence in the United States also appears to have stabilized, which also may contribute to the stabilizing prevalence of the metabolic syndrome."
Women had higher prevalence of metabolic syndrome than men between 2003-04 and 2011-12. On assessing prevalence by race/ethnicity during this period, Hispanics were found to be most affected, followed by non-Hispanic whites and blacks.
The most worrying finding, however, was that prevalence of metabolic syndrome increased with age. While the condition affected 18.3% of individuals aged 20-39 between 2003-04 and 2011-12, it was found to affect 46.7% of people aged 60 and older.
Among individuals aged 60 and older, more than half of women and half of Hispanics had metabolic syndrome.
The team says the high prevalence of the condition among seniors is a "concerning observation" given that the population in the US is aging.
Though metabolic syndrome can significantly raise the risk of diabetes, stroke, heart disease and other cardiovascular illnesses, the American Heart Association (AHA) say there are a number of ways a person can reduce these risks.
They recommend increasing physical activity, reducing weight and following a diet rich in fruits, vegetables, whole grains and fish. The AHA also recommend working with a health care provider to monitor and manage blood pressure, cholesterol and blood glucose.
In November 2014, Medical News Today reported on a study claiming that healthy gut bacteria could help treat or prevent metabolic syndrome.