The rate of metabolic syndrome has fallen in the past decade, even as the trends for its five components rose and fell, and were widely divergent depending upon gender, race, and with the advent of drugs to treat conditions such as high blood pressure and hyperlipidemia, researchers concluded.
Researchers derived prevalence estimates in adults from the National Health and Nutrition Examination Survey 1999 to 2010 in two-year survey waves. Metabolic syndrome was defined as patients who met three of the five biological thresholds: waist circumference of 102 cm or more in men and 88 cm or more in women; fasting plasma glucose of 100 mg/dL or more; blood pressure of 130/85 mm Hg or more; triglycerides of 150 mg/dL or more; and high-density lipoprotein-cholesterol of less than 40 mg/dL in men and less than 50 mg/dL in women.
Results appeared in the Journal of the American College of Cardiology.
The age-adjusted prevalence of metabolic syndrome decreased from 25.5% to 22.9% (ptrend=0.024). Mexican-Americans, particularly women, had a higher prevalence than other subgroups.
Researchers noted, "While the prevalence of metabolic syndrome has declined in the total population when measuring clinical targets, there is a divergence in trends for its individual components, mainly in high waist circumference for the total population and among the gender and race/ethnic groups."
For example, hypertriglyceridemia decreased from 33.5% to 24.3%, as did elevated blood pressure (32.3% to 24.0%), in both cases because of increased awareness of the conditions and pharmacological treatments for them. But there were increases in the rates of hyperglycemia from 12.9% to 19.9% and in elevated waist circumference from 45.4% to 56.1%, with wide variations by gender and race. Researchers attributed decreases in elevated blood pressure, suboptimal triglycerides and HDL-C to increases in anti-hypertensive and lipid-modifying drugs.
"The increasing prevalence of abdominal obesity, particularly among females, highlights the urgency of addressing abdominal obesity as a health care priority," researchers wrote. Because outcomes for the five components of metabolic syndrome varied demographically, researchers suggested weighting metabolic syndrome components depending on patient's ethnicity rather than having just one definition.