Prevalence and trends of metabolic syndrome in the adult U.S. population, 1999-2010

Objectives: This study sought to characterize the prevalence of metabolic syndrome (MetS), its 5 components, and their pharmacological treatment in U.S. adults by sex and race/ethnicity over time.

Background: MetS is a constellation of clinical risk factors for cardiovascular disease, stroke, kidney disease, and type 2 diabetes mellitus.

Methods: Prevalence estimates were estimated in adults (≥ 20 years of age) from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2010 (in 2-year survey waves). The biological thresholds, defined by the 2009 Joint Scientific Statement, were: 1) waist circumference ≥ 102 cm (males adults) and ≥ 88 cm (female adults); 2) fasting plasma glucose ≥ 100 mg/dl; 3) blood pressure of ≥ 130/85 mm Hg; 4) triglycerides ≥ 150 mg/dl; and 5) high-density lipoprotein-cholesterol (HDL-C) <40 mg/dl (male adults) and <50 mg/dl (female adults). Prescription drug use was estimated for lipid-modifying agents, anti-hypertensives, and anti-hyperglycemic medications.

Results: From 1999 and 2000 to 2009 and 2010, the age-adjusted prevalence of MetS (based on biologic thresholds) decreased from 25.5% (95% confidence interval [CI]: 22.5% to 28.6%) to 22.9% (95% CI: 20.3% to 25.5%). During this period, hypertriglyceridemia prevalence decreased (33.5% to 24.3%), as did elevated blood pressure (32.3% to 24.0%). The prevalence of hyperglycemia increased (12.9% to 19.9%), as did elevated waist circumference (45.4% to 56.1%). These trends varied considerably by sex and race/ethnicity. Decreases in elevated blood pressure, suboptimal triglycerides, and high-density lipoprotein-cholesterol prevalence have corresponded with increases in anti-hypertensive and lipid-modifying drugs, respectively.

Conclusions: The increasing prevalence of abdominal obesity, particularly among female adults, highlights the urgency of addressing abdominal obesity as a healthcare priority. The use of therapies for MetS components aligns with favorable trends in their prevalence.