OBJECTIVE: The number of people with metabolic syndrome is increasing worldwide, and changes in socioenvironmental factors contribute to this increase. Therefore, investigation of changes in metabolic syndrome and its components in South Korea, where rapid socioenvironmental changes have occurred in recent years, would be foundational in setting up an effective strategy for reducing this increasing trend. RESEARCH DESIGN AND METHODS: We compared the prevalence and pattern of metabolic syndrome among participants in the Korean National Health and Nutrition Examination Surveys for 1998, 2001, 2005, and 2007. In each survey, stratified, multistage, probability–sampling designs and weighting adjustments were conducted to represent the entire Korean population. The revised National Cholesterol Education Program criteria were used as the definition of metabolic syndrome. All biochemical parameters were measured in a central laboratory. RESULTS: A total of 6,907 (mean ± SE age 45.0 ± 0.2 years), 4,536 (45.5 ± 0.2), 5,373 (47.1 ± 0.2), and 2,890 (49.9 ± 0.3) Koreans over 20 years of age have participated in the studies in 1998, 2001, 2005, and 2007, respectively. The age-adjusted prevalence of metabolic syndrome increased significantly from 24.9% in 1998, 29.2% in 2001, and 30.4% in 2005 to 31.3% in 2007. Among the five components, the level of low HDL cholesterol increased the most, by 13.8% over the 10 years. Abdominal obesity and hypertriglyceridemia followed, with 8.7 and 4.9% increases, respectively. CONCLUSIONS: Because dyslipidemia and abdominal obesity were major factors in increasing the prevalence of metabolic syndrome in Koreans for the past 10 years, lifestyle interventions should be conducted at the national level to reduce the burden and consequences of metabolic syndrome.

Introduction The importance of managing the metabolic syndrome has been emphasized in the prevention of cardiovascular disease. Although South Koreans have a low prevalence of obesity, little information is available about the prevalence of the metabolic syndrome and its associated risk factors. Methods Data was obtained from individuals aged 20–79 years from the Korean National Health and Nutrition Examination Survey 1998, a cross-sectional health survey of a nationally representative sample of non-institutionalized civilian South Koreans. The prevalence of the metabolic syndrome, as defined by the Third Report of the National Cholesterol Education Program Adult Treatment Panel (NCEP ATP III), was determined, and lifestyle factors associated with predisposition to the metabolic syndrome were analysed. Results Among South Korean adults, the age-adjusted prevalence of the metabolic syndrome was 14.2% for men and 17.7% for women, whereas the age-adjusted prevalence of obesity (body mass index (BMI) ≥30 kg/m²) was 1.7% and 3.0% for men and women, respectively. Age, unemployment, higher BMI, and current smoking were associated factors for the metabolic syndrome regardless of gender. Moderate exercise (2–3 sessions/week) in men and light alcohol drinking (<15 g/day) in women decreased the odds of the metabolic syndrome. Conclusions Metabolic syndrome is present in more than 15% of South Koreans despite a low prevalence of obesity. Higher BMI and current smoking were identified as independent modifiable risk factors of the metabolic syndrome. Weight control and smoking cessation may therefore decrease the prevalence of the metabolic syndrome in South Korean adults.