Prevalence and Clinical Characteristics of the Metabolic Syndrome in Middle-Aged Korean Adults

Background : To evaluate the prevalence and clinical characteristics of metabolic syndrome as defined by the NCEP-ATP III criteria in middle aged Korean rural people. Methods : Cross-sectional study including 5330 participants (2197 males, 3133 females), over the age 40. Metabolic syndrome according to NCEP-ATP III criteria was defined if three or more of the following criteria were satisfied: 1) Abdominal obesity: Waist circumference (WC) in men > 102 cm and in women > 88 cm. 2) Hypertriglyccridcmia: 150 mg/dL. 3) Low HDL cholesterol: 130/85 mmHg. 5) High fasting glucose: 110 mg/dL. We also applied WHO-APR (Asian Pacific Region) criteria for abdominal obesity (WC in men > 90 cm and in women > 80 cm) instead of NCEP-ATP III criteria. Insulin resistance was analysed by HOMA-IR. Results : Age-adjusted overall prevalence of metabolic syndrome by NCEP-ATP III criteria was 24.8% (17.6% in men, 30.0% in women). The prevalence of metabolic syndrome for each age group in men was as follows: age 40 through 49 (18.8%), 50 through 59 (17.4%), 60 through 69 (18.3%), and over 70 (14.5%). In women: age 40 through 49 (22.3%), 50 through 59 (32.7%), 60 through 69 (39.9%), and over 70 (39.3%). In men, the prevalence decreased with aging, but not in women with consistent increment. Age-adjusted prevalence of abdominal obesity was 1.6% (men) & 25.3% (women) by NCEP-ATP III criteria, but 22.5% (men) & 55.6% (women) by WHO-APR criteria. Among various components of metabolic syndrome, the prevalence of hypertriglyceridemia was well correlated with the changing pattern of the prevalence of metabolic syndrome. Relative risk of metabolic syndrome increased as HOMA-IR & fasting insulin levels did. Conclusion : In middle aged Korean adults, metabolic syndrome defined as NCEP-ATP III criteria was strongly correlated to the degree of insulin resistance. The peak age of metabolic syndrome in men was age 40 through 49, and the prevalence decreased with aging. Therefore, early intervention for risk factors of metabolic syndrome might be required in men. On the other hand, prevention for cardiovascular disease will be needed for perimenopausal women due to considerably increased prevalence in the age 50 through 59.