Risks for cardiovascular disease, stroke, ischaemic heart disease, and diabetes mellitus associated with the metabolic syndrome using the new harmonised definition: findings from nationally representative longitudinal data from an Asian population

Abstract

Objective: We examined the risk of cardiovascular disease, stroke, ischaemic heart disease, and diabetes with the metabolic syndrome according to the new harmonised definition and its components using a national longitudinal data set from an Asian population.

Methods: Data of 9791 men and women aged 20+ from 1998 and 2001 Korea National Health and Nutrition Examination Surveys were individually linked to national hospitalisation and mortality data using unique personal identification numbers. During a 5.8-year follow-up through 2005, 288 incident cardiovascular events (184 strokes and 122 cases of ischaemic heart disease) and 85 new diabetes cases have been detected.

Results: Men and women with the metabolic syndrome had 48%, 39%, 64%, and 127% greater risks of cardiovascular disease, stroke, ischaemic heart disease, and diabetes, respectively, than those without the metabolic syndrome. The increased risks of cardiovascular disease, ischaemic heart disease, and diabetes remained significant after adjusting for health behaviours, bio-clinical factors, family history, and socio-demographic factors. Analysis results on population attributable risks showed that about a quarter of total diabetes occurrence and more than 10% of cardiovascular disease was attributable to the metabolic syndrome. The number of metabolic syndrome components was linearly associated with risks of outcomes. High blood pressure was significantly associated with all four outcomes while hypertriglyceridemia and hyperglycemia were also important for ischaemic heart disease and diabetes, respectively.

Conclusions: Reduction of metabolic risk factors is necessary in South Korea to lower the burden of associated diseases, especially ever-increasing ischaemic heart disease and diabetes.