Epidemiological Evidence of Type 2 Diabetes Mellitus, Metabolic Syndrome, and Cardiovascular Disease in Japan

Although epidemiological studies in the US and Europe have confirmed that type 2 diabetes mellitus (DM) is associated with an increased risk of cardiovascular disease (CVD) events, evidence is limited in Japan. Earlier studies in Japan showed that hypertension has a major effect on atherosclerosis in relatively lean subjects, with type 2 DM contributing more to CVD events, because of a decline in blood pressure levels in both sexes and an increase in body mass index in men. Recent cohort studies in Japan using baseline assessments carried out during the 1990 s have confirmed that type 2 DM is associated with an increased risk of coronary heart disease (CHD) and all types of stroke, except hemorrhagic stroke. In addition, the metabolic syndrome, a constellation of metabolic risk factors, was shown to predict CVD events in Japanese people, independent of the presence or absence of obesity. The strong association of type 2 DM with CHD (hazard ratio: 1.5-4) and ischemic stroke (hazard ratio: 2-4) events was confirmed in Japanese adults. Individuals with impaired glucose tolerance or impaired fasting glucose were also shown to have an increased risk of a CHD event, but not a stroke. (Circ J 2012; 76: 1066-1073)