Epidemiology of glucose intolerance, dyslipidemia, and stroke: the Hisayama Study

Abstract

According to the findings of the Hisayama Study, an epidemiological study of cardiovascular disease in the general Japanese population, the incidence of ischemic stroke decreased greatly from 1960s to 1990s in men and from 1960s to 1970s in women as a result of the spread of hypertension treatment. However, the decreasing trends in the ischemic stroke incidence are probably due to the increase in the prevalence of metabolic risk factors such as glucose intolerance and hypercholesterolemia. In this review, we evaluated the associations of metabolic risk factors with the risk of stroke using the data from the Hisayama Study. (1) In a 7-year follow-up survey of 2,851 residents of Hisayama town aged 40 to 79 years, elevated hemoglobin (Hb) A1c levels were significantly and linearly associated with an increased risk of developing ischemic stroke. Subjects with HbA1c of 5.5% or higher had a significantly higher risk of ischemic stroke than those with HbA1c of 5.0% or lower, suggesting that elevated HbA1c, even in the prediabetic range, was a significant risk factor for the development of ischemic stroke. (2) A 24-year follow-up study for 2,452 Hisayama residents aged 40 years or over demonstrated that elevated non-high-density lipoprotein cholesterol levels were a significant risk factor for the development of atherothrombotic brain infarction. In conclusion, the intensive management of these metabolic risk factors is needed for further prevention of ischemic stroke in Japanese population.