Department of Social Medicine

Public Health

Epidemiology and prevention of lifestyle diseases
  • Implementation and evaluation of preventative measures for lifestyle diseases
  • Epidemiology of environmental, social and genetic factors on lifestyle diseases, with emphasis on cardiovascular diseases
  • Epidemiology of thrombus formation, blood pressure, serum lipid levels and glucose tolerance
  • Epidemiology of atherosclerosis, vascular disease and breathing-related sleep disorders
  • Large-scale epidemiology studies of Japan and Western Pacific Region
Professor Hiroyasu Iso
Public Health
We have experienced a decline in acute infections and an increase in chronic disease in the postwar Japan. Currently, we are investigating epidemiology and preventative strategy of chronic disease such as cardiovascular disease, diabetes mellitus, and dementia through its association with individual lifestyle.

Epidemiology, Prevention, and Global Health with Emphasis on Lifestyle and Chronic Disease

We are conducting epidemiological studies and preventative measures of cardiovascular diseases (stroke and ischemic heart disease) that is the leading causes of death in the world. Epidemiological studies of cardiovascular disease in Japan began in the early 1960s after the epidemic of tuberculosis calmed down. Instead, stroke emerged as a major public health problem among the productive age group, which was attributed to the lifestyle of the Japanese. Our investigation and preventative activity for stroke go back to 1963 and have been achieved many results (Japan Medical Association Medical Award 2015) [1,2].

The connection between cardiovascular disease and blood cholesterol reported in 1958 spawned a new science all over the world that gave consideration to nutrition, lifestyle, social factors and genetic factors on disease risk, exemplified by the famous Framingham Heart Study. We have found that low blood cholesterol levels are associated with a higher risk for cerebral hemorrhage (Figure 1) [3], as too is a low intake of saturated fatty acids [4, 5]. We also found that intake of fish (unsaturated fatty acid), which is a characteristic of the Japanese diet, is associated with reduced risk of stroke [6] and ischemic heart disease [7].

We are further conducting research on the effects of lifestyle and social factor on diseases. Our findings include relationships between fast eating and obesity [8], fruit intake and diabetes [9], and the impact of stress [10], life enjoyment [11], combination of healthy lifestyle [12], physical activity [13, 14], sedentary life [15], skipping breakfast [16], socioeconomic factors [17] and marital status [18] on the risk of cardiovascular disease. Our goal is to use these data to recommend preventative lifestyle based on scientific evidence and reduce the disease risks for individuals.

These relationships can be elucidated using decades of cohort studies that continuously observe tens of thousands of participants carefully. We are conducting Circulatory Risk in Community Study (CIRCS) for over 50 years, the Japan Collaborative Cohort Study for Evaluation of Cancer Risk (JACC Study), and the Japan Public Health Center-based Prospective Study (JPHC Study). Furthermore, we started a new cohort study on newborns to examine the interaction between genetics and lifestyle factors for better health outcomes in the next generation.

From a global perspective, economic growth in developing countries are being accompanied by a rapid increase in premature death due to lifestyle diseases (Figure 2). To tackle with this problem, we are working with Harvard University and the University College of London and conducting field surveys in China and the Republic of Palau in collaboration with the Ministry of Health, Labor and Welfare and WHO.

【References】

1. Iso. Jpn J Public Health 33:153-163, 1986.
2. Shimamoto et al. Circulation 79:503-515, 1989.
3. Iso et al. NEJM 320:904-910, 1989.
4. Iso et al. Circulation 103:856-863, 2001.
5. Iso et al. Am J Epidemiol 157:32-39, 2003.
6. Iso et al. JAMA 285:304-12, 2001
7. Iso et al. Circulation 113:195-202,2006.
8. Maruyama et al. BMJ 21;337:a2002, 2008.
9. Muraki et al. BMJ 347:f5001, 2013
10. Iso et al. Circulation 106:1229-1236, 2002.
11. Shirai et al. Circulation 120:956-963, 2009.
12. Eguchi et al. Eur Heart J 33: 4 467-77, 2012.
13. Noda et al. J Am Coll Cardiol 46:1761-1767, 2005.
14. Kubota et al. Circulation, in press.
15. Shirakawa et al. Circulation 134:355-357, 2016.
16. Kubota et al. Stroke 47:477-481, 2016.
17. Honjo et al. Stroke 45:2592-2598, 2014.
18. Honjo et al. Stroke 47:991-998, 2016.