Tameo Takahashi

Seasonal variation in serum cholesterol levels--evidence from the UK and Japan.

Using data from 140,000 men and 32,000 women in the UK and 30,000 men and 12,000 women in Japan, we performed spectral analyses to test for seasonal variation in serum cholesterol levels. In both countries and both sexes we found a strong seasonal effect, cholesterol levels being some 3-5% higher in winter than in summer. This was independent of seasonal changes in body mass. Mean monthly cholesterol levels were negatively correlated with mean monthly air temperatures (r = -0.60 to -0.71). The observed seasonal differences were larger than the inter-assay coefficient of variation for the cholesterol determination method employed and have important consequences for long-term epidemiological or intervention studies.

Seasonal variation in serum cholesterol levels in health screening populations from the U.K. and Japan

We have performed time series analyses on data from 140,000 men and 32,000 women in the U.K. and 30,000 men and 12,00 women in Japan, seen over periods ranging from 4 to 6 1/2 years, in order to test for seasonal variation in serum cholesterol levels. In both countries and both sexes we found a strong seasonal effect, with mean cholesterol levels being some three to five percent higher in winter than in summer. Mean monthly cholesterol levels were negatively correlated with mean monthly air temperatures (r=−0.60 to −0.71). The seasonal differences observed were independent of changes in body weight, and have important implications both for long-term epidemiological or follow-up studies, and for the interpretation of patient data.

Levels of Cardiovascular Risk Factors in Japanese People Living in the UK

Aim: We set out to compare levels of cardiovascular risk factors (blood pressure, body mass and serum lipids) in Japanese people living in the UK with those of Japanese people living in Japan and also with residents of the UK. Methods: Blood samples were taken from individuals attending routine health screening at three centres. The study group comprised 879 men and 723 women born in Japan but living in the UK; 21 248 Japanese men and 8282 Japanese women living in Japan; and 46 623 Caucasian men and 4914 Caucasian women living in the UK. Results: In both men and women we found significantly higher mean blood pressures and cholesterol levels and lower mean triglyceride levels in the expatriate Japanese compared with those still living in Japan. These differences were independent of exercise, smoking and drinking habits and were not related to self-reported levels of stress. They were present even in those Japanese who had been living in the UK for less than 1 year. Higher cholesterol levels were associated with consumption of a Western diet in women but not in men, whereas mean triglyceride levels were lower in men, but not women, eating Western food. Conclusion: Our findings suggest that the levels of risk factors such as blood pressure and serum lipids are for the most part culturally, rather than genetically, determined.

The use of computerized risk assessment for personal instruction in the primary prevention of ischaemic heart disease in a Japanese Automated Multiphasic Health Testing and Services Center.

The major objectives of ningen dock, or multiphasic health testing and services, have been moving from secondary prevention to primary prevention. The main reason for this is that recently the majority of the diseases involved have been chronic diseases which develop slowly and without visible symptoms--often the patient is unaware of the fact that he has a disease until the disease reaches an advanced stage. Of course such diseases, since they exhibit few or no symptoms, are hard to detect. Secondary preventive care becomes difficult in such a situation, and primary preventive care is even more difficult. The major diseases of this type at present are neoplastic and arteriosclerotic diseases. Secondary prevention, leading to early detection, has proved more effective in treating cases of neoplastic diseases, while primary prevention, with its consequent reduction of risk factors, has proved to be more useful in dealing with arteriosclerotic diseases. It is therefore highly recommended that computers installed for health testing be utilized for evaluating risk factors and presenting the results to the examinees through colour displays and other devices such as primary care instructions for them. It is relatively easy now to collect time series data and store them in computers. For people who have no symptoms or complaints, a combination of personal and group instructional methods is necessary for carrying out primary care health instructions.