Anthropometric measures, blood pressure and major laboratory examination results in the health check-up examination among the JPHC study participants at baseline survey. Japan Public Health Center-based Prospective Study on Cancer and Cardiovascular Diseases.

Health check-up data were compared in all 11 populations included in the cohort. The collected sample size was 23,313 in Cohort I and 24,654 in Cohort II. Height was greater in two urban populations, and body mass index (BMI) was largest in the two populations in Okinawa prefecture. Blood pressure was higher in the populations in northeast part of Japan and Okinawa prefecture, and lower in Suita. Serum total cholesterol level was higher in Okinawa and two urban populations, and lower in the populations in northeast part of Japan, and in Arikawa and Saku.


INTRODUCTION
Along with the questionnaires which was administered to all the target population, data was collected for health check ups carried annually by the local municipalities under the Health Services for the Elderly Act, which are inexpensive or free for all people in any area of Japan who hold a resident card, aged 40 years old and over, and who are not offered periodical health examinations at their place of work. In this paper, we tried to compare the results of the health check ups to see the difference in the basic health status in each population, though the rates of attendance to the examination were relatively low.

METHODS
The examinations were primarily done in 1990 for Cohort I and in 1993 for Cohort II. But owing to the different conditions, data was collected differently in some populations; in Ishikawa the data was collected in the years 1990 to 1992, in Katsushika in 1990 to 1992, in Suita sub-cohort 1 & 2 in 1993 to 1994 and in Kasama in 1993 and 1994.
As for the data, the health check up data made by the municipality governments under the Health Services for the Elderly Act was collected and linked to the cohort subjects. Data from other sources were added when available. The items required by the law were blood pressure measurement, serum total cholesterol, aspartate aminotransferase, alanine aminotransferase, blood glucose, blood hemoglobin concentration, red blood cell counts, hematocrit, urinary glucose, urinary protein and urinary occult blood in 1990 when data for Cohort I was mainly collected and in addition to these, serum triglyceride, serum yglutamyl transferase and serum high density lipoprotein (HDL) cholesterol in 1993 when main data for Cohort II were collected. The proportions of the examined subjects for each item are listed in Table 1.
The ages of the subjects in Katsushika and Suita sub-cohort 1 were just 40 or 50 years old, so the exact comparisons with other populations seem impossible in these two populations. So the descriptions concerning to these populations are not done in the results.

RESULTS
1. Height, weight and body mass index (BMI) (= body weight (kg)/height2 (m)) ( Table 2-4) In both sexes, height was taller in Suita, an urban population, and less in Ishikawa, Ninohe, Miyako and Kashiwazaki. Body weight in men was heavier in Miyako and Suita, and lower in S-88 Health Check-Up Data in JPHC Baseline  Table 3. Mean and standard deviation (S.D.) of body weight (kg) by sex and age in each population. S-90 Health Check-Up Data in JPHC Baseline Table 5. Mean and standard deviation (S.D.) of systolic blood pressure (mmHg) by sex and age in each population .  Table 7. Mean and standard deviation (S.D .) of serum total cholesterol (mg/dl) by sex and age in each population . Health Check-Up Data in JPHC Baseline Table 9. Mean and standard deviation (S.D.) of serum high density lipoprotein (HDL) cholesterol (mg/dl) by sex and age in each population.    (Table 10) Blood hemoglobin concentration in men was highest in Ishikawa. For the levels in men 40 to 59 years old, mean value was 15.7g/dl in Ishikawa, and for all the other populations the values were between 14.6 and 15.5g/dl. In women, the difference was smaller than in men, and the mean value in each population was between 12.7 to 13.5g/dl.

DISCUSSION
Standardization of data collection was not done systematically in this survey for blood pressure measurements and serum lipid measurements, but all the laboratories had attended individually the standardization system operated by Japanese medical association. Center for Disease Control (CDC) of USA standardization methodology for the measurement of serum total cholesterol level was applied for the Cohort II populations by lida et al 1). Standardization of the data collection methodology and the measurement of serum lipid level will be made for all the populations in the intermediate 5th year examination of this cohort study.
Comparisons were made for the data from the Japanese national surveys and American National Health and Nutrition Examination Surveys (NHANES) (Table 11) 2). Systolic blood pressure was generally less than the value given in the Japanese national survey in 1990, and was similar to that of US whites in NHANES II data in men and women 3). Diastolic blood pressure was less than the values in the Japanese national surveys and NHANES II. The examination years in the pre-sent survey are between 1990 and 1993, so the data may be similar to the data of the Japanese national survey in 1990. However, the present result showed a lower value. Sampled population might have caused the difference, but the values this time are lower than any divided districts in the national survey report. The sample sizes were bigger in each area in the present survey, in contrast to the smaller size in each district in the national survey. One possible reason might be that the populations in this survey happened to be chosen lower blood pressure areas. Another possible reason might be the bias due to the attendance rate of the response rate in this survey being lower than in the national survey.
Serum total cholesterol level was just less than that of the Japanese national data a in 1990, and NHANES III data 41 in 1990. The reason may be similar to the one just mentioned concerning to blood pressure level. However, strictly, this has to be concluded after the standardization of the laboratory data will be finished in the intermediate year examination.