A considerable portion of patients with aortic aneurysms is asymptomatic. In order to know the prevalence rates of asymptomatic aortic aneurysms, the cases of aortic aneurysms found incidentally in an autopsy series from 1960 to 1989 were reviewed. In the Annual of the Pathological Autopsy Cases in Japan, 1, 469 (971 male and 498 female) cases were found. The overall age-adjusted prevalence rates of asymptomatic aortic aneurysms increased from 2.08 to 2.48 for males, and from 1.26 to 1.85 for females, per 1, 000 autopsy cases, respectively, during the period. Abdominal aortic aneurysms were the most frequent in males but dissecting ones were the leading type in females. The prevalence rates of abdominal and dissecting aortic aneurysms increased in both sexes, and the rate of thoracic aortic aneurysms decreased in females. J Epidemiol, 1995; 5 : 159-163.
A Case-control study was conducted in 110 patients with colorectal cancer and, as control groups, 84 with gastric cancer, 50 with other cancer and 111 with benign gastroenterological disease. In this study we try to make it clear whether colorectal cancer has really familial aggregation and whether a positive family history can be used as one of screening procedures, by getting information more exactly about family history and by taking account of family size into analysis. 9.1% (OR 1.20) of colorectal cancer group and 11.3% (OR 1.70) of colon cancer group had positive family history of colorectal cancer, as compared with the benign disease group. 1.8% of their first-degree relatives were affected by colorectal cancer. No significant difference was seen, although these proportions were higher than those in 3 control groups. These results suggest familial aggregation of colorectal cancer is not so large as reseachers have mentioned so far, although a tendency for familial aggregation was found in colon cancer. At the present stage in Japan, we should not perform screening for the first-degree relatives only by positive family history from the reason of efficiency, though those of patients with clinically diagnosed or suspected HNPCC should be screened. J Epidemiol, 1995; 5 : 165-169.
To clarify the prevalence of vertebral fractures (VFs) of Japanese, a population survey was conducted in a small village in Japan. To measure bone mineral density, 50 males and 50 females in each of four age strata (40-49, 50-59, 60-69, 70-79), totaling 400 individuals were recruited almost randomly from a cohort of 1543 residents (716 men and 827 women) set up based on the resident registration as of 1988. Three hundred and ninety of the participants agreed to undergo routine two dimensional X-ray examinations. Diagnosis of VF was performed by four orthopedic surgeons according to the criteria established by the Ministry of Health and Welfare. The prevalence rates having one or more VFs by sex and age in 40's, 50';s, 60's and 70's were shown as follows ; for males, 4.3, 14.6, 22.0 and 24.5% and for females, 2.1, 10.2, 14.0 and 44.9% respectively. There was little difference between 60's and 70's in males. To the contrary, in females, 70's has almost twice higher prevalence than 60's. Among persons with VF, one third of them had two or more VFs. Regarding shapes and sites of VF, wedge was the most common shape of VF, and there were found most frequently fractured were in the thraco-lumbar transition zone (25.5% Th12 and 23.4% L1 in fractured males, and 19.7% Th12 and 14.8% L1 in fractured females). J Epidemiol, 1995; 5 : 171-175.
The purpose of this study was to investigate whether the reproductive life history, including hormonal environment, was a risk factor for gastric cancer in females by age groups or by histological subgroups. A case-control study with incident cases accompanied by individually matched one or two controls was carried out, using self administered questionnaire which included personal profile, smoking and drinking habits, dietary habits, past history of disease and reproductive life history. Analysis was made for 116 females cases and matched 144 controls separately by two histological type subgroups (differentiated and undifferentiated type) and by two age groups (young and older), using proportional hazard model to obtain relative risks with 95% C.I. For the undiffer- entiated gastric cancer in female under 40 years of age, mean of cumulative estradiol concentration (CEC) during all pregnant period and mean pregnant period per pregnancy revealed increased relative risk (R.R.) of 7.7 (95% C.I.: 1.41-41.75) (for each 1 ng/ml) and 3.1 (95% C.I.: 1.01-9.55) (for each 10 weeks), respectively. In the same group, 4 bowls or more rice consumption per day and drinking showed significant protective effect (R.R.: 0.20, 95% C.I.: 0.04-0.90 and R.R.: 0.23, 95% C.I.: 0.07-0.70, respectively). For differentiated gastric cancer in both age groups and undifferentiated one in older female, these factors stated above have no striking effect for gastric cancer occurrence. For differentiated type, several dietary habits were suggested to be risk factors for gastric cancer, although they were not statistically significant. On the other hand, for undifferentiated type, this tendency was not observed. This study suggests that etiologic factors for gastric cancer might be differed between histological types, and that undifferentiated type gastric cancer in young female with pregnancy has some etiological relation with reproductive histories. J Epidemiol, 1995; 5 : 177-185.
Serum lipid and apolipoprotein profiles are influenced by both genetic and environmental factors. However, the relative effects of these factors on the phenotypic variations remain unclear. In this study, the relative contributions of selected genetic and lifestyle factors to inter-individual variations in serum lipid and apolipoprotein levels were estimated by using the multiple regression model in a rural Japanese population. Four restriction fragment length polymorphisms (RFLPs) were tested with Xba I and EcoR I at the apolipoprotein B (apo B), and Msp I and Sac I at the apo Al-CIII gene loci. The contribution of individual RFLP to serum total cholesterol ranged from 0.08% to 1.60%; serum low density lipoprotein cholesterol, 0.06% to 1.69%; triglycerides, 0.04% to 0.89%; apo B, 0.06% to 1.99%; high density lipoprotein cholesterol, 0.05% to 2.59%; apo AI, 0.54% to 2.73%; apo AII, 0.12% to 1.96% and apo CIII, 0.13% to 0.48%. These percentages were almost the same as or a little lower than those of some lifestyle variables - dietary factors (Keys dietary score, and energy-adjusted intake of carbohydrate, fiber and n-3 fatty acids), smoking, alcohol consumption and physical activity-to the serum traits. J Epidemiol, 1995 ; 5 : 187-196.
In order to assess current dietary intake of water-soluble, water-insoluble and total fiber, fiber contents were estimated from food items in 24-hour total duplicate samples, utilizing a recently published tables of dietary fiber in foods coupled with supplemental procedures for better coverage of food items. The food duplicates were collected from 370 middle-aged Japanese subjects in 18 study sites in 12 prefectures across Japan during a period from 1990 to 1993. The coverage by the original database was 86% on an average (by weight of crude fiber-containing foods), whereas the coverage was 99% when supplemental procedures were applied in addition. The average ingested amount was 3.2 g/day for water-soluble fiber and 18.3 g/day for total fiber. No sex- or age- dependent difference was observed. Thus, current dietary intake of fiber by middle-aged Japanese people appears to be marginally sufficient. The leading sources were vegetables both for soluble (1.4 g/day) and total fiber (6.2 g/day), followed by cereals (0.3 and 3.1 g/day, respectively), fruits (0.8 and 2.7 g/day) and then pulse (0.4 and 2.3 g/day). J Epidemiol, 1995; 197-204.
The per capita daily intake of dietary fiber (DF) in Japan between 1917 and 1991 was assessed using statistical reports regarding nutrition, food consumption, production, and trade balance. The reported contents of DF for each food category were used ; these values were based on the modified Southgate method and modified Prosky AOAC method. Average per capita daily consumptions of total DF calculated by the modified Southgate method were 30.3 g in 1917-1924 and 15. 6 g in 1991. Those calculated by modified Prosky AOAC method were 28.6 g in 1917-1924 and 14. 5 g in 1991. Both calculation methods yielded values indicating that the DF intake had been almost constant in the last 20 years. Differences in the calculated values of DF obtained by the two methods are attributed mainly to the difference in the measured values for rice. J Epidemiol, 1995; 5 : 205-210.