We defined curable-duration of gastric cancer as the duration during which a gastric cancer is detectable by screening by contrasted indirect roentogenography and is also curable by therapy, and estimated its distribution using data from a group consisting of 66, 386 employees. The total of observed person-years was 179, 204. The distribution of curable-duration was shown to be M-shaped ; the two peaks were at under 1 year and over 4 years. Consequently it was concluded that one should attend screening by contrasted indirect roentogenography at an interval of 2 or 3 years, and that this will make the screening programs more efficient. J Epidemiol, 1992; 2 : 69-73.
A cross-sectional study to assess the associations between lifestyle factors and cancer risk was conducted in five areas of Japan (Ninohe in Iwate, Yokote in Akita, Katsushika-kita in Tokyo, Saku in Nagano and Ishikawa in Okinawa) with different cancer mortality patterns. The subjects were randomly selected men aged 40 to 49 years and their spouses, and they all volunteered to participate in this study. The study included a questionnaire on lifestyle performed by interview, a health check-up and sampling of blood and urine. Furthermore, a 24-hour urine collection and 3-day nutritional survey were added as supplementary items. The overall participation rate was 72% (634/880) : 77% in Ninohe, 78% in Yokote, 61% in Katsushika-kita, 71% in Saku, and 76% in Ishikawa. The wives of 59% (373/634) of the male participants also entered the study. A 24-hour urine collection and 3-day nutritional survey were also conducted in about one third of the participants. Profiles of participants revealed significant differences among each study area, such as length of residence, marital status, and occupation. J Epidemiol, 1992; 2 : 75-81.
A cross-sectional study on associations between lifestyle factors and cancer risks was conducted in five areas of Japan. The study design and participation rate were described in the part I. In this paper, we showed the baseline data of lifestyle and health-related items with special reference to geographic difference. Medical history of peptic ulcer, family history of stomach cancer and any cancer, smoking and drinking habits, anthropometric features such as height, weight and body mass index, and biochemical parameters such as HDL cholesterol, uric acid, and abnormal GOT were significantly different among men by study areas. Urinary excretion level of sodium, potassium, calcium and magnesium, and nutritional intake level of energy, fat and carbohydrate also revealed the significant differences. The wives of male participants also showed the similar geographical difference. Correlation analysis was conducted between age-adjusted mortality rates of selected cancer sites and prevalence or average values of lifestyle and health-related factors. Significant associations were found between esophageal cancer and consumption of alcohol and cigarette, and stomach cancer and both medical histories of peptic ulcer and salt excretion in 24-h urine. J Epidemiol, 1992; 2 : 83-89.
Usefulness of urinary cotinine (COT)/creatinine (Cr) ratio, a widely accept practical indicator of tobacco smoke uptake, was evaluated in 4 groups of healthy male volunteers (21 in total) with different cigarette doses of 0, 10, 20 and 30 cigarettes per day. 24-hour urine samples were collected on the 7th day of successive controlled smoking to determine urinary COT, thiocyanate (SCN) and Cr concentrations. Although urinary COT concentration exhibited close correlation (r=0.91, p<0.01) with cigarette dose, this correlation was weakened to r=0.82 (p<0.01) when it was standardized by urinary Cr concentration. Urinary SCN concentration was, in contrast, unrelated to cigarette dose (r=0.09), which however become correlated (r=0.71, p<0.05) after Cr standardization, in part due to the variation of urinary Cr concentration which was found inversely linked to cigarette dose (r= -0.47, p<0.05). Multiple regression analyses revealed that extent of urine volume-dependent decrease in urinary COT concentrationwas of several orders smaller in magnitude than that of urinary SCN or Cr concentrations as estimated on the basis of standardized partial regression coefficients. These results suggested that urinary COT/Cr ratio, compared to urinary COT concentration, tends to exaggerate the actual smoke uptake in the individuals with increased urine flow as well as in the smokers with smoking-associated decrease in urinary Cr concentration. J Epidemiol, 1992; 2 : 91-95.
Methods of quantifying physical activity in a population-based sample are needed to examine the relation of physical activity to cardiovascular diseases. We examined validity and reproducibility of an interviewer-administered physical activity questionnaire for men aged 40-59 years in a rural Japanese population. Validity was tested by comparing the estimate of physical activity from a 24-hour diary and maximum oxygen uptake from ergometer exercise test for forty-five men. There was no difference in the estimates of energy expenditure between the questionnaire and the 24-hour diary in each job classfication. Significant correlations were obtained between total activity estimated by the questionnaire and the 24-hour diary (r=0.66) and between the total activity and maximum oxygen uptake (r=0.30). Correlation coefficients between the test and retest at 1-2 year interval for 83 men were 0.67 for total activity, 0.62 for activity at work, 0.59 for leisure time activity and 0.24 for other activity. Using this questionnaire, energy expenditure in total physical activity was measured in 539 men aged 40-59 years living in a rural community of Akita, northeast Japan. Greater physical activity was associated with higher serum HDL-cholesterol levels, lower relative weight index. There was no significant association of physical activity with blood pressure levels, serum total cholesterol, cigarette smoking, and alcohol intake. Thus, greater physical activity was not always associated with lower coronary risk factors except for HDL-cholesterol. Prospective studies will be needed to clarify the relation of physical activity with cardiovascular disease in Japanese. J Epidemiol, 1992; 2 : 97-104.
To examine the usefulness of hyperfructosaminemia as an index of risk state of abnormal glucose metabolism for coronary atheroscrelotic disease, serum fructosamine concentration was compared between 130 male cases with coronary stenosis, aged 60 years or younger, and 260 age-matched male controls. Past history of diabetes mellitus (DM) and information on confounders such as serum lipid concentration, obesity, smoking habits, and family history of ischemic heart disease were obtained from all the subjects. There was no difference in frequency of the past history of DM between the cases (8.5%) and the controls (6.9%), but that of hyperfructosaminemia (cases : 36.2%, controls : 15.0%) was significantly higher in the cases than in the controls (p<0.01). When confounding effects by other risk factors were adjusted by multiple logistic regression analysis, the odds ratio of the past history of DM (1.19, 95% confidence interval : 0.47˜3.03) was not significant, but that of hyperfructosaminemia (3.59, 95% confidence interval : 1.94˜6.65) was significant after the past history of DM was replaced by it. Thus, abnormal glucose metabolism evaluated by hyperfructosaminemia was an independent coronary risk factor, although that evaluated by the past history of DM was not. These results suggest that serum fructosamine is a useful index of coronary risk state related to abnormal glucose metabolism. J Epidemiol, 1992; 2 : 105-110.
A meta-analysis was applied to the published case-control studies of ovarian cancer in order to examine the association of tubal sterilization and induced abortion with ovarian cancer. Among 65 case-control studies published between 1981 and 1991, six articles reported the numbers of women who underwent tubal sterilization and four articles reported the numbers ofwomen undergoing induced abortion in both cases and their controls. The test for combinability of these 6 or 4 odds ratios revealed that these odds ratios were combinable in terms of tubal sterilization or induced abortion. It was shown that tubal sterilization was significantly associated with a reduced risk for ovarian cancer (the summary odds ratio=0.55, 95% confidence interval or 95% CI 0.45-0.68), even after excluding nulliparous women from the analysis (the summary odds ratio=0.52, 95% Cl 0.36-0.74), and that induced abortion was also related to a decreased risk for ovarian cancer (the summary odds ratio=0.81, 95% Cl 0.63-1.04 based on the 4 combinable odds ratios; the summary odds ratio= 0.64, 95% Cl 0.46-0.89 based on the 2 studies in Asian countries). Several etiological inferences were made with regard to these findings, and some proposals for further research were addressed in ovarian cancer epidemiology. J Epidemiol, 1992; 2 : 111-118.