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Biomedical subjects

K Wakai

Publications and source records attributed to K Wakai.

At least 37 records · Page 2Linked to original sources

Validity and reliability of single-item questions about physical activity.

The Japan Collaborative Cohort Study for Evaluation of Cancer Risk Sponsored by Monbusho (JACC Study) included in its self-administered questionnaires some single-item questions concerning physical activity. We examined the validity of the questions among 1,730 Japanese adults and the reliability of the questions among 1,075 Japanese adults. The validity of the sports and physical exercise questions was estimated by comparing the self-administered questionnaire responses with the time spent on the activity and the energy expenditure index for the previous 12-month period, elicited by the interviewing method used in the Japan Lifestyle Monitoring Study with a minor modification. The Spearman's rank correlation coefficients ranged from 0.43 to 0.60, showing moderate correlations. On the other hand, test-retest reliability was estimated by comparing the responses from two separate surveys conducted roughly one year apart. Weighted kappa coefficients of sports and physical exercise questions, classified according to sex and age, ranged from 0.39 to 0.56, showing moderate reliability; and those of a question about walking ranged from 0.25 to 0.39, showing fair reliability. We suggest that measuring physical activity level with these single-item questions may be appropriate for establishing baseline data that reflects long-term physical activity in a large-scale cohort study targeting lifestyle-related diseases.

Adult↗

Nationwide epidemiological survey of chronic pancreatitis in Japan.

The aim of this study was to estimate the number of patients treated for chronic pancreatitis in 1994 in Japan and to explore the clinico-epidemiological features of chronic pancreatitis. Two surveys were conducted. Stratified random sampling was used to select departments in which patients with chronic pancreatitis were treated, and two different questionnaires were administered to obtain relevant information. From the first survey, the total number of patients treated for chronic pancreatitis in Japan in the year 1994 was estimated as 32,000 (95% confidence interval, 25,000-39,000). Clinico-epidemiological features, based on the 2,523 patients reported from the second survey, were subsequently clarified. The sex ratio (male/female) of the patients was 3.5. Alcoholic pancreatitis was the most common type in males (68.5%), and idiopathic pancreatitis in females (69.6%). Compared with the findings in the last survey in 1985, the proportion of patients with alcoholic pancreatitis has decreased slightly, from 58.7% to 55.5%, while that of idiopathic chronic pancreatitis has increased in both males and females. Patients diagnosed by advanced techniques such as computed tomography (CT) and endoscopic retrograde cholangiopancreatography (ERCP) accounted for 68.1% of the total. The number of patients with chronic pancreatitis treated in 1994 in Japan, was estimated as 32,000, with an overall prevalence rate of 45.4 per 100,000 population in males and 12.4 per 100,000 population in females.

Adolescent↗

Fat intake and breast cancer risk in an area where fat intake is low: a case-control study in Indonesia.

BACKGROUND: Associations of fat and other macronutrients with breast cancer risk are not clear in areas where fat intake is low. METHODS: We conducted a hospital-based case-control study from 1992 to 1995 in Jakarta, Indonesia. RESULTS: The study, based on 226 cases and 452 age and socioeconomic status matched controls, provided the following findings. (a) In the pre-marriage period, the greater the fat or protein consumption, the larger the risk, whereas decreasing risk with increasing carbohydrate intake was detected. The odds ratio (OR) for the highest quartile of intake relative to the lowest was 8.47 (95% CI: 4.03-17.8) for fat, 2.19 (95% CI: 1.30-3.69) for protein, and 0.16 (95% CI: 0.08-0.31) for carbohydrate. A positive association with fat and a negative one with carbohydrate were also observed for the post-marriage period, but of weaker magnitude compared to the pre-marriage period. (b) The effects of macronutrient intakes were stronger among premenopausal than among postmenopausal women. (c) Most of the associations of protein and carbohydrate were insignificant after adjustment for fat intake. CONCLUSIONS: These findings suggest that fat intake might be an important determinant of breast cancer among populations with a low fat diet in Indonesia.

Adult↗

Foods and nutrients in relation to bladder cancer risk: a case-control study in Aichi Prefecture, Central Japan.

To elucidate the role of diet in the etiology of bladder cancer, we conducted a case-control study from 1996 to 1999 in Aichi Prefecture, Central Japan. Cases were patients newly diagnosed with bladder cancer, and one hospital control was selected for each case, matching gender, age, and hospital. A well-validated food frequency questionnaire was adopted to estimate intakes of nutrients and food groups. Odds ratios (ORs) adjusted for smoking and occupational history were computed using conditional logistic models. The analyses based on 297 cases and 295 controls revealed the following. 1) The more the intake of milk and dairy products, the lower the OR; the ORs across quartiles in all subjects were 1.02, 0.73, and 0.52. Fruit intake was negatively associated with the risk, particularly in men (ORs across quartiles = 0.76, 0.77, and 0.52). Green-yellow vegetables were associated with a decreased risk in the highest quartile of consumption in men (OR = 0.57). 2) Dietary intakes of retinol and saturated fatty acids were related to a reduced risk in all subjects (ORs across quartiles = 0.75, 0.54, and 0.66 and 0.55, 0.54, and 0.60, respectively). Monounsaturated fatty acids had an inverse association with bladder cancer risk in men.

Adult↗

Depressive mood and suicide among middle-aged workers: findings from a prospective cohort study in Nagoya, Japan.

BACKGROUND: In Japan, mortality from suicide has peaked around 50 years old among men, with increasing trend after 65 years old, and this peak became more apparent in recent years. Beside this, "psychological autopsy" has revealed depression as one of the most important risk factors for suicide. There is, however, no cohort study which examined the relationship between depressive mood measured by simple method and suicide in middle-aged general population. METHODS: In 1989, baseline information was collected by a self-administered questionnaire, and 18,450 workers were followed up to March 31, 1995. All deaths observed during active service were identified, and when retired, its date was recorded. Among 5,352 male workers aged between 40 to 54, 11 committed suicide during follow-up period of 5 years. Analysis were carried out by Cox's proportional hazard model, controlling for age. RESULTS: Those who slept 9 hours or more per night demonstrated 12.14-fold risk of suicide compared with those who slept less than 9 hours. Smokers were more likely to commit suicide than non-smokers. Those who answered affirmatively to more than 7 out of 12 questions, which were derived from Zung self-rating depression scale, experienced an increased risk of suicide (RR 9.95; 95%CI: 1.89-52.44), even after adjusting for other confounding factors. CONCLUSION: We found an association between depressive mood and subsequent suicide in a middle-aged workers. Detailed observation and follow-up of those with depressive mood should be systematically organized with due attention and caution.

Adult↗

Maternal active and passive smoking and fetal growth: A prospective study in Nagoya, Japan.

In order to examine the effect of maternal active and passive smoking on fetal growth, we carried out a population-based cohort study. A self-administered questionnaire was distributed to 15,207 women who notified their pregnancy from April, 1989 to March, 1991. A total of 7,411 mother-singleton infant pairs were analyzed in this study. Paternal smoking status and maternal hours exposed to environmental tobacco smoke (ETS) were used as indicators of passive smoking. Infants born to active smoking mothers were 96 g lighter, on an average, at birth than those born to non-smokers, and the relative risk for intrauterine growth retardation was 1.79 (95% confidence interval (CI) = 1.05-3.04) among active smoking mothers. Infants with smoking fathers weighted 11 g lighter, on an average, than those with non-smoking fathers, and mean birth weight of infants was reduced by 19 g among mothers exposed to ETS. The relative risk for intrauterine growth retardation in non-smoking pregnants with a smoking husband and those exposed to ETS was 0.95 (95% CI = 0.72-1.26) and 0.95 (95% CI = 0.71-1.26), respectively. Our findings indicated an adverse effect of maternal active smoking on fetal growth in Japanese pregnant population, but with small influence of maternal passive smoking.

Analysis of Variance↗

Sleep patterns and total mortality: a 12-year follow-up study in Japan.

A population-based cohort study was conducted to assess the relationship between total mortality and self-reported sleep patterns as regards not only to sleep duration but also subjective sleep quality. A total of 5,322 inhabitants in Gifu Prefecture, Japan, completed a self-administered questionnaire on health status and lifestyles including habitual sleep patterns, and were followed-up for an average of 11.9 years. Relative risks were computed by using Cox proportional hazards models. Both longer and shorter sleep, compared to 7-8 hour-sleep, was related to significantly increased risk of total mortality in males (relative risk [RR] for > or = 10 hours = 1.94, and RR for < 7 hour = 1.90), but not in females. Females complaining of poor awakening state experienced a higher mortality risk compared to those who woke up normally (RR: 1.97). Males who usually fell asleep easily showed a marginally lower mortality risk compared to those who fell asleep normally (RR: 0.70). Female users of sleeping pills were at an elevated risk (RR: 1.89). These findings were almost unchanged after adjustment for sleep duration and other confounders. Poor self-reported quality of sleep seemed to be associated with an increased risk of mortality independently of sleep duration.

Adult↗

Risk modification in lung cancer by a dietary intake of preserved foods and soyfoods: findings from a case-control study in Okinawa, Japan.

To disclose the association of dietary intake of preserved foods and soyfoods with lung cancer risk, we analyzed the data from a case-control study conducted in Okinawa, Japan, from 1988 to 1991. The analysis, based on 333 cases and 666 age-, sex- and residence-matched population controls, provided the following major findings. (1) The more the miso soup intake, the higher the risk (test for trend: P = 0.001 for males; P = 0.043 for females). (2) Frequent intake of pickles (excluding salted fish) tended to be linked with an elevated risk in males. The adjusted odds ratio (OR) for once or twice per week or more, relative to less than once a month was 1.88 (95% confidence interval (CI): 1.26-2.81). (3) Frequent intake of soybeans was associated with a decreased risk in men (OR: 0.63, 95% CI: 0.40-0.98 for once or twice per week or more, relative to less than once a month). (4) Daily consumers of tofu were at a decreased risk, particularly for squamous cell carcinoma; the OR (95% CI) being 0.55 (0.34-0.89) in males and 0.14 (0.02-0.89) in females. These findings suggested deleterious effects of preserved foods and protective ones of soyfoods rich in isoflavones.

Adenocarcinoma↗

Risk factors for IgA nephropathy: a case-control study in Japan.

To disclose the risk factors for immunoglobulin A nephropathy (IgAN), we conducted a case-control study in the Tokai area of central Japan. The subjects were 94 patients, aged 20 years or older at diagnosis, who had histologically confirmed IgAN. Two sex-, age-, and residence-matched controls were randomly selected for each case from the general population. Information on medical history and lifestyle was collected using a self-administered questionnaire. The strength of association between IgAN and a potential risk factor was assessed by calculating an odds ratio. A family history of chronic nephritis, susceptibility to the common cold, preference for salty foods, frequent consumption of raw eggs, and a high intake of carbohydrates, including rice, were significantly associated with an increased risk for IgAN. Alcohol consumption, use of antioxidant vitamin supplements, and a high intake of protein, fat, monounsaturated fatty acids, and all/n-3 polyunsaturated fatty acids were somewhat protective against IgAN. Episodes of tonsillitis and exposure to organic solvents were found not to be associated with the risk in the present study. Our findings may provide some clues to the cause of IgAN.

Adult↗

Trends in site-specific mortality from oral and pharyngeal cancer among Japanese males, 1950-94.

In order to obtain some etiological clues for oral and pharyngeal cancer in Japanese males, we examined mortality trends from cancer of the lip, buccal cavity and pharynx by site with other descriptive epidemiological features (1950-94). The data were obtained from Vital Statistics (Ministry of Health and Welfare, Japan). The 45-year trend in mortality was evaluated by computing crude and age-adjusted mortality rates, age-specific mortality rates, with birth cohort analysis. The crude mortality rate from cancer of the lip, buccal cavity and pharynx has increased by 3.7-fold, and age adjusted mortality rate by 1.7-fold in the 45-year period, with different mortality trends by site. In general, age-specific mortality has also been increasing with advancing age. The birth cohort analysis showed that the higher the mortality rate, the younger the birth cohort, but with different effects of birth cohort by site. Mortality from cancer of the lip, buccal cavity and pharynx has consistently been increasing in Japanese males from 1950 to 1994, with similar upward mortality trends for some specific sites.

Adult↗

Associations of medical status and physical fitness with periodontal disease.

To determine the possible associations of medical status and physical fitness with periodontal disease, a cross-sectional study was conducted. The subjects were 517 males and 113 females aged 23 to 83 years who participated in a multiphasic health test at the Aichi Prefectural Center of Health Care, Japan, from 1992 to 1997. Their periodontal status was assessed by means of the CPITN scoring system. To assess the strength of associations between the examined factors and the score, odds ratios were computed using ordinal logistic models. Conventional risk factors such as old age, smoking habits, and higher fasting plasma glucose and simplified debris index increased the risk of periodontal disease. Hypertension, hematuria, leucocytosis or thrombocytosis, positive C-reactive protein and higher serum alkaline phosphatase were positively associated with the score, whereas higher serum high-density lipoprotein cholesterol was related to a lower risk. Poor physical fitness affecting aerobic capacity, foot balance and reaction was associated with a higher CPITN score. These associations were independent of the conventional risk factors. Although these new potential risk factors should be further investigated for their causal relationship, our findings suggested a close relationship of oral health to medical status and physical fitness.

Adult↗

Sudden death in the working population: a collaborative study in central Japan.

AIM: Few epidemiological data are available describing the sudden death of persons in their prime. This study aims to elucidate when and how sudden death occurs among employees. METHODS: A total of 196775 employees from 10 workplaces in Central Japan were surveyed for non-traumatic sudden death during 1989-1995. Demographic data and information regarding onset were collected by their workplace healthcare professionals. RESULTS: We identified 251 male and 13 female cases of sudden death. The annual incidence was 21.9 (for men) and 5.7 (for women) per 100000 population. Sudden death occurred more frequently in April when the new business year starts (risk ratio [95% confidence interval], 1.62 [0.94-2.79]) than in other months, without seasonality. Sudden death peaked on Sundays (risk ratio, 1.90 [1.20-2.99]) and Saturdays (risk ratio, 1.36 [0.83-2.21]) as compared with weekdays, and was likely to occur in the small hours (risk ratio, 1.71 [0.94-3.10] at 00-0300 h and 1.47 [0.79-2.72] at 0300-0600 h vs at 0900-1200 h. Only 17% of employees died at work, which was significantly less than expected (P<0.001). CONCLUSION: These findings differed from those of elderly people and suggest that sudden death of persons in their prime is related to occupational stress and its relief.

Adult↗

Dietary intake and sources of isoflavones among Japanese.

We examined the dietary intake and sources of isoflavones (daidzein and genistein) among Japanese subjects based on dietary records (DRs). The subjects comprised two groups: 1,232 who completed one-day DRs (Group 1) and 88 men and women who kept four four-day (16-day) DRs. For quantitative data on the level of daidzein and genistein in soy foods, we extensively reviewed the literature, particularly for Japanese soy foods, and adopted the median value for each food. The median intake of daidzein was 12.1 and 9.5 mg/day among Groups 1 and 2, respectively, while the corresponding values for genistein were 19.6 and 14.9 mg/day. The top four foods (tofu, miso, natto, and fried tofu) covered about 90% of the population intake of daidzein and genistein. It did not seem feasible to estimate one's intake of isoflavones by using dietary recording/recall in epidemiological studies, since the day-to-day variation in intake was too large, the within-person coefficient of variation being 89.1% for daidzein and genistein. Therefore, we should use other methods, such as food-frequency questionnaires, focusing on the four major sources of isoflavones, to assess individual isoflavone intake.

Diet↗

Favorable life-style modification and attenuation of cardiovascular risk factors.

In order to develop an effective counseling system for prevention of cardiovascular diseases, the association of a favorably changed life-style with improved risk factors was examined. Participants were 7,321 office workers aged 30-69 years from in and around Nagoya city. The age-adjusted odds ratio (OR) and its 95% confidence interval (CI) were calculated to assess the likelihood of risk factor improvement by favorable life-style modifications during a 3-year period. Those who began to eat breakfast and increased their vegetable intake normalized their previously abnormal diastolic blood pressure with more than twice the likelihood (adjusted OR [95% CI] 2.89 [1.29-6.46] and 2.60 [1.18-5.75], respectively). 'Began to eat breakfast' was also significantly associated with normalized total cholesterol (TC) (1.84, [1.05-3.21]). 'Stopped eating till full' significantly normalized the body mass index (2.03; [1.25-3.28]), uric acid (1.65; [1.07-2.52]) and TC (1.43; [1.04-1.97]). Those who started regular exercise significantly normalized their high-density lipoprotein-cholesterol (HDL-C) abnormality with 1.69-times the likelihood (1.69; [1.24-2.29]) and those who began to walk briskly also improved their TC abnormality (1.85; [1.19-2.89]). HDL-C was normalized with 2.55-times the likelihood in those who quit smoking (2.55; [1.68-3.86]). Because favorable life-style modifications can attenuate abnormal cardiovascular risk factors, then proper advice on specific risk factors should be routinely given at each health check-up in order to prevent the onset of cardiovascular diseases in subsequent years.

Adult↗

Agreement between self- and partner reports obtained by a self-administered questionnaire: medical and lifestyle information.

We examined agreement between the subjects' self- and partner-reports of such epidemiological information as medical and family history, smoking and drinking habit and physical activity. Information was obtained by a self-administered questionnaire which was completed by 224 workers (subjects) and by their partners in 1997. Agreement was assessed by calculating kappa statistic, intraclass correlation coefficient (ICC), and per cent agreement. Per cent agreement ranged from a low of 76.2 for general life stress to a high of 98.0 for angina/myocardial infarction and diabetes mellitus as present illness. Kappa values ranged from a low of 0.34 for general life stress to a high of 0.86 for smoking habit. Compared to subjects, their partners tended to report lower level of both exposures (continuous variables) and presence (dichotomous variables). The average kappa was 0.64 for wife-surrogates, whereas 0.53 for husband-surrogates. Overall, our finding suggested that partners could provide acceptable information for the concrete and directly-observable variables (e.g. such present illness as hypertension which required daily medication, or smoking/drinking habit itself), but not so for detailed/subjective variables (e.g. number of cigarettes smoked per day or general life stress).

Adult↗

A simple food frequency questionnaire for Japanese diet--Part I. Development of the questionnaire, and reproducibility and validity for food groups.

We developed a simple food frequency questionnaire (FFQ) based on one-day dietary records (DRs) among 1001 subjects in Nagoya, Japan. A total of 97 foods and dishes were selected through a two-step procedure; first by ranking food items according to the contribution to the population intake of nutrient variables, and second by stepwise multiple regression analyses of individual food items as the independent variables and of total nutrient intake as the dependent variables. For simplicity, questions on portion sizes were not included except for a few selected food items, which resulted in short time (about 20 minutes) to complete the questionnaire. This FFQ was validated for food groups by referring to four 4-day DRs among 88 men and women in central Japan, from 1996 to 1997. The energy-, sex- and age-adjusted test-retest correlation coefficients between the two FFQs administered at an one year interval ranged from 0.34 to 0.78. The de-attenuated, energy-, sex- and age-adjusted correlation coefficients between the second FFQ and the DRs were larger than 0.40 for most food groups, indicating the usefulness of this simple FFQ with its sufficient validity in epidemiological surveys.

Adult↗