Oral symptoms predict mortality: a prospective study in Japan.

Several studies have reported positive associations between oral infections and systemic diseases. The purpose of the present study was to evaluate the effects of oral symptoms on mortality from cardiovascular disease (CVD) and pneumonia. Using data from a cohort study in Japan, we analyzed 4,139 individuals aged 40-79 years. The baseline questionnaire included the following items related to oral symptoms: 'sensitive teeth', 'difficulty in chewing tough food substances', 'bleeding gums', and 'mouth feels sticky'. We used the Cox proportional hazard model to estimate hazard ratios (HRs) and 95% confidence intervals (95%CIs) for mortality, after adjustments for lifestyle, socio-economic factors, and history of diseases. Persons complaining that their 'mouth feels sticky' had a two-fold higher risk of pneumonia (HR = 2.1; 95%CI, 1.2-3.6), while those complaining of 'sensitive teeth' had a lower risk of CVD (HR = 0.4; 95%CI, 0.2-0.9). Some oral symptoms may be predictors of mortality from pneumonia and CVD.

Individual and joint impact of family history and Helicobacter pylori infection on the risk of stomach cancer: a nested case-control study.

We used 202 cases of stomach cancer and 394 controls nested within the Japan Collaborative Cohort Study For Evaluation of Cancer Risk (JACC study) to investigate whether family history has an independent effect on the risk of stomach cancer after controlling for the Helicobacter pylori infection. A positive history of stomach cancer in one or more first-degree relatives was associated with an increased risk of the disease in women, but not in men after controlling for H. pylori infection and other confounding variables. Women with both a family history and H. pylori infection were associated with more than five-fold increased risk of the disease (OR 5.10, 95% CI 1.58-16.5) compared to those without these factors. These results suggest the existence of inherited susceptibility to the disease in women, and that measurements of H. pylori infection together with the family history allow meaningful evaluation of risk beyond that provided by either factor alone.

A nested case-control study of stomach cancer in relation to green tea consumption in Japan.

To evaluate whether green tea consumption provides protection against stomach cancer, the relative risks (RRs) were calculated in the Japan Collaborative Study for Evaluation of Cancer Risk, sponsored by the Ministry of Health and Welfare (JACC Study). The study was based on 157 incident cases and 285 controls aged 40-79 years. Cox proportional hazards regression analysis was used to estimate the RRs for stomach cancer. It was found that green tea consumption had no protective effect against stomach cancer. After adjustment for age, smoking status, H. pylori infection, history of peptic ulcer, and family history of stomach cancer along with certain dietary elements, the risks associated with drinking one or two, three or four, five to nine, and 10 or more cups of green tea per day, relative to those of drinking less than one cup per day, were 1.3 (95% confidence interval (CI): 0.6-2.8), 1.0 (95% CI: 0.5-1.9), 0.8 (95% CI: 0.4-1.6), and 1.2 (95% CI: 0.6-2.5), respectively (P for trend=0.899). We found no inverse association between green tea consumption and the risk of stomach cancer.

A prospective study of blood transfusion history and liver cancer in a high-endemic area of Japan.

BACKGROUND: The high prevalence of liver cancer in Japan may be owing to infection with hepatitis C virus (HCV), for which the major transmission route is blood transfusion. However, among the general population, there have been few follow-up studies of people with a history of transfusion. The purpose of this study was to examine whether such a history correlates with the development of liver cancer among the general population of this high-endemic area. STUDY DESIGN AND METHODS: The baseline survey was conducted between 1986 and 1991 among the population (15,597 people, aged 30-79) of Fukuoka prefecture, Japan. The participants were assessed for their transfusion history and other covariates using a baseline questionnaire. The relative risk (RR) of blood transfusion for liver cancer was estimated using the Cox proportional hazard model. RESULTS: The RRs of transfusion for subsequent liver cancer were 1.86 (95% confidence interval (CI) = 1.05-3.29) in men and 4.20 (95% CI = 1.83-9.61) in women, after adjusting for covariates. Transfusion was associated with an increased risk of liver cancer, mainly in the group without hepatitis and cirrhosis (RR = 1.81, 95% CI = 0.84-3.91 - men; RR = 4.39, 95% CI = 1.37-14.02 - women). CONCLUSION: A history of blood transfusion carried a significant risk of developing liver cancer in the study region. The people with a history of transfusion should be monitored more aggressively for viral infections and liver disease, as they may not report the infection or they may be unaware that they are infected.

A prospective study of stomach cancer death in relation to green tea consumption in Japan.

To evaluate whether green tea consumption provides protection against stomach cancer death, relative risks were calculated using Cox proportional hazards regression analysis in the Japan Collaborative Study for Evaluation of Cancer Risk, sponsored by the Ministry of Health and Welfare (JACC Study). The study was based on 30 370 men and 42 481 women aged 40-79. After adjustment for age, smoking status, history of peptic ulcer, family history of stomach cancer along with certain dietary items, the risks associated with drinking one or two, three or four, five to nine, and 10 or more cups of green tea per day, relative to those of drinking less than one cup per day, were 1.6 (95% CI: 0.9-2.9), 1.1 (95% CI: 0.6-1.9), 1.0 (95% CI: 0.5-2.0), and 1.0 (95% CI: 0.5-2.0), respectively, in men (P for trend=0.669), and 1.1 (95% CI: 0.5-2.5), 1.0 (95% CI: 0.5-2.5), 0.8 (95% CI: 0.4-1.6), and 0.8 (95% CI: 0.3-2.1), respectively, in women (P for trend=0.488). We found no inverse association between green tea consumption and the risk of stomach cancer death.

Dietary factors and stomach cancer mortality.

The present study examined the relationship between stomach cancer and the low intake of fresh fruit and vegetables and/or a high intake of pickled, preserved or salted foods and frequent use of cooking oil. During 139,390 person-year of follow-up of over 13,000 subjects, 116 died from stomach cancer. Using a Cox proportional hazards-regression analysis of relative risk (RR, 95% CI) controlling for age, sex, smoking and other dietary factors, a significant decline was found with a high consumption of green and yellow vegetables (RR=0.4, 95% CI=0.2-0.9). Reductions of between 40 and 50% were also observed with a high consumption of fresh foods (fruit, cuttle fish, tofu, and potatoes), but these associations were not statistically significant. The risk was significantly increased by the high consumption of processed meat (RR=2.7, 95% CI=1.0-7.4) and by the frequent use of cooking oil (RR=4.0, 95% CI=1.3-11.8). The high consumption of pickled food and traditional soups also increased risk, but not significantly. The findings suggest that a diet high in salt and low in vitamins may be associated with an increase in stomach cancer.

Prospective study of diabetes mellitus and liver cancer in Japan.

BACKGROUND: Previous studies have identified the association between diabetes mellitus and liver cancer. However, the detail of this association is still unclear, in terms of confounding factors, the trend according to the duration of diabetes, and the interaction between diseases associated with the liver cancer and this association. The purpose of the present study was to examine the association between diabetes and liver cancer in view of the trend and the interaction. METHODS: The baseline survey was conducted during the period 1986-1989 among the general population of Fukuoka Prefecture, Japan (15 417 persons aged 30-79 years). The respondents were assessed for history of diabetes, age at which they had had diabetes, and other covariates by means of a baseline questionnaire. A total of 7308 persons aged 40-79 years were retrieved for the main analysis and 4902 persons for a subcohort from which the information on history of diseases associated with liver cancer were obtained. The relative risks (RRs) and their 95% confidence intervals (CIs) were estimated using the Cox proportional hazards model. RESULTS: After adjustment for smoking, alcohol and the diseases associated with liver cancer, the RR for liver cancer was 2.06 (95% CI=1.01-4.19). Diabetes increased the risk of liver cancer in persons with hepatitis and/or cirrhosis (RR=2.90, 95% CI=1.13-7.41). However, the RR of diabetes for liver cancer was 1.35 (95% CI=0.41-4.43) in persons without hepatitis and cirrhosis. The trend according to the duration of diabetes was not seen. CONCLUSIONS: A significant association between diabetes and liver cancer was observed. Moreover, this association was modified by hepatitis and cirrhosis.

[Six cases of occupational skin diseases caused by cement: considerations from the aspect of occupational dermatology].

Cement, in particular Portland cement, is now widely used in the field of civil engineering and the construction industry. High alkalinity of wet cement and its tiny content of water-soluble chromate can cause occupational skin diseases. In this paper, we report four cases of contact dermatitis by cement and two cases of cement burn. The occupation of the patients included two plasterers, a truck driver, a manufacturer of cement ware and two construction workers. Skin of the hands and fingers of the cement dermatitis cases was dry and fissured, and had hyperkeratotic papules and erythemas or acute exudative eczematous lesions. In one of these cases, the eczematous lesions spread to the face, extremities and trunk. All cases resulted in a positive patch testing for sodium dichromate. The cement burn cases developed severe necrotic ulcers on the leg and/or foot following prolonged contact with wet cement inside their boots. Patch testing was negative for chromate. A field trip to a construction worksite showed that method of working as well as worker's clothing at present could not thoroughly protect the skin. Therefore we concluded that better protective clothing and gloves should be used and that working conditions be improved. Most skin diseases caused by cement occur among workers at small-scale enterprises. Therefore it is desirable that regional occupational health centers, which were established to promote the health care system for workers at small-scale enterprises, take prompt measures to avoid the skin diseases.

An international comparison of the involvement of epidemiology in the most frequently cited publications in the field of clinical medicine.

The objectivity, validity and credibility of research in clinical medicine can be enhanced by the appropriate involvement of epidemiology. However, the overall contribution of epidemiology to clinical research, either as a methodology or as a resource for research, has been poorly quantified. We therefore assessed the involvement of epidemiology in influential publications in the field of clinical medicine, and made an international comparison on a quantitative basis. The 500 most frequently cited papers published during 1981-96 in the field of clinical medicine in the US, the UK, and Japan were compared in terms of epidemiological involvement using predetermined criteria. The three criteria were based on the indexing of relevant MeSH keywords, publication types, or the departmental affiliations of the authors. For all three criteria, the proportion of clinical papers with epidemiological involvement was the highest in the US, followed by the UK, whereas it was the lowest in Japan. The difference was almost four-fold between the US and Japan. There was also an increasing trend of epidemiological involvement in publications of clinical medicine over the years, which was more apparent in the US than in either the UK or Japan. These findings may reflect inter-country differences in resources as well as in the stance towards evidence-based health sciences.

Comparison of three in vitro assay systems used for assessing cytotoxic effect of heavy metals on cultured human keratinocytes.

The cell viability assay using cultured cells is of great advantage to elucidate the biological effect of potentially toxic substances. Recently, a novel assay system, Tetracolor One cell proliferation assay (Seikagaku Co., Tokyo, Japan), has been developed. In this report, we compare the results of the Tetracolor One assay regarding the cytotoxic effect of three heavy metal salts on cultured adult keratinocytes to those of the neutral red dye uptake assay and the MTT eluted stain assay. In this study, these three methods showed almost similar results. Compared to the other two methods, however, the Tetracolor One assay, which requires only one-step procedure before spectrophotometric measurement, is easier to use, and errors in measurement, which may be produced through the multistep procedure, are much less in this assay. Therefore, we believe that the Tetracolor One assay system is useful for assessing the cytotoxic effect of heavy metals on cultured human keratinocytes.

Characteristic lifestyles in 6-year-old children with obese parents: Results of the toyama birth cohort study.

OBJECTIVE: The aim of this study was to identify characteristic lifestyles in children with obese parents. METHODS: 8,030 children (4,072 males and 3,958 females) aged 6 to 7 years were investigated. A questionnaire relating to the lifestyles of children was distributed through elementary schools for completion by parents. The heights and weights of parents were self-reported. A parent with a body mass index (weight in kilograms divided by the square of height in meters) greater than the 90th percentile for gender (26.7 kg/m(2) for fathers and 24.3 kg/m(2) for mothers) was defined as an obese parent. A chi-square test for each trend was applied to evaluate an increasing trend in the frequency or level of each lifestyle in children with obese parents. RESULTS: Children with obese parents were significantly associated with increasing trends in the proportions categorized by irregular intake of breakfast, faster eating, longer TV watching, and shorter sleeping hours. CONCLUSIONS: These lifestyles are considered to be possible risk factors for the development of obesity. These characteristic lifestyles observed in children with obese parents could strengthen the relationship between child and parental body compositions, in addition to the genetic predisposition to obesity in children with obese parents. These findings indicate that education with lifestyle modification for obese parents will be required to prevent further weight gain in children with obese parents.

Evaluation of dietary intake using carbon and nitrogen isotope analysis of human hair of Chinese living in southern part of China.

We examined dietary intakes among 69 people of three ethnic groups (Yao Chinese, Zhung Chinese and Han Chinese) in the autonomous country of Bama in China where many elderly people have a long life span in 1998. Dietary intake was evaluated using carbon and nitrogen isotope ratios of human hair (delta 13C, delta 15N) standardized by standard gas. The distributions of delta 13C in Yao Chinese and Han Chinese were scattered from -21 to -17/1000, which were close to that of C4 plants such as corn and millet. The distribution of delta 13C in Zhung Chinese was located from -25 to -22/1000, which was near that of C3 plants such as rice, wheat and potato. These values showed a much wider range when compared with delta 13C in Chinese living in urban areas. On the other hand, delta 15N in each group was distributed in the area ranged from 8 to 11/1000. The result of delta 13C was consistent with data obtained from a nutritional survey, but that of delta 15N was a little higher than expected. The carbon and nitrogen isotope ratios of human hair among three ethnic groups showed characteristic distributions, although the relation between these isotope ratios and longevity is uncertain.

Prospective study on the relation of cigarette smoking with cancer of the liver and stomach in an endemic region.

BACKGROUND: Smoking has not been confirmed as a risk factor for cancers of the liver and stomach. The authors examined prospectively the relationship between smoking and these cancers in an endemic region. METHODS: The data used were a cohort study on the relationship between lifestyle and health in the region having the highest liver cancer mortality in Japan. Of the cohort members, 4050 males aged > or =40 years were included in the present analysis with a 9-year mean follow-up. Cox proportional hazards regression was used to estimate relative risks (RR) for cancer of the liver, stomach, smoking-related sites and others, while adjusting for age, residence, and alcohol intake. RESULTS: By the end of the study period, 59 cases of liver cancer and 53 cases of stomach cancer were identified. Current smokers, compared to subjects who had never smoked, had a threefold risk of liver cancer (RR = 3.3; 95% CI: 1.2-9.5) and a twofold risk of stomach cancer (RR = 2.2; 95% CI: 0.8-5.7). Sub-cohort analysis showed that adjustment for history of chronic liver disease did not attenuate the risk of liver cancer. Light/medium smokers had almost the same risk of these cancers as heavy smokers, while they showed a relatively low risk of smoke-related cancers. CONCLUSIONS: The present results indicate that smoking is a risk factor of liver and stomach cancer in a population with a high background risk for these cancers. However, causal inferences should be made cautiously due to a lack of information on known risk factors.

Effects of radiotherapy after hyperbaric oxygenation on malignant gliomas.

The purpose of this non-randomized trial was to evaluate the efficacy of radiotherapy combined with hyperbaric oxygen (HBO) in patients with malignant glioma. Between 1987 and 1997, 29 patients in whom computerized tomography (CT) or magnetic resonance imaging (MRI) scans showed post-operative residual tumours were locally irradiated with nitrosourea-based chemotherapy. Treatments were consecutively combined with HBO at two institutions since 1991 and 1993. Fifteen patients were irradiated daily after HBO, and the periods of time from decompression to irradiation were within 15 and 30 min in 11 and four patients respectively. Fourteen other patients were treated without HBO. Tumour responses were assessed by CT or MRI scans and survival times were compared between the treated groups. In the HBO group, 11 of 15 patients (73%) showed > or = 50% tumour regression. All responders were irradiated within 15 min after decompression. In the non-HBO group, four of 14 patients (29%) showed tumour regression. The median survivals in patients with and without HBO were 24 and 12 months, respectively, and were significantly different (P < 0.05). No serious side-effects were observed in the HBO patients. In conclusion, irradiation after HBO seems to be a useful form of treatment for malignant gliomas, but irradiation should be administered immediately after decompression.

The relationship between lifestyle, social characteristics and obesity in 3-year-old Japanese children.

It has been observed that obese children receive genetic and environmental effects that are associated with them being overweight. With regard to the latter, lifestyles such as eating habits and physical activity have been focused on. In the present study, the social characteristics which would dominate their lifestyles were investigated as background variables. For this purpose, 9668 Japanese children aged three years who were all born in Toyama prefecture, Japan, in 1998, served as birth cohort subjects. For the comparison between obese (Kaup Index; mass in kg/(height in m)2 > or = 18) and nonobese (Kaup index < 18) children, irregular snack intake, physical inactivity and reduced sleeping hours were chosen as statistically significant obesity-related lifestyle indicators for the children. For social characteristics, family construction (expanded family with grandparents/nonexpanded family), main caregiver (mother/other), attending a nursery school (yes/no) and mother's employment (full-time worker/other) were chosen. These were significantly associated with the obesity-related lifestyles mentioned above using multiple logistic regression analysis adjusted for other variables of social characteristics as well as for gender and birth month (July-December/January-June). The two greatest population-attributable risk percentages were observed for mother as main caregiver (-36.5%) and attending a nursery school (-28.9%) for irregular snack intake. Therefore, these two social characteristics substantially reduced the number of children with irregular snack intake. On the other hand, the two social characteristics were reversed in children with reduced sleeping hours (population-attributable risk percentage of mother as main caregiver: 15.4%; attending a nursery school: 17%). In contrast with favourable effects on snack intake these social characteristics showed an adverse influence on the sleeping habits of children.

Serum concentrations of carotenoids, alpha-tocopherol, fatty acids, and lipid peroxides among Japanese in Japan, and Japanese and Caucasians in the US.

Serum concentrations of carotenoids, alpha-tocopherol, fatty acids, and thiobarbituric acid-reactive substances (TBARS) were measured in 217 Japanese residents of Japan, and in 99 Japanese and 100 Caucasian residents of the US, aged from 50 y to 74 y. In females, serum values of carotenoids such as beta-carotene (BC) and zeaxanthin & lutein (ZL) were highest among Japanese in Japan, followed by Japanese in the US and Caucasians in the US. In males, these values, except for serum BC values, were also highest among Japanese in Japan. Moreover, serum values of n-3 polyunsaturated fatty acids (n-3PUFAs) such as eicosapentaenoic acid and docosahexaenoic acid were significantly higher among Japanese in Japan than among Japanese and Caucasians in the US in both sexes. In contrast, serum values of n-6 polyunsaturated fatty acids such as linoleic acid and arachidonic acid were lowest among Japanese in Japan. For women, serum levels of n-9 unsaturated fatty acids were lowest among Japanese living in Japan. Serum TBARS values were highest among Japanese in Japan, followed by Japanese in the US and Caucasians in the US. A significant positive correlation was observed between serum values of TBARS and n-3 PUFAs among Japanese both in Japan and in the US. Serum TBARS values showed a significant inverse relationship with the serum values of BC and ZL among Japanese in Japan and with those of BC among Japanese in the US. These relationships were not always observed among Caucasians in the US. The results of this study suggest that the high TBARS values among Japanese in Japan may depend in part on lipid peroxidation induced in vitro by n-3PUFAs, while high reduction of lipid peroxidation could be expected among Japanese in Japan with high antioxidants such as BC and ZL. In conclusion, serum levels of nonprovitamin A carotenoids such as ZL may be a useful intake marker of vegetables. Dietary intakes of dark green vegetables and fish rich in n-3PUFAs might be more important in the prevention of some sites of cancer and of ischemic heart disease.

Body mass decrease after initial gain following smoking cessation.

BACKGROUND: Although smoking cessation is strongly associated with subsequent weight gain, it is not clear whether the initial gain in weight after smoking cessation remains over time. METHOD: Cross-sectional analyses were made, using data from periodic health examinations for workers, on the relationship between body mass index (BMI) and the length of smoking cessation. In addition, linear regression coefficients of BMI on the length of cessation were estimated according to alcohol intake and sport activity, to examine the modifying effect of these factors on the weight of former smokers. RESULTS: Means of BMI were 23.1 kg/m2, 23.3 kg/m2, 23.6 kg/m2 for light/medium smokers, heavy smokers and never smokers, respectively. Among former smokers who had smoked > or = 25 cigarettes a day, odds ratio (OR) of BMI >25 kg/m2 were 1.88 (95% confidence interval [CI] : 1.05-3.35), 1.32 (95% CI : 0.74-2.34), 0.66 (95% CI: 0.33-1.31) for those with 2-4 years, 5-7 years, and 8-10 years of smoking cessation, respectively. The corresponding OR among those who previously consumed <25 cigarettes a day were 1.06 (95% CI: 0.58-1.94), 1.00 (95% CI: 0.58-1.71), and 1.49 (95% CI: 0.95-2.32). CONCLUSIONS: The results suggest that although heavy smokers may experience large weight gain and weigh more than never smokers in the few years after smoking cessation, they thereafter lose weight to the never smoker level, while light and moderate smokers gain weight up to the never smoker level without any excess after smoking cessation.

Association between self-reported stressful feeling by SACL and mortality in a Japanese community.

A cohort study consisting of 4,291 residents of a Japanese community has been conducted since 1987. The associations between stressful feelings measured by Stress Arousal Checklist (SACL) and mortality of all causes and cancer were examined. The relative risks (RRs) for mortality for 7 years for high stressful state (SACL score: 7-17) and moderate stressful state (3-6) subjects compared with low stressful state subjects (0-2) were 1.1 (95% CI = 0.69-1.68), 1.3 (95% CI = 0.85-2.00) for all causes and 1.5 (95% CI = 0.80-2.99), 1.3 (95% CI = 0.67-2.61) for cancer respectively, after being adjusted for sex, age, smoking, drinking, exercise and medical-care use. When each item of the SACL was examined independently, six out of 17 items of SACL which were "not comfortable", "not contented", "not cheerful", "dejected", "nervous", "not pleasant" showed elevated RRs for all causes of mortality with statistical significance (RRs: 1.4, 1.4, 1.7, 1.7, 1.5, 1.5, respectively), after being adjusted for the possible confounding factors stated above. Especially, the adjusted RRs of "not cheerful" and "dejected" for all causes was 1.7 (95% CI = 1.20-2.33), 1.7 (95% CI = 1.17-2.46), respectively. The results suggested that stressful feelings of "not cheerful" and "dejected" might increase mortality.

[The association of self-rated health and mortality--a 7-year follow-up study of a Japanese community].

This study aims to examine whether self-rated health is an independent predictor of cause-specific mortality even after the influence by a variety of factors in relation to mortality reported by previous studies have been excluded. This study included randomly selected 4,259 inhabitants (1,827 men and 2,432 women) in Y city, Fukuoka prefecture, Japan, aged from 30 to 79 in 1987. These subjects were surveyed in 1987 by self-administered questionnaires regarding self-rated health as well as life habits, and followed up for their vital status and underlying causes of death. After excluding the individuals who were lost to follow up or who didn't respond to the question on self-rated health, 4,046 individuals were analysed to see the relationship between self-rated health and cause-specific mortality by Cox proportional hazard models, controlling for sex, age, smoking, BMI, medical care use and ADL. It was shown that relative risks for all causes, cancer, circulatory disease and other causes among the unhealthy group were 2.95 (95% CI: 1.93-4.50), 2.96 (1.53-5.73), 2.32 (0.86-6.26) and 4.09 (2.12-7.89), relatively. In the analyses of the subgroup (subjects without diseases in 1987 or subjects excluding deceased cases within first 3 years after follow-up), to avoid selection bias, the association between self-rated health and mortality was substantially similar to the results obtained in the former analysis, even the association was weakened. Even after excluding both of the subjects with diseases in 1987 and the subjects who died in the first 3 years after follow-up, self-rated health could be associated with mortality from all causes (RR = 1.89, 95%CI; 0.91-3.94). From the results it is suggested that self-rated health itself can be the independent predictor of mortality.

[A sero-epidemiological study on atrophic gastritis and Helicobacter pylori infection].

The aim of this study is to clarify the relationship between the incidence of atrophic gastritis and Helicobacter pylori infection. A case control study was conducted in 1995. Cases and controls were selected among those who took an annual health examination in a rural area of Fukuoka Prefecture. Cases are those who were not diagnosed as having atrophic gastritis in 1991 or 1992 but were diagnosed as having atrophic gastritis in 1995 by the examination of serum pepsinogens. Controls are those who were not diagnosed as having atrophic gastritis between 1991, or 1992 and 1995. Helicobacter pylori infection was evaluated by anti Helicobacter pylori IgG in 1995. The odds ratio for atrophic gastritis was calculated using Logistic regression analysis. The odds ratio of age and sex was not significant, but the odds ratio of Helicobacter pylori infection was significantly elevated (5.2, 95% confidence interval: 2.08-13.17). As for the influence of sex difference on the incidence of atrophic gastritis by Helicobacter pylori infection, the odds ratio among males was not significant (1.4, 95% confidence interval: 0.30-6.10), but the odds ratio among females was significantly high (9.8, 95% confidence interval: 2.82-34.11). These results suggest that Helicobacter pylori infection is associated with the incidence of atrophic gastritis. There may be a risk difference between males and females in the incidence of atrophic gastritis caused by Helicobacter pylori infection.