Serum Levels of Antioxidant Vitamins in Relation to Coronary Artery Disease: A Case Control Study of Koreans

With the changes in trends of disease pattern from infectious to chronic degenerative disease, cardiovascular disease has been considered as the major cause of death in Korea.Numerous studies have been done on the antioxidant effects of some vitamins in the prevention of chronic illness, but not many in relation to the cardiovascular disease.Therefore, the relation between antioxidant vitamins, mainly α-tocopherol (α-T) and B-carotene (B-C), and coronary artery disease (CAD) such as angina pectoris and myocardial infarction has been investigated in this study.The blood samples were obtained from the CAD patients who were angiographically diagnosed within a month (100 case group). Patients who had an experience of PTCA or CABG were excluded from the study. Control subjects were healthy adults who had normal EKG values, no chest pain and no past history of cardiac disease (100 control group). All subjects were free of serum lipid lowering drugs. Serum α-T and B-C were analysed using HPLC. In addition to antioxidant vitamins, serum lipids (total cholesterol, HDL, TG) were also measured. Each case and control was matched in terms of age and sex. And all the CAD risk factors such as blood pressure, smoking, alcohol, serum lipid profile and BMI were adjusted to determine pure effect(s) of α-T and B-C on the CAD.The concentrations of both α-T and B-C were significantly lower in the CAD group than those in control group (P<0.05); in CAD group, mean values of α-T and B-C were 11.9±7.2 (μg/ml), 35.8±3.1 (μg/dl) respectively. As for the levels of B-C, it shows inverse relation with age, but not for the α-T Ievels. Serum levels of both vitamins did not show any significant differences in terms of sex, but men have a tendency o higher levels of B-C,but lower levels of α-T

Associations of lifestyle and diet with the risk of nasopharyngeal carcinoma in Singapore:a case–control study

Background: Nasopharyngeal carcinoma(NPC) is a commonly diagnosed cancer in Southeast Asia. Many studies have examined the risk factors for NPC, yet the roles of some risk factors remain inconclusive. The purpose of this study was to examine associations between modifiable lifestyle factors and the risk of NPC in the Singaporean population.Methods: We conducted a case–control study in Singapore with 300 patients and 310 controls who were recruited between 2008 and 2012. Each control was selected and individually matched to each patient based on sex, ethnicity, and age(±5 years). A total of 290 pairs of cases and controls were matched successfully. We examined lifestyle factors such as tobacco smoking, alcohol drinking, various salted and preserved food consumption, and weaning practices.Results: After adjusting for covariates, multivariate analysis showed that those participants who were current smokers and had ever smoked tobacco had a higher risk of NPC than participants who had never smoked, with odds ratios(ORs) of 4.50(95% confidence interval [CI] 2.58–7.86; P < 0.001) and 2.52(95% CI 1.54–4.12; P < 0.001), respectively. Those who consumed salted vegetables at least once a week also showed a significantly increased risk of NPC than those who never or rarely consumed salted vegetables, with an OR of 4.18(95% CI 1.69–10.38; P = 0.002).Conclusion: Smoking(currently and ever-smoked) and consuming salted vegetables once a week or more were lifestyle risk factors for NPC, and changes of these factors for the better may reduce the risk of NPC.

Risk factors of intrahepatic cholangiocarcinoma in patients with hepatolithiasis:a case-control study

BACKGROUND:Why 3.3% to 10% of all patients with hepatolithiasis develop intrahepatic cholangiocarcinoma (ICC) remains unknown.We carried out a hospital-based case-control study to identify risk factors for the development of ICC in patients with hepatolithiasis in China.METHODS:Eighty-seven patients with pathologically diagnosed hepatolithiasis associated with ICC and 228 with hepatolithiasis alone matched by sex,age (±2 years),hospital admittance and place of residence were interviewed during the period of 2000-2008.Odds ratios (OR) and 95% confidence intervals (CI) were calculated for each risk factor.RESULTS:Among the patients with hepatolithiasis associated with ICC,the mean age was 57.7 years and 61.0% were female Univariate analysis showed that the significant risk factors for ICC development in hepatolithiasis were smoking,family history of cancer,appendectomy during childhood (under age 20),and duration of symptoms >10 years.In multivariate stepwise logistic regression analysis,smoking (OR=1.931,95% CI:1.000-3.731),family history of cancer (OR=5.175,95% CI:1.216-22.022),and duration of symptoms >10 years (OR=2.348 95% CI:1.394-3.952) were independent factors.CONCLUSION:Smoking,family history of cancer and duration of symptoms >10 years may be risk factors for ICC in patients with hepatolithiasis.

TNF-α and IL-1RA Polymorphisms and Silicosis Susceptibility in Chinese Workers Exposed to Silica Particles:A Case-Control Study

Abstract Objective To assess the association of TNF-α and IL-1RA SNPs with the risk of silicosis in Chinese workers exposed to silica particles. Methods Case-control study design was used to enroll 68 silicotic patients induced by silica particles and 68 healthy workers matched for length of silica particle exposure as controls. Both cases and controls were from the same company in southwest China, and each of them was requested to complete a questionnaire. Blood samples were drawn for genomic DNA extraction from each participant. The genotyping of TNF-α （-238 and -308） and IL-1RA （＋2018） was performed using polymerase chain reaction-based restriction fragment length polymorphism （PCR-RFLP） and SYBR green-based quantitative polymerase chain reaction {qPCR）, respectively. Unconditional logistic regression model was used to estimate odds ratios （ORs） and their 95% confidential intervals （Cl） for SNPs. Results No significant differences were found between cases and controls in particles exposure length, body mass index （BMI）, and status of smoking and alcohol consumption except for age （P=O.O01） and blood type （P=0.042）. The frequencies of TNF-c（（-238） and IL-1RA （＋2018） genotypes in cases were significantly different from those in controls, （P=O.O01 and P=0.O02, respectively）, while a borderline significant difference was found in the frequencies of TNF-α（-308） between cases and controls （P=0.063）. The variants of three SNPs increased the risk of silicosis in the Chinese workers exposed to silica particles. The adjusted ORs of TNFα（-308）, TNF-α（-238） and IL-1RA （＋2018） were 2.8 （95% Ch 2.1-7.5）, 20.9 （95% Ch 2.8-236.4） and 4.0 （95% CI： 2.6-10.2）, respectively. Conclusion It is suggested that cytokine polymorphisms of TNF-ct （-238, -308） and IL-1RA （＋2018） are associated with the risk of silicosis in the Chinese workers exposed to silica particles. Further independent studies on the interaction between SNPs and exposure to silica particles with a larger sample size are therefore warranted.

Risk of Active Pulmonary Tuberculosis among Patients with Coal Workers'Pneumoconiosis:A Case-control Study in China

The aim of this study was to estimate the association between occupational, environmental, behavioral risk factors, and active pulmonary tuberculosis（PTB） among coal workers＇ pneumoconiosis（CWP） patients. A matched case-control study was conducted in 86 CWP patients with active PTB and 86 CWP controls without TB. A standardized questionnaire was used for risk factors assessment. Conditioned logistic regression analysis was used to identify associations between the risk factors and active PTB among CWP patients. The results showed that the stage of CWP, poor workplace ventilation, family history of TB, and exposure to TB were independent risk factors for active PTB in patients with CWP with which recommendations for improving work environments, and for case finding activities in patients with CWP could be made.

Case Control Study of Impulsivity,Aggression,Pesticide Exposure and Suicide Attempts Using Pesticides among Farmers

A case-control study was conducted to investigate associations between organophosphate pesticide（OP）exposure,aggression,impulsivity,and attempted suicide.Questionnaires were used to collect information;impulsivity and aggression were measured by the Barratt Impulsivity Scale（BIS）and the Aggression Inventory（AI）.

A Case-Control Study on Leisure Time Physical Activity (LTPA) during the Last Three Months of Pregnancy and Foetal Outcomes in Italy

The association between Leisure Time Physical Activity (LTPA) during pregnancy and foetal outcomes has been extensively investigated. However, epidemiological studies specifically referred to LPTA in the last months of pregnancy are scarce. We evaluated the association between LPTA and the risk of both preterm delivery and small for gestational age (SGA) during the last three months of pregnancy in Italy. A nationwide case-control study was performed in nine Italian cities. A total of 299 preterm delivery, 364 SGA and 855 controls were enrolled in the study. A self-administered questionnaire was used to assess socio-demographic variables, medical and reproductive history, life-style habits and LTPA referred to the last three months of pregnancy. Univariate and multivariate regression analyses were performed in order to estimate Odds ratios and 95% CI. LTPA during the last three months of pregnancy decreases the risk of preterm delivery (adjusted OR = 0.56;95% CI 0.39 - 0.79). Among the different types of physical activity, walking, the most frequently referred activity, appears significantly protective against preterm delivery (adjusted OR = 0.53;95% CI 0.36 - 0.81). Moreover, a small protective effect of walking was evidenced against SGA (adjusted OR = 0.72;95% CI 0.51 - 1.00). In conclusion, a mild physical activity such as walking in the last three months of pregnancy seems to reduce the risk of preterm delivery and, at a lesser extent, of SGA, confirming the beneficial effects of physical activity along the whole pregnancy.

Mass screening-based case-control study of diet and prostate cancer in Changchun, China

Aim： To investigate possible correlation factors for prostate cancer by a population-based case-control study in China. Methods： We carded out a mass screening of prostate cancer in Changchun, China, using a prostate-specific antigen assisted by Japan International Cooperation Agency. From June 1998 to December 2000, 3 940 men over 50 years old were screened. Of these, 29 men were diagnosed with prostate cancer. We selected 28 cases and matched them with controls of low prostate-specific antigen value （〈 4.1 ng/mL） by 1：10 according to age and place of employment. A case-control study of diet and prostate cancer was then carded out. Results： After adjustment for education, body mass index （BMI）, smoking, alcohol consumption, marriage and diet, intake of soybean product was discovered to be inversely related to prostate cancer. Men who consumed soybean product more than twice per week on different days had a multivariate odds ratio （OR） of 0.38 （95% confidence interval [CI], 0.13-1.12）. In addition, men who consumed soybean products more than once per day had a multivariate OR of 0.29 （95% CI, 0.11-0.79） compared with men who consumed soybean products less than once per week. The P for trend was 0.02, which showed significant difference. There was no significant difference in P trend for any dairy food. Even when we matched the cases and controls by other criteria, we found that soybean food was the only preventive factor associated with prostate cancer. Conclusion： Our study suggests that consumption of soybeans, one of the most popular foods in Asia, would decrease the risk of prostate cancer.

Environmental and Psycho-social Factors Related to Prostate Cancer Risk in the Chinese Population:a Case-control Study

Objective To study the risk environmental and psycho-social factors associated to prostate cancer （PCa） in Chinese population. Methods 250 PCa patients and 500 controls were enrolled in this case-control study. Information was collected and logistic regression analysis was used to estimate the odds ratios （OR） and 95% confidence intervals （95% CI） for relationship between lifestyle, eating habits and psycho-social factors with PCa risk. Results Green vegetables and green tea were associated with a decreased risk of PCa （0R=0.39, 95% CI： 0.28-0.53; 0R=0.59, 95% Cl： 0.40-0.87, respectively）. Family history of PCa （0R=7.16, 95% CI： 2.01-25.49）, history of prostate diseases （0R=2.28, 95% Cl： 1.53-3.41）, alcohol consumption （0R=1.97, 95% CI： 1.33-2.90）, red meat consumption （0R=1.74, 95% CI： 1.20-2.52）, barbecued （0R=2.29, 95% CI： 1.11-4.73） or fried （0R=2.35, 95% CI： 1.24-4.43） foods were related with increased PCa risk. Negative psycho-social factors including occupational setbacks （0R=1.61, 95% CI： 2.00-2.59）, marital separation （0R=1.94, 95% CI： 1.29-2.91）, self-contained suffering {0R=2.37, 95% CI： 1.58-3.55）, and high sensitivity to the personal comments （0R=1.73, 95% CI： 1.18-2.54） were related to PCa. Conclusion Regular consumption of green vegetables and green tea may suggest protective effects on PCa. Alcohol consumption, red meat consumption and barbecued or fried foods were associated with PCa. Negative psycho-social factors may also play a role in the incidence of PCa in Chinese population.

Risk factors for the occurrence of insulinoma: a case-control study

BACKGROUND: The etiology of insulinoma is poorly understood. Few studies investigated the possible roles of environmental factors and lifestyle in the pathogenesis of insulinoma. The aim of this study is to identify risk factors associated with occurrence of insulinoma in the Chinese population. METHODS: This study consisted of 196 patients with insulinoma and 233 controls. Demographic information of the patients and controls and risk factors of the disease were analyzed. Univariate and unconditional multivariable logistic regression analyses were made to estimate odds ratios (ORs) and possible risk factors. RESULTS: Approximately 68.88% (135/196) of the patients were from rural areas in contrast to 10.30% (24/233) of the controls (P【0.0001). This difference was confirmed by the multivariate analysis (OR=4.950; 95% CI: 2.928-8.370). Family history of pancreatic endocrine tumor (OR=16.754; 95% CI: 2.125-132.057) and other cancers (OR=2.360; 95% CI: 1.052-5.291) was also related to a high-risk population of insulinoma. CONCLUSION: Rural residents or people who have a family history of pancreatic endocrine tumor and other cancers are a high-risk population of insulinoma.

How Work Organization Affects the Prevalence of WMSDs: A Case-control Study

Objective In this study, we aimed at exploring the association between work-related musculoskeletal disorders（WMSDs） and work organization based on a case-control study. Methods A total of 1938 workers who claimed to suffer from WMSDs were selected from Beijing, Henan, Hubei, and the Guangdong province. The control group consisted of 2009 workers employed in similar industries without severe disease or musculoskeletal discomforts. We used a modified version of the questionnaire developed by the NMQ and the DMQ to investigate individual and work-related factors. Results A total of 13 variables（P〈0.1） were selected by the chi-square test and finally, 7 variables entered into the equation, with 6 variables reaching statistical significance（P〈0.05）. The odds ratios（OR） of ＇work changing with season＇ and ＇sufficient rest time＇ did not reach 1（0.749 and 0.441, respectively）. In addition, ＇sufficient rest time＇ seemed to be the stronger protective factor according to its higher standardized coefficient. And ＇repetitive work every minute＇, ＇constantly repetitive work＇（every day）, ＇shortage of site personnel＇, and ＇often switching shifts with others＇ seemed to be the risk factors. Conclusion Work organization may have comprehensive effects on the occurrence of WMSDs. This pattern of associations suggests that further investigation into the mechanism of how work organization affects the prevalence of WMSDs is required.

Nutrient patterns and risk of cataract：a case-control study

AIM：To assess the relation between nutrient patterns and cataract risk.METHODS：This is a hospital-based case-control study with 97 cataract patients and 198 matched controls.Dietary consumption was collected through a valid food frequency questionnaire（FFQ）.Nutrient patterns were detected by applying factor analysis.Unconditional logistic regression models were used to estimate odds ratio（ORs） and 95%CIs.RESULTS：We extracted 5 main nutrient patterns.Factor 1 included niacin,thiamin,carbohydrates,protein,zinc,vitamin B6 and sodium（sodium pattern）.Factor 2 was characterized by oleic acid,monounsaturated fats,polyunsaturated fats,linoleic acid,trans fatty acid,linolenic acid,vitamin E and saturated fats（fatty acid pattern）.The third factor represented high intake of vitamin B12,vitamin D,cholesterol and calcium（mixed pattern）.The 4^（th） pattern was high in intake of beta and alpha carotene,vitamin A and vitamin C（antioxidant pattern）.Finally,the 5^（th） pattern loaded heavily on docosahexaenoic acid（DHA） and eicosapentaenoic acid（EPA）（omega-3 pattern）.In crude and multivariate analysis,the sodium pattern was associated with increased risk of cataract（OR=1.97,95%CI：1.09-3.96）.The fatty acid pattern elevated the risk of cataract（OR=1.94,95%CI：1.1-3.86）.Antioxidant pattern was associated with a significant 79% reduced risk（2^（nd） category compared with the 1st）.Omega-3 pattern was significantly negatively associated with risk of cataract（P=0.04）.CONCLUSION：These findings imply that nutrient patterns reflecting a combined consumption of nutrients might be important in the etiology of cataract.Additional studies with more efficient designs are warranted to confirm our findings.

Association between Prenatal Environmental Factors and Child Autism: A Case Control Study in Tianjin,China

Objective To investigate the association between autism and prenatal environmental risk factors.Methods A case-control study was conducted among 193 children with autism from the specialeducational schools and 733 typical development controls matched by age and gender by usingquestionnaire in Tianjin from 2007 to 2012. Statistical analysis included quick unbiased efficientstatistical tree （QUEST） and logistic regression in SPSS 20.0.Results There were four predictors by QUEST and the logistic regression analysis, maternal airconditioner use during pregnancy （OR=0.316, 95% CI： 0.215-0.463） was the single first-level node（χ2=50.994, P=0.000）; newborn complications （OR=4.277, 95% CI： 2.314-7.908） and paternalconsumption of freshwater fish （OR=0.383, 95% CI： 0.256-0.573） were second-layer predictors（χ2=45.248, P=0.000; χ2=24.212, P=0.000）; and maternal depression （OR=4.822, 95% CI： 3.047-7.631）was the single third-level predictor （χ2=23.835, P=0.000）. The prediction accuracy of the tree was 89.2%.Conclusion The air conditioner use during pregnancy and paternal freshwater fish diet might bebeneficial for the prevention of autism, while newborn complications and maternal depression might bethe risk factors.

A Case-control Study on Children with Guillain-barre Syndrome in North China

To explore the risk factors for Guillain-barre syndrome. Methods Case-control study design was used in 51 cases of Guillain-barre syndrome,and 51 matched controls.All of the 51 cases in this study had been examined by electrophysiology. Serum IgG antibodies specific for C. jejuni were determined in all the subjects by ELISA. Each case and control were interviewed using an ad hoc questionnaire, including his/her demographic information,onset of the illness, their personal hygiene and so on. Results The study showed that Guillain-barre syndrome was associated with a few factors, such as polio vaccine immunization before onset of illness (OR=7.27), no hand washing after defecation and before meals (OR=6.15). Infection of C. jejuni was strongly associated with the illness (OR=9.5,P<0.001). Conclusion It is suggested that occurrence of Guillain-barre syndrome may correlate to infection of C. jejuni and poor personal hygiene in children.

Association between diabetes mellitus,hypertension,hyperlipidemia,chronic viral hepatitis,and the risk of multiple myeloma:a case-control study

Objective This case-control study aimed to investigate whether diabetes mellitus(DM),hypertension,hyperlipidemia,and chronic viral hepatitis are risk factors for multiple myeloma(MM).Moreover,the clinical characteristics of MM patients with or without the abovementioned exposure factors were analyzed.Methods In total,340 MM patients and 680 patients with benign diseases who were hospitalized from January 2012 to December 2017 were classified under the case group and control group,respectively.Data about medical history of DM,hypertension,hyperlipidemia and chronic viral hepatitis were collected by reviewing medical records.Univariate and multivariate analyses were conducted to compare the history of DM,hypertension,hyperlipidemia,and viral hepatitis between the two groups.Considering DM,hypertension,hyperlipidemia,and chronic viral hepatitis as exposure factors,clinical characteristics,such as renal function and presence of fungal and other types of infections,between the exposed and nonexposed groups were analyzed.Results No significant difference was observed in the prevalence of DM,hypertension,and hyperlipidemia between the case and control groups.MM patients had a higher prevalence of chronic viral hepatitis than those with benign diseases.No significant difference was observed in the prevalence of renal dysfunction,fungal infection,and non-fungal infections in MM patients with or without DM,hypertension,and hyperlipidemia.MM patients with chronic viral hepatitis had a significantly higher prevalence of nonfungal infections during hospitalization than those without.Conclusion No significant association was noted between MM and DM,hypertension,and hyperlipidemia.Chronic viral hepatitis is correlated to a significantly higher risk of MM,and MM patients with chronic viral hepatitis were more susceptible to non-fungal infections during hospitalization.Although a non-significant trend was observed in this study,we believe that DM and hypertension might be associated with a higher risk of MM.Thus,large-scale studies must be conducted to validate the results of the current study.

A Case-control Study on High-risk Factors for Newborn Hearing Loss in Seven Cities of Shandong Province

To investigate the high-risk factors for newborn hearing loss and to provide information for preventing the development of hearing loss and delaying its progression, from May 2003 to June 2006, neonates who failed to pass the universal newborn hearing screening （UNHS） were referred to Jinan Newborn Hearing Screening and Rehabilitation Center from 7 newborn hearing screening centers in seven cities of Shandong province. One-to-one pair-matched case-control method was employed for statistical analysis of the basic features of definitely identified cases. High-risk factors relating to the bilateral hearing loss were evaluated by univariate and multivariate Logistic regression analysis. Our results revealed that 721 transferred newborns who didn＇t pass the heating screening received audiological and medical evaluation and 367 were confirmed to have hearing loss. Of them, 177 neonates with hearing loss who met the matching requirements were included in the study as subjects. Univariate analysis showed that high-risk factors related to hearing loss incuded age of father, education backgrounds of parents, parity, birth weight, gestational weeks, craniofacial deformity, history of receiving treatment in neonatal intensive care unit （NICU）, neonatal disease, family history of otopathy and family history of congenital hearing loss. Multivariate Logistic regression analysis revealed that 4 independent risk factors were related to bilateral hearing loss, including parity （OR=16.285, 95% CI 3.379--78,481）, neonatal disease （OR=34;968, 95% CI 2.720 449.534）, family history of congenital hearing loss （OR=69.488, 95% CI 4.417--1093.300） and birth weight （OR=0.241, 95% CI 0.090--0.648）. It is concluded that parity, neonatal disease and family history of heating loss are the promoting factors of bilateral hearing loss in neonates and appropriate intervention measures should be taken to deal with the risk factors.

Risk Factors for Birth Defects: A Conditional LogisticRegression Analysis of a Case-Control Study in Guang-dong Province of China

Information was obtained from the same questionnaire (23 risk factors listed) of cases and controls. We used a multivariate logistic model, which described variables significantly increased risk of birth defects. The risk factors included maternal educational levels, medicine taken during pregnancy and antenatal care. It was suggested to strengthen antenatal care was the main preventive measure against birth defects.

Driver Sleepiness and Risk of Car Crashes in Shenyang, a Chinese Northeastern City: Population-based Case-control Study

Objective To estimate the association of driver sleepiness with the risk of car crashes. Methods A population-based case-control study was conducted in Shenyang, a northeastern city in China, between November 2001 and July 2002. The case group comprised 406 car drivers involved in crashes, and 438 car drivers recruited at randomly selected sites, and on the day of week, and the time of day when they were driving on highways in the study region during the study period were used as control groups. Face-to-face interviews with drivers were conducted according to a well-structured questionnaire covering the circumstances of their current trip and their background information. Stanford sleepiness scale and Epworth sleepiness scale were used to quantify acute sleepiness and chronic sleepiness respectively. Results There was a strong association between chronic sleepiness and the risk of car crash. Significantly increased risk of crash was associated with drivers who identified themselves as sleepy (Epworth sleepiness score≥10 vs <10; adjusted odds ratio 2.07, 95% confidence interval 1.30 to 3.29), but no increased risk was associated with measures of acute sleepiness. Conclusions Chronic sleepiness in car drivers significantly increases the risk of car crash. Reductions in road traffic injuries may be achieved if fewer people drive when they are sleepy.

Interaction and Its Solution in Individual Matching Case-control Study

Objective To indicate the deficiency of the classical method for analyzing data on individual matching case-control study in consideration of the interaction between the study factor (exposure) and the matching factor, and to find out a proper method for handling this deficiency. Method First, experimental data with 50 pairs of cases and controls were used for strata analysis according to the values of a matching factor to illustrate the possible interaction between a risk factor (exposure) and the matching factor. Second, a detailed procedure was proposed for analyzing such data. Results Interaction between the study factor and matching factor was demonstrated by using strata analysis and unconditional logistic regression analysis. Therefore the results from the classical analysis for such data might be incorrect. Conclusion Data from individual matching case-control study design should be dealt with strata analysis or multivariate analysis to explore and evaluate the possible interaction between the s

Glutathione S-transferases M1,T1 genotypes and the risk of gastric cancer:A case-control study

AIM Glutathione S-transferases (GSTs are involved in the detoxification of many potential carcinogens and appear to play a critical role in the protection from the effects of carcinogens. The contribution of glutathione Stransferases M1 and T1 genotypes to susceptibility to the risk of gastric cancer and their interaction with cigarette smoking are still unclear. The aim of this study was to determine whether there was any relationship between genetic polymorphisms of GSTM1 and GSTT1 and gastric cancer.METHODS A population based case - control study was carried out in a high-risk area, Changle County, Fujian Province, China. The epidemiological data were collected by a standard questionnaire and blood samples were obtained from 95 incidence gastric cancer cases and 94 healthy controls. A polymerase chain reaction method was used to detect the presence or absence of the GSTM1 and GSTT1 genes in genomic DNA. Logistic regression model was employed in the data analysis.RESULTS An increase in risk for gastric cancer was found among carriers of GSTM1 null genotype. The adjusted odds ratio (OR) was 2.63 [95% Confidence Interval (95% CI) 1.17-5.88], after controlling for age,gender, cigarette smoking, alcohol drinking, and fish sauce intake. The frequency of GSTT1 null genotype in cancer cases (43.16%) was not significantly different from that in controls (50.00%). However, the risk for gastric cancer in those with GSTM1 null and GSTT1 nonnull genotype was significantly higher than in those with both GSTM1 and GSTT1 non-null genotype (OR = 2.77,95% Cl 1.15- 6.77). Compared with those subjects who never smoked and had normal GSTM1 genotype, Ors were 1.60 (95% CI: 0.62- 4.19) for never smokers with GSTM1 null type, 2.33 (95% CI 0.88- 6.28) for smokers with normal GSTM1, and 8.06 (95% CI 2.83- 23.67) for smokers with GSTM1 null type.CONCLUSIONS GSTM1 gene polymorphisms may be associated with genetic susceptibility of stomach cancer and may modulate tobacco-related carcinogenesis of gastric cancer.