A Case-control Study of Environmental Risk Factors for Nonsyndromic Cleft of the Lip and/or Palate in Xuzhou,China

In this study, we sought to determine the association between environmental factors and nonsyndromic cleft of the lip and/or palate （NSCLP） to understand the etiology of the disease. A total of 200 NSCLP cases and 327 controls were recruited at the Maternal and Child Health Hospital of Xuzhou City. We conducted face-to-face interviews with the mothers of both cases and controls. The factors increasing the risk of NSCLP were a positive family history [odds ratio （OR）=56.74], pesticide exposure （OR=8.90）, and indoor decoration pollution （OR= 4.32）. On the other hand, the factors decreasing the risk of NSCLP were a high education level （OR=0.22） and supplementation of folic acid （OR=0.23） and multivitamins （OR=0.16）. Positive family history, pesticide exposure, and indoor decoration pollution are associated with the risk of NSCLP. In contrast, high education level and folic acid and multivitamin supplementation are protective factors against NSCLP.

Lyme Borreliosis-associated Risk Factors in Residents of Beijing Suburbs: a Preliminary Case-control Study

A population-based case-control study was conducted to evaluate the relative fac^tors in the environments, agricultural works, outdoor activities, and the effectiveness of Lyme borreliosis （LB）- associated personal protective measure.c; in Beijing. Thirty-four cases and 272 controls were personally interviewed by well-trained interviewers. Venous blood samples were taken from eac：h subject. Sowing or harvesting in summer （OR=2.571, 95% CI： 1.109-5.962）, living in house with weeding in the yard （OR=2.247, 95% CI： 1.062-4.755）.

Multicenter case-control study of the risk factors for ulcerative colitis in China

AIM:To evaluate potential risk factors in the development of ulcerative colitis(UC) in China.METHODS:A total of 1308 patients with UC and 1308 age-matched and sex-matched controls were prospectively studied in China.The UC cases were collected from 17 hospitals in China from April 2007 to April 2010.Uniform questionnaires were designed to investigate risk factors including smoking,appendectomy,stress,socio-economic conditions,nonsteroidal antiinflammatory drugs(NSAIDs),oral contraceptives,diet,breastfeeding,infections and family sanitary conditions.Group comparisons by each factor were done using simple logistic regression analysis.Conditional logistic regression was used for multivariate analysis.RESULTS:By univariate analysis,the variables predictive of UC included feeling stress,light and heavy alcoholic drinking,spicy food,sugar consumption and infectious diarrhea,while heavy tea intake and tap water consumption were protective against UC.On multivariate analysis,the protective factor for UC was tap water consumption [odds ratios(OR) = 0.424,95%CI:0.302-0.594,P < 0.001];while the potential risk factors for UC were heavy sugar consumption(OR = 1.632,95%CI:1.156-2.305,P < 0.001),spicy food(light intake:OR = 3.329,95%CI:2.282-4.857,P < 0.001;heavy intake:OR = 3.979,95%CI:2.700-5.863,P < 0.001),and often feeling stress(OR = 1.981,95%CI:1.447-2.711,P < 0.001).Other factors,such as smoking habit,appendectomy,breastfeeding,a history of measles,rural or urban residence,education,oral contraceptives,and NSAID use have not been found to have a significant association with the development of UC in the present study.CONCLUSION:Our study showed tap water consumption was a protective factor for UC,while spicy food,heavy sugar consumption and often feeling stress were risk factors for UC in this Chinese population.

Incidence, risk factors, and cumulative risk of delirium among ICU patients: A case-control study

Objectives: Delirium is a common acute cognitive impairment syndrome among intensive care unit (ICU) patients.This study was aimed to investigate the incidence,risk factors,and cumulative risk of delirium among ICU patients.Methods: A case-control study including clinical records of 452 patients were retrospectively analyzed.Delirium was assessed using the Confusion Assessment Method for the ICU and Richmond Agitation -Sedation Scale.Results: We found that 163 out of the 452 patients (36.1%) had delirium.Multivariate analysis showed that use of sedatives,length of ICU hospitalization,and physical restraint were independent risk factors for delirium.The additive effect of all three factors resulted to an odds ratio of 30.950.Conclusion: The incidence of delirium remained high.Thus,nurses shall strengthen the monitoring of delirium,regularly access the patient's level of calmness,and limit the use of physical restraint.

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.

Risk Factors of Low Back Pain among the Chinese Occupational Population:A Case-control Study

Objective To explore the risk factors of low back pain among the Chinese occupational population in several major industries. Methods A total of 7200 subjects （3600 cases and 3600 controls） were randomly sampled from a cross-sectional study, and they were investigated for individual and occupational factors of low back pain. The potential risk factors were first selected by using chi-square tests. Secondly, collinearity diagnosis proceeded by using the Kendall＇s rank correlation. Finally, binary logistic regression model was used for multi-factor analysis. Results Collinearity diagnosis showed that there was a severe collinearity problem among the potential risk factors of low back pain. Logistic regression model included 20 variables with statistical significance. Bending neck forward or holding neck in a forward posturefor long periods （0R=1.408） was the most important risk factor inducing low back pain in this study, followed by bending heavily with the trunk （0R=1.402）, carrying out identical work almost for the whole day （0R=1.340）. Additionally, suHicient normal break was a protective factor of low back pain. Conclusion Low back pain among the Chinese occupational population was associated with body height, occupation, work organization, physical work, working posture, and others. All these risk factors could be regarded as the indicators of low back pain, and some relevant preventive measures should be taken to reduce low back pain risk.

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.

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 S-transferases 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 GSTT1 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 GSTT1 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 GSTT1 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 GSTT1 null and GSTT1 non-null genotype was significantly higher than in those with both GSTT1 and GSTT1 non-null genotype (OR = 2.77, 95% CI 1.15-6.77). Compared with those subjects who never smoked and had normal GSTT1 genotype, ORs were 1.60 (95% CI:0.62-4.19) for never smokers with GSTT1 null type, 2.33 (95% CI 0.88-6.28) for smokers with normal GSTT1, and 8.06 (95% CI 2.83-23.67) for smokers with GSTT1 null type. CONCLUSIONS: GSTT1 gene polymorphisms may be associated with genetic susceptibility of stomach cancer and may modulate tobacco-related carcinogenesis of gastric cancer.

Genetic polymorphisms in pri-let-7a-2 are associated with ischemic stroke risk in a Chinese Han population from Liaoning, China: a case-control study

Ischemic stroke is a complicated disease, and its pathogenesis has been attributed to the occurrence of genetic polymorphisms.Evidence has suggested that the microRNA let-7a is involved in the pathogenesis of ischemic stroke.Pri-miRNA is the primary transcript, which undergoes several processing steps to generate pre-miRNA and, later, mature miRNAs.In this case-control study, we analyzed the distribution of prilet-7a-2 variants in patients at a high risk for ischemic stroke and the interactions of pri-let-7a-2 variants and environmental factors.Blood samples and clinical information were collected from 1086 patients with ischemic stroke and 836 healthy controls between December 2013 and December 2015 at the First Affiliated Hospital of China Medical University.We found that the rs1143770 CC genotype and the C allele were associated with a decreased risk of ischemic stroke, whereas the rs629367 CC genotype was associated with an increased risk for ischemic stroke.Moreover, these two single-nucleotide polymorphisms were in linkage disequilibrium in this study sample.We analyzed gene-environment interactions and found that rs1143770 exerted a combined effect on the pathogenesis of ischemic stroke, together with alcohol use, smoking, and a history of hypertension.Therefore, the detection of pri-let-7a-2 polymorphisms may increase the awareness of ischemic stroke risk.This study was approved by the Institutional Ethics Committee of the First Affiliated Hospital of China Medical University, China(approval No.2012-38-1) on February 20, 2012, and was registered with the Chinese Clinical Trial Registry(registration number: ChiCTR-COC-17013559) on December 27, 2017.

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.

hOGG1 Ser326Cys polymorphism modifies the significance of the environmental risk factor for colon cancer

AIM:To determine the association of hOGG1 (8-oxoguanine glycosylase I,OGG1) polymorphism of Ser326Cys substitution with colon cancer risk and possible interaction with known environmental risk factors. METHODS:A case-control study with 125 colon cancer cases and 247 controls was conducted, RESULTS:There was no major difference in Ser326Cys genotype distribution between cases and controls.The meat intake tended to increase the odds ratio for colon cancer with an OR of 1.72 (95 % confidence interval;CI=1.12-2.76). Such tendency was more prominent in Cys/Cys carriers (OR=4.31,95 % CI=1.64-11.48),but meat intake was not a significant risk factor for colon cancer in Ser/Ser or Ser/ Cys carriers.The OR for colon cancer was elevated with marginal significance in smokers who were Cys/Cys carriers (OR=2.75,95 % CI=1.07-7.53) but not in Ser/Ser or Ser/ Cys carriers. CONCLUSION:These results suggest that the hOGG1 Ser326Cys polymorphism is probably not a major contributor to individual colon cancer susceptibility overall,but the Cys/ Cys genotype may alter the impact of some environmental factors on colon cancer development.

A 1:1 ratio case-control study on coronavirus disease 2019

Objective:To compare the characteristics of COVID-19 patients and healthy people,including living habits and living environment in Danzhou,Hainan province,to provide evidence for policy making for disease control.Methods:Case-control study was used,and the 1:1 control group in Danzhou based on the matching conditions including same age and sex,age±2 years.The main contents of the questionnaire included social democracy characteristics,living habits,living environment,and exposure history.Results:There were 14 COVID-19 patients in Danzhou.In the comparison of the daily habits,it was found that the number of people in the case group who had the habit of wearing masks after catching a cold was lower than that in the control group.And the number of people in the case group who had the habit of spitting was higher than that in the control group.Besides,the results of the survey on eating habits showed that there was less than half of the subjects used serving chopsticks and spoons when having dinner with family members or others,both in the case group and the control group.In the comparison of preferred food types,6 people(42.9%)in the case group preferred cold vegetables,while only 2 people(14.3%)in the control group preferred cold vegetables.In comparison with the travel history and contact history of COVID-19,12 people(85.7%)in the case group had travel history in Wuhan or other regions,but only two in the control group had a history of living in Wuhan or other places.1:1 paired analysis showed that 5 pairs of had habits of spitting in the case group but had no habits of spitting in control group,and 1 pair had habits of spitting in control group but had no habits of spitting in the case group,the OR value was 5.0.Besides,there were 2 pairs of had the habit of wearing a mask when they went out after catching a cold in control group but not in the case group,and 4 pairs of had the habit of wearing a mask when they went out after catching a cold in control group but no such habit in case group,and the OR value was 0.5.In the investigation of dietary habits,the comparison results of whether like cold vegetables,tea and parties showed that the OR values were all greater than 1.Conclusion:For infectious diseases,exposure history was the most important risk factor.In future studies,possible risk factors should be more comprehensively investigated.

1:4 case-control study on coronavirus disease 2019

Objective:To analyze the risk factors of COVID-19 infection in Danzhou,Hainan province.Methods:Case-control study was used,and the 1:4 control group of healthy residents(in Danzhou,Haikou,Beijing)were selected based on the matching conditions including same age and sex,age±2 years.The main contents of the questionnaire included living habits,dietary habits living environment,and exposure history.Results:There were 14 COVID-19 patients in Danzhou.And the control group included 56 residents from Danzhou,Haikou and Beijing.It was found that 85.7%(12/14)of the subjects in the case group exercise regularly.The exercise places were mainly community parks in Danzhou and Haikou,while mainly gyms or stadiums in Beijing.For dietary habits,control group in Beijing tended to using serving chopsticks when having dinner with family members or others than that in the case group(50.0%vs.21.4%,78.6%vs.35.7%).The results of exposure history showed that living in Wuhan or other city with cases reports in recent two months,contacting people who had living history in Wuhan or other city with cases reports in recent two months,and contacted people who confirmed COVID-19 infection or had symptoms recent two months were risk factors.Conclusion:For infectious diseases,exposure history was the most important risk factor.The influence of lifestyle differences may be smaller compared with exposure,and the individual specificity might lead to the infection-related factors difficult to found.In future studies,matching variables should be carefully selected in the case-control study of infectious diseases,and possible risk factors should be more comprehensively investigated.

Evidence and thinking on risk factors of hypertensive intracerebral hemorrhage: a meta-analysis

Background:To explore the related risk factors of hypertensive intracerebral hemorrhage(ICH)through meta-analysis,and to provide evidence-based medical basis for preventing ICH in hypertensive patients.Methods:The databases of CNKI,Wanfang,VIP,CBM,PubMed,Web of Science and Cochrane Library were searched by computer.Case control study on risk factors for hypertensive intracerebral hemorrhage were collected from the database establishment to October 2021.Two reviewers independently screened the literature,extracted the data,and evaluated the bias risk of the included studies.Meta-analysis was conducted on the results of the included studies using RevMan5.3 software.Results:A total of 7 studies were included,including 1512 patients.Meta-analysis results showed that:Smoking history(OR=6.23,95%CI(4.32,8.99),P<0.00001),drinking history(OR=7.24,95%CI(1.96,26.72),P=0.003),diabetes mellitus(OR=47.52,95%CI(10.31,219.31),P<0.00001),coronary heart disease(OR=9.90,95%CI(2.96,33.13),P=0.0002),daily salt intake(OR=10.21,95%CI(2.69,38.79),P=0.0006),failure to take medication regularly on time(OR=10.62,95%CI(5.40,20.91),P<0.00001),total cholesterol(OR=6.58,95%CI(2.45,17.65),P=0.0002),triglyceride(OR=8.63,95%CI(6.70,11.12),P<0.00001),body mass index(OR=6.63,95%CI(4.56,9.64),P<0.00001)and experiencing severe economic difficulties(OR=23.97,95%CI(14.82,38.77),P<0.00001)were risk factors for hypertensive intracerebral hemorrhage.Conclusion:Controlling smoking,drinking,reducing daily salt intake,controlling body weight,preventing diabetes and coronary heart disease,low-fat diet,controlling total cholesterol and triglyceride,taking antihypertensive drugs regularly and improving economic status can prevent hypertensive cerebral hemorrhage.

Mitochondrial DNA as a Risk Factor for False Positives in Case-Control Association Studies

During the last decade, hundreds of studies have been pub- lished examining whether significant associations exist be- tween mitochondrial DNA （mtDNA） variants and/or haplogroups （clades） and particular diseases （generally com- mon/complex diseases） （Fig. 1）. However, several authors have gathered evidence indicating a high incidence of false positive findings in mtDNA case-control association studies. Raule et al. （2007） and Herrnstadt and Howell （2004） showed various problems affecting mtDNA case-control association studies. Salas et al.

Risk factors for gastric cancer:a large-scale,population-based case-control study

Background:Early detection of gastric cancer(GC)has been the topic of major efforts in China.This study aimed to explore the risk factors associated with GC and to provide evidence for the selection of a high-risk population of GC.Methods:Based on the cancer screening cohort of the National Cancer Screening Program in Urban China,GC patients diagnosed by endoscopy and pathological examinations constituted the case group,and controls were 1:3 matched by sex and age(±5 years)individually.The variables were selected by univariable analysis of factors such as body mass index(BMI),dietary habits,lifestyle,stomach disease history,and family history of GC;and multivariable logistic regression was used to analyze the influencing factors of GC and to calculate the odds ratio(OR)of related factors and its 95%confidence interval(CI).Results:A total of 215 GC cases and 645 matched healthy controls were included in the final analysis,with a median age of 61 years for the case and control groups.Overall analysis showed that high educational level(above primary school)(OR=0.362,95%CI=0.219–0.599,P<0.001),overweight/obesity(BMI≥24 kg/m2;OR=0.489,95%CI=0.329–0.726,P<0.001),cigarette smoking(OR=3.069,95%CI=1.700–5.540,P<0.001),alcohol consumption(OR=1.661,95%CI=1.028–2.683,P=0.038),history of stomach disease(OR=6.917,95%CI=4.594–10.416,P<0.001),and family history of GC in first-degree relatives(OR=4.291,95%CI=1.661–11.084,P=0.003)were significantly correlated with the occurrence of GC.Subgroup analyses by age and gender indicated that GC risk was still increased in the presence of a history of stomach disease.A history of chronic gastritis,gastric ulcer,or gastric polyposis was positively associated with GC,with adjusted ORs of 4.155(95%CI=2.711–6.368),1.839(95%CI=1.028–3.288),and 2.752(95%CI=1.197–6.326).Conclusions:Subjects who smoke,drink,with history of stomach disease and family history of GC in first-degree relatives are the high-risk populations for GC.Therefore,attention should be paid to these subjects for GC screening.

Risk Factors of Chronic Kidney Disease in Chronic Hepatitis B:A Hospital-based Case-control Study from China

Background and Aims:Chronic kidney disease(CKD)usually occurs during the chronic infection of hepatitis B virus(HBV).However,the risk factors of CKD in an HBV population have not been completely demonstrated.Our present study aimed to investigate the risk factors of CKD in chronic HBV infection using a hospital based cross-sectional study in the northern area of China.Methods:During January 2013 to December 2017,a total of 94 patients with CKD complicated by chronic HBV infection were consecutively enrolled in the study,as well as 548 age-and sex-matched hepatitis B patients without CKD who were enrolled as controls.Univariate and multivariate regression analyses were used to determine the effects of each variable after adjusting for cofounding factors.Results:Multivariate analysis showed that HBeAg-positive status(odds ratio[OR]=2.099,95%CI 1.128-3.907),dyslipidemia(OR:3.025,95%CI 1.747-5.239),and hypertension(OR:12.523,95%CI 6.283-24.958)were independently associ-ated with the incidence of CKD,while duration of HBV in-fection(≥240 months)(OR:0.401,95%CI 0.179-0.894),Log10 HBsAg(OR:0.514,95%CI 0.336-0.786),and coro-nary heart disease(OR:0.078,95%CI 0.008-0.768)were protective factors for the incidence of CKD.Duration of HBV infection,Log10 HBsAg,HBeAg-positive status and dyslipidemia remained the risk factors for CKD after adjusting for diabetes mellitus,hypertension,and coronary heart disease.Conclusions:Duration of HBV infection,Log10 HB-sAg,HBeAg-positive status and dyslipidemia contributed to the incidence of CKD during chronic HBV infection in a Chinese population.

Periodontal disease is associated with increased coronary heart disease risk:A meta-analysis based on 38 case-control studies

AIM: To investigate whether periodontal disease(PD) is associated with increasing coronary heart disease(CHD) risk by performing a meta-analysis.METHODS: Two authors independently searched Pub Med and China National Knowledge Infrastructure up to January 10 th, 2013 for relevant case-control studies that investigated the association between PD and CHD. After quality assessment using Newcastle-Ottawa Scale and data extraction by two independent authors, the overall and subgroup meta-analyses were performed and publication bias were examined using the Comprehensive Meta-Analysis V2 software. Potential publication bias was assessed using visual inspection of the funnel plots, Egger linear regression test, and trims and fill method.RESULTS: Finally 38 relevant case-control studies were identified, involving 4950 CHD patients and 5490 controls. Eleven studies were rated low quality and 27 were high quality. Based on random-effects, a significant association was identified between PD and CHD(OR 3.79, 95%CI: 2.23-6.43, P < 0.001, I2 = 98.59%), and sensitivity analysis showed that this result was robust. Subgroup analyses according to adjusted/unadjusted ORs, source of control, methodological quality, end point, assessment of PD/CHD, and ethnicity also indicated a significant association. Publication bias was detected, and the estimated OR including the "missing" studies did not substantially differ from our estimate with adjustment for missing studies(OR 4.15, 95%CI: 2.62-6.54, P < 0.001).CONCLUSION: Based on the meta-analysis, PD is probably associated with CHD risk independently and significantly.

Prenatal and perinatal risk factors for solid childhood malignancies: A questionnaire-based study

Importance:Childhood solid tumors account for the highest proportion of childhood cancers and are one of the leading causes of death in childhood.However,their pathogenesis is unclear.Objective:To explore prenatal and perinatal risk factors for solid malignancies in children.Methods:We enrolled 71 consecutive pediatric patients (44 boys and 27 girls;median age,30 months) with solid tumors who were diagnosed and treated at our center from January 2013 to December 2016 as the case group.We also enrolled 211 age-and residence-matched healthy children (ratio of approximately 3:1 with the case group) as the control group.We conducted a questionnaire-based survey with the parents of these 282 children.Univariate and multivariate conditional logistic regression analyses of the collected data were performed.Results:Confirmed solid malignancies included neuroblastoma (n =32),rhabdomyosarcoma (n =18),retinoblastoma (n =7),renal tumors (n =3),and other tumors (n =11).Risk factors for solid childhood tumors in the univariate analysis were the parents' age,gravidity,parity,abortion history,vaginal bleeding,family history of malignancy,and prenatal use of folic acid or hematinics/iron supplements (P ＜ 0.05),and those in the multivariate analysis were higher parity (odds ratio [OR],2.482;95％ confidence interval [CI],1.521-4.048),family history of malignancy (OR,3.667;95％ CI,1.679-8.009),and prenatal use of hematinics/iron supplements (OR,2.882;95％ CI,1.440-5.767).In contrast,use of prenatal folic acid was protective (OR,0.334;95％ CI,0.160-0.694).Interpretation:A family history of malignancy,use of prenatal hematinics/iron supplements,and higher parity are risk factors for solid childhood tumors,whereas use of prenatal folic acid is a protective factor.

A case－control study on risk factors of stress fractures in military recruits during basic training

Stress fracture(SF) is an important training injury with a high incidence during recruits' basic training. In order to primarily investigate its risk factors and to provide etiologic threads for a further study,we carried out a case control study on SF. The results of univariate analysis and multivariate logistic regression analysis revealed that attending training on the occasion of injury or fatigue , and a lower length ratio of tibia and pelvic limb were the main risk factors of SF. The authors are of the opinion that compared with the absolute length of tibia , the relative length of tibia(tibia length/pelvic limb length) may be more relevant to the tibia biomechanical characteristics. , The harm of attending training under the circumstances of injury or fatigue is discussed in this paper.