Risk of acute myeloid leukaemia and multiple myeloma in workers exposed to benzene.

OBJECTIVE--To determine the risk of developing acute myeloid leukaemia (AML) and multiple myeloma in a cohort of workers exposed to benzene. The results were used to show the importance of taking specificity of disease into consideration in causation analysis. METHODS--Data were derived from a cohort of workers employed at two Goodyear plants in Ohio in the manufacture of Pliofilm. Based on data in the Pliofilm study, several papers that examined the relation between exposure to benzene and leukaemia (all cell types combined) have been published. In the current analyses based on updated data in the study, standardised mortality ratios (SMRs) and 95% confidence intervals (95% CIs) were calculated for AML and multiple myeloma by cumulative exposure to benzene. The results based on AML were compared with those for leukaemia (all cell types combined) published previously. RESULTS--An exposure response relation was shown between cumulative exposure to benzene and AML. No increased risk of AML was detected for cumulative exposure to benzene below 200 ppm-years (SMR 0.91). Above 200 ppm-years, risk of AML rose drastically; reaching a significant SMR of 98.37 for > 400 ppm-years. For multiple myeloma, no relation with exposure to benzene was detected. CONCLUSION--Analysis specific to AML shows the importance of taking specificity of disease into consideration in causation analysis. This investigation shows that previous analyses based on all leukaemia cell types combined have incorrectly set the estimated threshold too low, and have underestimated risk above the threshold. Current regulatory policies that rely on previous analyses based on all leukaemia cell types combined should be re-examined.     

Risk factors for acute leukemia in children: a review

Although overall incidence is rare, leukemia is the most common type of childhood cancer. It accounts for 30% of all cancers diagnosed in children younger than 15 years. Within this population, acute lymphocytic leukemia (ALL) occurs approximately five times more frequently than acute myelogenous leukemia (AML) and accounts for approximately 78% of all childhood leukemia diagnoses. Epidemiologic studies of acute leukemias in children have examined possible risk factors, including genetic, infectious, and environmental, in an attempt to determine etiology. Only one environmental risk factor (ionizing radiation) has been significantly linked to ALL or AML. Most environmental risk factors have been found to be weakly and inconsistently associated with either form of acute childhood leukemia. Our review focuses on the demographics of childhood leukemia and the risk factors that have been associated with the development of childhood ALL or AML. The environmental risk factors discussed include ionizing radiation, non-ionizing radiation, hydrocarbons, pesticides, alcohol use, cigarette smoking, and illicit drug use. Knowledge of these particular risk factors can be used to support measures to reduce potentially harmful exposures and decrease the risk of disease. We also review genetic and infectious risk factors and other variables, including maternal reproductive history and birth characteristics.     

Parental risk factors of childhood acute leukemia: a case-control study

Background: Leukemia is the most common cancer in children, accounting for near to half of all childhood cancers. Different risk factors might be effective in the occurrence of this cancer such as parental characteristics. This study was done in West Azarbaijan Province in order to determine the relation between parental characteristics and acute leukemia in children. Methods: This matched case-control study was conducted on children less than 15 years affected by acute leukemia from March 20, 2003 to March 20, 2009. Two control groups were selected, one from hospital and the other from the study population. Cases and controls were matched on age and sex. Logistic regression model was used for data analysis. Results: This study was done on 130 patients, 108 (83.1%) were affected by Acute Lymphoblastic Leukemia and 22 (16.9%) by Acute Myeloblastic Leuke-mia. Seventy two of the patients were male (55.4%) and 58 were female (44.6%). There was a statistically significant correlation between acute leuke-mia and variables such as mother's education [OR=4.2, 95% CI: 2.42, 7.34], mother's history of using Oral Contraceptive Pills [OR=1.77, 95% CI: 1.05, 2.82] and parental relationship [OR=2.05, 95% CI: 1.30, 3.23]. Conclusion: It seems that some parental characteristics have an important role in etiology of childhood leukemia.     

多发性骨髓瘤患者继发败血症的危险因素分析

目的探讨多发性骨髓瘤(MM)患者化疗后败血症的危险因素,以期临床早期预防。方法选择1997年1月-2012年10月血液科住院的MM患者,其中败血症患者42例为研究组,另从同期住院无败血症的MM患者中随机抽取57例作为对照组,对继发败血症的危险因素进行分析,采用法国生物梅里埃公司VITEK-AMS60全自动分析仪进行菌种鉴定,采用GNS-120药敏卡进行最低抑菌浓度(MIC)测定,采用SPSS16.0软件对数据进行处理。结果败血症患者发热42例、畏寒31例、寒颤23例,分布率分别为100.00%、73.81%、54.76%;单因素分析显示,血清白蛋白<30g/L、肾功能不全、骨髓瘤未缓解、血清β-微球蛋白≥3.5mg/L与MM患者败血症发病显著相关(P<0.001);多因素logistic回归分析显示,血清白蛋白<30g/L(OR=3.621)、肾功能不全(OR=3.075)与多发性骨髓瘤患者败血症发病呈正相关,差异有统计学意义(P<0.05);而骨髓瘤达缓解状态(CR/PR)(OR=0.074)与MM患者败血症发病呈负相关(P<0.05);败血症患者共分离出42株病原菌,革兰阳性菌12株,占28.57%,革兰阴性菌25株占59.53%,真菌5株占11.90%。结论血清白蛋白<30g/L、肾功能不全是MM患者发生败血症的重要因素,而骨髓瘤达缓解状态是MM患者发生败血症的保护因素,医师应关注MM患者发生败血症的危险因素,早期给予积极治疗。     

Occupational and other environmental factors and multiple myeloma: a population based case-control study.

Epidemiological studies on the aetiology of multiple myeloma are reviewed as a background to this population based case-control study performed in an area with a high incidence of multiple myeloma. The purpose was to identify and evaluate several suspected environmental factors in relation to this disease. A total of 275 confirmed cases diagnosed in four counties in northern Sweden during four years were compared with the same number of control subjects drawn from population registries. The controls were matched for age, sex, county, and vital status. Occupations and work associated exposures to chemicals and other potential carcinogens were assessed by an extensive questionnaire that also included questions on smoking habits, residential building materials, vicinity to electrical power lines, and leisure time contact with animals, electrical equipment, and chemicals. Information obtained from the questionnaires was completed by telephone interviews when necessary. Univariate analysis and multivariate logistic regression were performed. The study confirmed an association found earlier between farming and multiple myeloma. Some domestic animals (cattle, horses, and goats) and two types of pesticides (phenoxyacetic acids and DDT) were indicated as risk factors within farming. Exposure to electromagnetic fields, asbestos, and organic solvents were negatively associated with myeloma in this study.     

Occupational and other environmental factors and multiple myeloma: a population based case-control study.

Epidemiological studies on the aetiology of multiple myeloma are reviewed as a background to this population based case-control study performed in an area with a high incidence of multiple myeloma. The purpose was to identify and evaluate several suspected environmental factors in relation to this disease. A total of 275 confirmed cases diagnosed in four counties in northern Sweden during four years were compared with the same number of control subjects drawn from population registries. The controls were matched for age, sex, county, and vital status. Occupations and work associated exposures to chemicals and other potential carcinogens were assessed by an extensive questionnaire that also included questions on smoking habits, residential building materials, vicinity to electrical power lines, and leisure time contact with animals, electrical equipment, and chemicals. Information obtained from the questionnaires was completed by telephone interviews when necessary. Univariate analysis and multivariate logistic regression were performed. The study confirmed an association found earlier between farming and multiple myeloma. Some domestic animals (cattle, horses, and goats) and two types of pesticides (phenoxyacetic acids and DDT) were indicated as risk factors within farming. Exposure to electromagnetic fields, asbestos, and organic solvents were negatively associated with myeloma in this study.     

Smoking and risk of acute myeloid leukemia: results from a Los Angeles County case-control study

Acute myelogenous leukemia (AML) is a heterogeneous disease with distinct histologic subtypes likely to have distinct risk factors. The authors examined smoking and the risk of adult AML by French-American-British (FAB) subtype in a Los Angeles County, California, population-based case-control study of 412 cases diagnosed between 1987 and 1994 and 412 matched controls. Consistent with previous studies, smoking was not a substantial risk factor for AML overall (odds ratio (OR) = 1.2, 95% confidence interval (CI): 0.9, 1.6). However, increased risk was observed for FAB subtype M2 (OR = 2.3, 95% CI: 1.1, 4.4), particularly for subjects aged 60-75 years (OR = 3.3, 95% CI: 1.1, 10.0). For M2, significant dose-response was associated with total years smoked (p = 0.02), cigarettes per day (p = 0.007), and product filter status (filtered vs. nonfiltered; p = 0.03). The authors estimate that 42% (standard error = 13%) of M2 cases are attributable to smoking. There were no or weak associations between smoking and increased AML risk for other FAB subtypes. The finding by this study of an association between smoking and FAB subtype M2 confirms a previously published report and suggests that earlier findings of no or weak smoking-AML associations may have been due to lack of subtype-specific analysis.     

Risk factors for haemorrhagic stroke: a case-control study

A hospital based pair-matched case-control study was undertaken to identify risk factors for haemorrhagic stroke. The study took place in the Government Medical College Hospital, Nagpur, India, a tertiary care hospital. The study consisted of 166 hospitalised computerised tomography scan proved cases of haemorrhagic stroke (International Classification Diseases 9, 431-432), and an age and sex matched control per case. The controls were selected from patients who attended the study hospital for conditions other than stroke. The study included hypertension, serum total cholesterol, alcohol intake, smoking, diabetes mellitus, obesity, physical inactivity, type A personality, use of anticoagulants/antiplatelets, family history of stroke, history of cardiac diseases, past history of transient ischaemic attack, history of claudication and oral contraceptive use in women, as risk factors for haemorrhagic stroke. Bivariate analysis included odds ratio (OR), 95% confidence intervals (CI) for OR and McNemar's chi2 test. Multivariate analysis was carried out by conditional multiple logistic regression analysis. Attributable Risk Percent (ARP), Population Attributable Risk Percent (PARP) and their 95% CI were estimated for significant factors. On conditional multiple logistic regression five risk factors-hypertension (OR=1.9, 95% CI 1.5-2.5), serum total cholesterol (OR=2.3, 95% CI 1.4-4.9), use of anticoagulants and antiplatelet agents (OR=3.4, 95% CI 1.1-10.4), past history of transient ischaemic attack (OR=8.4, 95% CI 2.1-33.6) and alcohol intake (OR=2.1, 95% CI 1.3-3.6) were significant. Estimates of ARP and PARP for these factors confirmed their etiological and preventable role respectively. The current study recognised the significance of five risk factors, which are preventable. These risk factors may be considered for devising effective risk factor intervention strategy for haemorrhagic stroke.     

Risk factors for open-angle glaucoma: a case-control study

The objective of this study was to identify possible risk factors associated with open-angle glaucoma (OAG). A case-control study included patients seen at an ophthalmologic clinic. Cases were all consecutive new patients with either unilateral or bilateral OAG detected during the study period. Controls were a random sample of all other patients aged 30 or more, seen in the same department in the same period. Data on demographic, anthropometric and diet habits as well as medical characteristics were collected from 144 patients by medical examination and interview. The study took place at the University Department of Ophthalmology and general private practice of ophthalmology, both in the city of Kinshasa. Forty consecutive patients with OAG and 104 controls were chosen randomly between all consecutive non OAG patients. Odds ratio (OR) are presented for the relation between OAG and age, sex, ethnicity, family history of glaucoma, the length of stay in Kinshasa, body mass index, hypertension, diabetes mellitus, cigarette smoking, alcohol, diet habits. Adjusted odds ratio resulting from stepwise logistic regression was employed. Results indicate: family history of glaucoma (OR, 18; 95% CI, 5.80-59.00; P < 0.001), age (OR, 1.05; 95% CI, 1.01-1.09; P = 0.025), body mass index (OR, 1.09; 95% CI, 1.01-1.18; P = 0.05), hyperopia (OR, 2.9; 95% CI, 1.05-7.08; P = 0.03), Mongo ethnic group (OR, 3.5; 95% CI, 1.11-12.20; P = 0.03) and consumption of rice (OR, 4.6; 95% CI, 1.65-12.20; P = 0.004) conferred a significantly greater risk of OAG. This study seems confirm that Mongo ethnic group is associated with an increased risk of OAG.     

Risk factors for alcohol dependence: a case-control study

Several possible risk factors for ICD-10 alcohol dependence were studied by comparing cases (117 men, 188 women) with controls (248 men, 300 women). Logistic regression analyses showed that parental alcohol problems and high trait anxiety were significantly related to high occurrence of alcohol dependence in both men and women. In women, high antisocial behaviour, high impulsivity, and high externality were also related to high occurrence of alcohol dependence. High facial flushing and high stimulation when intoxicated were related to low occurrence of alcohol dependence in both men and women. In men, this was also the case for high social support. Several interactions were observed. In contrast to earlier studies, there was no significant association between alcohol dependence and left-handedness.     

Risk factors for cryptorchidism: a nested case-control study

Summary. .A nested case-control study of cryptorchidism (i.e. undescended testicles) was undertaken as part of a hospital-based cohort study of 6699 singleton male neonates in New York City. Since some of the cryptorchid infants experienced spontaneous descent of their testes, separate analysis was performed for this third group of late descenders' ( n = 140). Cases ( n = 63) represented infants whose testes remained undescended at the one year assessment. Controls ( n =219) represented the next male infant who was delivered immediately after an infant who was cryptorchid at birth. The only independent risk factors for cryptorchidism were Asian ethnic group (adjusted odds ratio (OR) = 3.90,95% confidence interval (CI) = 1.22-12.41), swollen legs or feet during pregnancy (adjusted OR=2.16, 95% CI = 1.15-4.04), a family history of cryptorchidism (adjusted OR=4.32, 95% CI = 1.91-9.80), low birthweight (adjusted OR = 4.10, 95% CI = 1.39-12.08), and use of analgesics during pregnancy (adjusted OR = 1.93/95% CI = 1.03-3.62). Multiple logistic regression analysis was also performed to identify those factors that were associated with late testicular descent. In this analysis the independent risk factors were black or Hispanic ethnicity (adjusted OR = 2.05, 95% CI = 1.09-3.83), a family history of cryptorchidism (adjusted OR = 4.25,95% CI = 1.84-9.78), consumption of cola-containing drinks during the pregnancy (adjusted OR = 2.09, 95% CI = 1.10-3.99), a low birthweight delivery (adjusted OR = 9.78, 95% CI = 3.39-28.20), and preterm birth (adjusted OR = 4.01, 95% CI = 1.66-9.70).     

97例胆结石危险因素的病例对照研究

目的 探讨胆结石患病的主要危险因素。方法 病例对照研究。结果 多因素Ｌｏｇｉｓｔｉｃ回归分析表明,有统计学意义的危险因素依次为：家族史（ＯＲ＝２２．２５,Ｐ〈０．０１）、油腻饮食（ＯＲ＝８．１９,Ｐ〈０．０５）、血脂增高（ＯＲ＝６．３０,Ｐ〈０．０１）、饮酒（ＯＲ＝４．８４,Ｐ〈０．０５）。结论 家族史、油腻饮食、血脂产高和饮酒是胆结石患病的主要危险因素。     

Risk factors for breast cancer: pooled results from three Italian case-control studies

The role of menstrual and reproductive factors, family history, and body weight in the epidemiology of breast cancer has been reassessed in a meta-analysis of three large case-control studies of breast cancer from several Italian regions, for a total data set of 4,072 cases and 4,099 controls. Multiple logistic regression equations were used to obtain relative risks adjusted for study, center, age, and various combinations of risk factors considered. Relative to women with menarche at age 15 or over, those with earlier menarche had a 20-30% higher breast cancer risk. However, there was no tendency for the risk to increase with lower age at menarche, and the association with menarche was stronger at younger age. The risk of breast cancer was directly related to age at menopause (relative risk (RR) = 0.7 for less than 45 years vs. greater than or equal to 50 years), age at first live birth (RR = 1.8 for greater than or equal to 28 years vs. less than 22 years), and family history of breast cancer in first-degree relatives (RR = 2.0). The effect of these factors was similar in various age strata. After allowance for age at first live birth, the risk of breast cancer did not differ among women with one to four live births, but it was significantly below unity (RR = 0.6) for those with five or more live births. Furthermore, there was a clear modifying effect of age at diagnosis on parity-related risk, since parous women had elevated breast cancer risk below age 35 and reduced risk above age 40.(ABSTRACT TRUNCATED AT 250 WORDS)     

Multiple myeloma and occupational risk factors: a case-control study]

In order to identify possible relationships between multiple myeloma (MM) and occupational factors, a hospital-based case control type study was carried out on 94 cases of MM and on 188 controls matched for sex, age (S.D. = 2 years) and area of residence, suffering from orthopaedic trauma and free of chronic/degenerative or tumoral diseases. All jobs done for at least a year in a period of 5-30 years before diagnosis were considered. Statistical analysis showed a significant correlation between MM and agricultural work (OR 1.82; I.C. 95% 1.03-3.25), which agrees with the data in the literature. The etiopathogenetic hypotheses reported in the literature are discussed and proposals for further research are made.     

Risk factors for adenomatous endometrial hyperplasia: a case-control study

A population-based case-control study of histologically confirmed endometrial neoplasia was conducted in Toronto, Canada, between 1977 and 1978. Pathologic slide review resulted in classification of patients to diagnostic categories of endometrial carcinoma, endometrial carcinoma in situ, and endometrial hyperplasia. This report concerns the subset of patients classified as having adenomatous endometrial hyperplasia. Two age-matched neighborhood controls were selected for each case, and analyses included only those case-control sets in which the case and at least one control were concordant on menopausal status. Among postmenopausal women (87 cases and 151 controls), noncontraceptive estrogen use was a statistically significant risk factor (adjusted odds ratio (OR) = 6.7), as was heavy body weight relative to height (Quetelet index) (adjusted OR = 3.2). Long-term (5+ years) estrogen use conferred an estimated relative risk of more than 20, but use of oral contraceptives did not alter risk significantly. Among premenopausal women (62 cases and 97 controls), a high Quetelet index appeared to be a significant protective factor, even when adjusted for oral contraceptive use (adjusted OR = 0.2). While oral contraceptive use was not associated with a change in risk, long duration of use was highly, but statistically not significantly, protective against hyperplasia. The data for pre- and postmenopausal women indicate that both endogenous and exogenous estrogen exposure are important factors in the etiology of adenomatous endometrial hyperplasia.     

A case-control study of multiple myeloma and occupation

Lifetime job histories from a population-based, case-control study were analyzed to investigate the relationship between multiple myeloma and employment in various occupations and industries. Interviews were obtained from 89% (692) of eligible incident cases and 83% (1683) of eligible controls. An elevated risk was observed among persons ever employed as painters [odds ratio (OR) + 2.1, 95% confidence interval (CI) + 1.2–3.6], particularly for those employed for 10 or more years (OR + 4.1, 95% CI + 1.8–10.4). A small excess risk was observed among agricultural workers employed for 10 or more years (OR + 1.3, 95% CI + 1.0–2.2), with a higher relative risk observed among farm laborers (OR + 1.8, 95% CI + 1.0–4.0). Among agricultural workers who reported having been highly exposed to pesticides, the OR was 5.2 (95% CI + 1.6–21.1). Some evidence, based on smaller numbers, was also found to support an association with firefighting and employment in the petroleum- and coal-products manufacturing industries. Little evidence was found to support the previously noted association with wood exposure, and no evidence for an association with employment in the rubber or petroleum refining industries was found. This study lends further support to previously reported associations between multiple myeloma and employment among painters and agricultural workers. © 1993 Wiley-Liss, Inc.     

Risk factors for imipenem-resistant Pseudomonas aeruginosa: a comparative analysis of two case-control studies in hospitalized patients

Risk factors for acquisition of imipenem-resistant Pseudomonas aeruginosa by hospitalized patients were assessed at a tertiary care hospital. Two case-control studies with different control groups were used. In Study 1, patients with imipenem-resistant P. aeruginosa (IRPA) (case group) were compared with patients selected at random from the same unit. In Study 2, the case group was compared with patients with imipenem-susceptible P. aeruginosa (ISPA). Ninety-three patients with IRPA and 93 control patients were included in Study 1, and 93 IRPA patients and 65 patients with ISPA were included in Study 2. Carbapenem treatment [odds ratio (OR) 5.82], mechanical ventilation (OR 3.22) and hospital admission in the previous year (OR 2.59) were associated with IRPA in Study 1. An interaction between carbapenem and vancomycin was found to be a significant risk factor for IRPA (OR for carbapenem in patients with vancomycin use 43.71). In Study 2, carbapenem exposure (OR 12.82) and renal failure (OR 5.00) were associated with IRPA. Our study confirmed that carbapenem exposure is the main risk factor for IRPA, and found that the use of both carbapenem and vancomycin can increase this effect.     

单纯性尿道下裂发病影响因素病例对照研究

目的了解单纯性尿道下裂发病的影响因素,为预防和减少单纯性尿道下裂的发病提供理论依据。方法采用以医院为基础的1:1病例对照研究方法对2010年5月—2011年4月在中国医科大学附属盛京医院住院的85例先天尿道下裂患儿及同期住院的85例其他疾病患儿父母进行面访调查。结果病例组父亲高中及以上文化程度、母亲高中及以上文化程度、胎儿低出生体重、母亲孕前月经不调、孕前用药、孕早期摄入蛋白质、孕早期服用叶酸、孕期出现异常情况、孕前及孕早期接触化学物及父亲职业接触化学物和家庭从事农牧业生产的比例分别为23.5%、28.2%、32.9%、28.2%、32.9%、47.1%、20.0%、50.6%、42.4%、68.2%和49.4%;对照组分别为50.6%、47.1%、5.9%、15.3%、18.2%、63.5%、36.5%、25.9%、16.5%、42.4%和32.9%,差异均有统计学意义(P<0.05);多因素Lo-gistic回归分析结果表明,胎儿低出生体重(OR=2.12,95%CI=1.18,4.14)、母亲孕期出现异常情况和孕前(OR=3.09,95%CI=1.41,6.80)及孕早期接触化学物是单纯性尿道下裂发病的危险因素;父亲高中及以上文化程度(OR=2.12,95%CI=1.18,4.14)是单纯性尿道下裂发病的保护因素。结论胎儿低出生体重、母亲孕期出现异常情况和母亲孕前及孕早期接触化学物的儿童更易患单纯性尿道下裂。