Maternal prenatal exposure to environmental factors and risk of childhood acute lymphocytic leukemia: A hospital-based case-control study in China

Objective: To investigate an association between maternal prenatal exposure to several environmental factors and risk of childhood acute lymphocytic leukemia (ALL), and the possible interactions in the Chinese population.Methods: 345 cases with ALL and their 1:1 age, gender, residence region matched controls aged 0–15 years were recruited from four hospitals in Henan Province from 2014 to 2016. Information was collected by interviews using a questionnaire. Unconditional logistic regression adjusted for age, gender, residence region and relevant confounders was carried out to generate the odds ratios (ORs) and 95% confidence intervals (CIs).Results: Our data indicate that maternal prenatal exposure to interior housing renovation (adjusted OR: 2.98, 95% CI: 1.51–5.86) or pesticides (adjusted OR: 1.48, 95% CI: 1.67–2.28) increased the risk of childhood ALL. Various subgroup analyses stratified by child's gender, age at diagnosis and other factors also supported these results. However, no interaction was detected between exposure to internal housing renovation and pesticides using an additive model. No significant links between maternal exposures to, environmental tobacco smoking (ETS), antipyretic analgesia intake, or viral infectious diseases with risk of ALL were detected.Conclusion: Findings in our study are in line with the existing literatures, which support the hypothesis that maternal prenatal exposure to interior housing renovation and pesticides are risk factors for childhood ALL. Notably, we found no interaction between these two risk factors, these findings may inform prevention and early detection strategies.     

Risk factors in autism spectrum disorder: A Tunisian case-control study

BackgroundAutism spectrum disorder (ASD) is a neurodevelopmental condition that causes disability in social interaction, communication, and restrictive and repetitive behaviors. Common environmental factors like prenatal, perinatal, and/or postnatal factors play a key role in ASD etiologies. Moreover, specific metabolic disorders can be associated with ASD.Subjects and methodsWe performed a retrospective case-control study in child psychiatry clinics, involving 51 children with ASD and 40 typical development controls (TDC).ResultsWe found a correlation between children being breastfed for less than 6 months, having fathers more than 40 years old at childbirth in ASD compared to TDC group. Our study also associated low blood cholesterol and low erythrocyte magnesium levels with increased risk for ASD.ConclusionFindings support the implication of total cholesterol (TC) and erythrocyte magnesium level in defining autism outcome.     

Risk factors for preeclampsia in women from Colombia: a case-control study

Background

Preeclampsia (PE) is a multi-causal disease characterized by the development of hypertension and proteinuria in the second half of pregnancy. Multiple risk factors have been associated with the development of PE. Moreover, it is known that these risk factors vary between populations from developed and developing countries. The aim of this study is to identify which risk factors are associated with the development of preeclampsia (PE) among Colombian women.

Methods

A multi-centre case-control study was conducted between September 2006 and July 2009 in six Colombian cities. Cases included women with PE (n = 201); controls were aged-matched pregnant women (n = 201) without cardiovascular or endocrine diseases for a case-control ratio of 1∶1. A complete medical chart, physical examination and biochemical analysis were completed before delivery. Multivariable logistic regression was used to calculate odds ratios (OR) and 95% confidence intervals (CI) of potential risk factors associated with PE.

Results

The presence of factors present in the metabolic syndrome cluster such as body mass index >31 Kg/m2 (OR = 2.18; 1.14–4.14 95% CI), high-density lipoprotein <1.24 mmol/L (OR = 2.42; 1.53–3.84 95% CI), triglycerides >3.24 mmol/L (OR = 1.60; 1.04–2.48 95% CI) and glycemia >4.9 mmol/L (OR = 2.66; 1.47–4.81 95%CI) as well as being primigravidae (OR = 1.71; 1.07–2.73 95% CI) were associated with the development of PE, after adjusting for other variables.

Conclusion

Factors present in the cluster of metabolic syndrome and primigravidity were associated with a greater risk of PE among Colombian women. Understanding the role of this cluster of risk factors in the development of PE is of crucial importance to prevent PE and remains to be determined.     

Risk factors for breast cancer in women biopsied for benign breast disease: A nested case-control study

Aim: Women with a history of benign breast disease are at increased risk of subsequent breast cancer. However, few studies have examined whether established breast cancer risk factors other than histology are associated with an altered risk of breast cancer in women with benign breast disease. We used a nested case-control design within a large, multi-center cohort of women biopsied for benign breast disease (BBD) to estimate odds ratios for breast cancer in association with exposure to a range of personal and lifestyle factors. Methods: Cases were women biopsied for BBD who subsequently developed breast cancer; controls were individually matched to cases on center and age at diagnosis and were women biopsied for BBD who did not develop breast cancer in the same follow-up interval as that for the cases. After excluding women with prevalent breast cancer, 1357 records (661 case records and 696 records) were available for analysis. We used conditional logistic regression to obtain crude and multivariable-adjusted estimates of the association between specific factors and risk of breast cancer. Results: In multivariable analyses age at first live birth, number of pregnancies, and postmenopausal status were inversely associated with risk of breast cancer. The odds ratio for women with age at first birth <25 years and ≥3 pregnancies, relative to nulliparous women, was 0.49, 95% confidence interval 0.13–0.79, and that for postmenopausal women relative to premenopausal women was 0.60, 95% CI 0.37–0.99. Conclusions: Further study of personal factors influencing the risk of breast cancer in women with BBD may help to identify subgroups of the population at increased risk of invasive disease.     

Risk factors of Streptococcus suis infection in Vietnam. A case-control study

Background

Streptococcus suis infection, an emerging zoonosis, is an increasing public health problem across South East Asia and the most common cause of acute bacterial meningitis in adults in Vietnam. Little is known of the risk factors underlying the disease.

Methods and Findings

A case-control study with appropriate hospital and matched community controls for each patient was conducted between May 2006 and June 2009. Potential risk factors were assessed using a standardized questionnaire and investigation of throat and rectal S. suis carriage in cases, controls and their pigs, using real-time PCR and culture of swab samples. We recruited 101 cases of S. suis meningitis, 303 hospital controls and 300 community controls. By multivariate analysis, risk factors identified for S. suis infection as compared to either control group included eating “high risk” dishes, including such dishes as undercooked pig blood and pig intestine (OR₁ = 2.22; 95%CI = [1.15–4.28] and OR₂ = 4.44; 95%CI = [2.15–9.15]), occupations related to pigs (OR₁ = 3.84; 95%CI = [1.32–11.11] and OR₂ = 5.52; 95%CI = [1.49–20.39]), and exposures to pigs or pork in the presence of skin injuries (OR₁ = 7.48; 95%CI = [1.97–28.44] and OR₂ = 15.96; 95%CI = [2.97–85.72]). S. suis specific DNA was detected in rectal and throat swabs of 6 patients and was cultured from 2 rectal samples, but was not detected in such samples of 1522 healthy individuals or patients without S. suis infection.

Conclusions

This case control study, the largest prospective epidemiological assessment of this disease, has identified the most important risk factors associated with S. suis bacterial meningitis to be eating ‘high risk’ dishes popular in parts of Asia, occupational exposure to pigs and pig products, and preparation of pork in the presence of skin lesions. These risk factors can be addressed in public health campaigns aimed at preventing S. suis infection.     

Risk factors for severe malaria in Bamako, Mali: a matched case-control study

The aim of this case-control study was to identify epidemiological risk factors for severe malaria among children living in Bamako, a malaria-endemic area. For this, 260 healthy community controls were matched to 130 patients with severe malaria. Conditional multiple logistic regression analysis indicated that all examined independent factors associated with severe malaria are directly related to characteristics of the child's mother, with the exception of the child's own yellow fever vaccination history (odds ratio (OR): 1.93, 95% confidence intervals (CI(95%)) [1.10-3.37]). The following characteristics were all associated with a decreased risk of severe malaria in the child: maternal education (OR: 0.52, CI(95%) [0.31-0.86]), the mother's adequate knowledge about malaria (OR: 0.46, 95% CI(95%) [0.25-0.86]), her use of mosquito bed nets (OR: 0.53, CI(95%) [0.30-0.92]) and breast-feeding for at least 2 years (OR: 0.57, CI(95%) [0.33-0.94]). Conversely, chronic maternal disease (OR: ?3.16, CI(95%) [1.31-7.61]) was associated with an increased risk of severe malaria. These findings strongly support the hypothesis that maternal factors are central to the development of severe malaria in children. Programmes aiming to improve both maternal health and maternal education may reduce the incidence of severe malaria in children and should therefore be advocated in Bamako and in areas with similar epidemiological patterns for malaria.     

Risk factors for winter outbreak of acute diarrhoea in France: case-control study.

OBJECTIVES: To assess the potential role of consumption of shellfish (particularly raw oysters) and tap water in the winter epidemic of acute diarrhoea in France. DESIGN: Population based, case-control study during the 1995-6 winter epidemic of acute diarrhoea in France. SETTING: A national network comprising 1% of general practitioners in France. SUBJECTS: 568 pairs of cases and controls consulting in general practice and interviewed by 209 doctors from 26 December 1995 to 31 January 1996. Cases and controls were matched for age, doctor, and time of consultation. MAIN OUTCOME MEASURES: Adjusted relative risk of diarrhoea estimated from conditional logistic regression. RESULTS: The risk of acute diarrhoea was not increased in people who had recently eaten raw oysters (odds ratio 1.1; 95% confidence interval 0.9% to 1.4%) or other shellfish such as clams, cockles, and mussels, or in those people who usually consumed tap water rather than bottled water (0.8; 0.6% to 1.1%). The risk was, however, increased in people who had had recent contact wit ha person with diarrhoea either within the household (adjusted odds ratio 5.0) or in the workplace (3.1), and in people who lived with a child < or = 2 years of age (1.6). Recent treatment with either oral penicillin or cephalosporin was also independently associated with acute diarrhoea in winter. CONCLUSIONS: The winter epidemic of acute diarrhoea in France is probably not caused by consumption of either shellfish or tap water. A viral aetiology, however, is suggested by the speed with which the acute diarrhoea is transmitted.     

Incidence of multiple myeloma in Kailuan cohort: A prospective community-based study in China

BackgroundPrevious retrospective studies showed that the incidence and mortality rates for MM in China were lower than those in western countries. A large-scale prospective study on incidence and mortality rates of MM is still lacking.MethodsBased on the prospective Kailuan Cohort study in China, we included all patients with MM in Kailuan Cohort from June 1, 2008 to December 31, 2016. Using the numbers of diagnosed cases and deaths during the study period as the numerators and the corresponding observed person-years as the denominators respectively, we calculated crude incidence and mortality rates. The 95% confidence intervals for crude incidence rate and mortality rate were estimated base on Poisson distribution. Rates were standardized by direct standardization according to the China population in 2000 and Segi’ world standard population.ResultsA total of 22 members from Kailuan Cohort were first diagnosed with MM between 2008 and 2016. The calculated crude incidence rates were 2.8 (95% CI, 1.7–4.2) per 100,000 person-years for all participants. The standardized incidence rate was 0.9 per 100,000 person-years (95% CI, 0.5–2.1) when standardized by 2000 China population census data, and 1.0 per 100,000 person-years (95% CI, 0.6–1.8) when standardized by Segi’s world standard population (WSP). The calculated crude mortality rates were 2.3 (95% CI, 1.4–3.6) per 100,000 person-years. The mortality standardized by 2000 China population census data was 0.7 per 100,000 person-years (95% CI, 0.3–1.9), and 0.9 per 100,000 population (95% CI, 0.5–1.7) when standardized by Segi’s WSP. Both incidence and mortality for males were higher than that for females almost in all age groups. Both rates increased steadily with age.ConclusionIn this community-based prospective cohort study, we found that the incidence of MM in China was far lower than that in American and Europe.     

Risk factors for low birth weight: Results from a case-control study in southern Spain

The main objective of this study is to examine the effect of several variables, including altitude of maternal residence, on delivering a low birth weight (LBW) newborn. A case-control study was done. Two hundred forty cases (single newborn weighing less than 2,500 g) and 374 controls (single newborn weighing more than 2,499 g) were included. Information was gathered from the clinical chart of delivering women, through a personal interview and the Spanish Census Bureau (for altitude). Predictors of LBW were assessed through stepwise logistic regression analysis. Several well-known LBW risk factors were identified: hypertension, weight gain during pregnancy, body size (mainly maternal prepregnancy weight), low social class, primiparity, and several conditions (spontaneous delivery, abruptio placentae). Altitude was an independent predictor of LBW at term (more than 37 weeks of gestational age) but not for preterm LBW. Nevertheless, a relationship between altitude and birth weight was not found in controls, although a moderate decreasing gradient with altitude was observed. The limitations of these findings are discussed. Am J Phys Anthropol 105:419–424, 1998. © 1998 Wiley-Liss, Inc.     

Risk factors for neonatal encephalopathy in Kathmandu, Nepal, a developing country: unmatched case-control study

This unmatched case-control study determined the risk factors for neonatal encephalopathy among term infants in Kathmandu, Nepal. Study participants included 131 infants with neonatal encephalopathy born between January 1995 and July 1996, and 635 unmatched infants systematically recruited over 12 months. The prevalence of neonatal encephalopathy was 6.1% per 1000 live births, of which 63% were infants with moderate encephalopathy. Antepartum risk factors included multiple births (odds ratio, OR = 22), primiparity (OR = 2.0), and nonattendance for antenatal care (OR = 2.1). Intrapartum risk factors were particulate meconium (OR = 18), noncephalic presentation (OR = 3.4), prolonged rupture of membranes (OR = 3.8), and other complications. In addition, induction of labor with oxytocin was associated with encephalopathy in 12 of 41 deliveries (OR = 5.7). Overall, 78 affected infants (60%) compared with 36 controls (6%) either had evidence of intrapartum compromise or were born after an intrapartum difficulty likely to result in fetal compromise. Moreover, maternal hemoglobin concentration 8.0 g/dl (OR = 2.5) and thyroid stimulating hormone 5 ml U/l (OR = 2.1) were associated with encephalopathy. Intrapartum risk factors remain important for neonatal encephalopathy in developing countries. There is some evidence of a protective effect from antenatal care. The use of oxytocin in low-income countries where intrapartum monitoring is suboptimal presents a major risk to the fetus. Further studies are required to explore the association between maternal deficiency states and neonatal encephalopathy.     

Response to thalidomide in multiple myeloma: impact of angiogenic factors

Thalidomide has antiangiogenic and immunomodulatory effects, mediated by several cytokines such as vascular endothelial growth factor (VEGF), fibroblastic growth factor (FGF-2), hepatocyte growth factor (HGF), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha). Although extramedullary plasmacytomas (EMP) have a high vascularization, the response of these patients to thalidomide is controversial. Thirty-eight patients with refractory/relapsed MM were treated with thalidomide. Eleven patients had EMP when therapy was initiated. Serum specimens were obtained in patients before treatment was started and at the time of maximum response in responding patients or at thalidomide discontinuation in non-responders. Serum levels of VEGF, HGF and FGF-2 were determined in 18 patients whereas IL-6 and TNF-alpha were measured in 19 patients. Sixteen of the 38 patients (42%) responded to thalidomide. The response rate was significantly higher in patients without EMP (59% vs 0%, p = 0.0006 ). VEGF serum levels were significantly higher in responding patients. In contrast, baseline serum levels of HGF were significantly lower in responders. Neither VEGF nor HGF serum levels showed correlation with the presence of EMP. Baseline TNF-alpha serum levels were significantly lower in responding patients and in those without EMP. The serum levels of FGF-2 and IL-6 did not correlate with response to treatment or presence of EMP.     

Risk of testicular cancer in subfertile men: case-control study

ObjectiveTo evaluate the association between subfertility in men and the subsequent risk of testicular cancer.DesignPopulation based case-control study.SettingThe Danish population.ParticipantsCases were identified in the Danish Cancer Registry; controls were randomly selected from the Danish population with the computerised Danish Central Population Register. Men were interviewed by telephone; 514 men with cancer and 720 controls participated.ResultsA reduced risk of testicular cancer was associated with paternity (relative risk 0.63; 95% confidence interval 0.47 to 0.85). In men who before the diagnosis of testicular cancer had a lower number of children than expected on the basis of their age, the relative risk was 1.98 (1.43 to 2.75). There was no corresponding protective effect associated with a higher number of children than expected. The associations were similar for seminoma and non-seminoma and were not influenced by adjustment for potential confounding factors.ConclusionThese data are consistent with the hypothesis that male subfertility and testicular cancer share important aetiological factors.

Key messages

• The incidence of testicular cancer has increased in the past 50 years, and there is some evidence to suggest that sperm quality has decreased in the same period
• It has been hypothesised that common aetiological factors may exist for testicular cancer and for male subfertility
• The association between male subfertility and subsequent risk of testicular cancer is strong and consistent with the hypothesis of a common aetiology
• The association is similar for seminoma and non-seminoma, and it persists when several potentially confounding factors are taken into account

     

Prenatal polymetallic exposure and small for gestational age: A case-control study in Taiyuan,China

BackgroundStudies focused on independent effects of metals on small for gestational age, failing to account for potential interdependence among metals.MethodsIn this case-control study, we selected 187 pregnant women and 187 matched controls from the First Hospital of Shanxi Medical University. Determination of 12 elements in the venous blood of pregnant women before delivery by ICP-MS. Logistic regression, weighted quantile sum regression (WQSR) and Bayesian kernel machine regression (BKMR) were used to estimate the overall effect and identify important mixture components that drive the associations with SGA.ResultsAn increased risk of SGA was associated with As (OR= 1.06,95%CI: 1.01,1.12), Cd (OR= 1.24,95%CI: 1.04,1.47) and Pb (OR= 1.05,95%CI: 1.02,1.08), while Zn (OR= 0.58,95%CI: 0.45,0.76) and Mn (OR= 0.97,95%CI: 0.94,0.99) were protective factors for SGA. In the WQSR positive model, the mixture of heavy metals has a positive combined effect on SGA (OR= 1.74,95%CI: 1.15, 2.62), with Sb and Cd having the highest weights. The BKMR models confirmed that the metal mixture was associated with decreased risk of SGA when the concentration of 12 metals was between the 30th percentile and the 65th percentile, and Zn and Cd had the greatest independent effect. Zn and SGA may not be linearly correlated, higher Zn level may reduce the effect of Cd on the risk of SGA.ConclusionsOur study suggested that exposure to multiple metals was associated with risk of SGA, and the observed association with multiple metals was dominated by Zn, Cd. Sb exposure during pregnancy may also increase the risk of SGA.     

Neonatal risk factors for cerebral palsy in very preterm babies: case-control study.

OBJECTIVE: To identify neonatal risk factors for cerebral palsy among very preterm babies and in particular the associations independent of the coexistence of antenatal and intrapartum factors. DESIGN: Case-control study. SETTING: Oxford health region. SUBJECTS: Singleton babies born between 1984 and 1990 at less than 32 weeks'' gestation who survived to discharge from hospital: 59 with cerebral palsy and 234 randomly selected controls without cerebral palsy. MAIN OUTCOME MEASURES: Adverse neonatal factors expressed as odds ratios and 95% confidence intervals. RESULTS: Factors associated with an increased risk of cerebral palsy after adjustment for gestational age and the presence of previously identified antenatal and intrapartum risk factors were patent ductus arteriosus (odds ratio 2.3; 95% confidence interval 1.2 to 4.5), hypotension (2.3; 1.3 to 4.7), blood transfusion (4.8; 2.5 to 9.3), prolonged ventilation (4.8; 2.5 to 9.0), pneumothorax (3.5; 1.6 to 7.6), sepsis (3.6; 1.8 to 7.4), hyponatraemia (7.9; 2.1 to 29.6) and total parenteral nutrition (5.5; 2.8 to 10.5). Seizures were associated with an increased risk of cerebral palsy (10.0; 4.1 to 24.7), as were parenchymal damage (32; 12.4 to 84.4) and appreciable ventricular dilatation (5.4; 3.0 to 9.8) detected by cerebral ultrasound. CONCLUSION: A reduction in the rate of cerebral palsy in very preterm babies requires an integrated approach to management throughout the antenatal, intrapartum, and neonatal periods.     

Risk factor for clear cell renal cell carcinoma in Chinese population: a case-control study

Background: Risk factors for clear cell renal cell carcinoma (ccRCC) differ among populations and remain controversial. We carried out a hospital-based case–control study to examine the effects of health status, lifestyle, and some genetic polymorphisms on ccRCC risk in Chinese subjects. Methods: Between 2007 and 2009, 250 newly diagnosed, histologically confirmed ccRCC cases and 299 sex-, age-matched healthy controls provided complete information including consumption of tea and alcohol, smoking, occupational exposure, body mass index (BMI), hypertension, diabetes, and urolithiasis by face-to-face interview in Shanghai. Genetic polymorphisms of cytochrome P450 mono-oxygenase (CYP1A1: 6235T>C, 4889A>G, and 4887C>A), glutathione S-transferase (GSTP1: 342A>G), and N-acetyltransferase (NAT2: 481C>T, 590G>A, and 857G>A) were identified by PCR-RFLP and DNA sequencing. Adjusted odds ratio (AOR) and 95% confidence interval (CI) were derived through multivariate logistic regression. Results: Green tea intake (≥500 ml/d) was inversely associated with ccRCC risk, with an AOR of 0.34 (95% CI 0.21–0.55). BMI (≥25 kg/m²), hypertension, and urolithiasis were independently associated with an increased risk of ccRCC, with AOR (95% CI) of 2.10 (1.32–3.34), 2.49 (1.57–3.93), and 3.33 (1.12–9.89), respectively. No association was observed between smoking, alcohol consumption, or occupational exposure with ccRCC risk. The polymorphisms and their interactions with the environmental exposures were mostly not associated with ccRCC risk. Conclusion: BMI (≥25 kg/m²), hypertension, and urolithiasis are independently associated with an increased risk, whereas green tea intake (≥500 ml/d) is independently associated with a decreased risk of ccRCC. The polymorphisms of the xenobiotic-metabolizing enzymes are weakly associated with ccRCC risk in Chinese subjects.     

Home care for persons with AIds: a case-control study to identify determinants of referral to a hospital-based scheme.

We conducted a multicenter, hospital-based case-control study to identify specific characteristics of AIDS patients which determine referral to hospital care at home. The cases were patients referred to a hospital-based home care scheme, in the metropolitan area of Rome, during 1997. Each case was matched with two controls. Social, demographic and clinical characteristics were collected at referral. Univariate and multivariate analysis were performed. In the study period, 119 cases and 238 controls were recruited. In logistic regression analysis, social characteristics were not found to affect referral to the hospital-at-home scheme. A severely impaired functional status--assessed by the Functional Independent Measure--identified by a score below 100 (Odds Ratio [OR]=15.2, 95% confidence interval [CI] 2.8-82.7), and the need for prolonged intravenous therapy (OR=12.4, 95% CI=3.3-46.3) were the only two independent predictors of home-care referral. We conclude that home care, even in a period when new potent combination antiretroviral therapies are widely available, is an important integrated service component for persons with AIDS with severe functional impairment or requiring intravenous therapy.