A cohort study of association between sleep duration and cognitive impairment in the elderly aged 65 years and older in China / 中华流行病学杂志

Objective: To explore the effect of sleep duration on the risk of cognitive impairment in the elderly in China. Methods: Baseline data of 9 679 elderly individuals with intact cognition were collected from the Chinese Longitudinal Healthy Longevity Survey (CLHLS) in 2005, and followed up was conducted until 2018. Cox proportional hazards model was used to analyze the association between different sleep durations and the risk for cognitive impairment in the elderly. Results: Compared with elderly with sleep duration of 6 hours per day, those with sleep duration less than 5 hours had increased risk for cognitive impairment by 30% (HR=1.30, 95%CI: 1.05-1.62), and those with sleep durations of 7 hours, 8 hours and more than 9 hours had increased risk for cognitive impairment by 34% (HR=1.34,95%CI: 1.09-1.64), 40% (HR=1.40,95%CI: 1.17-1.69) and 43% (HR=1.43,95%CI: 1.19-1.70), respectively. Trend test showed that the risk of cognitive impairment increased with the extension of sleep duration (>6 h), and there was a dose-response relationship (P<0.001). However, self-rated sleep quality was not associated with the risk for cognitive impairment in the elderly. Conclusions: The shorter and longer sleep duration were associated an increased risk of cognitive impairment in the elderly aged ≥65 years in China, suggesting that optimizing sleep duration might delay the occurrence of cognitive impairment.

A cohort study on the influence of the chronic diseases on falls among middle-aged and older Chinese / 中华流行病学杂志

Objective: To analyze the influence of chronic diseases on falls among middle-aged and older Chinese. Methods: Baseline data of 13 670 middle-aged and older adults recruited from China Health and Retirement Longitudinal Study (CHARLS) in 2011 were used and followed up to 2018, among those were 7 443 (54.45%) middle-aged people aged 45-59 and 6 227 (45.55%) older adults aged 60 and above. The Cox proportional hazards model was used to analyze the effects of different types, the number of chronic diseases and the interaction between chronic illness and other factors on the fall risk of middle-aged and older people. Results: After adjusting for confounding factors, respiratory diseases increased the risk of falls by 21% (HR=1.21, 95%CI:1.02-1.45), and arthritis increased the risk of falls by 27% (HR=1.27,95%CI: 1.12-1.43) in the group aged 45-59, kidney disease increased the risk of falls by 26% (HR=1.26, 95%CI: 1.03-1.53) in the group aged 60 and above. A linear dose-response relationship between the number of chronic diseases and fall risk (χ2=133.61, P<0.001) was found in all the age groups. The interaction between having chronic diseases and the factors of females (HR=1.64, 95%CI: 1.43-1.89), impaired activities of daily living (ADL) (HR=1.66, 95%CI: 1.39-1.99), and having a fall history (HR=2.58, 95%CI: 2.24-2.97) increased the risk of falls. Conclusions: There is a positive linear relationship between the number of chronic diseases and the fall risk among Chinese aged 45 and above. The female middle-aged and elderly patients with chronic diseases and the middle-aged and elderly patients with impaired ADL or a history of falls are the high-risk groups for falls that need to be focused on intervention. The window of fall injury prevention should be moved forward to the middle-aged stage in time.

Risk factors of high birth weight in rural areas of Shanxi Province / 中华疾病控制杂志

@# Objective To estimate the association between the risk of high birth weight(HBW) and maternal environmental and behavioral factors exposure during pregnancy in rural areas. Methods Data were collected from the surveillance system of birth population and adverse pregnancy outcome in Pingding County, Shanxi Province during 2007 and 2012, where we followed up 204 controls with normal birth weight, 125 cases with HBW≥4 200 g and 171 cases with HBW 4 000-4 200 g. Case control study was performed to explore the potential risk factors of HBW. Results The total number of births was 18 749, including 1 177 cases of high birth weight, with an incidence rate of 6.28% between 2007 and 2012. Concerning the case control study on HBW<4 200 g, after adjusting parental reproductive age and parity, the risk of HBW was 3.10(95% CI：1.67-5.76)times higher among women with gestational weeks ≥42 than that of women with gestational weeks < 42. The risk of HBW in boys was 2.30(95% CI：1.46-3.63)times higher than that in girls. No significant association was observed between maternal BMI before pregnancy and the risk of HBW；Regarding the case control study on HBW≥4200 g, after adjusting maternal reproductive age and parity, the risk of HBW was 3.01(95% CI:1.49-6.08) times higher among women with gestational weeks≥42 than that of those with gestational weeks <42. The risk of HBW was 1.91(95% CI:1.15-3.16)times higher among women with pre-pregnancy BMI≥24 than that of those with pre-pregnancy BMI< 24. The risk of HBW was 2.59(95% CI:1.06-6.32)times higher in women who ate soybean products ≥4 times a week than that of those who ate soybean products less than once a week. Conclusion It would be of public health significance to reduce the risk of high birth weight, which can be reduced by managing pre-pregnancy BMI, diet during pregnancy and controlling gestational week.

Association between contraceptive choice and the risk of induced abortion among floating married women of childbearing age / 中华流行病学杂志

Objective To find the association between factors related to contraception,reproductive health and the risk of induced abortion among floating married women of childbearing age,so as to provide basis for improving the access to health services for floating women of childbearing age.Methods Using data from the reproductive health survey on floating population from five cities in 2005,factors as demographic characteristics,contraceptive choice,settings and access to health services,induced abortion among the floating married women of childbearing age were described.Multivariate logistic regression was used to investigate the association the factors relative to contraception,reproductive health and the risk of induced abortion between 543 cases and 1796 controls.Results The risks of induced abortion among those under 30-years-old floating married women of childbearing age were 2.08-fold (95％CI:1.26-3.42) of the group at the age of 40 years old.The risk of abortion among floating married women at childbearing age who were taking short-acting contraceptive methods,was 2.56-fold (95％ CI:1.84-3.56) of those using the long-acting methods of contraception.The induced abortion risk of floating women at childbearing age who paid the contraceptive implement out of their own pockets,was 1.72-fold (95％ CI:1.32-2.24) of those who got it free of charge.The risks of abortion among women who recieved the contraceptive devices through maternal and child health centers,general hospitals or street residential committees were 2.69-fold (95％CI:1.71-4.22),2.49-fold (95％CI:1.68-3.68) and 1.81-fold (95％CI:1.20-2.72) of those who received them from urban or rural family planning stations,respectively.The induced abortion risk for women who were ignorant of emergency contraception,was 1.41-fold (95％ CI:1.12-1.78) of those who had the knowledge.The abortion risks of floating women at childbearing age who get the contraceptive knowledge from the colleagues,relatives or friends were 1.85 times (95％ CI:1.28-2.67) of those from family planning workers.Conclusion Factors,including age,short-acting contraceptive methods,paid access to contraceptive implement,ignorance of emergency contraception might largely contribute to the increased risk of induced abortion among floating married women of childbearing age,which called for future attention.

Impact of periconceptional multi-micronutrient supplementation on gestation: a population-based study / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To examine the effect of periconceptional multi-micronutrient supplementation on gestation and birth outcomes.</p><p><b>METHODS</b>A population-based community intervention program was conducted in 18 counties in China. Participants were divided into an intervention group, who received multi-micronutrient supplementation from at least 3 months before pregnancy throughout the first trimester, and a control group. Pregnant women were followed up to record information about birth outcomes. Maternal socio-economic characteristics and main birth outcomes were evaluated. Gestational age was further analyzed using survival analysis, to determine the time distribution of delivery.</p><p><b>RESULTS</b>Periconceptional multi-micronutrient supplementation was associated with higher birth weight, birth length and occipitofrontal head circumference, and with lower incidence rates for stillbirth, low birth weight, and preterm birth. Moreover, periconceptional multi-micronutrient supplementation changed the time distribution of delivery, making the deliveries more clustered in the period between day 275 and day 295 of gestation.</p><p><b>CONCLUSION</b>Our study shows that periconceptional multi-micronutrient supplementation is beneficial for fetal development and optimizes all measured aspects of health in neonates in socioeconomically disadvantaged areas in China. The change in time distribution of deliveries caused by multi-micronutrient supplementation needs further clarification.</p>

Study on the risk factors of induced abortion among floating women of childbearing age in 5 cities of China / 中华流行病学杂志

Objective To understand the status of abortion and risk factors among floating women of childbearing age and to provide reference for further improvement of induced abortion services in this population.Methods Data on demography,working,and living conditions as well as the use of contraceptive among 4687 persons from a reproductive health survey regarding floating population in five cities in 2005,were involved,while multivariate logistic regression model was used to find out the relationship.Results The risks of abortion among the younger than 30 age group and the 30-39 age groups were 2.21 times (95％CI:1.47-3.34) and 2.38 times (95％CI:1.53-3.70) of the 40-49 age group,respectively.The higher education degree these women had,the higher the risk of abortion was.The risks of abortion among groups having elementary,junior high,senior high school and above,were 2.15 times (95％CI:1.15-4.03),2.47 times (95％CI:1.33-4.57) and 2.61 times (95％CI:1.34-5.11) of those illiterate women.Those having working experience of 2-4 years,5 years or above at the places where the survey was completed,the risks were 2.62 times (95％CI:1.83-3.76)and 7.78 times (95％CI:5.63-10.75) of the less than 2-year-experienced group.The abortion risk of floating women at childbearing age who were living together with their spouses was 1.49 (95％CI:1.05-2.11) times of those women who were not.Conclusion The demographic and lifestyle as well as working features of floating women at childbearing age might increase their risk of abortion.Providing health education regarding these risk factors on the floating women at childbearing age could effectively reduce and prevent the risk of abortion risk among them.

Maternal periconceptional consumption of pickled vegetables and risk of neural tube defects in offspring / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Maternal exposure to nitrate, nitrite, and N-nitroso compounds from drinking water or diet has been associated with an increased risk of neural tube defects (NTDs) in some studies. Pickled vegetables contain relatively large amounts of nitrite and N-nitroso compounds. We examined the association between maternal periconceptional consumption of pickled vegetables and NTDs in Shanxi Province of northern China.</p><p><b>METHODS</b>Data were derived from a population based case-control study of major external birth defects in four counties of Shanxi Province. Participants included 519 NTDs cases identified between 2003 and 2007 and 694 healthy controls. Exposure information was collected within 1 week after delivery. Multivariable non-conditional Logistic regression model was used to estimate the adjusted odds ratio (OR) controlling for potential confounding variables.</p><p><b>RESULTS</b>The risk of NTDs was positively associated with the frequency of the consumption of pickled vegetables by the mother. Compared with pickled vegetables consumption at < 1 meal/week, the adjusted OR for consumption at 1 - 3, 4 - 6, and > 6 meals/week were 1.3 (95% confidence interval (CI): 1.0, 1.8), 1.9 (1.1, 3.2), and 3.6 (1.9, 6.9), respectively. A protective effect was found for maternal meat consumption at ≥ 1 meal/week (adjusted OR: 0.6, 95%CI: 0.4, 0.7) and egg or milk consumption at ≥ 1 meal/week (adjusted OR: 0.6, 95%CI: 0.4, 0.8).</p><p><b>CONCLUSION</b>Maternal periconceptional consumption of pickled vegetables may increase the risk for NTDs in Shanxi Province.</p>

Cesarean delivery on maternal request and childhood intelligence: a cohort study / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Cesarean section births have been steadily increasing over the past decade and have become an epidemic in China. Cesarean delivery on maternal request is a major contributor to this upward trend, and there has been of much concern about its impact on maternal and child health. Most of mothers believe that cesarean delivery on maternal request can improve the child's intelligence, but direct evidence is sparse. In this cohort study, we aimed to directly assess the impact of cesarean delivery on maternal request on childhood intelligence.</p><p><b>METHODS</b>Intelligence quotient (IQ) of 4144 preschool children from 21 cities/counties of Zhejiang and Jiangsu province whose mothers were registered in a population-based perinatal surveillance program during 1993-1996 was assessed with Chinese Wechsler Young Children Scale of Intelligence (C-WYCSI) in 2000. The outcomes were full-scale IQ, verbal IQ, and performance IQ of C-WYCSI. Mode of delivery and covariates were obtained from the surveillance program. We estimated unadjusted and adjusted effects of cesarean delivery on maternal request and assisted vaginal delivery on IQ scores compared with spontaneous vaginal delivery using regression analysis.</p><p><b>RESULTS</b>The mean full-scale, verbal, and performance IQ for all children was 99.3 ± 16.1, 93.6 ± 17.7, and 105.3 ± 14.3. In crude analysis, cesarean delivery on maternal request versus spontaneous vaginal delivery was associated with an increase of 3.9 (95% confidence interval, 0.6 to 7.2) points in full-scale IQ, 4.8 (1.2 to 8.4) points in verbal IQ, and 2.4 (-0.6 to 5.3) points in performance IQ. After adjusting for maternal education, occupation, and IQ, the advantage was reduced to 1.6 (-1.3 to 4.5), 2.3 (-0.8 to 5.5), and 0.6 (-2.0 to 3.3) points for full-scale, verbal, and performance IQ, respectively. Assisted vaginal delivery versus spontaneous vaginal delivery was not associated with IQ scores in any analysis.</p><p><b>CONCLUSION</b>Neither cesarean delivery on maternal request nor assisted vaginal delivery affected children's IQ.</p>

Sexual dysfunction in diabetic women / 中华男科学杂志

Diabetes mellitus is a common problem, and female sexual dysfunction is one of its complications in diabetic women. Recent studies show that the major risk factors of sexual dysfunction in diabetic women are diabetes-induced vascular disease, neuropathy, endocrine abnormalities and psychological problems and so on. This article outlines the advances in the recent studies of female sexual dysfunction in diabetic women.

Unusual patterns of neural tube defects in a high risk region of northern China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To study the prevalence of different types of neural tube defects (NTDs) in Luliang Prefecture, Shanxi province, where the prevalence of NTDs is unusually high and the correlation between NTDs prevalence and patterns.</p><p><b>METHODS</b>A surveillance population-based birth defects was performed in Luliang Prefecture, Shanxi province.</p><p><b>RESULTS</b>The results of our study showed that the prevalence of NTDs was 2-fold higher in Luliang Prefecture than in other areas of Shanxi province. Unusual patterns of NTDs were found, however, multiple NTDs were relatively common in Luliang Prefecture, accounting for over 13% of all NTDs cases in China.</p><p><b>CONCLUSION</b>The prevalence of NTDs is associated with its patterns.</p>

Effect of pathoanatomic diagnosis on the quality of birth defects surveillance in China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To provide evidence for more accurate diagnosis of birth defects based on the pathoanatomy of congenital malformations.</p><p><b>METHODS</b>Data used in this study were obtained from Luliang City Hospital and three county hospitals of Shanxi province between February 2004 and March 2006. Autopsy and pathological examination of 160 dead fetuses and stillbirths were performed. Photos of dead fetuses and stillbirths were taken, tissues were cut into sections for pathological examination under microscope, all pathological information was recorded, and percentage of birth defects was calculated.</p><p><b>RESULTS</b>The proportion of dead fetuses and stillbirths with or without congenital malformations was 84.4% (135/160) and 15.6% (25/160), respectively. There were 16 categories of major external and internal birth defects in 135 cases of such defects. Congenital heart defects, anencephaly and spina bifida had a higher prevalence rate in the study period. The prevalence rate of non-malformation death and birth defects < 28 gestational weeks and internal anomalies > or = 28 gestational weeks was 14.61% (61/4175) and 17.25% (72/4175), respectively. A total of 413 in situ anomalies were found in 135 cases of autopsy. Spina bifida, anencephaly, congenital heart defects, aplasia or accessory lobe of lung, renal agenesis and dysplasis and congenital hydrocephaly were more closely associated with severe malformations than with mitis malformations. The cases of dead fetuses and stillbirths with multiple malformations (> or = 2 in situ anomalies) had a higher proportion (74.1%), whereas those with isolated malformations had a lower proportion (25.93%).</p><p><b>CONCLUSION</b>The occurrence of congenital malformations in different embryonic developmental stages affects multiple organs. Postmortem examination of internal and multiple malformations of fetal deaths and stillbirths can provide more accurate diagnostic information for birth defects.</p>

Prevalence of visual,hearing,speech,physical,intellectual and mental disabilities in China,2006 / 中华流行病学杂志

Objective To explore the prevalence of visual,hearing,speech,physical,intellectual and mental disabilities in China,2006.Methods The reference time of the Second National Sample Survey on Disability was zero hour,April 1,2006,and 2 526 145 individuals were investigated from 31 provinces autonomous regions or municipalities under the"Disability Classification and Standards for the Second National Sampling Survey on Disability".The classified prevalence rates of 6 types of disability was analyzed.Results (1)The overall prevalence of disabilities was 6.39%,which was 1.49 percent higher than the prevalence rate in 1987.The prevalence of physical disability was the highest(2.34%),while the speech disability was the lowest(0.53%).(2)29.49% of all the disabled persons were classified as severe who suffered grade-1 and grade-2 while 70.51% of them were moderately and mildly disabled suffering from grade-3 and grade-4.Over 65% of the speech disability and over 45% of the mental disability were identified.which were much higher than the other 4 types of disability.(3)The correlation between age,gender.residential place and each of 6 types of disability were statistically significant(P＜0.001).(4)Among all the disabling factors of speech disability and mental retardation disability,congenital factors made great contribution(22.67% and 22.41% respectively).Conclusion According to the analysis results,the characteristics of disabled persons in China were as follows:ageing population had high prevalence rate of disability;all the population mainly suffered moderate and mild disability,but the proportion of severe disability was not low;the prevalence rate was higher and the main reasons caused disability were diversification in rural area.

Application of 'Family-Based Association Test' in studying genetic epidemiology / 中华流行病学杂志

To introduce the application of Family-Based Association Test (FBAT) in detecting the association or linkage between marker alleles and phenotype or traits in genetic epidemiology. A brief overview on basic steps involved in design, implementation, principles of application, available software as well as the use and feature of FBAT method, were explained based on data from nuclear family. Advantages of FBAT were compared to conventional genetic statistics approaches. Data showed that this approach might make the most use of parental genotype,genotype of affected offspring and their phenotype to test the association between biallelic or multi-allelic markers, phenotype or traits to their conditional distributions given the minimal sufficient statistics under the null hypothesis for the genetic model. Covariates, such as traits or environmental exposures, might be included into this proudure so as to effectively control the bias of population admixture through adjustment of variables. FBAT could be used for genetic analysis with data from nuclear family since it is more advantageous than the conventional statistical methods.

The relationships between exposure of periconceptional environmental risk factors and risks of common, structural birth defects / 中华流行病学杂志

<p><b>OBJECTIVE</b>This paper is to explore the relationships between the occurrence of structural birth defects and environmental risk factors on birth defects.</p><p><b>METHODS</b>A survey was conducted by using a population-based case control study. A total number of 388 structural birth defects, which were detected after 28 weeks' gestational age to 7th day after birth in various hospitals were recruited in Wuxi from 2002 to 2004. The control group consisted of 1607 normal live births born in the same period. Multiple logistic regression model was used to analyze relationships between environmental risk factors and occurrence of structural birth defects after controlling women's education level and childbearing age.</p><p><b>RESULTS</b>Among those factors which affected birth defects, the exposure to toxic substances in working environment was the highest risk factor, with OR value as 5.37 (95 % CI : 3.60-7.99). Suffering from reproductive tract infections, high fever during first trimester gestation, and taking potential teratogenic drugs such as hypnotics and anti-convulsion drug agents, might significantly increase the risk of structural birth defects, with OR values (95% CI) as 3.38 (1.33-8.56), 3.57 (1.73-7.37) and 2.75 (1.57-4.83) respectively. However, the correlation between oral contraceptives intake within six months before pregnancy and risk of birth defects had no statistical significance. In addition, pollution of the residential environment, staying up all night and raising pets at home, had relatively lower association with birth defects, with OR values (95% CI) as 2.28 (1.75-2.98), 1.96 (1.21-3.18) and 2.50 (1.66-3.76) respectively, yet with a higher proportion of exposure to those factors in pregnant women. There was a significant increase in occurrence risks of birth defects with increase in the number of exposure to environmental risk factors. OR values for having one, two, three kinds of environmental risk factors were 1.60, 4.32 and 10.23 respectively.</p><p><b>CONCLUSION</b>The common structural birth defects were affected by a number of environmental risk factors. There was also a dose-response relationship between the number of environmental risk factors and occurrence risks of structural birth defects noticed in our study.</p>

Study on the differences of exposure levels to the environmental risk factors during periconceptional period between intended and unintended pregnancies / 中华流行病学杂志

<p><b>OBJECTIVE</b>This paper was to analyze the difference of exposure levels of the environmental risk factors on birth defects during peri-conceptional period between intended and unintended pregnancies, and to estimate the role of intended pregnancies in reducing exposure of environmental risk factors.</p><p><b>METHODS</b>Data used in this paper were from a retrospective survey of maternal women from 2002 through 2004 conducted in Wuxi city. The total number of women under study was 1628. Logistic regression model was employed to control women's childbearing age and education level for analysis of the role of intended pregnancies in reducing risk of unsafe use of medicine during pregnancy, exposure to toxic substance in working or living environments and unhealthy lifestyles.</p><p><b>RESULTS</b>The proportion of intended pregnancies was 73.2%. The proportion of intended pregnancies in urban women was slightly lower than that in rural women,and the proportion of intended pregnant women whose childbearing age was over 30 years old,was significantly higher than that whose childbearing age was under 30 years old. There were significant differences in exposure risks of unsafe use of medicine and some unhealthy lifestyles between the intended and the unintended. In the intended group, the proportions of taking the suspicious teratogenic drugs and staying up were 2.5% and 2.9% respectively, significantly lower than those in unintended group whose proportion were 6.0% and 5.5%. When compared with the unintended pregnant women, the exposure risk of taking the suspicious teratogenic drugs and staying up in intended pregnant women decreased by 60% and 50% respectively.</p><p><b>CONCLUSION</b>Intended pregnancies could significantly reduce the risk of taking the suspicious teratogenic drugs and unhealthy lifestyles. Reducing the incidence of unwanted pregnancy and increasing the proportion of intended pregnancies were both cost-effective methods for preventing birth defects.</p>

Study on the association between transforming growth factor alpha gene TaqI variant and cleft lip with or without cleft palate / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the association between transforming growth factor alpha gene (TGFalpha) TaqI variant and nonsyndromic cleft lip with or without cleft palate (nsCL/P) in Chinese population.</p><p><b>METHODS</b>TGFalpha TaqI variant was detected using polymerase chain reaction-restriction fragment length polymorphism for DNA samples of the 149 triads with nsCL/P affected child. We performed the Transmission/disequilibrium test and the family-based association study (FBAT) to identify the associations between this variant and risk of nsCL/P.</p><p><b>RESULTS</b>Significant distortion of C2 allele at TGFalpha TaqI locus in nsCL/P groups (P > 0.05) was not found. In the family-based association test, C2 allele and offspring C2C1 genotype was not found to be significantly associated with an increase risk of nsCL/P (P > 0.05).</p><p><b>CONCLUSION</b>Our findings did not suggest an association between offspring TGFalpha TaqI variant and the increased risk of nsCL/P in Chinese population.</p>

Association between parental transforming growth factor alpha gene TaqI variant, paternal smoking and the cleft lip with or without cleft palate / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study the association between transforming growth factor alpha gene (TGFalpha) TaqI variant and nonsyndromic cleft lip with or without cleft palate (nsCL/P) in Chinese population, and the interaction with parental smoking.</p><p><b>METHODS</b>TGFalpha TaqI variant was detected using RFLP-PCR for DNA samples of the 170 triads with nsCL/P affected child. We performed the transmission/disequilibrium test (TDT) and the family-based association study (FBAT) to test the associations between this variant and risk of nsCL/P.</p><p><b>RESULTS</b>It was not found significant distortion of C2 allele at TGFalpha TaqI locus in nsCL/P groups (P > 0.05), however, by stratified analysis, we found that the rate of C2 allele transmission among nuclear families whose fathers were smoking was 1/5 (0.062 - 0.711) as compared with that among nuclear families whose fathers were not smoking, and the OR of interaction between TGFalpha variant and parental smoking is 0.102 (0.017 - 0.619).</p><p><b>CONCLUSION</b>The parental smoking may interact with TGFalpha variants of Chinese populations in occurrence of nsCL/P, but it remains to have more investigations.</p>

Interaction between maternal periconceptional supplementation of folic acid and reduced folate carrier gene polymorphism of neural tube defects / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To search the interaction between reduced folate carrier gene (RFC1 A80G) polymorphism of children with neural tube defects (NTDs) and maternal periconceptional no supplementation of folic acid. The purpose is to provide the epidemiological evidence for finding genetic marker of NTDs.</p><p><b>METHODS</b>RFC1 (A80G) genotype was detected using PCR-restricted fragment length polymorphism for the blood DNA of 104 trios with NTDs-affected child, and 100 control families with non-malformed control children. The authors investigated the gene-environment interactions between the offspring RFC1 genotype and maternal periconceptional folic acid supplementation through a case-control study.</p><p><b>RESULTS</b>It was observed that the offspring with the GG genotype were associated with a 2.56-fold increased risk of NTDs when compared to those with the AA genotype (OR = 2.56; 95% CI = 1.04-6.36) in this population under investigation. The risk of mothers who did not take folic acid for having an NTDs-affected infants was 7.69 (95% CI = 2.86-21.75). Among the mothers who did not utilize folic acid supplements, the NTDs risk was 3.30 (95% CI = 1.15-9.65) for offspring with the GG genotype, compared to the reference (AA) genotype. Children who had the GG genotype and whose mothers did not take folic acid had an elevated risk for NTDs (OR = 8.80, 95% CI = 2.86 - 29.82), compared to "offspring with AA or GA genotype" and "maternal folic acid use", the interactive coefficient being 1.45.</p><p><b>CONCLUSION</b>The above findings indicate that the RFC1 genotype (GG) is a possible susceptible gene marker for an increased NTDs risk in Chinese population, and there is a potential gene-nutrient interaction between offspring RFC1 GG genotype and maternal periconceptional intake of folic acid on the risk of NTDs. However,the sample size of this study was limited, a larger sample of population-based study is required to pursue the initial observation.</p>

A parental case control study on the association between reduced folate carrier gene polymorphism and neural tube defects / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the association between reduced folate carrier gene (RFC1 A80G) polymorphism and the risk for child with neural tube defects (NTDs), and to provide epidemiological evidence for the existence of NTDs genetic marker.</p><p><b>METHODS</b>RFC1 (A80G) genotypes were detected using RFLP-PCR for blood DNA of 104 families with NTDs-affected children and 100 control families with no history of child-affected birth defects. Case-control study and transmission/disequilibrium test(TDT) for the RFC1 genotype of NTDs pedigree were carried out.</p><p><b>RESULTS</b>The G allele frequency of children with NTDs was higher than that of controls when compared to A allele( OR = 1. 64, 95% CI :1.08-2.49). The offspring of the GG genotype were associated with a 2.56-fold increased risk of NTDs when compared to the AA genotype (OR = 2.56, 95% CI: 1.04-6.36) in our study population. There was evidence of association between G allele and the risk of parent having a child with NTDs (OR = 1.56, 95% CI: 1.07-2.28) in the TDT analysis.</p><p><b>CONCLUSION</b>Our findings indicated that there was potential association between offspring RFC1 GG genotype and the risk of NTDs, and the G allele was a possible susceptible gene marker for an increased NTDs risk in the Chinese population.</p>

A case control study on the relationship between trace elements and human neural tube defects / 中华流行病学杂志

<p><b>OBJECTIVE</b>To explore the relationship between multi-trace elements levels in hair and human neural tube defects as well as other risk factors.</p><p><b>METHODS</b>Using 88 paired cases and controls, an 1:1 matched case control study was carried out. The study subjects were collected from the China-U. S. Collaborative Project on Neural Tube Defects Prevention and Birth Defects Surveillance System. Risk factors were obtained by field investigation with standardized questionnaires and hair trace elements levels were determined by AAS and ICP-MS methods. Microwave digestion was used to digest hair samples. The detected elements would include three groups, namely nutritional elements: Cr, Mn, Cu, Zn, Co, Mo; toxic elements: Pb, As, Cd, Hg; and Lanthanons: Y, La, Pr, Nd. Cox Proportional Hazard Regression Model was used to perform risk factors analysis.</p><p><b>RESULTS</b>Pregnancy fever appeared to be a risk factor of neural tube defects (OR = 6.525, P = 0.034) while hair zinc level (OR = 0.541 microg/100 g, P = 0.02) and times of prenatal physical examination (OR = 0.634, P < 0.001) served as two protective factors appeared in the last model.</p><p><b>CONCLUSION</b>Zinc deficiency might serve as a risk factor for human neural tube defects, suggesting that the avoidance of pregnancy infection together with more periodical prenatal physical examination might reduce the incidence of neural tube defects.</p>