Body mass index and asthma in adults in families of subjects with asthma in Anqing, China.
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Adult↗
Biomedical subjects
Xiping Xu
Publications and source records attributed to Xiping Xu.
Familial aggregation of bronchodilator response: a community-based study.
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Asthma↗
Ascaris lumbricoides infection is associated with increased risk of childhood asthma and atopy in rural China.
There is growing international interest in the possible relationships between helminthic infection and allergic disease, although the nature of the relationships remains uncertain and controversial. The interrelationships of current and past infection with Ascaris lumbricoides and asthma and atopy were investigated in a cross-sectional sample of 2,164 children between the ages of 8 and 18 years from Anqing Province, China. The children were sampled from a larger family-based study of the genetics of asthma. The prevalence of either a history of or a positive stool examination for Ascaris was 24.5%. Asthma was defined for analytic purposes using previously validated, stringent criteria including airways responsiveness to methacholine. Independently of the other factors assessed, infection with A. lumbricoides was associated with increased risk of asthma (p < 0.001), an increased number of skin tests positive to aeroallergens (p < 0.001), and an increased dose-response slope to methacholine (p = 0.003). The association of sensitization to common aeroallergens with increased asthma risk was enhanced in those children infected with Ascaris, and such infection was associated with an increased risk of asthma independent of sensitization to aeroallergens in this selected population. These data suggest a complex relationship between ascariasis and susceptibility to childhood asthma among predisposed children that may involve an interaction with the immune response to inhaled aeroallergens.
Adolescent↗
Maternal cigarette smoking, metabolic gene polymorphism, and infant birth weight.
CONTEXT: Little is known about genetic susceptibility to cigarette smoke in relation to adverse pregnancy outcomes. OBJECTIVE: To investigate whether the association between maternal cigarette smoking and infant birth weight differs by polymorphisms of 2 maternal metabolic genes: CYP1A1 and GSTT1. DESIGN, SETTING, AND PARTICIPANTS: Case-control study conducted in 1998-2000 among 741 mothers (174 ever smokers and 567 never smokers) who delivered singleton live births at Boston Medical Center. A total of 207 cases were preterm or low-birth-weight infants and 534 were non-low-birth-weight, full-term infants (control). MAIN OUTCOME MEASURE: Birth weight, gestation, fetal growth by smoking status and CYP1A1 MspI (AA vs Aa and aa, where Aa and aa were combined because of small numbers of aa and similar results), and GSTT1 (present vs absent) genotypes. RESULTS: Without consideration of genotype, continuous maternal smoking during pregnancy was associated with a mean reduction of 377 g (SE, 89 g) in birth weight (odds ratio [OR], 2.1; 95% confidence interval [CI], 1.2-3.7). When CYP1A1 genotype was considered, the estimated reduction in birth weight was 252 g (SE, 111 g) for the AA genotype group (n = 75; OR, 1.3; 95% CI, 0.6-2.6), but was 520 g (SE, 124 g) for the Aa/aa genotype group (n = 43 for Aa, n = 6 for aa; OR, 3.2; 95% CI, 1.6-6.4). When GSTT1 genotype was considered, the estimated reduction in birth weight was 285 g (SE, 99 g) (OR, 1.7; 95% CI, 0.9-3.2) and 642 g (SE, 154 g) (OR, 3.5; 95% CI, 1.5-8.3) for the present and absent genotype groups, respectively. When both CYP1A1 and GSTT1 genotypes were considered, the greatest reduction in birth weight was found among smoking mothers with the CYP1A1 Aa/aa and GSTT1 absent genotypes (-1285 g; SE, 234 g; P<.001). Among never smokers, genotype did not independently confer an adverse effect. A similar pattern emerged in analyses stratified by maternal ethnicity and in analyses for gestation. CONCLUSIONS: In our study, maternal CYP1A1 and GSTT1 genotypes modified the association between maternal cigarette smoking and infant birth weight, suggesting an interaction between metabolic genes and cigarette smoking.
Adult↗
Comparison of self-assessment of solvent exposure with measurement and professional assessment for female petrochemical workers in China.
OBJECTIVE: The primary objective of this paper is to examine the validity of self-assessment of solvent exposure by comparing it with professional assessment and actual measurements. METHODS: Self-assessment of exposures to benzene, toluene, styrene, and xylene was obtained from 132 female workers. The exposures were also estimated by an occupational hygienist and by actual measurement. Self-assessment, professional assessment, and measurement were then compared with each other. RESULTS: Fair to good agreement was found between self-assessment, professional assessment, and measurement for benzene, styrene, and xylene. The agreement between self-assessment and measurement was poor for toluene, whereas the agreement between self-assessment and professional assessment was good. The latter was caused by a biased professional assessment. CONCLUSIONS: Workers' self-assessment and professional assessment provided useful information for benzene, styrene, and xylene exposure, but not for toluene exposure. False agreement can be obtained when professional assessment was used as reference in validity study.
Adult↗
Preconception folate and vitamin B(6) status and clinical spontaneous abortion in Chinese women.
OBJECTIVE: To assess the association between preconception homocysteine and B vitamin status and risk of clinical spontaneous abortion in women from Anqing, China. METHODS: All women were aged 21-34 years, had never smoked, and were primigravid. Patients (n = 49) were women with a clinically recognized pregnancy who experienced a fetal death before 100 days' gestation. Controls (n = 409) were women who maintained a pregnancy that ended in a live birth. Homocysteine, folate, and vitamins B(6) and B(12) concentrations were measured in plasma obtained before conception. RESULTS: Mean vitamin B(6) concentration was lower in patients than in controls (34.0 versus 37.9 nmol/L, P =.04). In addition, the risk of spontaneous abortion tended to increase with decreasing plasma vitamin B(6) and folate concentration (P for trend =.06 and.07, respectively), although the significance of these trends was further reduced in logistic models that included age, body mass index, and both vitamins. The risk of spontaneous abortion was four-fold higher among women with suboptimal plasma concentrations of both folate and vitamin B(6) (folate less than or equal to 8.4 nmol/L and vitamin B(6) less than or equal to 49 nmol/L) than in those with higher plasma concentrations of both vitamins (odds ratio 4.1, 95% confidence interval 1.2, 14.4). Homocysteine and vitamin B(12) status were not associated with spontaneous abortion risk. CONCLUSION: Suboptimal preconception folate and vitamin B(6) status, especially when they occur together, may increase the risk of clinical spontaneous abortion. Additional prospective studies are needed to confirm these findings and to determine whether antenatal B vitamin supplementation reduces spontaneous abortion risk.
Abortion, Spontaneous↗
Preconception homocysteine and B vitamin status and birth outcomes in Chinese women.
BACKGROUND: The associations between homocysteine, B vitamin status, and pregnancy outcomes have not been examined prospectively. OBJECTIVE: We assessed the associations of preconception homocysteine and B vitamin status with preterm birth and birth of low-birth-weight (LBW) and small-for-gestational-age (SGA) infants in Chinese women. DESIGN: This was a case-control study of women aged 21-34 y. Preterm cases (n = 29) delivered living infants at <37 wk gestation; term controls (n = 405) delivered infants at > or =37 wk. LBW cases (n = 33) had infants weighing <2500 g; normal-birth-weight controls (n = 390) had infants weighing > or =2500 g. SGA cases (n = 65) had infants below the 10th percentile of weight-for-gestational-age; appropriate-for-gestational-age controls (n = 358) had infants above this cutoff. Nonfasting plasma concentrations of homocysteine, folate, and vitamins B-6 and B-12 were measured before conception. RESULTS: Elevated homocysteine (> or =12.4 micro mol/L) was associated with a nearly 4-fold higher risk of preterm birth (OR: 3.6; 95% CI: 1.3, 10.0; P < 0.05). The risk of preterm birth was 60% lower among women with vitamin B-12 > or =258 pmol/L than among vitamin B-12-deficient women (OR: 0.4; 95% CI: 0.2, 0.9; P < 0.05) and was 50% lower among women with vitamin B-6 > or =30 nmol/L than among vitamin B-6-deficient women (OR: 0.5; 95% CI: 0.2, 1.2; NS). Folate status was not associated with preterm birth, and homocysteine and B vitamin status were not associated with LBW or SGA status. CONCLUSIONS: Elevated homocysteine and suboptimal vitamin B-12 and B-6 status may increase the risk of preterm birth. These results need to be confirmed in larger prospective studies.
Adult↗
Does standing at work during pregnancy result in reduced infant birth weight?
The purpose of this study was to investigate the association between infant birth weight and standing at work during pregnancy. A total of 1222 pregnant women employed in a large petrochemical corporation in Beijing, China, were enrolled in the study, after receiving permission from the government to have a child. The subjects were followed up from that time through their entire pregnancy, for a total of up to 12 months. All subjects delivered at the company staff hospital between 1996 and 1998. Various work-related physical activities during pregnancy were assessed using a structured questionnaire, and generalized additive models (GAMs) were performed to examine their association with birth weight. Of the assessed activities, only standing was significantly associated with birth weight. After adjusting for potential confounders, maternal standing hours per day at work was found to be significantly associated with reduced birth weight (-17.7 g, P = 0.03).
Adult↗
Angiotensin converting enzyme gene insertion/deletion polymorphism and cardiovascular disease: therapeutic implications.
Cardiovascular disease is the major cause of morbidity and mortality in Westernised societies. It is well known that the aetiology of this devastating disorder involves both genetic and environmental factors. Sequence variants of the components of the renin-angiotensin-aldosterone system and the kallikrein-kinin system are suggested to have significant influences on cardiovascular homeostasis. Both gene targeting and transgenic studies in mice have clearly suggested a critical role of the angiotensin converting enzyme (ACE) gene in blood pressure regulation. Furthermore, an up-regulation of myocardial ACE gene expression has been observed in patients with heart failure. Thus, the ACE gene has been recognised as a top candidate gene for cardiovascular research. Over the past decade, the insertion/deletion (I/D) polymorphism of a 287-bp Alu element in intron 16 of the ACE gene has attracted significant attention and has been extensively investigated in a spectrum of cardiovascular phenotypes, because of its correlation with serum ACE activity. A large majority of previous studies have shown a positive association between the DD genotype and an increased risk of myocardial infarction, but results in hypertension, left ventricular hypertrophy, cardiomyopathy and restenosis after percutaneous transluminal coronary angioplasty remain quite controversial. Since ACE inhibitors are widely used in hypertension and congestive heart failure, we also review the literature on the relationship of ACE I/D polymorphism with ACE inhibitor response. It appears that this polymorphism has some moderate impact on the cardiovascular response to ACE inhibitors but there is no consensus as to which allele confers a more pronounced effect. In addition, previous data are suggestive of an association between the ACE I allele and a greater risk of increased occurrence of ACE inhibitor-induced cough, but such a relationship needs further confirmation. Overall, since ACE I/D is only an intronic marker, the true locus that controls the ACE enzyme activity remains to be identified, and could be located within either the ACE gene or another nearby gene such as the human growth hormone gene. We note that since associations tend to vary across different gender or ethnic groups, or across different socio-ecological settings, consideration of potential gene-gene and gene-environment interactions should be made. Furthermore, the dissection of the genetic underpinning of cardiovascular disease needs delineation of all molecular variants of the key physiological pathways that influence cardiovascular function.
Angiotensin-Converting Enzyme Inhibitors↗
Insertion/deletion polymorphism of the ACE gene is associated with type 2 diabetes.
In an attempt to examine the role of an ACE gene insertion/deletion (I/D) polymorphism in type 2 diabetes, we conducted a case-control association study among 132 couple-pairs from northern China. The genotype frequencies for II, ID, and DD were 39.8, 39.8, and 20.3%, respectively, in the case group and 44.8, 44.8, and 10.4% in the control group. The DD frequency was significantly higher in the case group than in the control group (chi(2)(1) = 4.77, P = 0.03), suggesting that the DD genotype is associated with an increased susceptibility to type 2 diabetes in our study population.
Adult↗
[Association between alpha-1-antichymotrypsin gene polymorphism and cerebral hemorrhage].
OBJECTIVE: To explore the association between alpha-1-antichymotrypsin (ACT) gene A/T polymorphism and cerebral hemorrhage among Chinese people. METHODS: The DNA of peripheral leucocytes was extracted from 220 patients with cerebral hemorrhage and 276 controls. PCR- RELP was used to determine the ACT gene polymorphism. Multiple Logistic regression was performed to explore the risk factors for cerebral hemorrhage. RESULTS: After adjusting age, gender, alcohol drinking, smoking, education,history of diabetes mellitus and primary hypertension, the analysis showed: (1) the ACT AT and TT genotypes increased the risk of cerebral hemorrhage (OR = 2.33 and 2.17 respectively, P < 0.05), but were not associated with primary hypertension. Such association was more prevalent in hypertensive cerebral hemorrhage. (2) Primary hypertension significantly increased the risk of cerebral hemorrhage (OR = 8.17 P = 0.000). (3) A significant gene environment interaction, super multiplicative type 4 interaction, was shown between both ACT AT and TT genotypes and primary hypertension with an interaction index (r) value of 2.84 and an OR value of 15.92. A significant additive type 3 gene-environment interaction was shown between both ACT AT and TT genotypes and diabetes mellitus with an OR value of 2.89. CONCLUSION: ACT gene polymorphism and primary hypertension are both independent risk factors of cerebral hemorrhage. The ACT AT and TT genotypes show a significant gene-environment interaction, however, of different types, with both primary hypertension and diabetes mellitus in the occurrence of cerebral hemorrhage.
Adult↗
[The distributive features of three kinds of metabolic genes polymorphisms in population of Han nationality in south area of China].
OBJECTIVE: To find out the distributive features of some metabolic genes polymorphisms in Han population of south area of China. METHODS: Study population was obtained from the controls of a community based case-control study, which included 290 blood relatives (inner control) and 404 non-blood relatives (outer control). RESULTS: Frequencies of CYP1A1, GSTM1 and GSTT1 polymorphisms had no significant difference among confounding factors, such as sex, living areas, stomach cancer family history and history of tobacco smoking etc. Some controls showed significant difference in age group and alcohol drinking which would be adjusted in analysis of the relationship between polymorphisms and cancers. CYP1A1 Ile/Val and Val/Val genotypes were 33.43% and 5.62% respectively, which were similar to other results from Chinese and Japanese, but higher than those from Caucasians in American, Europe and African-Americans. GSTM1 null allele frequency was 53.48% in our population, which showed difference even among Chinese in different areas. GSTT1 null allele frequency was 45.78%, which was significantly higher than that in Caucasians and African-American. CONCLUSION: The frequencies of CYP1A1 Ile/Val, Val/Val and GSTT1 null in Han population in south area of China are significantly higher than those in other races, while the ethnic difference of frequency of GSTM1 null is less.
China↗
Association of GYS1 and beta(3)-AR gene with postprandial hyperglycemia and serum uric acid in type 2 diabetes mellitus.
OBJECTIVE: To determine the relationships of Met416Val and XbaI polymorphism of muscle glycogen synthase (GYS1) gene and Trg64Arg variant of the beta(3)-adrenergic-receptor (beta(3)-AR) gene with type 2 diabetes mellitus (DM) and its intermediate phenotypes in the Chinese population. METHODS: Polymerase chain reaction-oligonucleotide ligation assay and restriction fragment length polymorphism assay were used to evaluate the GYS1 and beta(3)-AR gene polymorphisms in 102 pairs of case-control Chinese spouses. RESULTS: Subjects with Met416Val variant had a significantly higher 2-hour post-glucose level than subjects without this variant had in diabetic group (P = 0.032). The Met416Val polymorphism of GYS1 gene was not significantly associated with the risk of type 2 DM (adjusted OR = 1.67; 95% CI: 0.73 - 3.81, P = 0.223). Subjects with Trp64Arg variant had a significantly higher serum uric acid level than subjects without this variant had in diabetic group (P = 0.034). The combination of BMI and Arg64 allele carrier of the beta(3)-AR gene increased the diabetic risk over four-fold (adjusted OR = 4.00; 95% CI: 1.53 - 10.45, P = 0.005). CONCLUSIONS: In the Chinese population, Met416Val polymorphism is identified in a subgroup of diabetic subjects with high 2-hour post-glucose. It will explain why some diabetic patients appear to be genetically predisposed to developing high postpradial glucose level. The presence of the Arg64 allele in the beta(3)-AR gene may predispose patients to higher serum uric acid level.
Adult↗
[Study on the Relationship between susceptibility of stomach neoplasm cancer and polymorphism of inducible nitric oxide synthase gene].
OBJECTIVE: To study the relationship between polymorphism of inducible Nitric Oxide Synthase (iNOS) gene and the susceptibility of intestinal type stomach cancer and stomach cardia cancer in Chinese people. METHODS: A community-based case-control study was designed. Ninety-three intestinal type of stomach cancer and 50 stomach cardia cancer patients with endoscopy and pathology diagnosis were identified as cases. Two hundred and forty-six controls served as controls. RESULTS: C-->T polymorphism was found in exon 16 of iNOS gene, which changed the coding amino acid from serine to leucine, and formed a recognition site identified by Tsp 509 I restriction enzyme (we called it C-->T polymorphism). The T allele gene frequency in the control group was 13.21%. No statistically significant difference was found between C-->T polymorphism alone and the increased susceptibility to intestinal stomach cancer or stomach cardia cancer. A significant type 2 multiplicative interaction was found in increasing both the risk of intestinal stomach cancer and stomach cardia cancer when both C-->T polymorphism and tobacco smoking exposure existed. An additive interaction model, which showed statistically significant difference, was found to increase only the risk of stomach cardia cancer when CagA antibody shared negative but C-->T polymorphism occurred. CONCLUSION: C-->T polymorphism of iNOS gene was considered as one of the possible susceptible genes, which specifically increased the risk of tobacco-related but CagA negative types of intestinal stomach cancer and stomach cardia cancer.
Antibodies, Bacterial↗
[The impact of night work near the day of ovulation on outcome of pregnancy].
OBJECTIVE: To investigate the effect of night work near the day of ovulation on outcome of pregnancy. METHODS: Daily early morning urine samples were collected from eligible shift women workers, and human chorionic gonadotropin(hCG), follicle-stimulating hormone(FSH), the urinary steroid metabolites of estrogen and progesterone(PDG, E1C) were measured to confirm the day of ovulation and early fetal loss(EFL). Questionnaires were used to know workshift, other occupation exposures, and related information. RESULTS: 12 clinical spontaneous abortion(SAB), 18(EFL) and 44 clinical living birth were analyzed in relation to SAB, EFL and night shift near the day of ovulation by using single factor and multi-factor logistic regression. The result showed that night shift on the day of ovulation and the day before or after ovulation was related with SAB both in single- and muti-factorial analysis(single factor: OR = 2.48, 95% CI 1.10-5.60; multi-factor; OR = 3.90, 95% CI 1.28-11.90). CONCLUSION: Night shift near the day of ovulation may be related to SAB.
Abortion, Spontaneous↗
Bayesian haplotype inference for multiple linked single-nucleotide polymorphisms.
Haplotypes have gained increasing attention in the mapping of complex-disease genes, because of the abundance of single-nucleotide polymorphisms (SNPs) and the limited power of conventional single-locus analyses. It has been shown that haplotype-inference methods such as Clark's algorithm, the expectation-maximization algorithm, and a coalescence-based iterative-sampling algorithm are fairly effective and economical alternatives to molecular-haplotyping methods. To contend with some weaknesses of the existing algorithms, we propose a new Monte Carlo approach. In particular, we first partition the whole haplotype into smaller segments. Then, we use the Gibbs sampler both to construct the partial haplotypes of each segment and to assemble all the segments together. Our algorithm can accurately and rapidly infer haplotypes for a large number of linked SNPs. By using a wide variety of real and simulated data sets, we demonstrate the advantages of our Bayesian algorithm, and we show that it is robust to the violation of Hardy-Weinberg equilibrium, to the presence of missing data, and to occurrences of recombination hotspots.
Algorithms↗
Parental exposure to organic solvents and reduced birth weight.
The authors investigated the association of birth weight with maternal and paternal exposure to organic solvents in 1,222 couples employed in a large petrochemical corporation in Beijing, China, during the period between 1994 and 1998. A trained interviewer assessed parental exposures to organic solvents. The authors used generalized additive models to examine the association between birth weight and parental exposure to organic solvents. After the authors adjusted for potential confounders, maternal exposure to solvents was significantly associated with reduced birth weight (-81.7 gm, 95% confidence interval = -106.3, -3.1), and reduced birth weights of female babies and of younger mothers' babies were statistically significant. Maternal exposure to organic solvents was associated with reduced birth weight in this population, but paternal exposure to organic solvents was not similarly associated.
Adult↗