Biomedical subjects

Alspac Study Team

Publications and source records attributed to Alspac Study Team.

7 recordsLinked to original sources

PubMed2006

Socio-demographic characteristics of UK families using pesticides and weed-killers.

Pesticides are widely used in the home and garden to kill insects, weeds and other unwanted pests. There is mounting evidence that this usage may also have health consequences particularly on children. Using the ALSPAC cohort of 13,391 families with self-reported usage data up to age 4 years of the study child, the main users of pesticides appeared to be older, Caucasian, better educated, have higher incomes and more likely to own their home or to belong to non-manual social classes compared to less frequent users. There was some suggestion that different factors may affect weed-killer compared to other pesticide use. In particular, income appeared unrelated to other pesticide use. This may reflect different attitudes to indoor compared to garden applications. Alternatively, it may reflect whether the main user was the mother or the partner. Some authorities are currently encouraging domestic users to consider other non-chemical means of pest control before using pesticides. These results may help in targeting particular groups if further reductions in pesticide usage are desired. They have also helped in identifying the important confounders for adjusting future analyses on the potential health consequences of pesticides and weed-killers.

Demography↗

PubMed2006

Exploring the differences between mono- and polysymptomatic nocturnal enuresis.

OBJECTIVE: Recently the heterogeneity of nocturnal enuresis has been manifest in the distinction between mono- and polysymptomatic forms, based on the absence or presence of bladder overactivity, respectively. Although this classification has important clinical implications, there is a lack of empirical work relating to associated symptom expression and psychological functioning. The aim of this study was to identify variables associated with the two forms of nocturnal enuresis by means of a large population survey. MATERIAL AND METHODS: From a cohort of 11,021 parents surveyed as part of the Avon Longitudinal Study of Parents and Children when their children were aged 7(1/2) years, 8242 questionnaires were returned, with 7935 children meeting the inclusion criteria. Parents were invited to complete a questionnaire containing items relating to bedwetting, toileting behaviour, day-time wetting, bowel functioning and psychological variables. RESULTS: A total of 194 children met the Diagnostic and Statistical Manual of Mental Disorders-IV definition of nocturnal enuresis, of whom 133 (68.5%) were classified as monosymptomatic and 61 (31.5%) as polysymptomatic. Those with the polysymptomatic form were significantly more likely to have multiple episodes of bedwetting, to show signs (such as fidgeting) of needing to urinate during the day, to need a reminder to toilet during the day and to have day-time wetting and soiling. CONCLUSIONS: The proportion of mono- to polysymptomatic nocturnal enuresis was 2:1. Children with the polysymptomatic form had a number of associated bladder and bowel problems. Clinically it is important to distinguish between the two types of nocturnal enuresis in order to identify the most appropriate treatment intervention.

Child↗

PubMed2005

Genetic variation in the type 2 insulin-like growth factor receptor gene and disparity in childhood height.

OBJECTIVE: The type 2 insulin-like growth factor receptor (IGF2R) is thought to regulate insulin-like growth factor-II (IGF-II) bioavailability by degrading it in the lysosomes after uptake. We hypothesised that polymorphisms in the IGF2R gene could alter size at birth and childhood growth. DESIGN AND METHODS: The hypothesis was tested in a normal birth cohort (Avon Longitudinal Study of Parents and Children) by genotyping the IGF2R gene gly1619arg polymorphism, which causes a non-conservative amino acid change in the IGF-II binding region, using PCR and restriction fragment length polymorphism analysis. RESULTS: The IGF2R gly1619arg genotype was not associated with any measure of size at birth, but A/A homozygotes grew more slowly, as determined by their change in height standard deviation scores (SDS) over the first three years (-0.70 (0.72); n = 12), than G/G homozygotes (0.00 (1.09); n = 561) (p = 0.03). They remained shorter during childhood and by the age of 7 years respective height SDS were: 0.73 (1.02) (n = 12) and 0.01 (0.99) (n = 634) (p = 0.01). These height differences persisted after adjusting for parental heights and gender. There were no detectable differences in weights at 7 years. CONCLUSION: Allelic variation in the gly1619arg SNP of the IGF2R gene is associated with disparity in childhood stature which could reflect altered binding of IGF-II to its receptor.

Alleles↗

PubMed2002

Male employment in some printing trades is associated with prolonged time to conception.

We investigated whether male employment in defined occupational groups was associated with decreased fecundity as revealed by prolonged time to conception. The analysis was carried out on data from questionnaires completed over a period of 21 months by 4808 couples with a planned pregnancy and collected as part of the Avon Longitudinal Study of Pregnancy and Childhood. Previously logistic regression had identified nine non-occupational factors associated with taking >6 or >12 months to conceive and this model was used to analyse the association of the fathers ever having worked in defined occupational groups with delayed conception. If the man had worked in 'Printing and related trades' (OPCS code 56), couples had a statistically significantly increased odds ratio (OR) of taking >6 [1.86 (1.21, 2.94)] or >12 months [1.96 (1.13, 3.39)] to conceive [OR (95% confidence intervals)] after adjustment for non-occupational factors. The association with time to conception was stronger in the subgroup 'Other printing related trades' (OPCS code 569) but no statistically significant associations after adjustment for other factors were found for other printing jobs.

Animals↗

PubMed2002

Antenatal anxiety predicts child behavioral/emotional problems independently of postnatal depression.

OBJECTIVE: To examine the hypothesis that the effects of postnatal depression on children's behavioral/emotional problems are explained by antenatal maternal mood. METHOD: The current study investigated this hypothesis in the Avon Longitudinal Study of Parents and Children, a prospective, community-based study that has followed a cohort of women since pregnancy (n = 7,144) who delivered their baby between April 1, 1991, and December 31, 1992. Self-report measures of maternal anxiety and depression were assessed at repeated intervals in pregnancy and the postnatal period. Children's behavioral/emotional problems were assessed by parent report at age 4 years. RESULTS: After controlling for smoking, alcohol use, birth weight for gestational age, maternal age, child sex, and socioeconomic status, postnatal depression at 8 weeks (OR = 2.27 [1.55-3.31]) and 8 months (OR = 1.68 [1.12-2.54]) was associated with children's behavioral/emotional problems. Subsequent analyses that included antenatal maternal mood indicated that antenatal anxiety in late pregnancy and not antenatal depression was also independently associated with behavioral/emotional problems at age 4 (OR = 1.72 [1.14-2.59]); 8 week postnatal depression remained a significant predictor after antenatal maternal mood was statistically controlled for (OR = 1.56 [1.04-2.32]). CONCLUSIONS: Antenatal anxiety and postnatal depression represent separate risks for behavioral/emotional problems in children and act in an additive manner.

Affective Symptoms↗

PubMed2002

Hygiene levels in a contemporary population cohort are associated with wheezing and atopic eczema in preschool infants.

BACKGROUND: The hygiene hypothesis states that insufficient exposure to certain infectious agents during childhood increases the risk of developing asthma and atopic diseases. Improvements in hygiene levels may be partly responsible for this decline in exposure. AIMS: To assess whether hygiene levels in infancy are associated with wheeze and/or atopic eczema, independent of a number of possible confounding factors. METHODS: Data were gathered from the Avon Longitudinal Study of Parents and Children (ALSPAC). Parental self completion questionnaires provided symptom data on infant wheeze and atopic eczema at 0-6 months and 30-42 months, respectively. A simple hygiene score was derived using questionnaire responses at 15 months, which ranged from least hygienic to most hygienic. Multivariable logistic regression models analysed the effect of hygiene scores on health outcomes, while adjusting for a number of important confounding variables. RESULTS: Increasing hygiene scores were independently associated with wheezing (OR = 1.04; 95% CI: 1.00 to 1.08) and atopic eczema (OR = 1.04; 95% CI: 1.01 to 1.07) between 30 and 42 months, but not in the first six months. The odds ratio was higher for atopic eczema if the rash was reported to have become sore and oozy (OR = 1.09; 95% CI: 1.02 to 1.16). CONCLUSIONS: High levels of hygiene at 15 months of age were independently associated with wheeze and atopic eczema reported between 30 and 42 months, and there was an increased risk for children with more severe eczema during this period. The importance of hygiene in public health should not be dismissed; however, the creation of a sterile environment through excessive cleanliness may potentially be harmful to the immune system.

Child, Preschool↗

PubMed2002

Factors associated with different hygiene practices in the homes of 15 month old infants.

BACKGROUND: Improved hygiene in Westernised regions of the world may be partly responsible for the increased prevalence of diseases of the immune system, such as asthma and atopy. There is a paucity of data on cleanliness norms in young children in the UK and there has been no attempt to identify factors that influence the adoption of particular hygiene practices in the home. AIMS: To examine levels of hygiene in a contemporary cohort of children and identify social and lifestyle factors influencing hygiene practices in the home. METHODS: The sample under study are participants in the Avon Longitudinal Study of Parents and Children (ALSPAC). Parental self completion questionnaires provided data on hygiene levels in children at 15 months of age, and a hygiene score was derived from these responses. Multivariable logistic regression models investigated associations between high hygiene scores (top quintile) and a number of perinatal, maternal, social, and environmental factors. RESULTS: Maternal smoking during pregnancy, low maternal educational achievement, and living in local authority housing were factors independently associated with high hygiene scores, as was increased use of chemical household products. High hygiene scores were inversely related to living in damp housing and attendance at day care. There were no gender or ethnic differences in hygiene score. CONCLUSION: Important data on cleanliness norms for infants have been presented. The adoption of hygiene practices is influenced to some degree by social, lifestyle, and environmental factors-with higher hygiene scores occurring in more socially disadvantaged groups. Increased use of chemical household products in the more socially disadvantaged groups within ALSPAC has emerged as an important confounder in any study of hygiene and ill health.

Animals↗