Peter Bundred

Prevalence of overweight and obese children between 1989 and 1998: population based series of cross sectional studies

Abstract Objective: To determine trends in weight, height, and body mass index in children between 1989 and 1998. Design: Retrospective series of cross sectional studies of routinely collected data. Setting: Primary care in the Wirral Health Authority. Participants: 35 662 infants aged 1-3 months (representing 88% of live births) and 28 768 children aged 2.9-4.0 years. 21 582 infants and children (25.1%) were excluded because of missing or inaccurate data. Main outcome measures: Weight, height, sex, and age routinely recorded by health visitors. Height, weight, and body mass index standardised for age and sex. SD score >1.04 for body mass index (>85th centile) was defined as overweight and >1.64 (>95th centile) as obese. Body mass index was not calculated in infants as it is difficult to interpret. Results: From 1989 to 1998 there was a highly significant increasing trend in the proportion of overweight children (14.7% to 23.6%; P<0.001) and obese children (5.4% to 9.2%; P<0.001). There was also a highly significant increasing trend in the mean SD score for weight (0.05 to 0.29; P<0.001) and body mass index (−0.15 to 0.31; P<0.001) but not height. Infants showed a small but significantly increasing trend in mean SD score for weight (−0.17 to −0.05; P=0.005). Conclusions: From 1989 to 1998 there was a highly significant increase in weight and body mass index in children under 4 years of age. Routinely collected data are valuable in identifying anthropometric trends in populations.

The second to fourth digit ratio and variation in the androgen receptor gene

Abstract The second to fourth digit ratio (2D:4D) is sexually dimorphic, with lower mean values in males compared to females. It has been suggested that the sex difference in 2D:4D is determined prenatally, 2D:4D is negatively related to prenatal testosterone and positively to prenatal oestrogen, and that 2D:4D is a marker for levels of sex steroids during brain organisation. There is growing evidence that many sex-dependent behaviours are correlated with 2D:4D. However, there is no direct evidence for an effect of prenatal sex steroids on the digit ratio. The response to prenatal testosterone is dependent on the amount produced and the foetal sensitivity to the hormone. Variation in the X-linked androgen receptor gene (AR) determines sensitivity to testosterone. Alleles of AR with low numbers of CAG triplets respond to testosterone with high transactivational activity, while high numbers of CAGs are associated with increased insensitivity to testosterone. We show in a sample of 50 men (49 Caucasian subjects, 1 Caucasian/Chinese subject) that 2D:4D is a phenotypic correlate of AR structure. Right-hand 2D:4D was positively correlated with CAG number and individuals with low 2D:4D in their right hand compared to left hand had AR alleles with low CAG numbers. We discuss the implications of our findings for our understanding of the aetiology of 2D:4D, its relationships with sex-dependent behaviours, and the evolutionary implications of variation in 2D:4D and AR.

Finger and toe ratios in humans and mice: implications for the aetiology of diseases influenced by HOX genes

The differentiation of gonads, fingers, and toes is influenced by HOXA and HOXD genes. Therefore variation in the development of the gonads, and their fetal products such as testosterone, may be reflected in the morphology of the fingers and toes. One trait, the relative length of the second and fourth digits (2D:4D), shows sex differences (lower values in males) which are determined early, and 2D:4D has been found to correlate with fetal growth, sperm counts, family size, autism, myocardial infarction, and breast cancer. HOX genes are highly conserved in mammals and they influence the differentiation of all the fingers and toes. We suggest that (a) 2D:4D and other ratios of finger and toe length show sex differences throughout the mammals including humans and mice, (b) finger and toe ratios correlate with sex determination, the fetal production of sex steroids, and fetal programming of disease, and (c) HOX gene influences on sex determination, the morphogenesis of the urinogenital system, fertility, haematopoiesis, and breast cancer suggests that finger and toe ratios in humans and mice may correlate with many sex dependent diseases.

The ratio of 2nd to 4th digit length: a proxy for transactivation activity of the androgen receptor gene?

The androgen receptor gene (AR) contains a domain which includes a variable number of CAG sequences and alleles with low numbers of CAG repeats show high transactivation activity when complexed with testosterone. The ratio of 2nd and 4th digit length (2D:4D) is negatively correlated with phenotypic effects of testosterone. Low numbers of CAG repeats and low 2D:4D are both associated with high sperm numbers and protection against breast cancer. This suggests that CAG number and 2D:4D are correlated i.e. low CAG number and low 2D:4D indicate high activation of androgen-responsive genes. Findings from AR studies predict that low 2D:4D will be associated with prostate and hepatocellular cancer, urolithiasis, ADHD, ankylosing spondylitis, spontaneous abortion, and polycystic ovaries, while high 2D:4D will be associated with motor neuron diseases and endometrial cancer. Findings from 2D:4D studies predict that short CAG length will be common in autism and Aspergers syndrome, while high numbers of CAG repeats will be found in men who are prone to early myocardial infarction.

Family Pet Ownership during Childhood: Findings from a UK Birth Cohort and Implications for Public Health Research

In developed nations, approximately half of household environments contain pets. Studies of Human-Animal Interaction (HAI) have proposed that there are health benefits and risks associated with pet ownership. However, accurately demonstrating and understanding these relationships first requires a better knowledge of factors associated with ownership of different pet types. A UK birth cohort, the Avon Longitudinal Study of Parents and Children (ALSPAC), were used to collect pet ownership data from the mothers, from gestation to child age 10 years old. 14,663 children were included in the study, of which mothers of 13,557 reported pet information at gestation, and 7,800 by age 10. Pet types recorded include cat, dog, rabbit, rodent, bird, fish and tortoise/turtle. The dataset also contains a number of demographic, socioeconomic and behavioural variables relevant to human health behaviour. Logistic regression was used to build multivariable models for ownership of each pet type at age 7 years. Family pet ownership increased during childhood, in particular rabbits, rodents and fish. A number of socioeconomic and demographic factors were associated with ownership of different pet types and the effects differed depending on the pet type studied. Variables which require consideration by researchers include gender, presence of older siblings, ethnicity, maternal and paternal education, maternal and paternal social class, maternal age, number of people in the household, house type, and concurrent ownership of other pets. Whether the mother had pets during her childhood was a strong predictor of pet ownership in all models. In HAI studies, care should be taken to control for confounding factors, and to treat each pet type individually. ALSPAC and other similar birth cohorts can be considered a potential resource for research into the effects of pet ownership during childhood.

Body mass index has risen more steeply in tall than in short 3-year olds: serial cross-sectional surveys 1988–2003

Objective:To monitor the changing relationship between body mass index (BMI) and height in young children.Design:Annual cross-sectional surveys using health-visitor-collected routine data 1988–2003.Setting:Wirral, England.Participants:Fifty thousand four hundred and fifty-five children (49% female) each measured once at the age of 3 years.Main outcome measures:Weight, height and derived BMI (weight/height2) adjusted for age and sex (British 1990 revised reference) using standard deviation scores.Results:From 1988 to 2003, mean BMI increased by 0.7 kg/m2, whereas mean height fell by 0.5 cm. Over the same period, the weight–height correlation rose from 0.59 to 0.71 (P<0.0001) owing to BMI increasing faster in the taller than the shorter children. Among the shortest 10% of children, mean BMI rose by 0.12 (95% confidence interval: −0.05–0.28) kg/m2 as against 1.38 (1.19–1.56) kg/m2 among the tallest 10%, a 12-fold difference. Adjustment for age, sex, seasonality, birth-weight and deprivation did not alter the findings.Conclusions:Among 3-year-old children in Wirral, where BMI has been rising for 16 years, the largest increase in BMI has occurred in the tallest children, whereas in the shortest BMI has hardly changed. Tall stature has, therefore, become important for child obesity. It suggests a drive to increasing adiposity in young children that involves both growth and appetite, with fast growing and hungrier children now more exposed to the ‘obesogenic’ environment.

Training, job demands and mental health of pre-registration house officers

This study aims to explore pre‐registration house officer (PRHO) perceptions of work role, job requirements and mental health, in order to enhance work role preparation by means of identifying potential areas for curriculum development.

Pet ownership, dog types and attachment to pets in 9--10 year old children in Liverpool, UK

BackgroundLittle is known about ethnic, cultural and socioeconomic differences in childhood ownership and attitudes to pets. The objective of this study was to describe the factors associated with living with different pet types, as well as factors that may influence the intensity of relationship or ‘attachment’ that children have to their pet. Data were collected using a survey of 1021 9–10 year old primary school children in a deprived area of the city of Liverpool, UK.ResultsDogs were the most common pet owned, most common ‘favourite’ pet, and species most attached to. Twenty-seven percent of dog-owning children (10% of all children surveyed) reported living with a ‘Bull Breed’ dog (which includes Pit Bulls and Staffordshire Bull Terriers), and the most popular dog breed owned was the Staffordshire Bull Terrier. Multivariable regression modelling identified a number of variables associated with ownership of different pets and the strength of attachment to the child’s favourite pet. Girls were more likely to own most pet types, but were no more or less attached to their favourite pet than boys. Children of white ethnicity were more likely to own dogs, rodents and ‘other’ pets but were no more or less attached to their pets than children of non-white ethnicity. Single and youngest children were no more or less likely to own pets than those with younger brothers and sisters, but they showed greater attachment to their pets. Children that owned dogs lived in more deprived areas than those without dogs, and deprivation increased with number of dogs owned. ‘Pit Bull or cross’ and ‘Bull Breed’ dogs were more likely to be found in more deprived areas than other dog types. Non-whites were also more likely to report owning a ‘Pit Bull or cross’ than Whites.ConclusionsGender, ethnicity and socioeconomic status were associated with pet ownership, and sibling status with level of attachment to the pet. These are important to consider when conducting research into the health benefits and risks of the common childhood phenomenon of growing up with pets.

Dog Ownership during Pregnancy, Maternal Activity, and Obesity: A Cross-Sectional Study

The Avon Longitudinal Study of Parents and Children (ALSPAC) is an observational study of 14273 UK pregnant singleton mothers in 1990/1991. We examined outcomes of self report of strenuous activity (hours per week) at 18 and 32 weeks of gestation, hours spent in leisure-time physical activities and types, and pre-pregnancy body mass index (BMI); overweight status was defined as pre-pregnancy BMI≥25 and obesity BMI≥30. Pet ownership and activity data were reported for 11,466 mothers. Twenty-five percent of mothers owned at least one dog. There was a positive relationship between participation in activity at least once a week and dog ownership (at 18 weeks, Odds ratio 1.27, 95% confidence interval 1.11–1.44, P<0.001). Dog owners were 50% more likely to achieve the recommended 3 hours activity per week, equivalent to 30 minutes per day, most days of the week (1.53, 1.35–1.72, P<0.001). Dog owners were also more likely to participate in brisk walking activity than those who did not have a dog (compared to no brisk walking 2–6 hrs per week 1.43, 1.23 to 1.67, P<0.001; 7+ hrs per week 1.80, 1.43 to 2.27, P<0.001). However, no association was found with any other types of activities and there was no association between dog ownership and weight status. During the time period studied, pregnant women who had dogs were more active, through walking, than those who did not own dogs. As walking is a low-risk exercise, participation of pregnant women in dog walking activities may be a useful context to investigate as part of a broader strategy to improve activity levels in pregnant women.

Melanin and HIV in sub-Saharan Africa.

HIV is common in sub-Saharan Africa. Sexually transmitted bacterial and fungal infections increase the chance of HIV infection. Melanin can prevent the penetration of skin and mucus membranes by microorganisms, and soluble melanin can inhibit HIV replication. We suggest that melanin may reduce the incidence of HIV infection through venereally acquired skin lesions, thus reducing the risk of sero-conversion and slow the progress to AIDS. Indigenous sub-Saharan peoples are highly melanized, but there is pigment variation between populations. We show that skin reflectance, a negative correlate of melanin, is positively associated with adult rate of HIV in sub-Saharan countries. There is no such relationship in populations outside sub-Saharan Africa. We suggest that melanin concentration in black people may correlate with resistance to HIV infection.