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Biomedical subjects

Tim J Cole

Publications and source records attributed to Tim J Cole.

At least 19 recordsLinked to original sources
PubMed2007

Infant nutrition and stereoacuity at age 4-6 y.

BACKGROUND: Breastfeeding has been reported to benefit visual development in children. A higher concentration of docosahexaneoic acid (DHA) in breast milk than in formula has been proposed as one explanation for this association and as a rationale for adding DHA to infant formula, but few long-term data support this possibility. OBJECTIVE: The objectives of the study were, first, to test the hypothesis that breastfeeding benefits stereoscopic visual maturation and, second, if that benefit is shown, to ascertain whether it is mediated by the dietary intake of DHA. DESIGN: Stereoacuity was measured by using the random dot E test (primary outcome), and visual acuity was measured by using the Sonksen-Silver acuity system (secondary outcome) in previously breastfed (n = 78) or formula-fed (n = 184) children aged 4-6 y who had been followed prospectively from birth. In the formula-fed group, children were randomly assigned to receive formula with either DHA or arachidonic acid (n = 94) or a control formula (n = 90) for the first 6 mo. RESULTS: Breastfed children had a significantly (P = 0.001) greater likelihood of foveal stereoacuity (high-grade or < 100 s/arc) than did formula-fed children (odds ratio: 2.5; 95% CI: 1.4, 4.5) independent of potential confounding (P = 0.005). Stereoacuity did not differ significantly between children randomly assigned to DHA-supplemented or control formula. None of the groups differed in Sonksen-Silver visual acuity. CONCLUSIONS: These findings support the hypothesis that breastfeeding benefits long-term stereoscopic development. An effect of DHA cannot be excluded, but the lack of difference in stereoacuity between infants randomly assigned to DHA-containing and those assigned to control formula raises the hypothesis that factors in breast milk other than DHA account for the observed benefits.

Breast Feeding↗
PubMed2006

Promotion of faster weight gain in infants born small for gestational age: is there an adverse effect on later blood pressure?

BACKGROUND: Being born small for gestational age is associated with later risk factors for cardiovascular disease, such as high blood pressure. Promotion of postnatal growth has been proposed to ameliorate these effects. There is evidence in animals and infants born prematurely, however, that promotion of growth by increased postnatal nutrition increases rather than decreases later cardiovascular risk. We report the long-term impact of growth promotion in term infants born small for gestational age (birth weight <10th percentile). METHODS AND RESULTS: Blood pressure was measured at 6 to 8 years in 153 of 299 (51%) of a cohort of children born small for gestational age and randomly assigned at birth to receive either a standard or a nutrient-enriched formula. The enriched formula contained 28% more protein than standard formula and promoted weight gain. Diastolic and mean (but not systolic) blood pressure was significantly lower in children assigned to standard compared with nutrient-enriched formula (unadjusted mean difference for diastolic blood pressure, -3.2 mm Hg; 95% CI, -5.8 to -0.5; P=0.02) independent of potential confounding factors (adjusted difference, -3.5 mm Hg; P=0.01). In observational analyses, faster weight gain in infancy was associated with higher later blood pressure. CONCLUSIONS: In the present randomized study targeted to investigate the effect of early nutrition on long-term cardiovascular health, we found that a nutrient-enriched diet increased later blood pressure. These findings support an adverse effect of relative "overnutrition" in infancy on long-term cardiovascular disease risk, have implications for the early origins of cardiovascular disease hypothesis, and do not support the promotion of faster weight gain in infants born small for gestational age.

Adult↗
PubMed2006

Non-invasive assessment of endothelial function: which technique?

OBJECTIVES: The purpose of this study was to compare 3 non-invasive techniques for assessment of endothelial function in adults and children and evaluate their utility in acute inflammation. BACKGROUND: Endothelial dysfunction is a key early event in pre-clinical atherosclerosis. Flow-mediated dilation (FMD), although the established technique, is expensive and technically demanding. Measurements of vascular responses to inhaled salbutamol by pulse wave analysis (PWA) or pulse contour analysis (PCA) are potential alternatives. METHODS: Sixteen adults (mean age 28 years, range 18 to 39) and 16 children (mean age 13 years, range 7 to 17) underwent concurrent vascular function testing on 2 occasions with ultrasound, PWA, and PCA. Eighteen men were also studied before and after typhoid vaccination. RESULTS: Reproducibility of FMD was high in adults and children (coefficient of variation [CV] = 7.1 and 6.3, respectively). Salbutamol responses were more variable with PWA (adults CV = 11.5, children CV = 17.1) and PCA particularly in children (adults CV = 18.2, children CV = 36.3). Flow-mediated dilation (p < 0.001) and PWA with salbutamol (p = 0.03) responses fell after typhoid vaccination, and PCA (p = 0.7) was unchanged. CONCLUSIONS: Vascular dysfunction during acute inflammation can be measured by FMD and by PWA with salbutamol. Flow-mediated dilation is less variable than PWA. Variability of PCA makes this technique currently unsuited to serial measures of endothelial function in children. Flow-mediated dilation remains the most reproducible method.

Adolescent↗
PubMed2006

Differential parental weight and height contributions to offspring birthweight and weight gain in infancy.

BACKGROUND: Parental weight and height correlate with offspring birthweight and weight gain, suggesting genetic and environmental influences on fetal growth. The differential contributions of the mother's and father's height and weight to birthweight, or weight gain in infancy, remain unclear and were examined using data from the UK Millennium Cohort Study. METHODS: We calculated z-scores for birthweight and conditional weight gain to age 9 months (weight gain adjusted for birthweight) for 6811 term white singleton infants living with natural parents, using the British 1990 growth reference. We also calculated parental height and weight z-scores. The effects of parental size on birthweight and weight gain were analysed using multivariable regression, with a novel reparameterization to test for differences in effect size between mother and father. RESULTS: Maternal weight had a far greater influence than paternal weight on birthweight [coefficient for the difference between parents (95% CI): 0.15 (0.100.20)], while parental height contributions were similar [0.03 (-0.02 to 0.07)]. Weights and heights of mothers and fathers contributed equally to infant weight gain [difference coefficients -0.03 (-0.09 to 0.02) and 0.02 (-0.03 to 0.07), respectively]. CONCLUSIONS: The influences of parental height and weight on birthweight and infant weight gain are similar for the two parents, with the exception of the influence of weight on birthweight where the mother is much more influential than the father. Parental size associations with infant growth result from a complex combination of genetic and environmental influences. This novel reparameterization of parental anthropometry is applicable to other studies examining parental influences on offspring size and growth across the life course.

Birth Weight↗
PubMed2006

Blood pressure centiles for Great Britain.

OBJECTIVE: To produce representative cross-sectional blood pressure reference centiles for children and young people living in Great Britain. DESIGN: Analysis of blood pressure data from seven nationally representative surveys: Health Surveys for England 1995-8, Scottish Health Surveys 1995 and 1998, and National Diet & Nutrition Survey 1997. METHODS: Blood pressure was measured using the Dinamap 8100 with the same protocol throughout. Weight and height were also measured. Data for 11 364 males and 11,537 females aged 4-23 years were included in the analysis, after excluding 0.3% missing or outlying data. Centiles were derived for systolic, diastolic, mean arterial and pulse pressure using the lambda-mu-sigma [corrected] (LMS) equations method. RESULTS: Blood pressure in the two sexes was similar in childhood, rising progressively with age and more rapidly during puberty. Systolic pressure rose faster and was appreciably higher in adult men than in adult women. After adjustment for age, blood pressure was related more to weight than height, the effect being stronger for systolic blood pressure. Pulse pressure peaked at 18 years in males and 16 years in females. CONCLUSIONS: These centiles increase our knowledge of blood pressure norms in contemporary British children and young people. High blood pressure for age should be defined as blood pressure above the 98th centile, and high-normal blood pressure for age as blood pressure between the 91st and 98th centiles. The centiles identify children and young people with increased blood pressure, and will be of benefit to both clinical practice and research.

Adolescent↗
PubMed2006

Timing of puberty determines serum insulin-like growth factor-I in late adulthood.

CONTEXT: IGFs may play an important role in disease etiology, especially cancer. Changes in diet can alter acute levels, but little is known about life course influences on IGF levels. OBJECTIVE: The objective of the study was to examine the association between timing of puberty and adulthood serum IGFs (IGF-I and IGF binding protein-3). DESIGN: This was a retrospective cohort study. SETTING: Male pupils who attended a single school in Southern England were part of the study. PARTICIPANTS: Participants in the study were a cohort of 1028 men born between 1927 and 1956 with anthropometric measures between 9 and 18 yr and adulthood serum IGF levels. MAIN OUTCOME MEASURE: The study measured serum IGF-I and IGF binding protein-3 at mean age 63 yr. RESULTS: Age at peak height velocity (APHV) was inversely associated with adult IGF-I levels. IGF-I decreased by 3.7 ng/ml (95% confidence interval 1.0-6.4, P = 0.007) for each sd increase in APHV. Prepubertal childhood height and body mass index were both inversely associated with APHV (P trend < 0.001). APHV was positively associated with adult height and inversely associated with adult body mass index. Adjustment for childhood, adult anthropometry, and other lifestyle factors did not substantially alter the association between APHV and adult IGF-I. CONCLUSIONS: This is the first study to document an association between timing of puberty and adult IGF-I levels. A better understanding of life course determinants of the IGF system may provide new insights into disease etiology and primary prevention.

Age Factors↗
PubMed2006

Development of adiposity in adolescence: five year longitudinal study of an ethnically and socioeconomically diverse sample of young people in Britain.

OBJECTIVE: To examine the developmental trajectory of obesity in adolescence in relation to sex, ethnicity, and socioeconomic status. DESIGN: Five year longitudinal cohort study of a socioeconomically and ethnically diverse sample of school students aged 11-12 years at baseline. SETTING: 36 London schools recruited to the study in 1999 by a stratified random sampling procedure. PARTICIPANTS: 5863 students participated in one or more years. MAIN OUTCOME MEASURES: Weight, height, and waist circumference measured annually by trained researchers; overweight and obesity defined according to International Obesity Task Force criteria; adiposity and central adiposity indexed by body mass index (BMI) and waist standard deviation scores relative to 1990 British reference values. RESULTS: In school year 7 (age 11-12), the prevalence of overweight and obesity combined was almost 25%, with higher rates in girls (29%) and students from lower socioeconomic backgrounds (31%) and the highest rates in black girls (38%). Prevalence of obesity increased over the five years of the study at the expense of overweight, but no reduction occurred in the proportion of students with BMIs in the healthy range. Waist circumferences were high compared with 1990 norms at age 11 (by 0.79 SD in boys and by 1.15 SD in girls) and increased further over time. Both BMI and waist circumference tracked strongly over the five years. CONCLUSIONS: Prevalence of overweight and obesity was high in London school students, with significant socioeconomic and ethnic inequalities. Little evidence was found of new cases of overweight or obesity emerging over adolescence, but few obese or overweight adolescents reduced to a healthy weight. The results indicate that persistent obesity is established before age 11 and highlight the need to target efforts to prevent obesity in the early years.

Adipose Tissue↗
PubMed2006

Randomized, placebo-controlled, calcium supplementation study in pregnant Gambian women: effects on breast-milk calcium concentrations and infant birth weight, growth, and bone mineral accretion in the first year of life.

BACKGROUND: Growth and bone mineral accretion in Gambian infants are poorer than those in Western populations. The calcium intake of Gambian women is low, typically 300-400 mg Ca/d, and they have low breast-milk calcium concentrations, which result in low calcium intakes for their breastfed infants. A low maternal calcium supply in pregnancy may limit fetal mineral accretion and breast-milk calcium concentrations and thereby affect infant growth and bone mineral accretion. OBJECTIVE: We investigated the effects of calcium supplementation in Gambian women during pregnancy on breast-milk calcium concentrations and infant birth weight, growth, and bone mineral accretion. DESIGN: A randomized, double-blind, placebo-controlled supplementation study was conducted in 125 Gambian women who received 1500 mg Ca/d (as calcium carbonate) or placebo from 20 wk of gestation until delivery. Infant birth weight and gestational age were recorded. Breast milk was collected, and infant anthropometric and bone measurements were performed at 2, 13, and 52 wk after delivery. Infant bone mineral status was assessed by using single-photon absorptiometry of the radius and whole-body dual-energy X-ray absorptiometry. RESULTS: Compliance with the supplement was high. No significant differences were detected between the groups in breast-milk calcium concentration, infant birth weight, or growth or bone mineral status during the first year of life. A slower rate of increase in infant whole-body bone mineral content and bone area was found in the supplement group than in the placebo group (group x time interaction: P = 0.03 and 0.02, respectively). CONCLUSION: Calcium supplementation of pregnant Gambian women had no significant benefit for breast-milk calcium concentrations or infant birth weight, growth, or bone mineral status in the first year of life.

Absorptiometry, Photon↗
PubMed2006

Monitoring infant weight gain: advice for practitioners.

It is current practice in the UK to include growth reference charts in the Personal Child Health Records. This has the potential to lead to frequent measurement of weight. While this can reassure parents and professionals alike, it can also lead to stress and anxiety if the child is not perceived to be gaining weight. 'Health for all Children' states that the 'interpretation of growth measurements requires skill and judgement, and is easier when several measurements are taken over a period of time'. This article aims to give healthcare professionals the information to be able to do this. It outlines best practice for weight monitoring of babies in the first year of life, according to current evidence, and offers a flowchart detailing the points to consider when assessing infant weight gain.

Child Development↗
PubMed2005

Statistical issues in life course epidemiology.

There is growing recognition that the risk of many diseases in later life, such as type 2 diabetes or breast cancer, is affected by adult as well as early-life variables, including those operating prior to conception and during the prenatal period. Most of these risk factors are correlated because of common biologic and/or social pathways, while some are intrinsically ordered over time. The study of how they jointly influence later ("distal") disease outcomes is referred to as life course epidemiology. This area of research raises several issues relevant to the current debate on causal inference in epidemiology. The authors give a brief overview of the main analytical and practical problems and consider a range of modeling approaches, their differences determined by the degree with which associations present (or presumed) among the correlated explanatory variables are explicitly acknowledged. Standard multiple regression (i.e., conditional) models are compared with joint models where more than one outcome is specified. Issues arising from measurement error and missing data are addressed. Examples from two cohorts in the United Kingdom are used to illustrate alternative modeling strategies. The authors conclude that more than one analytical approach should be adopted to gain more insight into the underlying mechanisms.

Causality↗
PubMed2005

Adult socioeconomic, educational, social, and psychological outcomes of childhood obesity: a national birth cohort study.

OBJECTIVES: To assess adult socioeconomic, educational, social, and psychological outcomes of childhood obesity by using nationally representative data. DESIGN: 1970 British birth cohort. PARTICIPANTS: 16,567 babies born in Great Britain 5-11 April 1970 and followed up at 5, 10, and 29-30 years. MAIN OUTCOME MEASURES: Obesity at age 10 and 30 years. Self reported socioeconomic, educational, psychological, and social outcomes at 30 years. Odds ratios were calculated for the risk of each adult outcome associated with obesity in childhood only, obesity in adulthood only, and persistent child and adult obesity, compared with those obese at neither period. RESULTS: Of the 8490 participants with data on body mass index at 10 and 30 years, 4.3% were obese at 10 years and 16.3% at 30 years. Obesity in childhood only was not associated with adult social class, income, years of schooling, educational attainment, relationships, or psychological morbidity in either sex after adjustment for confounding factors. Persistent obesity was not associated with any adverse adult outcomes in men, though it was associated among women with a higher risk of never having been gainfully employed (odds ratio 1.9, 95% confidence interval 1.1 to 3.3) and not having a current partner (2.0, 1.3 to 3.3). CONCLUSIONS: Obesity limited to childhood has little impact on adult outcomes. Persistent obesity in women is associated with poorer employment and relationship outcomes. Efforts to reduce the socioeconomic and psychosocial burden of obesity in adult life should focus on prevention of the persistence of obesity from childhood into adulthood.

Adult↗
PubMed2005

Calcium supplementation increases stature and bone mineral mass of 16- to 18-year-old boys.

The effect of calcium carbonate supplementation on bone growth and mineral accretion was studied in 143 boys aged 16-18 yr, randomized to 1000 mg Ca/d or a matching placebo for 13 months. Anthropometry and dual-energy x-ray absorptiometry of the whole body, lumbar spine, hip, and forearm were performed before, during, and after the intervention. The intervention resulted in greater bone mineral content (BMC) of the whole body (+1.3%, P = 0.02), lumbar spine (+2.5%, P = 0.004), and hip (total +2.3%, P = 0.01; neck +2.4%, P = 0.02; intertrochanter +2.7%, P = 0.01). This was associated with greater height (+0.4%, P = 0.0004, equivalent to 7 mm), lean mass (+1.3%, P = 0.02), and lumbar spine bone area (+1.5%, P = 0.003). The increases in BMC diminished after size adjustment, suggesting that the intervention effect was mediated through an effect on growth. The BMC response at the intertrochanter was greater in subjects with high physical activity (+4.4%, P = 0.05). There were no other significant interactions with physical activity, plasma testosterone, calcium intake, or tablet compliance. We conclude that calcium carbonate supplementation of adolescent boys increased skeletal growth, resulting in greater stature and bone mineral acquisition. Follow-up studies will determine whether this reflects a change in the tempo of growth or an effect on skeletal size that persists into adulthood.

Absorptiometry, Photon↗
PubMed2005

Factors affecting a mother's recall of her baby's birth weight.

BACKGROUND: The Millennium Cohort Study of UK babies born this century obtained maternal report of birth weight and data on the family's characteristics, including parental ethnicity, education, and social circumstances. Parental permission to link babies to their birth registration data provided the opportunity to investigate factors affecting accuracy of maternal recall of birth weight and to determine possible causes of error. METHODS: Logistic regression was used to investigate the relationship between maternal factors and recall of birth weight. Numerical and graphical methods were used to identify potential causes for birth weight discrepancies. RESULTS: Data were obtained from the birth registry and Millennium Cohort Study for 11 890 of the 14 294 cohort children born in England and Wales. Weight was reported in imperial units by 84% of mothers and this was more common in younger mothers. Accuracy within 100 g was 92% overall, varying from 94% among British/Irish white mothers to 69-89% for other ethnic groups and was lower among the long-term unemployed and those living in disadvantaged or ethnic wards. Explanations (mostly rounding and transcription errors) were identified for 27% of the discrepancies of 100 g or more. Conclusion Mothers' reports of their infants' birth weight showed high level of agreement with registration data, the mean discrepancy being consistently close to zero. However, the variance of the discrepancy differed according to ethnic group, ward type, and socioeconomic status. These sources of differential variability should be taken into account in analyses using birth weight, and possibly other reported data, from socially mixed populations.

Adult↗
PubMed2005

Television viewing in early childhood predicts adult body mass index.

OBJECTIVES: To examine the effects of duration, timing and type of television (TV) viewing at age 5 years on body mass index (BMI) in adult life. STUDY DESIGN AND METHODS: 1970 British Birth Cohort, followed up at 5 (N=13,135), 10 (N=14,875), and 30 years (N=11,261). OUTCOME MEASURES: Weekday and weekend TV viewing at 5 years, type of programs, and maternal attitudes toward TV at age 5 years. BMI z-score at 10 and 30 years. RESULTS: Mean daily hours of TV viewed at weekends predicted higher BMI z-score at 30 years (coefficient=0.03, 95% CI: 0.01, 0.05, P=.01) when adjusted for TV viewing and activity level at 10 years, sex, socioeconomic status, parental BMIs, and birth weight. Each additional hour of TV watched on weekends at 5 years increased risk of adult obesity (BMI > or =30 kg/m2) by 7% (OR=1.07, 95% CI 1.01, 1.13, P=.02). Weekday viewing, type of program and maternal attitudes to TV at 5 years were not independently associated with adult BMI z-score. CONCLUSIONS: Weekend TV viewing in early childhood continues to influence BMI in adulthood. Interventions to influence obesity by reducing sedentary behaviors must begin in early childhood. Interventions focusing on weekend TV viewing may be particularly effective.

Adult↗
PubMed2005

Zinc supplementation and psychosocial stimulation: effects on the development of undernourished Jamaican children.

BACKGROUND: Undernourished children have poor levels of development that benefit from stimulation. Zinc deficiency is prevalent in undernourished children and may contribute to their poor development. OBJECTIVE: We assessed the effects of zinc supplementation and psychosocial stimulation given together or separately on the psychomotor development of undernourished children. DESIGN: This was a randomized controlled trial with 4 groups: stimulation alone, zinc supplementation alone, both interventions, and control (routine care only). Subjects were 114 children aged 9-30 mo and below -1.5 z scores of the National Center for Health Statistics weight-for-age references who were recruited from 18 health clinics. Clinics were randomly assigned to receive stimulation or not; individual children were randomly assigned to receive zinc or placebo. The stimulation program comprised weekly home visits during which play was demonstrated and maternal-child interactions were encouraged. The supplementation was 10 mg Zn as sulfate daily or placebo. Development (assessed by use of the Griffiths Mental Development Scales), length, and weight were measured at baseline and 6 mo later. Weekly morbidity histories were taken. RESULTS: Significant interactions were found between zinc supplementation and stimulation. Zinc benefited the developmental quotient only in children who received stimulation, and benefits from zinc to hand and eye coordination were greater in stimulated children. Zinc supplementation alone improved hand and eye coordination, and stimulation alone benefited the developmental quotient, hearing and speech, and performance. Zinc supplementation also reduced diarrheal morbidity but did not significantly improve growth. CONCLUSION: Zinc supplementation benefits development in undernourished children, and the benefits are enhanced if stimulation is also provided.

Child Development↗