Leone Craig

Childhood Socioeconomic Position and Objectively Measured Physical Capability Levels in Adulthood: A Systematic Review and Meta-Analysis

Background Grip strength, walking speed, chair rising and standing balance time are objective measures of physical capability that characterise current health and predict survival in older populations. Socioeconomic position (SEP) in childhood may influence the peak level of physical capability achieved in early adulthood, thereby affecting levels in later adulthood. We have undertaken a systematic review with meta-analyses to test the hypothesis that adverse childhood SEP is associated with lower levels of objectively measured physical capability in adulthood. Methods and Findings Relevant studies published by May 2010 were identified through literature searches using EMBASE and MEDLINE. Unpublished results were obtained from study investigators. Results were provided by all study investigators in a standard format and pooled using random-effects meta-analyses. 19 studies were included in the review. Total sample sizes in meta-analyses ranged from N = 17,215 for chair rise time to N = 1,061,855 for grip strength. Although heterogeneity was detected, there was consistent evidence in age adjusted models that lower childhood SEP was associated with modest reductions in physical capability levels in adulthood: comparing the lowest with the highest childhood SEP there was a reduction in grip strength of 0.13 standard deviations (95% CI: 0.06, 0.21), a reduction in mean walking speed of 0.07 m/s (0.05, 0.10), an increase in mean chair rise time of 6% (4%, 8%) and an odds ratio of an inability to balance for 5s of 1.26 (1.02, 1.55). Adjustment for the potential mediating factors, adult SEP and body size attenuated associations greatly. However, despite this attenuation, for walking speed and chair rise time, there was still evidence of moderate associations. Conclusions Policies targeting socioeconomic inequalities in childhood may have additional benefits in promoting the maintenance of independence in later life.

The Prevalence of Metabolic Syndrome in Children: A Systematic Review of the Literature

BACKGROUND Metabolic syndrome has been identified as a condition of childhood relatively recently. The aim in this study was to describe the prevalence of metabolic syndrome in children allowing for differences in metabolic syndrome definitions. METHODS This was a systematic review of the OVID, EMBASE, and CINAHL databases, capturing details of overall prevalence and prevalence within groups categorized by obesity, gender, age, and ethnicity. RESULTS In all, 378 studies published since 2003 were identified, and of these 85 papers were included in the present review. When all studies were considered, the median prevalence of metabolic syndrome in whole populations was 3.3% (range 0%-19.2%), in overweight children was 11.9% (range 2.8%-29.3%), and in obese populations was 29.2% (range 10%-66%). Within-study analyses confirmed higher prevalence for obese compared to overweight (P=0.012) and obese compared to nonobese, nonoverweight children (P<0.001). Within-study analyses also revealed higher median metabolic syndrome prevalence for boys compared to girls (5.1% versus 3.0%, P<0.001) and also in older compared with younger children (5.6% versus 2.9%, P=0.001). Limited evidence was found to suggest differences between ethnic groups, and there were insufficient studies to determine whether metabolic syndrome prevalence was increasing over time. CONCLUSIONS This is the first systematic review of all of the relevant literature. It describes the magnitude of associations between metabolic syndrome and obesity, age, and gender. We find evidence that ethnicity and geography may be important to metabolic syndrome prevalence in children and these associations require further study.

A serial qualitative interview study of infant feeding experiences: idealism meets realism

Objective To investigate the infant feeding experiences of women and their significant others from pregnancy until 6 months after birth to establish what would make a difference. Design Qualitative serial interview study. Setting Two health boards in Scotland. Participants 72 of 541 invited pregnant women volunteered. 220 interviews approximately every 4 weeks with 36 women, 26 partners, eight maternal mothers, one sister and two health professionals took place. Results The overarching theme was a clash between overt or covert infant feeding idealism and the reality experienced. This is manifest as pivotal points where families perceive that the only solution that will restore family well-being is to stop breast feeding or introduce solids. Immediate family well-being is the overriding goal rather than theoretical longer term health benefits. Feeding education is perceived as unrealistic, overly technical and rules based which can undermine womens confidence. Unanimously families would prefer the balance to shift away from antenatal theory towards more help immediately after birth and at 3–4 months when solids are being considered. Family-orientated interactive discussions are valued above breastfeeding-centred checklist style encounters. Conclusions Adopting idealistic global policy goals like exclusive breast feeding until 6 months as individual goals for women is unhelpful. More achievable incremental goals are recommended. Using a proactive family-centred narrative approach to feeding care might enable pivotal points to be anticipated and resolved. More attention to the diverse values, meanings and emotions around infant feeding within families could help to reconcile health ideals with reality.

Age and gender differences in physical capability levels from mid-life onwards: the harmonisation and meta-analysis of data from eight UK cohort studies.

Using data from eight UK cohorts participating in the Healthy Ageing across the Life Course (HALCyon) research programme, with ages at physical capability assessment ranging from 50 to 90+ years, we harmonised data on objective measures of physical capability (i.e. grip strength, chair rising ability, walking speed, timed get up and go, and standing balance performance) and investigated the cross-sectional age and gender differences in these measures. Levels of physical capability were generally lower in study participants of older ages, and men performed better than women (for example, results from meta-analyses (N = 14,213 (5 studies)), found that men had 12.62 kg (11.34, 13.90) higher grip strength than women after adjustment for age and body size), although for walking speed, this gender difference was attenuated after adjustment for body size. There was also evidence that the gender difference in grip strength diminished with increasing age,whereas the gender difference in walking speed widened (p<0.01 for interactions between age and gender in both cases). This study highlights not only the presence of age and gender differences in objective measures of physical capability but provides a demonstration that harmonisation of data from several large cohort studies is possible. These harmonised data are now being used within HALCyon to understand the lifetime social and biological determinants of physical capability and its changes with age.

First trimester maternal tobacco smoking habits and fetal growth

Rationale Maternal smoking in pregnancy is associated with reduced birth weight and childhood lung function. This study determined when maternal smoking first influences fetal growth and how this relates to childhood respiratory outcomes. Methods A longitudinal cohort of 1924 pregnant women was recruited. Fetal ultrasound measurements at 11 weeks (crown–rump length, CRL) and at 20 weeks gestation (femur length, FL, and biparietal diameter, BPD) and birth measurements were recorded. Childhood respiratory symptoms and spirometry were ascertained. Results Of the 1924 original study participants, fetal size was determined in 903 in the first trimester, 1544 in the second trimester and at term in 1737 infants. Maternal smoking when first pregnant was reported in 593 (31%) and was not associated with reduced CRL. There was an inverse exposure-response relationship between cigarette consumption and FL (mean reduction in lowest compared with highest tertile 0.91 cm, p=0.033). Birth weight and length of those born to mothers who did (n=331) and did not (n=56) reduce cigarette consumption were similar and reduced compared with 186 infants whose mothers quit during the first trimester (p≤0.020). Children of mothers who continued smoking had increased wheeze at age 2 years (OR 1.58, p=0.017) and GP visits with wheeze at age 5 years (OR 2.18, p=0.030) and mean reduction in forced expiratory volume in 1 s of 62 ml (p=0.014) compared with controls. Conclusions Maternal smoking is associated with reduced fetal measurements in the second and third trimesters but not in the first trimester. Mothers who do not quit smoking during the first trimester deliver smaller infants who go on to have adverse respiratory outcomes in childhood.

Meal and snacking patterns of school-aged children in Scotland

Background:Current lifestyles and the choice and availability of foods may influence the eating patterns of children. The aim of this study was to investigate the meal and snacking patterns of school-aged children in Scotland.Methods:A sub-sample of 156 children (5–17 years) from the national Survey of Sugar Intake among Children in Scotland completed a 4-day non-weighed diet diary. Meals and snacks were defined using a food-based classification system based on ‘core’ and ‘non-core’ foods. The first eating event containing a solid food item up to and including 0900 hours (1100 hours on weekend days) was defined as breakfast. Frequency of meal and snack consumption was compared between age, sex, body mass index (BMI) and socio-economic sub-groups, between term-time and school holidays and between weekdays and weekend days. Intakes of total fat, saturated fatty acids (SFA) and non-milk extrinsic sugars (NMES) on these days were also compared.Results:Children ate a median of 3.3 meals plus 2.0 snacks per day, which did not vary between age and BMI groups. In all, 83% of children ate breakfast on all 4 days. Boys ate more meals than girls but the number of snacks was similar. Children from lower socio-economic groups tended to eat more meals and fewer snacks. Snacks accounted for 21% of the total daily energy intake, 22% of total fat, 24% of SFA and 39% of NMES intake. Daily intake of energy, total fat, SFA and NMES did not differ between term-time and holidays or weekdays and weekend days.Conclusions:Children tended to follow a traditional pattern of three meals a day, which was consistent between age and BMI subgroups and between school term-time and holidays.

Early childhood wheezing symptoms in relation to plasma selenium in pregnant mothers and neonates.

Objective Reduced dietary selenium intake has been linked to the development of asthma. We have investigated whether childhood wheezing symptoms, and asthma up to the age of 5 years are associated with plasma selenium and erythrocyte glutathione peroxidase (GPx) concentrations in pregnant mothers and neonates.

Associations between fetal size, maternal α-tocopherol and childhood asthma

Background The origins of respiratory disease might be traced back to exposures during fetal life. The aim of the present study was to explore whether there was a relationship between fetal size and respiratory outcomes at 5 years of age in the context of fetal exposure to vitamin E. Methods A longitudinal birth cohort study was recruited (n=1924). Antenatal ultrasound scan results were identified and the following recorded: crown–rump length (CRL) in the first trimester; femur length (FL) and biparietal diameter (BPD) in the second trimester. Maternal plasma α-tocopherol (vitamin E) was measured at the time of the first trimester scan. At 5 years, wheeze and asthma symptoms were reported by questionnaire, and spirometry was measured. Results CRL, spirometry and questionnaire data at 5 years were available for 835, 579 and 1145 individuals, respectively. There were positive associations between CRL and forced expiratory volume in 1 s (FEV1; 5 ml increase in FEV1 per mm CRL, p=0.001, n=283), forced vital capacity (FVC; 6 ml increase in FVC per mm CRL, p=0.001) and forced expiratory flow between 25% and 75% of FVC (FEF25–75; 0.008 ml/s increase in FEF25–75 per mm CRL, p=0.023), and inverse relationships with CRL and current wheeze (OR 0.59 per CRL quartile, p=0.026, n=547) and asthma (OR 0.55 per CRL quartile p=0.011). CRL was positively associated with maternal plasma α-tocopherol (p=0.002). Conclusions These findings support the concept of very early fetal programming of respiratory disease. Maternal vitamin E status may be one determinant for growth of the fetus and fetal lungs during early pregnancy.

First- and second-trimester fetal size and asthma outcomes at age 10 years.

RATIONALE Greater early fetal size is associated with reduced asthma risk and improved lung function in early childhood. OBJECTIVES To test the hypothesis that associations between early fetal size, asthma symptoms, and lung function persist into later childhood. METHODS In a longitudinal study, first- and second-trimester fetal measurements were recorded. At 10 years of age a respiratory questionnaire was completed. Spirometry, bronchial challenge, and skin-prick testing were undertaken in a subset. MEASUREMENTS AND MAIN RESULTS Fetal measurements were available in the first trimester for 853 individuals and the second trimester for 1,453. Questionnaires were returned for 927 children and 449 underwent detailed phenotyping. For each millimeter increase in first trimester size, asthma risk reduced by 6% (95% confidence interval[CI], 1–11) and FEV1 was higher by an average of 6 ml (95% CI, 1–11).First-trimester size was reduced in those with asthma at both 5 and 10 years compared with early or late onset wheeze (P , 0.02). Compared with persistent high growth in first and second trimesters,persistent low growth was associated with increased asthma risk(odds ratio, 2.8; 95% CI, 1.2–6.9) and a mean reduction in FEV1 of 103 ml (95% CI, 13–194), whereas increasing fetal size was associated with increased eczema risk (odds ratio, 2.5; 95% CI, 1.2–5.3). CONCLUSIONS Reduced fetal size from the first trimester is associated with increased risk for asthma and obstructed lung function in childhood. Relative change in size after the first trimester is associated with eczema.

Human cognitive ability is influenced by genetic variation in components of postsynaptic signalling complexes assembled by NMDA receptors and MAGUK proteins

Differences in general cognitive ability (intelligence) account for approximately half of the variation in any large battery of cognitive tests and are predictive of important life events including health. Genome-wide analyses of common single-nucleotide polymorphisms indicate that they jointly tag between a quarter and a half of the variance in intelligence. However, no single polymorphism has been reliably associated with variation in intelligence. It remains possible that these many small effects might be aggregated in networks of functionally linked genes. Here, we tested a network of 1461 genes in the postsynaptic density and associated complexes for an enriched association with intelligence. These were ascertained in 3511 individuals (the Cognitive Ageing Genetics in England and Scotland (CAGES) consortium) phenotyped for general cognitive ability, fluid cognitive ability, crystallised cognitive ability, memory and speed of processing. By analysing the results of a genome wide association study (GWAS) using Gene Set Enrichment Analysis, a significant enrichment was found for fluid cognitive ability for the proteins found in the complexes of N-methyl-D-aspartate receptor complex; P=0.002. Replication was sought in two additional cohorts (N=670 and 2062). A meta-analytic P-value of 0.003 was found when these were combined with the CAGES consortium. The results suggest that genetic variation in the macromolecular machines formed by membrane-associated guanylate kinase (MAGUK) scaffold proteins and their interaction partners contributes to variation in intelligence.