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1.  Longitudinal changes in lean mass predict pQCT measures of tibial geometry and mineralisation at 6-7 years 
Bone  2015;75:105-110.
Background
Studies in childhood suggest that both body composition and early postnatal growth are associated with bone mineral density (BMD). However, little is known of the relationships between longitudinal changes in fat (FM) and lean mass (LM), and bone development in pre-pubertal children. We therefore investigated these associations in a population-based mother-offspring cohort, the Southampton Women’s Survey.
Methods
Total FM and LM were assessed at birth and 6-7 years of age by Dual-Energy X-ray Absorptiometry (DXA). At 6-7y, total cross-sectional area (CSA) and trabecular volumetric BMD (vBMD) at the 4% site (metaphysis) of the tibia was assessed using peripheral quantitative computed tomography [pQCT (Stratec XCT-2000)]. Total CSA, cortical CSA, cortical vBMD and strength-strain index (SSI) were measured at the 38% site (diaphysis). FM, LM and bone parameters were adjusted for age and sex and standardised to create within-cohort z-scores. Change in LM (ΔLM) or FM (ΔFM) was represented by change in z-score from birth to 7y and conditioned on the birth measurement. Linear regression was used to explore the associations between ΔLM or ΔFM and standardised pQCT outcomes, before and after mutual adjustment and for linear growth. The β-coefficient represents SD change in outcome per unit SD change in predictor.
Results
DXA at birth, in addition to both DXA and pQCT scans at 6-7y, were available for 200 children (48.5% male). ΔLM adjusted for ΔFM was positively associated with tibial total CSA at both the 4% (β=0.57SD/SD, p<0.001) and 38% sites (β=0.53SD/SD, p<0.001), cortical CSA (β=0.48SD/SD, p<0.001) and trabecular vBMD (β=0.30SD/SD, p<0.001), but not with cortical vBMD. These relationships persisted after adjustment for linear growth. In contrast, ΔFM adjusted for ΔLM was only associated with 38% total and cortical CSA, which became non-significant after adjustment for linear growth.
Conclusion
In this study, gain in childhood LM was positively associated with bone size and trabecular vBMD at 6-7 years of age. In contrast, no relationships between change in FM and bone were observed, suggesting that muscle growth, rather than accrual of fat mass, may be a more important determinant of childhood bone development.
doi:10.1016/j.bone.2015.02.015
PMCID: PMC4556067  PMID: 25703480
Osteoporosis; epidemiology; body composition; pQCT; growth; childhood
2.  Diet quality across early childhood and adiposity at 6 years: the Southampton Women’s Survey 
BACKGROUND
Poor diet quality in early childhood is inconsistently linked to obesity risk. Understanding may be limited by use of cross-sectional data, and use of body mass index (BMI) to define adiposity in childhood.
OBJECTIVE
To examine the effects of continued exposure to diets of varying quality across early childhood in relation to adiposity at 6 years.
METHODS
1018 children from a prospective UK birth cohort were studied. Diet was assessed using food frequency questionnaires when the children were aged 6 and 12 months, 3 and 6 years; diet quality was determined according to scores for a principal component analysis-defined dietary pattern at each age (characterized by frequent consumption of fruit, vegetables and fish). At each age children were allocated a value of 0/1/2 according to third of the distribution (bottom/middle/top) their diet quality score was in; values were summed to calculate an overall diet quality index (DQI) for early childhood (range 0–8). Obesity outcomes considered at 6 years were dual-energy X-ray absorptiometry-assessed fat mass and BMI.
RESULTS
107 (11%) children had a DQI=0, indicating a consistently low diet quality; 339 (33%), DQI=1–3; 378 (37%), DQI=4–6; 194 (19%), DQI=7–8. There was a strong association between lower DQI and higher fat mass z-score at 6 years that was robust to adjustment for confounders [fat mass SDs per 1-unit DQI increase: β=−0.05 (95% CI: −0.09, −0.01), P=0.01]. In comparison with children who had the highest diet quality (DQI=7–8), this amounted to a difference in fat mass of 14% (95% CI: 2%, 28%) at 6 years for children with the poorest diets (DQI=0). In contrast, no independent associations were observed between DQI and BMI.
CONCLUSIONS
Continued exposure to diets of low quality across early childhood is linked to adiposity at the age of 6 years.
doi:10.1038/ijo.2015.97
PMCID: PMC4597330  PMID: 26121960
Diet quality; adiposity; childhood
3.  Chronic widespread bodily pain is increased among individuals with history of fracture: findings from UK Biobank 
Summary
In this cross-sectional analysis of the UK Biobank cohort, a history of fracture was associated with increased risk of current widespread chronic pain.
Purpose/Introduction
We aimed to test the hypothesis that a history of fracture is associated with reporting chronic widespread bodily pain (CWBP), using baseline data from the UK Biobank cohort, comprising 502,656 people aged 40–69 years.
Methods
The case definition of current chronic widespread bodily pain was based on a response of ‘yes’ to the question ‘do you have pain all over the body?’ and ‘yes’ to ‘and have you experienced pain all over the body for more than 3 months?’ Multivariable Poisson regression with robust standard errors was used to test the relationship between fracture (occurring within 5 years prior to the baseline interview, and recorded by self-report) at the spine, hip, upper limb or lower limb and CWBP, adjusting for confounders.
Results
Of 501,733 participants (mean age 56.5 years), 7130 individuals reported CWBP and 23,177 had a history of fracture affecting the upper limb, lower limb, spine and/or hip. Individuals with prior fracture were significantly more likely to report CWBP than those without. After adjustment for potential risk factors (age, gender, demographic, lifestyle and socioeconomic, and psychological), risk ratios were attenuated but remained statistically significant with a more than doubling of risk for CWBP with spine fractures in men (risk ratio (RR) 2.67, 95 % confidence interval (CI) 1.66–4.31; p < 0.001) and women (RR 2.13, 95 % CI 1.35–3.37, p = 0.001) and with hip fractures in women (RR 2.19, 95 % CI 1.33–3.59; p = 0.002).
Conclusions
In this cross-sectional analysis, previous fracture is associated with an increased likelihood of chronic widespread bodily pain, particularly with hip fractures in women, and spine fractures in both sexes. If replicated, these findings may help inform the identification of those most at risk of chronic widespread pain post-fracture, allowing preventative measures to be targeted.
doi:10.1007/s11657-015-0252-1
PMCID: PMC4683164  PMID: 26678491
Epidemiology; Chronic widespread pain; Fracture; UK Biobank; Stressors
4.  Maternal Factors Are Associated with the Expression of Placental Genes Involved in Amino Acid Metabolism and Transport 
PLoS ONE  2015;10(12):e0143653.
Introduction
Maternal environment and lifestyle factors may modify placental function to match the mother’s capacity to support the demands of fetal growth. Much remains to be understood about maternal influences on placental metabolic and amino acid transporter gene expression. We investigated the influences of maternal lifestyle and body composition (e.g. fat and muscle content) on a selection of metabolic and amino acid transporter genes and their associations with fetal growth.
Methods
RNA was extracted from 102 term Southampton Women’s Survey placental samples. Expression of nine metabolic, seven exchange, eight accumulative and three facilitated transporter genes was analyzed using quantitative real-time PCR.
Results
Increased placental LAT2 (p = 0.01), y+LAT2 (p = 0.03), aspartate aminotransferase 2 (p = 0.02) and decreased aspartate aminotransferase 1 (p = 0.04) mRNA expression associated with pre-pregnancy maternal smoking. Placental mRNA expression of TAT1 (p = 0.01), ASCT1 (p = 0.03), mitochondrial branched chain aminotransferase (p = 0.02) and glutamine synthetase (p = 0.05) was positively associated with maternal strenuous exercise. Increased glutamine synthetase mRNA expression (r = 0.20, p = 0.05) associated with higher maternal diet quality (prudent dietary pattern) pre-pregnancy. Lower LAT4 (r = -0.25, p = 0.05) and aspartate aminotransferase 2 mRNA expression (r = -0.28, p = 0.01) associated with higher early pregnancy diet quality. Lower placental ASCT1 mRNA expression associated with measures of increased maternal fat mass, including pre-pregnancy BMI (r = -0.26, p = 0.01). Lower placental mRNA expression of alanine aminotransferase 2 associated with greater neonatal adiposity, for example neonatal subscapular skinfold thickness (r = -0.33, p = 0.001).
Conclusion
A number of maternal influences have been linked with outcomes in childhood, independently of neonatal size; our finding of associations between placental expression of transporter and metabolic genes and maternal smoking, physical activity and diet raises the possibility that their effects are mediated in part through alterations in placental function. The observed changes in placental gene expression in relation to modifiable maternal factors are important as they could form part of interventions aimed at maintaining a healthy lifestyle for the mother and for optimal fetal development.
doi:10.1371/journal.pone.0143653
PMCID: PMC4682815  PMID: 26657885
6.  Maternal vitamin D status in pregnancy is associated with adiposity in the offspring: prospective observational study 
Objective
To determine the relationship between maternal vitamin D status in pregnancy and body composition in the offspring.
Design
Prospective mother-offspring cohort study.
Setting
Southampton, UK.
Participants
977 pregnant women whose serum 25-hydroxyvitamin D concentration (25(OH)D) was measured in late pregnancy and their offspring, followed up within 3 weeks of birth, and at 4 and 6 years of age.
Main outcome measures
Offspring lean and fat mass assessed using Dual X-ray Absorptiometry.
Results
Median daily vitamin D intake (from food and supplements) in late pregnancy was 3.7μg/day (IQR 2.7 to 5.7). 22% of the women took vitamin D supplements in late pregnancy, but only 8.5% of the women complied with UK guidance to take 10μg per day. Median maternal serum 25(OH)D in late pregnancy was 62nmol/l (IQR 43-89); 35% of the women studied had values below 50 nmol/l. Lower vitamin D status was associated with lower fat mass in the offspring at birth, but with greater fat mass at 4 and 6 years. It was not associated with lean mass at any of the ages studied. The opposing associations seen between maternal 25(OH)D (SDs) and fat mass (SDs) in the offspring at birth and at 6 years were robust to adjustment for a range of confounding factors, including maternal BMI and weight gain in pregnancy (β (95% CI) 0.08 (0.02, 0.15) and −0.10 (−0.17, − 0.02 respectively). The key independent predictors of higher maternal vitamin D status were season of measurement and taking vitamin D in dietary supplements in late pregnancy.
Conclusion
These data suggest that insufficient maternal vitamin D status in pregnancy could result in programmed differences in offspring fat mass. The findings require replication but add to a growing evidence base for a role of vitamin D in the origins of adiposity.
doi:10.3945/ajcn.112.037473
PMCID: PMC4632192  PMID: 22623747
7.  Further evidence of the developmental origins of osteoarthritis: results from the Hertfordshire Cohort Study 
Investigators have suggested a link between birth weight and both hand and lumbar spine osteoarthritis (OA). In this study, we sought to extend these observations by investigating relationships between growth in early life, and clinical and radiological diagnoses of OA at the hand, knee and hip, among participants from the Hertfordshire Cohort Study (HCS).
Data were available for 222 men and 222 women. Clinical OA was defined based on American College of Rheumatology (ACR) criteria. Radiographs were taken of the knees and hips, and graded for the presence of osteophytes and overall Kellgren and Lawrence (KL) score.
Lower weight at year one was associated with higher rates of clinical hand OA (OR 1.396, 95% CI 1.05, 1.85, p=0.021). Individuals with lower birth weights were more likely to have hip osteophytes, (OR 1.512, 95% CI 1.14, 2.00, p=0.004) and this remained robust after adjustment for confounders. Furthermore, a low weight at one year was also associated with a higher osteophyte number in the lateral compartment of the knee, after adjustment for confounders (OR 1.388, 95% CI 1.01, 1.91 p=0.043).
We have found further evidence of a relationship between early life factors and adult OA. These findings accord with previous studies.
doi:10.1017/S2040174414000373
PMCID: PMC4521289  PMID: 25154411
Osteoarthritis; Bone; Programming; Birth weight
8.  Pre-screening young postmenopausal women for BMD testing 
BoneKEy Reports  2014;3:544.
doi:10.1038/bonekey.2014.39
PMCID: PMC4078415  PMID: 24991407
9.  Genetic determinants of heel bone properties: genome-wide association meta-analysis and replication in the GEFOS/GENOMOS consortium 
Moayyeri, Alireza | Hsu, Yi-Hsiang | Karasik, David | Estrada, Karol | Xiao, Su-Mei | Nielson, Carrie | Srikanth, Priya | Giroux, Sylvie | Wilson, Scott G. | Zheng, Hou-Feng | Smith, Albert V. | Pye, Stephen R. | Leo, Paul J. | Teumer, Alexander | Hwang, Joo-Yeon | Ohlsson, Claes | McGuigan, Fiona | Minster, Ryan L. | Hayward, Caroline | Olmos, José M. | Lyytikäinen, Leo-Pekka | Lewis, Joshua R. | Swart, Karin M.A. | Masi, Laura | Oldmeadow, Chris | Holliday, Elizabeth G. | Cheng, Sulin | van Schoor, Natasja M. | Harvey, Nicholas C. | Kruk, Marcin | del Greco M, Fabiola | Igl, Wilmar | Trummer, Olivia | Grigoriou, Efi | Luben, Robert | Liu, Ching-Ti | Zhou, Yanhua | Oei, Ling | Medina-Gomez, Carolina | Zmuda, Joseph | Tranah, Greg | Brown, Suzanne J. | Williams, Frances M. | Soranzo, Nicole | Jakobsdottir, Johanna | Siggeirsdottir, Kristin | Holliday, Kate L. | Hannemann, Anke | Go, Min Jin | Garcia, Melissa | Polasek, Ozren | Laaksonen, Marika | Zhu, Kun | Enneman, Anke W. | McEvoy, Mark | Peel, Roseanne | Sham, Pak Chung | Jaworski, Maciej | Johansson, Åsa | Hicks, Andrew A. | Pludowski, Pawel | Scott, Rodney | Dhonukshe-Rutten, Rosalie A.M. | van der Velde, Nathalie | Kähönen, Mika | Viikari, Jorma S. | Sievänen, Harri | Raitakari, Olli T. | González-Macías, Jesús | Hernández, Jose L. | Mellström, Dan | Ljunggren, Östen | Cho, Yoon Shin | Völker, Uwe | Nauck, Matthias | Homuth, Georg | Völzke, Henry | Haring, Robin | Brown, Matthew A. | McCloskey, Eugene | Nicholson, Geoffrey C. | Eastell, Richard | Eisman, John A. | Jones, Graeme | Reid, Ian R. | Dennison, Elaine M. | Wark, John | Boonen, Steven | Vanderschueren, Dirk | Wu, Frederick C.W. | Aspelund, Thor | Richards, J. Brent | Bauer, Doug | Hofman, Albert | Khaw, Kay-Tee | Dedoussis, George | Obermayer-Pietsch, Barbara | Gyllensten, Ulf | Pramstaller, Peter P. | Lorenc, Roman S. | Cooper, Cyrus | Kung, Annie Wai Chee | Lips, Paul | Alen, Markku | Attia, John | Brandi, Maria Luisa | de Groot, Lisette C.P.G.M. | Lehtimäki, Terho | Riancho, José A. | Campbell, Harry | Liu, Yongmei | Harris, Tamara B. | Akesson, Kristina | Karlsson, Magnus | Lee, Jong-Young | Wallaschofski, Henri | Duncan, Emma L. | O'Neill, Terence W. | Gudnason, Vilmundur | Spector, Timothy D. | Rousseau, François | Orwoll, Eric | Cummings, Steven R. | Wareham, Nick J. | Rivadeneira, Fernando | Uitterlinden, Andre G. | Prince, Richard L. | Kiel, Douglas P. | Reeve, Jonathan | Kaptoge, Stephen K.
Human Molecular Genetics  2014;23(11):3054-3068.
Quantitative ultrasound of the heel captures heel bone properties that independently predict fracture risk and, with bone mineral density (BMD) assessed by X-ray (DXA), may be convenient alternatives for evaluating osteoporosis and fracture risk. We performed a meta-analysis of genome-wide association (GWA) studies to assess the genetic determinants of heel broadband ultrasound attenuation (BUA; n = 14 260), velocity of sound (VOS; n = 15 514) and BMD (n = 4566) in 13 discovery cohorts. Independent replication involved seven cohorts with GWA data (in silico n = 11 452) and new genotyping in 15 cohorts (de novo n = 24 902). In combined random effects, meta-analysis of the discovery and replication cohorts, nine single nucleotide polymorphisms (SNPs) had genome-wide significant (P < 5 × 10−8) associations with heel bone properties. Alongside SNPs within or near previously identified osteoporosis susceptibility genes including ESR1 (6q25.1: rs4869739, rs3020331, rs2982552), SPTBN1 (2p16.2: rs11898505), RSPO3 (6q22.33: rs7741021), WNT16 (7q31.31: rs2908007), DKK1 (10q21.1: rs7902708) and GPATCH1 (19q13.11: rs10416265), we identified a new locus on chromosome 11q14.2 (rs597319 close to TMEM135, a gene recently linked to osteoblastogenesis and longevity) significantly associated with both BUA and VOS (P < 8.23 × 10−14). In meta-analyses involving 25 cohorts with up to 14 985 fracture cases, six of 10 SNPs associated with heel bone properties at P < 5 × 10−6 also had the expected direction of association with any fracture (P < 0.05), including three SNPs with P < 0.005: 6q22.33 (rs7741021), 7q31.31 (rs2908007) and 10q21.1 (rs7902708). In conclusion, this GWA study reveals the effect of several genes common to central DXA-derived BMD and heel ultrasound/DXA measures and points to a new genetic locus with potential implications for better understanding of osteoporosis pathophysiology.
doi:10.1093/hmg/ddt675
PMCID: PMC4038791  PMID: 24430505
10.  Vitamin D and skeletal health in infancy and childhood 
During growth, severe vitamin D deficiency in childhood can result in symptomatic hypocalcaemia and rickets. Despite the suggestion from some studies of a secular increase in the incidence of rickets, this observation may be driven more by changes in population demographics than a true alteration to age, sex and ethnicity-specific incidence rates; indeed rickets remains uncommon overall and is rarely seen in fair-skinned children. Additionally, the impact of less severe vitamin D deficiency and insufficiency has received much interest in recent years, and in this review we consider the evidence relating vitamin D status to fracture risk and bone mineral density (BMD) in childhood and adolescence. We conclude that there is insufficient evidence to support the suggestion that low serum 25-hydroxyvitamin D [25(OH)D] increases childhood fracture risk. Overall, the relationship between 25(OH)D and BMD is inconsistent across studies and across skeletal sites within the same study; however there is evidence to suggest that vitamin D supplementation in children with the lowest levels of 25(OH)D might improve BMD. High quality randomised trials are now required to confirm this benefit.
doi:10.1007/s00198-014-2783-5
PMCID: PMC4224585  PMID: 25138259
vitamin D; rickets; bone mineral density; fracture; childhood
11.  Association between perinatal methylation of the neuronal differentiation regulator HES1 and later childhood neurocognitive function and behaviour 
Background Early life environments induce long-term changes in neurocognitive development and behaviour. In animal models, early environmental cues affect neuropsychological phenotypes via epigenetic processes but, as yet, there is little direct evidence for such mechanisms in humans.
Method We examined the relation between DNA methylation at birth and child neuropsychological outcomes in two culturally diverse populations using a genome-wide methylation analysis and validation by pyrosequencing.
Results Within the UK Southampton Women’s Survey (SWS) we first identified 41 differentially methylated regions of interest (DMROI) at birth associated with child’s full-scale IQ at age 4 years. Associations between HES1 DMROI methylation and later cognitive function were confirmed by pyrosequencing in 175 SWS children. Consistent with these findings, higher HES1 methylation was associated with higher executive memory function in a second independent group of 200 SWS 7-year-olds. Finally, we examined a pathway for this relationship within a Singaporean cohort (n = 108). Here, HES1 DMROI methylation predicted differences in early infant behaviour, known to be associated with academic success. In vitro, methylation of HES1 inhibited ETS transcription factor binding, suggesting a functional role of this site.
Conclusions Thus, our findings suggest that perinatal epigenetic processes mark later neurocognitive function and behaviour, providing support for a role of epigenetic processes in mediating the long-term consequences of early life environment on cognitive development.
doi:10.1093/ije/dyv052
PMCID: PMC4588869  PMID: 25906782
HES1; methylation; neurocognitive development; epigenetic; perinatal
12.  Regulation of Placental Calcium Transport and Offspring Bone Health 
Osteoporosis causes considerable morbidity and mortality in later life, and the risk of the disease is strongly determined by peak bone mass, which is achieved in early adulthood. Poor intrauterine and early childhood growth are associated with reduced peak bone mass, and increased risk of osteoporotic fracture in older age. In this review we describe the regulatory aspects of intrauterine bone development, and then summarize the evidence relating early growth to later fracture risk. Physiological systems include vitamin D, parathyroid hormone, leptin, GH/IGF-1; finally the potential role of epigenetic processes in the underlying mechanisms will be explored. Thus factors such as maternal lifestyle, diet, body build, physical activity, and vitamin D status in pregnancy all appear to influence offspring bone mineral accrual. These data demonstrate a likely interaction between environmental factors and gene expression, a phenomenon ubiquitous in the natural world (developmental plasticity), as the potential key process. Intervention studies are now required to test the hypotheses generated by these epidemiological and physiological findings, to inform potential novel public health interventions aimed at improving childhood bone health and reducing the burden of osteoporotic fracture in future generations.
doi:10.3389/fendo.2011.00003
PMCID: PMC3355895  PMID: 22649358
bone; placenta; osteoporosis; fracture; BMC; vitamin D; fetus; neonate
13.  Modifiable early-life risk factors for childhood adiposity and overweight: an analysis of their combined impact and potential for prevention1234 
Background: Early life may be a “critical period” when appetite and regulation of energy balance are programmed, with lifelong consequences for obesity risk. Insight into the potential impact of modifying early-life risk factors on later obesity can be gained by evaluating their combined effects.
Objective: The objective was to examine the relation between the number of early-life risk factors and obesity outcomes among children in a prospective birth cohort (Southampton Women's Survey).
Design: Five risk factors were defined: maternal obesity [prepregnant body mass index (BMI; in kg/m2) >30], excess gestational weight gain (Institute of Medicine, 2009), smoking during pregnancy, low maternal vitamin D status (<64 nmol/L), and short duration of breastfeeding (none or <1 mo). Obesity outcomes examined when the children were aged 4 and 6 y were BMI, dual-energy X-ray absorptiometry–assessed fat mass, overweight, or obesity (International Obesity Task Force). Data were available for 991 mother-child pairs, with children born between 1998 and 2003.
Results: Of the children, 148 (15%) had no early-life risk factors, 330 (33%) had 1, 296 (30%) had 2, 160 (16%) had 3, and 57 (6%) had 4 or 5. At both 4 and 6 y, there were positive graded associations between number of early-life risk factors and each obesity outcome (all P < 0.001). After taking account of confounders, the relative risk of being overweight or obese for children who had 4 or 5 risk factors was 3.99 (95% CI: 1.83, 8.67) at 4 y and 4.65 (95% CI: 2.29, 9.43) at 6 y compared with children who had none (both P < 0.001).
Conclusions: Having a greater number of early-life risk factors was associated with large differences in adiposity and risk of overweight and obesity in later childhood. These findings suggest that early intervention to change these modifiable risk factors could make a significant contribution to the prevention of childhood obesity.
doi:10.3945/ajcn.114.094268
PMCID: PMC4307207  PMID: 25646335
adiposity; childhood obesity; early life; obesity; lifecourse; prevention
14.  Childhood bone mineral content is associated with methylation status of the RXRA promoter at birth 
Maternal vitamin D deficiency has been associated with reduced offspring bone mineral accrual. Retinoid-X Receptor-alpha (RXRA) is an essential cofactor in the action of 1,25(OH)2-vitamin D, and RXRA methylation in umbilical cord DNA has been associated with later offspring adiposity. We tested the hypothesis that RXRA methylation in umbilical cord DNA collected at birth is associated with offspring skeletal development, assessed by dual-energy X-ray absorptiometry, in a population-based mother-offspring cohort (Southampton Women’s Survey). Relationships between maternal plasma 25(OH)-vitamin D concentrations and cord RXRA methylation were also investigated. In 230 children aged 4 years, higher % methylation at 4 out of 6 RXRA CpG sites measured was correlated with lower offspring % bone mineral content (%BMC) (β=−0.02 to −0.04%/SD, p=0.002 to 0.043) and BMC corrected for body size (β=−2.1 to −3.4g/SD, p=0.002 to 0.047), with a further site associated with %BMC only. Similar relationships for %BMC were observed in a second independent cohort (n=64). Maternal free 25(OH)-vitamin D index was negatively associated with methylation at one of these RXRA CpG sites (β=−3.3 SD/unit, p=0.03). In addition to the mechanistic insights afforded by associations between maternal free 25(OH)-vitamin D index, RXRA methylation in umbilical cord DNA, and childhood BMC, such epigenetic marks in early life might represent novel biomarkers for adverse bone outcomes in the offspring.
doi:10.1002/jbmr.2056
PMCID: PMC3836689  PMID: 23907847
Epigenetic; methylation; umbilical cord; RXRA; vitamin D; DXA
15.  Vitamin D supplementation in pregnancy: A systematic review 
1. ABSTRACT
Background
It is unclear whether the current evidence base allows definite conclusions to be made regarding the optimal maternal circulating concentration of 25(OH)-vitamin D during pregnancy, and how this might best be achieved. CRD42011001426.
Aim/ Research Questions
What are the clinical criteria for vitamin D deficiency in pregnant women?What adverse maternal and neonatal health outcomes are associated with low maternal circulating 25(OH)-vitamin D?Does maternal supplementation with vitamin D in pregnancy lead to an improvement in these outcomes (including assessment of compliance and effectiveness)?What is the optimal type (D2 or D3), dose, regimen and route for vitamin D supplementation in pregnancy?Is supplementation with vitamin D in pregnancy likely to be cost-effective?
Methods
We performed systematic review and where possible combined study results using meta-analysis to estimate the combined effect size.
Major electronic databases were searched up to June 2012 covering both published and grey literature. Bibliographies of selected papers were hand-searched for additional references. Relevant authors were contacted for any unpublished findings and additional data if necessary.
Inclusion and exclusion criteria
Subjects
Pregnant women or pregnant women and their offspring.
Exposure
Either assessment of vitamin D status (dietary intake, sunlight exposure, circulating 25(OH)-vitamin D concentration) or supplementation of participants with vitamin D or vitamin D containing food e.g. oily fish.
Outcomes
Offspring: Birth weight, birth length, head circumference, bone mass, anthropometry and body composition, risk of asthma and atopy, small for gestational dates, preterm birth, type 1 diabetes, low birth weight, serum calcium concentration, blood pressure and rickets. Mother: Preeclampsia, gestational diabetes, risk of caesarean section and bacterial vaginosis.
Results
76 studies were included. There was considerable heterogeneity between the studies and for most outcomes there was conflicting evidence.
The evidence base was insufficient to reliably answer question 1 in relation to biochemical or disease outcomes.
For questions 2 and 3, modest positive relationships were identified between maternal 25(OH)-vitamin D and 1) offspring birth weight in meta-analysis of 3 observational studies using log-transformed 25(OH)-vitamin D concentrations after adjustment for potential confounding factors (pooled regression coefficient 5.63g/10% change maternal 25(OH)D, 95% CI 1.11,10.16), but not in those 4 studies using natural units, or across intervention studies; 2) offspring cord blood or postnatal calcium concentrations in a meta-analysis of 6 intervention studies (all found to be at high risk of bias; mean difference 0.05mmol/l, 95% CI 0.02, 0.05); and 3) offspring bone mass in observational studies judged to be of good quality, but which did not permit meta-analysis.
The evidence base was insufficient to reliably answer questions 4 and 5.
Limitations
Study methodology varied widely in terms of study design, population used, vitamin D status assessment, exposure measured and outcome definition.
Conclusions
The evidence base is currently insufficient to support definite clinical recommendations regarding vitamin D supplementation in pregnancy. Although there is modest evidence to support a relationship between maternal 25(OH)-vitamin D status and offspring birth weight, bone mass and serum calcium concentrations, these findings were limited by their observational nature (birth weight, bone mass) or risk of bias and low quality (calcium concentrations). High quality randomised trials are now required.
doi:10.3310/hta18450
PMCID: PMC4124722  PMID: 25025896
16.  Maternal antenatal vitamin D status and offspring muscle development: findings from the Southampton Women’s Survey 
The Journal of clinical endocrinology and metabolism  2013;99(1):10.1210/jc.2013-3241.
Context
Maternal 25-hydroxy-vitamin D [25(OH)D] status in pregnancy has been associated with offspring bone development and adiposity. Vitamin D has also been implicated in postnatal muscle function but little is known about a role for antenatal 25(OH)D exposure in programming muscle development.
Objective
We investigated the associations between maternal plasma 25(OH)D status at 34 weeks gestation and offspring lean mass and muscle strength at 4 years of age.
Design and setting
A prospective UK population-based mother-offspring cohort: the Southampton Women’s Survey (SWS).
Participants
12583 non-pregnant women were initially recruited into SWS, of which 3159 had singleton pregnancies. 678 mother-child pairs were included in this analysis.
Main Outcomes Measured
At 4 years of age, offspring assessments included hand grip strength (Jamar Dynamometer) and whole body DXA (Hologic Discovery) yielding lean mass and %lean mass. Physical activity was assessed by 7-day accelerometry (Actiheart) in a subset of children (n=326).
Results
Maternal serum 25(OH)D concentration in pregnancy was positively associated with offspring height-adjusted hand grip strength (β=0.10 SD/SD, p=0.013), which persisted after adjustment for maternal confounding factors, duration of breastfeeding and child’s physical activity at 4 years (β=0.13 SD/SD, p=0.014). Maternal 25(OH)D was also positively associated with offspring %lean mass (β=0.11 SD/SD, p=0.006), but not total lean mass (β=0.06, p=0.15). This however did not persist after adjustment for confounding factors (β=0.09 SD/SD, p=0.11).
Conclusions
This observational study suggests that intrauterine exposure to 25(OH)D during late pregnancy might influence offspring muscle development through an effect primarily on muscle strength rather than muscle mass.
doi:10.1210/jc.2013-3241
PMCID: PMC3880861  PMID: 24178796
vitamin D; grip strength; muscle mass; fetal programming
17.  Programming of Osteoporosis and Impact on Osteoporosis Risk 
Osteoporosis is a skeletal disorder characterised by reduced bone quantity and quality and an increased susceptibility to fracture, and appears to be one of many chronic conditions that might be influenced by events early in life. Specifically, there is growing evidence of an interaction between the genome and the environment in the expression of the disease.
doi:10.1097/GRF.0b013e31829cb9b0
PMCID: PMC3732203  PMID: 23787708
osteoporosis; programming; bone; fracture; nutrition; cohort
18.  Objectively measured physical activity in four-year-old British children: a cross-sectional analysis of activity patterns segmented across the day 
Background
Little is known about preschool-aged children’s levels of physical activity (PA) over the course of the day. Using time-stamped data, we describe the levels and patterns of PA in a population-based sample of four-year-old British children.
Methods
Within the Southampton Women’s Survey the PA levels of 593 4-year-old children (51% female) were measured using (Actiheart) accelerometry for up to 7 days. Three outcome measures: minutes spent sedentary (<20 cpm); in light (LPA: ≥20 – 399 cpm) and in moderate-to-vigorous activity (MVPA: ≥400 cpm) were derived. Average daily activity levels were calculated and then segmented across the day (morning, afternoon and evening). MVPA was log-transformed. Two-level random intercept models were used to analyse associations between activity level and temporal and demographic factors.
Results
Children were active for 67% (mean 568.5 SD 79.5 minutes) of their daily registered time on average, with 88% of active time spent in LPA. All children met current UK guidelines of 180 minutes of daily activity. There were no differences in children’s average daily levels of sedentary activity and LPA by temporal and demographic factors: differences did emerge when activity was segmented across the day. Sex differences were largest in the morning, with girls being more sedentary, spending fewer minutes in LPA and 18% less time in MVPA than boys. Children were more sedentary and less active (LPA and MVPA) in the morning if they attended childcare full-time compared to part-time, and on weekend mornings compared to weekdays. The reverse was true for weekend afternoons and evenings. Children with more educated mothers were less active in the evenings. Children were less sedentary and did more MVPA on summer evenings compared to winter evenings.
Conclusions
Preschool-aged children meet current physical activity guidelines, but with the majority of their active time spent in LPA, investigation of the importance of activity intensity in younger children is needed. Activity levels over the day differed by demographic and temporal factors, highlighting the need to consider temporality in future interventions. Increasing girls’ morning activity and providing opportunities for daytime activity in winter months may be worthwhile.
doi:10.1186/1479-5868-11-1
PMCID: PMC3896827  PMID: 24405936
19.  Fetal and infant growth predict hip geometry at six years old: Findings from the Southampton Women’s Survey 
Pediatric research  2013;74(4):450-456.
Background
We investigated relationships between early growth and proximal femoral geometry at age six years in a prospective population-based cohort, the Southampton Women’s Survey.
Methods
In 493 mother-offspring pairs we assessed linear size (individual measure dependent on developmental stage) using high-resolution ultrasound at 11, 19 and 34 weeks gestation (femur length) and at birth, 1, 2, 3, 4 and 6 years (crown-heel length/height). Standard deviation (SD)-scores were created and conditional regression modelling generated mutually independent growth variables. Children underwent hip DXA (Dual X-ray absorptiometry) at 6 years (Hologic Discovery, Hologic Inc., MA); hip structure analysis software yielded measures of geometry and strength.
Results
There were strong associations between early linear growth and femoral neck section modulus (Z) at 6 years, with the strongest relationships observed for femur growth from 19-34 weeks gestation (β=0.26 cm3/SD, p<0.0001), and for height growth from birth to 1 year (β=0.25 cm3/SD, p<0.0001) and 1-2 years (β=0.33 cm3/SD, p<0.0001), with progressively weaker relationships over years 3 (β=0.23 cm3/SD, p=0.0002) and 4 (β=0.10 cm3/SD, p=0.18).
Conclusions
These results demonstrate that growth before age 3 years predicts proximal femoral geometry at six years old. The data suggest critical periods in which there is capacity for long term influence on the later skeletal growth trajectory.
doi:10.1038/pr.2013.119
PMCID: PMC3797011  PMID: 23857297
20.  Different Indices of Fetal Growth Predict Bone Size and Volumetric Density at 4 Years of Age 
We have demonstrated previously that higher birth weight is associated with greater peak and later-life bone mineral content and that maternal body build, diet, and lifestyle influence prenatal bone mineral accrual. To examine prenatal influences on bone health further, we related ultrasound measures of fetal growth to childhood bone size and density. We derived Z-scores for fetal femur length and abdominal circumference and conditional growth velocity from 19 to 34 weeks’ gestation from ultrasound measurements in participants in the Southampton Women’s Survey. A total of 380 of the offspring underwent dual-energy X-ray absorptiometry (DXA) at age 4 years [whole body minus head bone area (BA), bone mineral content (BMC), areal bone mineral density (aBMD), and estimated volumetric BMD (vBMD)]. Volumetric bone mineral density was estimated using BMC adjusted for BA, height, and weight. A higher velocity of 19- to 34-week fetal femur growth was strongly associated with greater childhood skeletal size (BA: r = 0.30, p < .0001) but not with volumetric density (vBMD: r = 0.03, p = .51). Conversely, a higher velocity of 19- to 34-week fetal abdominal growth was associated with greater childhood volumetric density (vBMD: r = 0.15, p = .004) but not with skeletal size (BA: r = 0.06, p = .21). Both fetal measurements were positively associated with BMC and aBMD, indices influenced by both size and density. The velocity of fetal femur length growth from 19 to 34 weeks’ gestation predicted childhood skeletal size at age 4 years, whereas the velocity of abdominal growth (a measure of liver volume and adiposity) predicted volumetric density. These results suggest a discordance between influences on skeletal size and volumetric density.
doi:10.1359/jbmr.091022
PMCID: PMC3793299  PMID: 20437610
EPIDEMIOLOGY; OSTEOPOROSIS; PROGRAMMING; DEVELOPMENTAL ORIGINS
21.  Maternal awareness of young children’s physical activity: levels and cross-sectional correlates of overestimation 
BMC Public Health  2013;13:924.
Background
Factors associated with parental awareness of children’s physical activity (PA) levels have not been explored in preschool-aged children. This paper investigates maternal awareness of preschool-aged children’s PA levels and determined correlates associated with maternal overestimation of PA.
Methods
Data from the Southampton Women’s Survey, a UK population-based study, were collected March 2006 through June 2009. Daily minutes of moderate-to-vigorous PA (MVPA) were derived using accelerometry in 478 4-year-old children. Mothers who were realistic or overestimated their child’s PA were identified. Log-binomial regression was used to analyse correlates of maternal overestimation of PA levels in children whose mothers perceived them to be active (n = 438).
Results
40.8% of children were classified as inactive: 89.7% of these were perceived to be active by their mothers (over-estimators). These mothers were more likely to think their child sometimes lacked skills required to be physically active (RR (95% CI) = 1.29(1.03-1.63)) and their child was more likely to attend nursery full-time (RR = 1.53(1.14-2.04)). They were less likely to have older children at home (RR = 0.71(0.56-0.90)).
Conclusions
Almost 90% of mothers of inactive preschool-aged children perceive their child to be active. Nursery-school attendance and having older siblings at home may be important to consider when designing behavioural interventions to increase PA in preschool children.
doi:10.1186/1471-2458-13-924
PMCID: PMC3852941  PMID: 24090173
Physical activity; Awareness; Preschool children
22.  Physical activity intensity, sedentary time, and body composition in preschoolers123 
Background
Detailed associations between physical activity (PA) subcomponents, sedentary time, and body composition in preschoolers remain unclear.
Objective
We examined the magnitude of associations between objectively measured PA subcomponents and sedentary time with body composition in 4-y-old children.
Design
We conducted a cross-sectional study in 398 preschool children recruited from the Southampton Women’s Survey. PA was measured by using accelerometry, and body composition was measured by using dual-energy X-ray absorptiometry. Associations between light physical activity, moderate physical activity (MPA), vigorous physical activity (VPA), and moderate-to-vigorous physical activity (MVPA) intensity; sedentary time; and body composition were analyzed by using repeated-measures linear regression with adjustment for age, sex, birth weight, maternal education, maternal BMI, smoking during pregnancy, and sleep duration. Sedentary time and PA were also mutually adjusted for one another to determine whether they were independently related to adiposity.
Results
VPA was the only intensity of PA to exhibit strong inverse associations with both total adiposity [P < 0.001 for percentage of body fat and fat mass index (FMI)] and abdominal adiposity (P = 0.002 for trunk FMI). MVPA was inversely associated with total adiposity (P = 0.018 for percentage of body fat; P = 0.022 for FMI) but only because of the contribution of VPA, because MPA was unrelated to fatness (P ≥ 0.077). No associations were shown between the time spent sedentary and body composition (P ≥ 0.11).
Conclusions
In preschoolers, the time spent in VPA is strongly and independently associated with lower adiposity. In contrast, the time spent sedentary and in low-to-moderate–intensity PA was unrelated to adiposity. These results indicate that efforts to challenge pediatric obesity may benefit from prioritizing VPA.
doi:10.3945/ajcn.112.045088
PMCID: PMC3785144  PMID: 23553158
23.  Correlates of Light and Moderate-to-Vigorous Objectively Measured Physical Activity in Four-Year-Old Children 
PLoS ONE  2013;8(9):e74934.
Background
Correlates of physical activity (PA) are hypothesized to be context and behaviour specific, but there is limited evidence of this in young children. The aim of the current study is to investigate associations between personal, social and environmental factors and objectively measured light and moderate-to-vigorous PA (LPA and MVPA, respectively) in four-year-old children.
Methods
Cross-sectional data were used from the Southampton Women’s Survey, a UK population-based longitudinal study. Four-year old children (n = 487, 47.0% male) had valid PA data assessed using accelerometry (Actiheart) and exposure data collected with a validated maternal questionnaire (including data on child personality, family demographics, maternal behaviour, rules and restrictions, and perceived local environment). Linear regression modelling was used to analyse associations with LPA and MVPA separately, interactions with sex were explored.
Results
LPA minutes were greater in children whose mothers reported more PA (vs. inactive: regression coefficient±standard error: 6.70±2.94 minutes), and without other children in the neighbourhood to play with (−6.33±2.44). MVPA minutes were greater in children with older siblings (vs. none: 5.81±2.80) and those whose mothers used active transport for short trips (vs. inactive: 6.24±2.95). Children accumulated more MVPA in spring (vs. winter: 9.50±4.03) and, in boys only, less MVPA with availability of other children in the neighbourhood (−3.98±1.70).
Discussion
Young children’s LPA and MVPA have differing associations with a number of social and environmental variables. Interventions targeting PA promotion in young children outside of formal care settings should consider including intensity specific factors.
doi:10.1371/journal.pone.0074934
PMCID: PMC3764204  PMID: 24040365
25.  Maternal late-pregnancy serum 25-hydroxyvitamin D in relation to childhood wheeze and atopic outcomes 
Thorax  2012;67(11):950-956.
Background
Studies exploring the relationship between prenatal vitamin D exposure and childhood asthma have yielded conflicting results. Higher vitamin D intake during pregnancy has been shown to lower the risk of childhood wheeze, yet a study of maternal late-pregnancy serum 25-hydroxyvitamin D suggested higher serum concentrations may be associated with increased childhood asthma.
Objective
To assess the relationship between mothers’ serum 25-hydroxyvitamin D status and asthma and wheeze phenotypes in their children at age 6 years. Secondly, to explore the relationship between maternal 25-hydroxyvitamin D status and objective measures of childhood atopy and lung function.
Methods
Serum 25-hydroxyvitamin D was measured at 34 weeks’ gestation in the mothers of 860 children born at term. Wheeze was classified as either transient or persistent/late using questionnaire data collated from 6, 12, 24 and 36 months and 6 years. At 6 years spirometry was performed and atopic status was determined by skin prick testing, exhaled nitric oxide was measured in 451 and bronchial hyperresponsiveness in 216 children.
Results
There were no significant associations between maternal late-pregnancy 25-hydroxyvitamin D status and either asthma or wheeze at age 6 years. Maternal vitamin D status was not associated with transient or persistent/late wheeze; no significant association was found between persistent/late wheeze when subdivided according to atopic status. No associations were found with skin sensitisation or lung function.
Conclusions
This study provides no evidence that exposure to higher concentrations of 25-hydroxyvitamin D in maternal serum during late pregnancy increases the risk of childhood asthma, wheeze or atopy.
doi:10.1136/thoraxjnl-2012-201888
PMCID: PMC3679514  PMID: 22707522
asthma epidemiology; asthma; paediatric asthma

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