Longitudinal Association Between Participation in Organized Sport and Psychosocial Development in Early Childhood.

OBJECTIVE: To explore whether the associations between developmental delays in the first year of life and psychosocial outcomes in preschool children are affected by participation in organized sport. STUDY DESIGN: Data were obtained from the infant cohort of the Growing Up in Ireland project. Parents reported on child development (Ages and Stages Questionnaire) at age 1 year, psychosocial characteristics (Strengths and Difficulties Questionnaire) at ages 3 and 5 years, and engagement in organized sport at age 5 years. Data were analyzed using mixed models. RESULTS: At age 1 year, 15% of the cohort was classified as having developmental delays. These children exhibited more behavioral difficulties (0.55, ±0.27; mean difference, ±95% confidence limits [CL]) (P < .0001) and fewer prosocial behaviors (-0.54, ±0.11) (P < .0001) at age 3 years. For boys in this group, engagement in sport was associated with a significant decrease in behavioral difficulties between ages 3 and 5 years (-0.44, ±0.39) (P = .03). Compared with those classified as lacking regular engagement (ie, never engaging, or engaging <1 hour/week), the relative effect of sport on changes in behavioral difficulties for boys with developmental delays was statistically significant (0.70, ±0.59) (P = .02). Participation in sport was not associated with significant changes in behavioral difficulties for girls, or a significant change in prosocial behaviors for boys or girls. CONCLUSIONS: Regular participation in sport by boys could attenuate some of the behavioral difficulties associated with early development. Lack of opportunities for engaging in sport could negatively affect boys' behavioral regulation in the preschool period.

Reliability of walking speed in basic and complex conditions in healthy, older community-dwelling individuals.

BACKGROUND: There is a paucity of reliability data for walking speed tests in complex conditions to assess functioning in healthy older individuals. AIMS: To evaluate the absolute intra- and intertest reliability of walking speed performed in basic and complex conditions in healthy older individuals. METHODS: Fifty-two men and women of mean age 69.7 ± 3.2 years were tested for habitual and maximal walking speed. Maximal speed was also assessed under different conditions, including walking on a path of reduced width; picking up objects; stepping over hurdles; stepping over hurdles wearing sunglasses and finally, carrying a box. Two testing sessions (separated by 4 weeks) of two trials each were administered. Reliability was analysed by intra-class correlation coefficient (ICC), minimal detectable change (MDC) and Bland-Altman plots with limits of agreement (LOA). RESULTS: Intrasession ICCs ranged from good to excellent (0.89-0.95) except for picking up objects (0.44). Intersession ICCs were moderate to good (0.60-0.78) and %MDCs were acceptable (14-24%). Bland-Altman plots suggested a good agreement between the two testing sessions at group level (mean differences from - 0.02 to - 0.11 m/s), and limited agreement between testing sessions at individual level (upper LOA from 0.13 to 0.37 m/s and lower LOA from - 0.29 to - 0.49 m/s). CONCLUSIONS: Complex walking speed tests are generally reliable measures displaying good and moderate intra- and inter-session reliability. Such tests seem a more suitable functional assessment tool for heathy older subjects compared with simple walking. Some learning effect may be present and further reliability studies are needed.

Dietary patterns and cardiovascular risk factors in adolescents and young adults: the Northern Ireland Young Hearts Project.

Dietary pattern (DP) analysis allows examination of the combined effects of nutrients and foods on the markers of CVD. Very few studies have examined these relationships during adolescence or young adulthood. Traditional CVD risk biomarkers were analysed in 12-15-year-olds (n 487; Young Hearts (YH)1) and again in the same individuals at 20-25 years of age (n 487; YH3). Based on 7 d diet histories, in the present study, DP analysis was performed using a posteriori principal component analysis for the YH3 cohort and the a priori Mediterranean Diet Score (MDS) was calculated for both YH1 and YH3 cohorts. In the a posteriori DP analysis, YH3 participants adhering most closely to the 'healthy' DP were found to have lower pulse wave velocity (PWV) and homocysteine concentrations, the 'sweet tooth' DP were found to have increased LDL concentrations, and decreased HDL concentrations, [corrected] the 'drinker/social' DP were found to have lower LDL and homocysteine concentrations, but exhibited a trend towards a higher TAG concentration, and finally the 'Western' DP were found to have elevated homocysteine and HDL concentrations. In the a priori dietary score analysis, YH3 participants adhering most closely to the Mediterranean diet were found to exhibit a trend towards a lower PWV. MDS did not track between YH1 and YH3, and nor was there a longitudinal relationship between the change in the MDS and the change in CVD risk biomarkers. In conclusion, cross-sectional analysis revealed that some associations between DP and CVD risk biomarkers were already evident in the young adult population, namely the association between the healthy DP (and the MDS) and PWV; however, no longitudinal associations were observed between these relatively short time periods.

Measures of static postural control moderate the association of strength and power with functional dynamic balance.

BACKGROUND AND AIMS: Age-related reductions in strength and power are considered to negatively impact balance control, but the existence of a direct association is still an issue of debate. This is possibly due to the fact that balance assessment is complex, reflects different underlying physiologic mechanisms and involves quantitative measurements of postural sway or timing of performance during balance tasks. The present study evaluated the moderator effect of static postural control on the association of power and strength with dynamic balance tasks. METHODS: Fifty-seven healthy 65-75 year old individuals performed tests of dynamic functional balance (walking speed under different conditions) and of strength, power and static postural control. RESULTS AND CONCLUSIONS: Dynamic balance performance (walking speed) was associated with lower limb strength and power, as well as postural control under conditions requiring postural adjustments (narrow surface walking r(2) = 0.31, p < 0.001). An interaction effect between strength and static postural control was found with narrow surface walking and talking while walking (change of ß 0.980, p < 0.001 in strength for 1 SD improvements in static postural control for narrow walking, and [Formula: see text] -0.730, p < 0.01 in talking while walking). These results indicate that good static postural control facilitates the utilisation of lower limb strength to better perform complex, dynamic functional balance tasks. Practical implications for assessment and training are discussed.

Physiotherapy for sleep disturbance in people with chronic low back pain: results of a feasibility randomized controlled trial.

OBJECTIVE: To determine the feasibility of a randomized controlled trial investigating the effectiveness of physiotherapy for sleep disturbance in chronic low back pain (CLBP) (≥12wks). DESIGN: Randomized controlled trial with evaluations at baseline, 3 months, and 6 months. SETTING: Outpatient physiotherapy department in an academic teaching hospital. PARTICIPANTS: Participants with CLBP were randomly assigned to a walking program (n=20; mean age ± SD, 46.4±13.8y), supervised exercise class (n=20; mean age ± SD, 41.3±11.9y), or usual physiotherapy (n=20; mean age ± SD, 47.1±14.3y). The 3-month evaluation was completed by 44 participants (73%), and 42 (70%) participants completed the 6-month evaluation. INTERVENTIONS: Participants received a physiotherapy-delivered 8-week walking program, an 8-week group supervised exercise class (1 class/wk), or 1-to-1 usual physiotherapy (advice, manual therapy, and exercise). MAIN OUTCOME MEASURES: Sleep was assessed by the self-reported Pittsburgh Sleep Quality Index (PSQI), Insomnia Severity Index (ISI), Pittsburgh Sleep Diary, and objective actigraphy. RESULTS: Groups were comparable at baseline. Most (95%, n=57) of the participants had sleep disturbance. The acceptability of actigraphy was excellent at baseline (58 of 60 participants), but dropped at 3 months (26 of 44 participants). There were improvements on the PSQI and ISI in all groups at 3 and 6 months, with predominantly medium effect sizes (Cohen d=0.2-0.5). CONCLUSIONS: The high prevalence of sleep disturbance indicated the feasibility of good recruitment in future trials. The PSQI would be a suitable screening tool and outcome measure alongside an objective nonobtrusive sleep outcome measure. The effectiveness of physiotherapy for sleep disturbance in CLBP warrants investigation in a fully powered randomized controlled trial.

Executive function moderates the role of muscular fitness in determining functional mobility in older adults.

BACKGROUND AND AIMS: Both physical and cognitive factors are known to independently predict functional mobility in older people. However, the combined predictive value of both physical fitness and cognitive factors on functional mobility has been less investigated. The aim of the present study was to assess if cognitive executive functions moderate the role of physical fitness in determining functional mobility of older individuals. METHODS: Fifty-seven 65- to 75-year-old healthy participants performed tests of functional mobility (habitual and maximal walking speed, maximal walking speed while picking up objects/stepping over obstacles), physical fitness (peak power, knee extensors torque, back/lower limb flexibility, aerobic fitness), and executive function (inhibition and cognitive flexibility). RESULTS: Maximal walking speeds were predicted by physical fitness parameters and their interaction with cognitive factors. Knee extensor torque emerged as the main predictor of all tested locomotor performances at maximal speed. The effect of peak power and back/lower limb flexibility was moderated by executive functions. In particular, inhibition and cognitive flexibility differed in the way in which they moderate the role of fitness. High levels of cognitive flexibility seem necessary to take advantage of leg power for walking at maximal speed. In contrast, high levels of inhibitory capacity seem to compensate for low levels of back/lower limb flexibility when picking up movements are added to a locomotor task. CONCLUSIONS: These findings may have important practical implications for the design and implementation of multi-component training programs aimed at optimizing functional abilities in older adults.

Assessment of musculo-articular and muscle stiffness in young and older men.

INTRODUCTION: The aim of this cross-sectional study was to concurrently assess musculo-articular stiffness (MAS) and muscle stiffness (MS) of the knee extensors in younger and older individuals. METHODS: Fourteen young (22.1 ± 3.0 years old) and 12 older (65.4 ± 5.7 years old) men were tested for maximal voluntary contraction (MVC), rate of torque development (RTD), muscle thickness, MAS, and MS of knee extensors. RESULTS: MVC, RTD, and muscle thickness were higher in the younger group (288.6 vs. 194.3 Nm, 1319.5 vs. 787.0 Nm s(-1), 23.1 vs. 17.7 mm, respectively, P < 0.05). MAS normalized to the load supported (30% of MVC) was not different between groups (87.9 vs. 88.5 Nm(-1) kg(-1)), whereas the older group exhibited a higher level of normalized MS (23.2 vs. 18.6 Nm(-1) kg(-1), P < 0.05). CONCLUSIONS: Determinants of MS have been highlighted along with their role in elevated MS. The unaltered level of MAS, which is functionally important in an aging population, might be achieved through a decrease in tendon stiffness.

Dietary patterns and bone mineral status in young adults: the Northern Ireland Young Hearts Project.

Studies of individual nutrients or foods have revealed much about dietary influences on bone. Multiple food or nutrient approaches, such as dietary pattern analysis, could offer further insight but research is limited and largely confined to older adults. We examined the relationship between dietary patterns, obtained by a posteriori and a priori methods, and bone mineral status (BMS; collective term for bone mineral content (BMC) and bone mineral density (BMD)) in young adults (20-25 years; n 489). Diet was assessed by 7 d diet history and BMD and BMC were determined at the lumbar spine and femoral neck (FN). A posteriori dietary patterns were derived using principal component analysis (PCA) and three a priori dietary quality scores were applied (dietary diversity score (DDS), nutritional risk score and Mediterranean diet score). For the PCA-derived dietary patterns, women in the top compared to the bottom fifth of the 'Nuts and Meat' pattern had greater FN BMD by 0·074 g/cm(2) (P = 0·049) and FN BMC by 0·40 g (P = 0·034) after adjustment for confounders. Similarly, men in the top compared to the bottom fifth of the 'Refined' pattern had lower FN BMC by 0·41 g (P = 0·049). For the a priori DDS, women in the top compared to the bottom third had lower FN BMD by 0·05 g/cm(2) after adjustments (P = 0·052), but no other relationships with BMS were identified. In conclusion, adherence to a 'Nuts and Meat' dietary pattern may be associated with greater BMS in young women and a 'Refined' dietary pattern may be detrimental for bone health in young men.

The relationship between active travel to school and health-related fitness in children and adolescents: a systematic review.

BACKGROUND: Active travel to school (ATS) has been identified as an important source of physical activity for youth. However, the relationship between ATS and health-related fitness (HRF) among youth remains unclear. METHODS: A systematic search of seven electronic databases (EMBASE, OVID MEDLINE, PsycINFO, PubMed, Scopus, SPORTDiscus and TRIS on line) was conducted in December 2009 and studies published since 1980 were considered for inclusion. RESULTS: Twenty seven articles were identified that explored the relationship between ATS and the following aspects of HRF: weight status/body composition, cardiorespiratory fitness, muscular fitness and flexibility. Forty-eight percent of the studies that examined the relationship between ATS and weight status/body composition reported significant associations, this increased to 55% once poor quality studies were removed. Furthermore, the findings from five studies, including one longitudinal study, indicate that ATS is positively associated with cardiorespiratory fitness in youth. However, the evidence for the relationships between ATS and muscular fitness or flexibility is equivocal and limited by low study numbers. CONCLUSIONS: There is some evidence to suggest that ATS is associated with a healthier body composition and level of cardiorespiratory fitness among youth. Strategies to increase ATS are warranted and should be included in whole-of-school approaches to the promotion of physical activity.

Physical activity in childhood and bone health.

The aim of this review is to provide a concise overview and update on recent advances in the field of physical activity in childhood and its effects on bone growth with an emphasis on the potential to prevent fractures. In addition, the review poses several unresolved questions in the field for future research.

Strength training and gross-motor skill exercise as interventions to improve postural control, dynamic functional balance and strength in older individuals.

BACKGROUND: Loss of balance control is commonly experienced by older individuals. Despite the large amount of research on the effects of exercise on balance the optimal exercise regime is yet to be identified. Most studies have concentrated on strength training due to associations between muscle weakness, balance disfunction and fall risk. The effects of gross-motor skill exercise for balance and postural control have been less investigated. The study aimed to compare the effectiveness of strength training (STT) and gross-motor skill exercise (GMT) on static postural control, dynamic functional balance and strength in healthy older individuals. METHODS: Thirty-eight individuals (65-85 years) participated to GMT or STT for 12 weeks, twice weekly. They were tested pre- and post-training for postural control (Romberg and Tandem positions on a force platform), dynamic functional balance (maximal walking speed in balance-challenging conditions), maximal isometric handgrip strength, maximal knee flexor and extensor strength. RESULTS: Improvements were observed in static postural balance (tandem position, P<0.05, -1.07 mm/s), walking speed (hurdles P<0.01, +0.08 m/s; narrow path P<0.05, +0.07 m/s; picking up P<0.01, +0.07 m/s) knee extensor strength (P<0.001, +10.9 Nm); knee flexor strength improved significantly in the SST group only (P<0.001, +13.9 Nm). There was no correlation between changes in strength and balance. CONCLUSIONS: Static postural balance and dynamic functional balance in healthy elderly may be improved through exercise targeting either muscular strength or coordination, agility and mobility. The present study helps fill the gap in research on gross-motor skill exercise and proposes a suitable exercise alternative to strength for managing static and dynamic balance decline.

Association between breast-feeding and anthropometry and CVD risk factor status in adolescence and young adulthood: the Young Hearts Project, Northern Ireland.

OBJECTIVE: To examine the association between breast-feeding and blood pressure, anthropometry and plasma lipid profile in both adolescence and young adulthood. DESIGN: Longitudinal study of biological and behavioural risk factors for CVD. SETTING: The Young Hearts Project, Northern Ireland. SUBJECTS: Schoolchildren aged 12 years and 15 years who participated in a cross-sectional study of lifestyle and health, and who were followed up as young adults aged 20-25 years. RESULTS: There was no significant difference in height, weight, BMI, skinfold thickness measurements, blood pressure or plasma lipid profile in adolescents who had been breast-fed compared with those who had not been breast-fed. However, by the time these adolescents had reached adulthood, those who had been breast-fed were significantly taller than those who had not been breast-fed (standing height, P = 0.013; leg length, P = 0.035). Specifically, the breast-fed group was on average taller by 1.7 cm (95 % CI 0.4, 3.0 cm) and had longer legs by 1.0 cm (95 % CI 0.1, 1.9 cm). There was no significant difference in other anthropometric measures, blood pressure or plasma lipid profile in adults who had been breast-fed compared with those who had not been breast-fed. CONCLUSIONS: Compared with those who had not been breast-fed, individuals who had been breast-fed were taller in adulthood. Given the known association of increased adult height with improved life expectancy, the results from the present study support a beneficial effect of breast-feeding.

Physiotherapy for sleep disturbance in chronic low back pain: a feasibility randomised controlled trial.

BACKGROUND: Sleep disturbance is becoming increasingly recognised as a clinically important symptom in people with chronic low back pain (CLBP, low back pain >12 weeks), associated with physical inactivity and depression. Current research and international clinical guidelines recommend people with CLBP assume a physically active role in their recovery to prevent chronicity, but the high prevalence of sleep disturbance in this population may be unknowingly limiting their ability to participate in exercise-based rehabilitation programmes and contributing to poor outcomes. There is currently no knowledge concerning the effectiveness of physiotherapy on sleep disturbance in people with chronic low back pain and no evidence of the feasibility of conducting randomized controlled trials that comprehensively evaluate sleep as an outcome measure in this population. METHODS/DESIGN: This study will evaluate the feasibility of a randomised controlled trial (RCT), exploring the effects of three forms of physiotherapy (supervised general exercise programme, individualized walking programme and usual physiotherapy, which will serve as the control group) on sleep quality in people with chronic low back pain. A presenting sample of 60 consenting patients will be recruited in the physiotherapy department of Beaumont Hospital, Dublin, Ireland, and randomly allocated to one of the three groups in a concealed manner. The main outcomes will be sleep quality (self-report and objective measurement), and self-reported functional disability, pain, quality of life, fear avoidance, anxiety and depression, physical activity, and patient satisfaction. Outcome will be evaluated at baseline, 3 months and 6 months. Qualitative telephone interviews will be embedded in the research design to obtain feedback from a sample of participants' about their experiences of sleep monitoring, trial participation and interventions, and to inform the design of a fully powered future RCT. Planned analysis will explore trends in the data, effect sizes and clinically important effects (quantitative data), and thematic analysis (qualitative data). DISCUSSION: This study will evaluate the feasibility of a randomised controlled trial exploring the effects of three forms of physiotherapy (supervised general exercise programme, individualized walking programme and usual physiotherapy, which will serve as the control group) on sleep quality in people with chronic low back pain. TRIAL REGISTRATION: Current controlled trial ISRCTN54009836.

The reduced folate carrier (SLC19A1) c.80G>A polymorphism is associated with red cell folate concentrations among women.

Low folate status may be a consequence of suboptimal intake, transport or cellular utilization of folate and, together with elevated homocysteine, is a recognized risk factor or marker for several human pathologies. As folate transport across cell membranes is mediated in part by the reduced folate carrier (RFC1), variants within SLC19A1, the gene that encodes RFC1, may influence disease risk via an effect on folate and/or homocysteine levels. The present study was undertaken to assess the association between the SLC19A1 c.80G>A polymorphism and folate/homocysteine concentrations in healthy young adults from Northern Ireland. The SLC19A1 c.80G>A polymorphism was not strongly associated with either serum folate or homocysteine concentrations in either men or women. However, in women, but not in men, this polymorphism explained 5% of the variation in red blood cell (RBC) folate levels (P= 0.02). Relative to women with the SLC19A1 c.80GG genotype, women with the GA and AA genotypes had higher RBC folate concentrations. Consequently, compared to women with the SLC19A1 c.80GA and AA genotypes, women who are homozygous for the 80G allele may be at increased risk of having a child affected with a neural tube defect and of developing pathologies that have been associated with folate insufficiency, such as cardiovascular disease.

Folate/homocysteine phenotypes and MTHFR 677C>T genotypes are associated with serum levels of monocyte chemoattractant protein-1.

Monocyte chemoattractant protein-1 (MCP-1) is a chemokine that recruits monocytes into the subendothelial cell layer in atherosclerotic lesions. Elevated homocysteine (hyperhomocysteinemia), which is usually associated with low-folate status, is a known risk factor for many pathologies with inflammatory etiologies. The present study was undertaken to examine whether there are associations between MCP-1 concentrations and folate/Hcy phenotype or methylenetetrahydrofolate reductase (MTHFR) 677C>T genotype in healthy young adults. In females, MCP-1 concentrations were positively correlated with Hcy and negatively correlated with both serum and red blood cell folate; female smokers and MTHFR 677T carriers had particularly elevated MCP-1 concentrations. Similar relationships were not seen in males. These findings may have implications for understanding the female predominance observed for a range of autoimmune diseases, such as systemic lupus erythematosus and rheumatoid arthritis.

Low Volume, Home-Based Weighted Step Exercise Training Can Improve Lower Limb Muscle Power and Functional Ability in Community-Dwelling Older Women.

Stepping exercise can be used as a scalable form of high intensity exercise to enhance important aspects of physical fitness in older populations. The addition of supplementary weights increases the resistive element of stepping, with the potential for training improvements in muscular strength, power, and functional abilities alongside other fitness outcomes. The aim of this study was to evaluate the effects of a low-volume, home-based weighted step exercise programme on muscular strength, power, and functional ability in previously inactive community-dwelling older women. Eleven participants, aged between 65⁻74 years, independently completed a six-week individualised and progressive step exercise training programme wearing a weighted vest. Knee extensor strength, lower limb power output, and physical function using a battery of functional tests were measured at baseline, following a 6-week control period, and again following the 6-week training programme. Following training, lower limb power output improved by 10⁻11% (p < 0.05) and was accompanied by a corresponding 9% (p < 0.01) improvement in stair climb time and 10% (p < 0.01) improvement in normalised stair climbing power, highlighting the beneficial effects of weighted stepping for transferable improvements in functional fitness. The magnitude of observed training improvements suggest that weighted step training has the potential to prolong independence and prevent age-related health conditions such as sarcopenia.

Association of Birth Weight With Type 2 Diabetes and Glycemic Traits: A Mendelian Randomization Study.

Importance: Observational studies have shown associations of birth weight with type 2 diabetes (T2D) and glycemic traits, but it remains unclear whether these associations represent causal associations. Objective: To test the association of birth weight with T2D and glycemic traits using a mendelian randomization analysis. Design, Setting, and Participants: This mendelian randomization study used a genetic risk score for birth weight that was constructed with 7 genome-wide significant single-nucleotide polymorphisms. The associations of this score with birth weight and T2D were tested in a mendelian randomization analysis using study-level data. The association of birth weight with T2D was tested using both study-level data (7 single-nucleotide polymorphisms were used as an instrumental variable) and summary-level data from the consortia (43 single-nucleotide polymorphisms were used as an instrumental variable). Data from 180 056 participants from 49 studies were included. Main Outcomes and Measures: Type 2 diabetes and glycemic traits. Results: This mendelian randomization analysis included 49 studies with 41 155 patients with T2D and 80 008 control participants from study-level data and 34 840 patients with T2D and 114 981 control participants from summary-level data. Study-level data showed that a 1-SD decrease in birth weight due to the genetic risk score was associated with higher risk of T2D among all participants (odds ratio [OR], 2.10; 95% CI, 1.69-2.61; P = 4.03 × 10-5), among European participants (OR, 1.96; 95% CI, 1.42-2.71; P = .04), and among East Asian participants (OR, 1.39; 95% CI, 1.18-1.62; P = .04). Similar results were observed from summary-level analyses. In addition, each 1-SD lower birth weight was associated with 0.189 SD higher fasting glucose concentration (ß = 0.189; SE = 0.060; P = .002), but not with fasting insulin, 2-hour glucose, or hemoglobin A1c concentration. Conclusions and Relevance: In this study, a genetic predisposition to lower birth weight was associated with increased risk of T2D and higher fasting glucose concentration, suggesting genetic effects on retarded fetal growth and increased diabetes risk that either are independent of each other or operate through alterations of integrated biological mechanisms.

A possible role for the PPARG Pro12Ala polymorphism in preterm birth.

The links between preterm birth, low birth weight, and adult vascular/metabolic morbidity remain unclear. Genetic susceptibility of babies related to these three conditions might contribute to this long-term association. We tested whether the Pro12Ala polymorphism of the peroxisome proliferator-activated receptor gamma (PPARG) gene could play a role in birth weight and duration of gestation. We genotyped two independent cross-sectional studies from Northern Ireland (n = 382 and 620). In combined populations, the PPARG Ala12 allele was associated (P = 0.03) with lower birth weight, primarily caused by shorter gestational duration (P = 0.04). The frequency of Ala12 allele carriers was higher (P = 0.027) in the group of individuals born before term (35%, n = 60) than in the group of individuals born at term (22%, n = 942). The odds ratios (95% CI) of preterm birth for Ala12 allele carriers were 1.9 (1.1-3.4), P = 0.022, and 4.2 (1.9-9.7), P = 0.0006 (adjusted for sex, maternal age, and study), when considering 37 or 35 weeks of pregnancy as a threshold for preterm birth, respectively. Interestingly, the same allele was also associated with a moderate decreased risk of miscarriages in mothers. In conclusion, the PPARG Pro12Ala polymorphism might represent a genetic susceptibility factor for preterm birth and constitute a link between preterm birth and metabolic diseases later in life.

An insertion/deletion polymorphism of the dihydrofolate reductase (DHFR) gene is associated with serum and red blood cell folate concentrations in women.

A low serum folate and high homocysteine phenotype is associated with an increased risk of neural tube defects (NTDs), cardiovascular diseases and other pathologies. Thus defining both genetic and non-genetic factors that may impact folate/homocysteine metabolism will enhance our understanding of the etiologic mechanisms underlying these conditions and facilitate risk assessment. Dihydrofolate reductase catalyzes the reduction of folic acid to dihydrofolate and thereafter to tetrahydrofolate. The impact of the dihydrofolate reductase (DHFR) c.86 + 60_78 insertion/deletion (ins/del) polymorphism on folate and homocysteine concentrations was analyzed using data from healthy young adults from Northern Ireland, collected as part of visit three of the Young Hearts Project. Among men the DHFR c.86 + 60_78 polymorphism was not significantly associated with serum or red blood cell folate concentrations, or with homocysteine concentrations. Among women the DHFR c.86 + 60_78 polymorphism explained 2% of the variation in RBC folate levels and 5% of the variation in serum folate levels, but did not appear to have an independent effect on homocysteine. Relative to women with the DHFR c.86 + 60_78 ins/ins and ins/del genotypes, del/del homozygotes had increased serum and red blood cell folate concentrations and may therefore be at decreased risk of having offspring affected by NTDs and of other adverse reproductive and health outcomes attributable to low folate.