Tracking of physical activity, fitness, body composition and diet from adolescence to young adulthood: The Young Hearts Project, Northern Ireland

Body mass index and body fat percentage are associated with decreased physical fitness in adolescent and adult female volleyball players

BACKGROUND

The objectives of this study were to examine (a) the prevalence of overweight/obesity, and (b) the relationship between body mass index (BMI), body fat percentage (BF) and physical fitness in adolescent and adult female volleyball players.

MATERIALS AND METHODS

Adolescent (n = 102, aged 15.2 ± 2.0 year) and adult (n = 57, 25.9 ± 5.0 year) players were examined for anthropometric characteristics and body composition, and performed the physical working capacity in heart rate 170 min(-1) test, a force-velocity test, the Wingate anaerobic test (WAnT), sit-and-reach test (SAR), handgrip strength test (HST) and countermovement vertical jump (CVJ).

RESULTS

Based on international BMI cut-off points, 27.5% (n = 28) of adolescent and 12.3% (n = 7) of adult participants were classified as overweight, with the prevalence of overweight being higher in girls than in women (χ(2) = 4.90, P = 0.027). BMI was correlated with BF in both age groups (r = 0.72, P < 0.001 in girls; r = 0.75, P < 0.001 in women). Normal participants had superior certain physical and physiological characteristics than those who were overweight. For instance, normal girls and women had higher mean power during WAnT than their overweight counterparts (P = 0.003 and P = 0.009 respectively). Except for flexibility, BMI and BF were inversely related with physical fitness (e.g., BMI vs. HST r = -0.39, P < 0.001 in girls; BF vs. CVJ r = -0.45, P < 0.001 in women).

CONCLUSION

The findings confirmed the negative effect of overweight and fatness on selected parameters of physical fitness. The prevalence of overweight in adolescent volleyball players was higher than in general population, which was a novel finding, suggesting that proper exercise interventions should be developed to target the excess of body mass in youth volleyball clubs.

Socioeconomic trajectories from birth to adolescence and risk factors for noncommunicable disease: prospective analyses

PURPOSE

To evaluate the associations between family socioeconomic trajectories from 0 to 11 years of age and risk factors for noncommunicable disease at 15 years.

METHODS

Individuals born in the city of Pelotas, Brazil, in 1993 are part of a birth cohort study. Socioeconomic position, collected at birth and at 11 years of age, was our main exposure. Risk factors for chronic disease were collected at 15 years. Body mass index was transformed into Z score using the World Health Organization standard. Transport and leisure-time physical activity, smoking, and alcohol consumption were assessed by self-report. Blood pressure was measured using a digital sphygmomanometer.

RESULTS

Of 5,249 cohort members, 85.7% were located at the 15-year follow-up visit. Rich adolescents were more likely to be overweight, be obese, and not use active modes of transport to school. Poor adolescents were more likely to smoke. In relation to socioeconomic trajectories, the odds of obesity were 46% higher among those who were "always rich" compared with those who were "always poor"; the odds of use of an inactive mode of transportation were 326% greater among the "always rich" than the "always poor," whereas the reverse was observed for smoking (odds of 200%). The "always rich" had one-half the odds of walking or cycling to school compared with those who became wealthy in the studied period.

CONCLUSIONS

Adolescent socioeconomic position is a stronger determinant of risk factors for noncommunicable diseases than socioeconomic trajectories. However, trajectories do matter, particularly in terms of use of active transportation to school.

Elevated body mass index and body fat percentage are associated with decreased physical fitness in soccer players aged 12-14 years

Purpose

Adolescents are in increased risk for the development of obesity, while sport has been suggested as an effective means against adolescent obesity. The objectives of this study were to examine (a) the prevalence of overweightness/obesity, (b) the relationship between body mass index (BMI) and body fat percent (BF), and (c) the association between BMI, BF and physical fitness in adolescent soccer players.

Methods

Members (n=136, aged 13.1±0.6 yr) of competitive soccer clubs were examined for physical and physiological characteristics.

Results

Based on international BMI cut-off points, 19.9% (n=27) of participants were classified as overweight. BMI was highly correlated with BF (r=0.77, P<0.001). BMI and BF were in inverse relationship with aerobic power (r= − 0.29, P<0.001; r= − 0.44, P<0.001, respectively), maximal anaerobic power (r= − 0.23, P=0.009; r= − 0.47, P<0.001) and local muscular endurance (r= − 0.36, P<0.001; r= − 0.67, P<0.001).

Conclusions

The strong relationship between BMI and BF suggest the further use of BMI in adolescent soccer players. The findings confirmed previous observations in the general population about the negative effect of overweight and fatness on physical fitness. The prevalence of overweightness among participants was similar with what is observed in general population. Therefore, sport participation cannot guarantee physiological body mass and body composition, and it is necessary to prescribe exercise targeting body mass and fat control.

Temporal relationships between screen-time and physical activity with cardiorespiratory fitness in English schoolchildren: a 2-year longitudinal study

OBJECTIVE

To determine the temporal relationships screen-time and physical activity have with cardiorespiratory fitness.

METHOD

Measures were made over two years (2008-2010) in 1500 participants aged 11.5 (SD 0.5) years at baseline.

RESULTS

Tracking coefficients were low-to-moderate for all measures. At follow-up, 25% of participants moved from having low (<2h) to high (≥ 2 h) daily screen-time and 6% became unfit according to FITNESSGRAM standards. Baseline screen-time was the strongest univariate predictor of becoming unfit. Multivariate analysis controlling for decimal age, BMI and deprivation confirmed baseline screen-time as the strongest independent predictor of becoming unfit over the 2-year study period (OR 2.4; 95%CI:1.4-4.0). Current (OR 2.3; 95%CI:1.3-4.0) and previous (OR 1.7; 95%CI:1.0-2.9) physical activity levels also independently predicted becoming unfit.

CONCLUSION

There is currently no guidance for limiting screen-time in UK children. These longitudinal data add to the cross-sectional evidence of lower physical activity and fitness in children reporting ≥ 2 h daily screen-time. More importantly, these data demonstrate that high screen-time during childhood is an independent predictor of lower cardiorespiratory fitness in adolescence.

Low maternal vitamin B12 status during pregnancy is associated with reduced heart rate variability indices in young children

Vitamin B12 plays a vital role in neuronal development, particularly in myelinogenesis. Demyelination of the autonomic nervous system occurs early in vitamin B12 deficiency. However, the impact of maternal vitamin B12 deficiency during pregnancy on neuronal function in the offspring is poorly documented. The objective of this study was to assess cardiac autonomic nervous activity in children born to mothers with low vitamin B12 status during pregnancy using heart rate variability (HRV) indices in the frequency domain. Seventy-nine healthy children between 3 and 8 years of age were evaluated from an ongoing birth cohort. The blood sample of the mother had been stored and was analysed for plasma vitamin B12 following enrolment of the child. Subjects were divided, based on the median maternal first trimester vitamin B12 status (114 pmol L(-1)), into lower (n = 40) and higher (n = 39) vitamin B12 status groups. A lead II electrocardiogram was recorded in the supine posture and subjected to HRV analysis. Low-frequency HRV in absolute units was reduced significantly in children of the lower vitamin B12 status group (P = 0.03) and was 53% that of the higher vitamin B12 status group. There was a significant association between low-frequency and total power HRV with cord blood vitamin B12 levels (ρ = 0.31 and 0.30, both P = 0.03). In summary, children born to mothers with a lower vitamin B12 status have a reduced cardiac sympathetic activity. The long-term implication of this needs to be evaluated by follow-up studies.

A systematic review of school-based interventions to prevent risk factors associated with noncommunicable diseases

Noncommunicable diseases (NCDs) are emerging as an important public health problem in developing countries. The risk factors for NCDs are initiated during childhood and adolescence. The aim of this review was to assess the effectiveness of school-based interventions for prevention of NCD risk factors (physical inactivity, diet, and tobacco consumption), and identify processes that affect the main outcome. The retrieved studies from 2001 to 2010 were analyzed for their methodological quality (using standard guidelines), settings, intervention components, and main outcomes. The literature search identified 37 studies. The proportion of studies showing a positive result was 83% (10/12) among those that involved family, 87%(7/8) that involved both community and family, and 76% (13/17) that involved school only. Overall, 80% of the studies reported at least some evidence of a positive intervention effect. The current literature search supports the effectiveness of school-based interventions for prevention of risk factors associated with NCDs.

Cohort profile: the Amsterdam Growth and Health Longitudinal Study

The Amsterdam Growth and Health Longitudinal Study (AGHLS) is a unique, multidisciplinary cohort study that was initially set up to examine growth and health among teenagers. Throughout the years, the AGHLS has aimed to answer research questions dealing with the relationships between the (natural) development of anthropometry, lifestyle and health from adolescence into adulthood. The AGHLS specifically focuses on anthropometrics, physical activity and fitness, cardiovascular disease risk, lifestyle, musculoskeletal health, psychological health and well-being. Besides this, many methodological issues related to the analysis of longitudinal data were also explored within the framework of the AGHLS. In 1976, students from two secondary schools from the greater Amsterdam area were included in the study. Between 1976 and 2006, 10 rounds of measurement were performed covering an age range between 13 and 43 years. The huge database collected so far has been primarily used to answer relevant research questions regarding the longitudinal relationship between lifestyle and health. Further information about the study can be obtained from the principal investigator Jos Twisk (jwr.twisk@vumc.nl), and up-to-date information on AGHLS can be found by visiting the website www.aggo.nl.

Centile curves and normative values for the twenty metre shuttle-run test in English schoolchildren

The aim of this study was to provide normative data for performance on the 20 m shuttle-run test of cardiorespiratory fitness in English schoolchildren. A total of 7366 10-16 year olds completed the 20 m shuttle-run test. We expressed performance as the number of shuttles completed, test score (shuttles and levels) and estimated peak oxygen consumption (VO2peak). We calculated descriptive statistics for each age-sex group to construct percentile curves and tables. To assess the cardiorespiratory fitness of our sample, we calculated the number of participants who fell below proposed cut-offs for low cardiorespiratory fitness based on either completed shuttles or VdotO2peak. These cut-offs did not agree in terms of frequency of classification. The classification based on estimated VO2peak suggested low fitness was more prevalent in males and that the incidence of low fitness increased with age in both sexes. These are the first normative data for shuttle-run performance in English youth and can now be used to interpret data from this cardiorespiratory fitness test. The two cut-offs used for low fitness did not agree and future research should establish a cut-off for test performance which can predict present or future ill-health.

Bidirectional cross-sectional and prospective associations between physical activity and body composition in adolescence: birth cohort study

The aim of this study was to investigate the cross-sectional and prospective associations between physical activity and body composition in adolescence. This is a prospective study, including 4,103 adolescents belonging to the Pelotas (Brazil) 1993 birth cohort, who were followed up at the mean ages of 11.3 and 14.7 years. Subsample analyses included 511 individuals with accelerometry and deuterium dilution data at 13.3 years. Sum of skinfolds at age 11.3 years was highly correlated with skinfolds at age 14.7 years (rho = 0.74, P < 0.001). More than 85% of participants remained in the same quintile or changed by not more than one quintile during the 3.4 year period. Tracking of physical activity was considerably lower, although still significant; the correlation was 0.24 (P < 0.001) and 61.4% of the adolescents moved one or less quintiles. In fully-adjusted models, no significant cross-sectional or longitudinal associations were found between physical activity and body composition, neither in boys nor in girls. These null results were confirmed in the 511 individuals with accelerometry and deuterium data. We provide evidence of tracking of physical activity and particularly body composition during adolescence. Our results do not support the hypothesis that physical activity and fatness are strongly related in adolescents.

Efficacy of a compulsory homework programme for increasing physical activity and healthy eating in children: the healthy homework pilot study

BACKGROUND

Most physical activity and nutrition interventions in children focus on the school setting; however, evidence suggests that children are less active and have greater access to unhealthy food at home. The aim of this pilot study was to examine the efficacy of a compulsory homework programme for increasing physical activity and healthy eating in children.

METHODS

The six-week 'Healthy Homework' programme and complementary teaching resource was developed under the guidance of an intersectoral steering group. Eight senior classes (year levels 5-6) from two diverse Auckland primary schools were randomly assigned into intervention and control groups. A total of 97 children (57 intervention, 40 control) aged 9-11 years participated in the evaluation of the intervention. Daily step counts were monitored immediately before and after the intervention using sealed multiday memory pedometers. Screen time, sports participation, active transport to and from school, and the consumption of fruits, vegetables, unhealthy foods and drinks were recorded concurrently in a 4-day food and activity diary.

RESULTS

Healthy Homework resulted in a significant intervention effect of 2,830 steps.day-1 (95% CI: 560, 5,300, P = 0.013). This effect was consistent between sexes, schools, and day types (weekdays and weekend days). In addition, significant intervention effects were observed for vegetable consumption (0.83 servings.day-1, 95% CI: 0.24, 1.43, P = 0.007) and unhealthy food consumption (-0.56 servings.day-1, 95% CI: -1.05, -0.07, P = 0.027) on weekends but not weekdays, with no interactions with sex or school. Effects for all other variables were not statistically significant regardless of day type.

CONCLUSIONS

Compulsory health-related homework appears to be an effective approach for increasing physical activity and improving vegetable and unhealthy food consumption in children. Further research in a larger study is required to confirm these initial results.

Tracking of children's body-mass index, television viewing and dietary intake over five-years

OBJECTIVE

To examine the tracking of children's body mass index, television viewing, and dietary intake over five-years.

METHODS

In 2002/3 (T1) parents of children aged 5-6 years (n=175) and 10-12 years (n=121), from Victoria, Australia, completed measures assessing their child's frequency of fruit, vegetable, and energy-dense sweet and savory snack consumption, and their child's television (TV) viewing. Children's height and weight were measured by researchers and sex-age adjusted body mass index (BMI) calculated. All measures were repeated in 2006 (T2) and 2008 (T3). Generalized estimating equations (GEE) (standardized stability coefficients, β) were used to assess tracking and were interpreted as: β <0.3=low, 0.3-0.6=moderate, and >0.6=high.

RESULTS

High standardized stability coefficients were found for BMI (β=0.74-0.92), TV viewing (β=0.65-0.73), and frequency of fruit consumption (β=0.73-0.89) among younger and older children. Moderate-to-high standardized stability coefficients were found for frequency of vegetable (β=0.52-0.86), energy-dense sweet (β=0.41-0.65), and savory snack consumption (0.40-0.67) among younger and older children.

CONCLUSIONS

BMI, TV viewing and dietary intake patterns are moderate-highly stable throughout childhood and into adolescence. Further research that identifies and targets high risk groups to prevent increased BMI, reduce TV viewing and promote healthy dietary behaviors may be justified.

Tracking of obesity-related behaviours from childhood to adulthood: A systematic review

Obesity in childhood carries a wide range of physical, psychological and social disbenefits and also increases the risk of adult obesity with its well-recognised, enhanced risk of several common complex diseases as well as adverse socioeconomic and psychosocial sequelae. Understanding the tracking of the two key modifiable behaviours, food consumption and physical activity, between childhood and adulthood may illuminate the childhood determinants of adult obesity and contribute to the development of effective interventions. We performed a systematic review of the available literature on tracking of both physical activity and of dietary intake between childhood and adulthood by searching MEDLINE, EMBASE, CINAHL, PSYCInfo, Google and Google Scholar. For inclusion, studies had to report baseline measurements when the children were less than, or equal to, 18 years and to report follow-up for at least 5 years to any age over 18 years. After removal of duplicates, 9625 search hits were screened by title and/or abstract and 79 potentially relevant papers were identified and full papers obtained. In total 39 papers were included in this analysis. Of these, 11 papers (from 5 studies) reported data on tracking of diet from childhood to adulthood and 28 papers (from 16 studies) reported data on tracking of physical activity or inactivity. Despite the diversity of study design and measurement methodology, we found evidence of tracking of both physical activity and of diet between childhood and adulthood with estimates of strength of tracking of a similar order for both behaviours. Because of the inherent methodological difficulties in quantifying habitual behaviour, it is likely that the reported estimates of strength of tracking under-estimate the true degree of tracking. The evidence of tracking reported here may give greater impetus to the development of interventions aimed to prevent the persistence of obesity from childhood into adulthood and its attendant adverse socioeconomic, psychosocial and health sequelae.

The influence of body mass index on long-term fitness from physical education in adolescent girls

BACKGROUND

Physical education (PE) can improve physical fitness; however, little research has evaluated PE's long-term influence. The purpose is to determine PE's longitudinal effects on fitness in a group of adolescent girls and to determine whether body mass index (BMI) status influenced any potential effects.

METHODS

Participants were enrolled in daily PE throughout their ninth grade. Data were collected at baseline and at the end of 9th, 10th, and 11th grades. BMI (kg/m(2) ) was classified into Centers for Disease Control and Prevention percentiles. Fitness was estimated from a 3-stage step test (change in exercise heart rate (HR) indicated improved fitness) and analyzed using repeated measures general linear modeling with adjustments for baseline BMI, baseline age, ethnicity, intervention status, and moderate-to-vigorous physical activity outside PE.

RESULTS

Complete data were available for 131 girls (61% of sample) who were predominantly African American, 13.8 ± 0.4 years, mean BMI 24.7 ± 6.1 kg/m(2) at the ninth-grade baseline. Overall, stage 1 HR (bpm) decreased from baseline to 9th grade (-5.5 ± 1.3, p < 0.0001), baseline to 10th grade (-7.2 ± 1.4, p < 0.0001), and baseline to 11th grade (-7.0 ± 1.5, p < 0.0001). Change differed by BMI status; fitness improvement was significant for normal and overweight, but not obese girls. After 2 years, change in stage 1 HR (bpm) was significantly different between BMI categories: normal-weight girls versus obese girls (-10.0 ± 3.2, p = 0.002) and overweight girls versus obese girls (-9.3 ± 3.9, p = 0.02).

CONCLUSION

Fitness differences by BMI exist after a PE program in adolescent girls: fitness improved and was maintained in normal-weight and overweight girls, whereby obese girls had no improvement in fitness.

Predictors of Physical Activity Patterns Across Adulthood: A Growth Curve Analysis

Activity level is a core but understudied individual difference. Understanding patterns of physical activity over long periods may be key to understanding why some individuals develop healthy lifestyles. The present study transformed qualitative information from the Terman Life Cycle Study to examine patterns of leisure time physical activity across four decades (1936-1972). Activities were converted into metabolic equivalent (MET) ratings, and then activity patterns, individual variation, and child and adult personality predictors of differing trajectories were examined using growth curve modeling. For overall activity, a quadratic model fit best, with decelerating decline as people aged. Males were consistently more active than females. Much individual variation was present, but childhood energy and sociability, and adult extraversion and neuroticism predicted average activity levels and change. Results suggest that physical activity needs to be understood within the context of the individual’s personality and long-term trajectory, not merely current motivations.

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.

Tracking of physical activity from childhood to adulthood: a review

The aim of the article was to review studies on the tracking of physical activity in all phases of life from childhood to late adulthood. The majority of the studies have been published since 2000. The follow-up time in most studies was short, the median being 9 years. In men, the stability of physical activity was significant but low or moderate during all life phases and also in longterm follow-ups. In women, the tracking was lower and in many cases non-significant. Among both sexes, stability seems to be lower in early childhood than in adolescence or in adulthood and lower in transitional phases, such as from childhood to adolescence or from adolescence to adulthood, than in adulthood. However, the differences in the stability of physical activity between age groups and between different phases of life were small. The number of tracking studies utilising objective methods to measure physical activity was so small that systematic differences in stability between self-report and objective methods could not be determined. A factor which caused differences in tracking results was the adjustment of correlations for measurement error and other error variance. Adjusted coefficients were clearly higher than unadjusted ones. However, adjustment was done only in very few studies. If the different methods used for estimating habitual physical activity and the failure to control for important covariates in studies of tracking are taken into account, physical activity appears to track reasonably well also in the longer term, for example from adolescence to adulthood. The results of the tracking studies support the idea that the enhancement of physical activity in children and adolescents is of great importance for the promotion of public health.

Sweets and sugar-sweetened soft drink intake in childhood in relation to adult BMI and overweight. The Cardiovascular Risk in Young Finns Study

OBJECTIVE

To investigate the associations of BMI and overweight in adulthood with consumption of sweets and sugar-sweetened soft drinks in childhood and with the change in consumption between childhood and adulthood.

DESIGN

Longitudinal 21-year follow-up study of Finnish children and adolescents from childhood to adulthood.

SETTING

The Cardiovascular Risk in Young Finns Study, comprising participants from both eastern and western Finland.

SUBJECTS

Boys (n 967) and girls (n 1172) aged 3-18 years at baseline in 1980.

RESULTS

The increase in consumption of sugar-sweetened soft drinks from childhood to adulthood was directly associated with BMI in adulthood in women (b = 0.45, P = 0.0001) but not in men. In women, BMI increased by 0.45 kg/m2 for every 10-unit increase per month. Consumption of sweets and sugar-sweetened soft drinks in childhood and adolescence was not associated with BMI in adulthood. The change in consumption of sweets was not associated with BMI in adulthood. The increase in the consumption of sugar-sweetened soft drinks from childhood to adulthood was associated with being overweight (OR = 1.90, 95 % CI 1.38, 2.61) in women, but not in men. No association was found between overweight (BMI >or= 25 kg/m2) in adulthood and consumption of sweets in childhood or the change in consumption from childhood to adulthood.

CONCLUSIONS

We conclude that direct associations exist between adulthood overweight and BMI and an increase in consumption of sugar-sweetened soft drinks in women. Thus sugar-sweetened soft drinks consumption may be important when considering weight management in women.

Does leisure-time physical activity in early adulthood predict later physical activity? Pro-Saude Study

INTRODUCTION: Leisure-Time Physical Activity (LTPA) is a health behavior that is considered relatively stable over the course of life; this life-long habit seems to be shaped during youth and early adulthood. LTPA is one of the few healthy behaviors more prevalent among men than among women. METHODS:Data from 3,199 participants of the Pro-Saude Study were analyzed - a cohort of employees of a university in Rio de Janeiro, collected with a self-reported multidimensional questionnaire. The association between LTPA in early adulthood and later was investigated using multinomial logistic regression, with estimated odds ratios (OR), considering three outcome categories: inactive, insufficiently active, and active. Past LTPA was grouped into three categories: never/rarely (reference category), sometimes and frequently/always. Estimates were adjusted for: age; participants' schooling, their father's and mother's schooling, and color/race. RESULTS:Analysis shows men who engaged in LTPA sometimes and almost always/always in early adulthood had an OR= 1.42 (95% CI: 0.70-2.89) and OR= 3.33 (95% CI: 1.82-6.10), respectively, of being physically active in later adulthood than those who did not engage in LTPA. Among women, the corresponding odds ratios were lower: OR = 1.19 (95% CI: 0.79-1.79) and OR =1.42 (95% CI: 1.00-2.04). CONCLUSION:LTPA during early adulthood is associated with physical activity later in adulthood, and this association is stronger in men than in women. Public policies that encourage LTPA among youth, with specific efforts directed at women, could increase the proportion of physically active adults.

Stability of physical activity across the lifespan

Physical activity is associated with various health-relevant psychosocial and physiological processes, but activity stability across extended time periods is inadequately understood. This lifespan longitudinal cohort study examined activity levels of 723 males and 554 females. Associations across time were computed and structural equation modeling compared a one factor model and a simplex model. Results showed activity levels are somewhat stable from childhood through middle and late adulthood. Further, a simplex model provided a better fit than a one factor model. Successful models and interventions to improve health will likely require a more nuanced, pattern-sensitive understanding of physical activity across time.

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.

Themed Review: Clinical Interventions to Promote Physical Activity in Youth

National recommendations call for children and adolescents to accumulate at least 60 minutes of moderate to vigorous physical activity on most days of the week and for physicians to counsel their patients about physical activity. Physical inactivity tracks from childhood into adulthood, and among youth, it is associated with unfavorable risk factor profiles that promote the development of cardiovascular and metabolic chronic diseases. Few studies of clinical interventions to promote physical activity in children and youth have been published, and the paucity of evidence describing effective interventions and significant barriers limit delivery of counseling. However, existing studies provide evidence about elements of counseling most likely to be effective to guide clinical interventions and inform future research. Based on a literature review, this article offers guidance for incorporating physical activity promotion into clinical care, identifies gaps in current evidence, and suggests methodologic considerations for future research.

Screen time and physical activity during adolescence: longitudinal effects on obesity in young adulthood

Background

The joint impact of sedentary behavior and physical activity on obesity has not been assessed in a large cohort followed from adolescence to adulthood.

Methods

Nationally representative longitudinal data from Waves II (1995; mean age: 15.9) and III (2001; mean age: 21.4) of the National Longitudinal Study of Adolescent Health (n = 9,155) were collected. Sex-stratified multivariate logistic regression analysis assessed the odds of obesity associated with Wave II MVPA and screen time, controlling for sociodemographic characteristics and change in MVPA and screen time from Wave II to III. Obesity was defined using body mass index (BMI, kg/m²) International Obesity Task Force cut-points at Wave II and adult cut-points at Wave III (BMI ≥ 30).

Results

In males, adjusted odds of prevalent obesity was strongly predicted by MVPA bouts [OR (95% CI): OR_{6 vs. 1 MVPA bouts} = 0.50 (0.40, 0.62); OR_{4 vs. 40 hrs screen time} = 0.83 (0.69, 1.00)]. In females, greater MVPA bouts and lower screen time correlated with lower prevalent obesity [OR (95% CI): OR_{6 vs. 1 MVPA bouts} = 0.67 (0.49, 0.91); OR_{4 vs. 40 hrs screen time} = 0.67 (0.53, 0.85)]. Longitudinally, adolescent screen time hours had a stronger influence on incident obesity in females [OR (95% CI): OR_{4 vs. 40 hrs} = 0.58 (0.43, 0.80)] than males [OR (95% CI): OR_{4 vs. 40 hrs} = 0.78 (0.61, 0.99)]. Longitudinal activity patterns were not predictive of incident obesity.

Conclusion

Reducing screen time during adolescence and into adulthood may be a promising strategy for reducing obesity incidence, especially in females.

Physical activity levels of normal-weight and overweight girls and boys during primary school recess

OBJECTIVE

This study aimed to compare moderate-to-vigorous physical activity (MVPA) and vigorous physical activity (VPA) in normal-weight and overweight boys and girls during school recess.

RESEARCH METHODS AND PROCEDURES

Four hundred twenty children, age 6 to 10 years, were randomly selected from 25 schools in England. Three hundred seventy-seven children completed the study. BMI was calculated from height and weight measurements, and heart rate reserve thresholds of 50% and 75% reflected children's engagement in MVPA and VPA, respectively.

RESULTS

There was a significant main effect for sex and a significant interaction between BMI category and sex for the percent of recess time spent in MVPA and VPA. Normal-weight girls were the least active group, compared with overweight boys and girls who were equally active. Fifty-one boys and 24 girls of normal weight achieved the 40% threshold; of these, 30 boys and 10 girls exceeded 50% of recess time in MVPA. Eighteen overweight boys and 22 overweight girls exceeded the 40% threshold, whereas 8 boys and 8 girls exceeded the 50% threshold.

DISCUSSION

Overweight boys were significantly less active than their normal-weight male counterparts; this difference did not hold true for girls. Even though nearly double the number of normal-weight children achieved the 40% of MVPA during recess compared with overweight children, physical activity promotion in school playgrounds needs to be targeted not only at overweight but at other health parameters, as 40 overweight children met the 40% MVPA target proposed for recess.

Adolescent skinfold thickness is a better predictor of high body fatness in adults than is body mass index: the Amsterdam Growth and Health Longitudinal Study

BACKGROUND

Body mass index (BMI) during adolescence is predictive of BMI at adult age. However, BMI cannot distinguish between lean and fat body mass. Skinfold thickness may be a better predictor of body fatness.

OBJECTIVE

The objective of this study was to evaluate the relations between BMI and skinfold thickness during adolescence and body fatness during adulthood.

DESIGN

We included 168 men and 182 women from the Amsterdam Growth and Health Longitudinal Study, a prospective study that conducted 8 measurements of BMI and skinfold thickness between 1976 and 2000. BMI and skinfold thickness during adolescence were analyzed in relation to adult body fatness measured at a mean age of 37 y with dual-energy X-ray absorptiometry.

RESULTS

None of the boys and 1.7% of the girls were overweight at baseline, whereas the prevalence of high body fatness during adulthood was 29% in men and 32% in women. At the ages of 12-16 y, skinfold thickness was more strongly associated with adult body fatness than was BMI. Age-specific relative risks for a high level of adult body fatness varied between 2.3 and 4.0 in boys and between 2.1 and 4.3 in girls in the highest versus the lowest tertile of the sum of 4 skinfold thicknesses. For the highest tertile of BMI, the relative risk varied between 0.8 and 2.1 in boys and between 1.3 and 1.8 in girls.

CONCLUSION

Skinfold thickness during adolescence is a better predictor of high body fatness during adulthood than is BMI during adolescence.

Health and nutrition education in primary schools in Crete: 10 years' follow-up of serum lipids, physical activity and macronutrient intake

The current study is a 4-year follow-up after the 6-year-long health and nutrition intervention programme applied in the primary schools of Crete. The aim of the current work was to identify whether the benefits obtained in certain health indices at the end of the intervention period were also present 4 years later. From a representative population of 441 pupils (250 from the intervention schools and 191 from the control schools), biochemical, dietary and physical activity data were obtained at baseline, at the end of the intervention period and after intervention (academic years 1992–1993, 1997–1998 and 2001–2002, respectively). The findings of the current study revealed that the favourable changes in serum lipids observed at the end of the intervention period were maintained from baseline to after intervention for total cholesterol (−24·3 (SE 1·65)V. −9·70 (SE 2·03) mg/dl;P=0·001), LDL-cholesterol (−18·6 (SE 1·41)V. −2·49 (SE 1·75) mg/dl;P<0·001), HDL-cholesterol (−8·34 (SE 0·75)V. −9·60 (SE 1·10) mg/dl;P=0·014) and total cholesterol:HDL-cholestrol ratio (0·31 (SE 0·06)V. 0·04 (SE 0·05);P=0·001). Similar favourable changes for the intervention group were observed in leisure-time physical activities (38·3 (SE 11·7)V. −13·2 (SE 10·9) min/week;P=0·038) and BMI (6·05 (SE 0·18)V. 6·67 (SE 0·21) kg/m2;P=0·014), whereas no changes were observed in the fitness and dietary indices examined. The findings of the current study are encouraging, indicating maintenance of the favourable changes observed in serum lipids, BMI and physical activity 4 years after the programme had ended

Adolescent physical activity and health: a systematic review

Physical activity in adolescence may contribute to the development of healthy adult lifestyles, helping reduce chronic disease incidence. However, definition of the optimal amount of physical activity in adolescence requires addressing a number of scientific challenges. This article reviews the evidence on short- and long-term health effects of adolescent physical activity. Systematic reviews of the literature were undertaken using a reference period between 2000 and 2004, based primarily on the MEDLINE/PubMed database. Relevant studies were identified by examination of titles, abstracts and full papers, according to inclusion criteria defined a priori. A conceptual framework is proposed to outline how adolescent physical activity may contribute to adult health, including the following pathways: (i) pathway A--tracking of physical activity from adolescence to adulthood; (ii) pathway B--direct influence of adolescent physical activity on adult morbidity; (iii) pathway C--role of physical activity in treating adolescent morbidity; and (iv) pathway D - short-term benefits of physical activity in adolescence on health. The literature reviews showed consistent evidence supporting pathway 'A', although the magnitude of the association appears to be moderate. Thus, there is an indirect effect on all health benefits resulting from adult physical activity. Regarding pathway 'B', adolescent physical activity seems to provide long-term benefits on bone health, breast cancer and sedentary behaviours. In terms of pathway 'C', water physical activities in adolescence are effective in the treatment of asthma, and exercise is recommended in the treatment of cystic fibrosis. Self-esteem is also positively affected by adolescent physical activity. Regarding pathway 'D', adolescent physical activity provides short-term benefits; the strongest evidence refers to bone and mental health. Appreciation of different mechanisms through which adolescent physical activity may influence adult health is essential for drawing recommendations; however, the amount of exercise needed for achieving different benefits may vary. Physical activity promotion must start in early life; although the 'how much' remains unknown and needs further research, the lifelong benefits of adolescent physical activity on adult health are unequivocal.

Tracking of physical activity from adolescence to adulthood: a population-based study

OBJECTIVE: To assess the association between regular physical activity in adolescence and leisure-time physical activity in adulthood, with emphasis on gender differences. METHODS: A population-based cross-sectional study was carried out in Pelotas, Southern Brazil, in 2003. A representative sample of households was selected in multiple stages and subjects aged 20-59 years were interviewed. Leisure-time physical activity was evaluated using the International Physical Activity Questionnaire. Data on adolescent physical activity were based on subjects' recall. RESULTS: Of 2,577 subjects interviewed, 27.5% were classified as adequately active, and 54.9% reported regular physical activity in adolescence. Subjects who engaged in regular physical activity during adolescence were more likely to be adequately active in adulthood (adjusted prevalence ratio 1.42; 95% CI: 1.23; 1.65). This effect was stronger in women (adjusted prevalence ratio: 1.51; 95% CI: 1.22; 1.86) than men (adjusted prevalence ratio: 1.35; 95% CI: 1.10; 1.67). CONCLUSIONS: Promoting physical activity in school age may be a successful intervention against the epidemic of adult inactivity. Although women were less likely to report regular physical activity in adolescence, the effect of this experience on adult behavior was stronger than in men.

Health and nutrition education program in primary schools of Crete: changes in blood pressure over 10 years

OBJECTIVE

To examine the long-term effects of the 'Cretan Health and Nutrition Education Program' on blood pressure.

SUBJECTS

A representative population of 176 pupils (85 from the intervention schools and 91 from the control schools).

DESIGN

Blood pressure, dietary, anthropometrical and physical activity data were obtained at baseline (academic year 1992-1993) and at follow-up examination (academic year 2001-2002).

RESULTS

The findings of the current study revealed that the increase over the 10-year period in systolic (SBP) and diastolic blood pressure (DBP) was higher in the control group (CG) than in the intervention group (IG) (P=0.003 and P<0.001 respectively). Regarding dietary indices, the IG were found to have a significantly higher intake of potassium (P=0.018) and magnesium (P=0.011) compared to the CG. Furthermore, the decrease in body mass index (BMI) z-score observed in the IG was found to differentiate significantly from the increase observed in the CG (P=0.042). On the contrary, the increase in leisure time, moderate to vigorous physical activities (MVPA) observed in the IG, was found to differentiate significantly from the decrease observed in the CG (P=0.032). Intervention's effect on SBP was mediated by changes in MVPA (beta=-0.20, P=0.030) and BMI (beta=0.19, P=0.048). Similarly, intervention's effect on DBP was mediated by changes in MVPA (beta=-0.18, P=0.048), BMI (beta=0.26, P=0.007) and magnesium intake (beta=-0.20, P=0.048).

CONCLUSION

The findings of the current study are encouraging, indicating favorable changes in blood pressure, micronutrients intake, BMI and physical activity over the 10 years of follow-up and 4 years after program's cessation, thus providing some support for the effectiveness of school-based health education programs in successfully tackling certain chronic disease risk factors early in life.

Adolescence: A Critical Period for Long-Term Tracking of Risk for Coronary Heart Disease?

Tracking of dietary and physical activity patterns throughout adolescence into adulthood is low, which indicates that risk patterns for coronary heart disease are not maintained. Biological risk factors for heart disease, particularly obesity and clusters of nutritionally modifiable risk factors (e.g. the metabolic syndrome), display somewhat higher tracking correlations. Tracking gives little guidance as to how to use this information for screening purposes. For behavioral and biological risk factors predictive values and sensitivities and specificities are generally low, suggesting that population-based approaches are likely to be more effective than targeting only the high-risk subset for reducing the risk of coronary heart disease.