Guidelines and Expert Consensus Documents summarize and evaluate all currently available evidence on a particular issue with the aim to assist physicians in selecting the best management strategies for a typical patient, suffering from a given condition, taking into account the impact on outcome, as well as the risk–benefit ratio of particular diagnostic or therapeutic means. Guidelines are not substitutes for textbooks. The legal implications of medical guidelines have been discussed previously.

A great number of Guidelines and Expert Consensus Documents have been issued in recent years by the European Society of Cardiology (ESC) as well as by other societies and organizations. Because of the impact on clinical practice, quality criteria for development of guidelines have been established in order to make all decisions transparent to the user. The recommendations for formulating and issuing ESC Guidelines and Expert Consensus Documents can be found on the ESC web site (http://www.escardio.org/knowledge/guidelines/rules).

In brief, experts in the field are selected and undertake a comprehensive review of the published evidence for management and/or prevention of a given condition. A critical evaluation of diagnostic and therapeutic procedures is performed, including assessment of the risk–benefit ratio. Estimates of expected health outcomes for larger societies are included, where data exist. The level of evidence and the strength of recommendation of particular treatment options are weighed and graded according to predefined scales, as outlined in the tables below.

The experts of the writing panels have provided disclosure statements of all relationships they may have which might be perceived as real or potential sources of conflicts of interest. These disclosure forms are kept on file at the European Heart House, headquarters of the ESC. Any changes in conflict of interest that arise during the writing period must be notified to the ESC. The Task Force report was entirely …

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European guidelines on cardiovascular disease prevention in clinical practice (version 2012) : the fifth joint task force of the European society of cardiology and other societies on cardiovascular disease prevention in clinical practice (constituted by representatives of nine societies and by invited experts).

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(12)60735-1.pdf

Correlates of physical activity: why are some people physically active and others not?

Overweight and obesity in youth are important public health concerns and are of particular interest because of possible long-term associations with adult weight status and morbidity. The aim of this study was to systematically review the literature and update evidence concerning persistence of childhood overweight. A computerized bibliographical search--restricted to studies with a prospective or retrospective longitudinal design--was conducted. Two authors independently extracted data and assessed the methodological quality of the included studies in four dimensions (i) study population and participation rate; (ii) study attrition; (iii) data collection and (iv) data analysis. Conclusions were based on a rating system of three levels of evidence. A total of 25 publications were selected for inclusion in this review. According to a methodological quality assessment, 13 studies were considered to be of high quality. The majority of these high-quality studies were published after 2001, indicating that recently published data, in particular, provide us with reliable information. All included studies consistently report an increased risk of overweight and obese youth becoming overweight adults, suggesting that the likelihood of persistence of overweight into adulthood is moderate for overweight and obese youth. However, predictive values varied considerably. Limiting aspects with respect to generalizability and methodological issues are discussed.

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Tracking of childhood overweight into adulthood: a systematic review of the literature

The "fetal" or "early" origins of adult disease hypothesis was originally put forward by David Barker and colleagues and stated that environmental factors, particularly nutrition, act in early life to program the risks for adverse health outcomes in adult life. This hypothesis has been supported by a worldwide series of epidemiological studies that have provided evidence for the association between the perturbation of the early nutritional environment and the major risk factors (hypertension, insulin resistance, and obesity) for cardiovascular disease, diabetes, and the metabolic syndrome in adult life. It is also clear from experimental studies that a range of molecular, cellular, metabolic, neuroendocrine, and physiological adaptations to changes in the early nutritional environment result in a permanent alteration of the developmental pattern of cellular proliferation and differentiation in key tissue and organ systems that result in pathological consequences in adult life. This review focuses on those experimental studies that have investigated the critical windows during which perturbations of the intrauterine environment have major effects, the nature of the epigenetic, structural, and functional adaptive responses which result in a permanent programming of cardiovascular and metabolic function, and the role of the interaction between the pre- and postnatal environment in determining final health outcomes.

https://www.physiology.org/doi/pdf/10.1152/physrev.00053.2003

Developmental Origins of the Metabolic Syndrome: Prediction, Plasticity, and Programming

Purpose: The range of variability between individuals of the same chronological age (CA) in somatic and biological maturity is large and especially accentuated around the adolescent growth spurt. Maturity assessment is an important consideration when dealing with adolescents, from both a research perspective and youth sports stratification. A noninvasive, practical method predicting years from peak height velocity (a maturity offset value) by using anthropometric variables is developed in one sample and cross-validated in two different samples. Methods: Gender specific multiple regression equations were calculated on a sample of 152 Canadian children aged 8-16 yr (79 boys; 73 girls) who were followed through adolescence from 1991 to 1997, The equations included three somatic dimensions (height, sitting height, and leg length), CA, and their interactions. The equations were cross-validated on a Combined sample of Canadian (71 boys, 40 girls measured from 1964 through 1973) and Flemish children (50 boys, 48 girls measured from 1985 through 1999). Results: The coefficient of determination (R2) for the boys' model was 0.92 and for the girls' model 0.91 the SEEs were 0.49 and 0.50, respectively, Mean difference between actual and predicted maturity offset for the verification samples was 0.24 (SD 0.65) yr in boys and 0,001 (SD 0.68) yr in girls. Conclusion: Although the cross-validation meets statistical standards or acceptance, caution 1, warranted with regard to implementation. It is recommended that maturity offset be considered as a categorical rather than a continuous assessment. Nevertheless, the equations presented are a reliable, noninvasive and a practical solution for the measure of biological maturity for matching adolescent athletes.

An assessment of maturity from anthropometric measurements.

Strength phenotypes are under strong genetic control, but much research is still required

Muscular strength and power are important components of fitness essential for the execution of a variety of daily and sporting activities. Static or isometric strength, explosive strength or power, and dynamic (sometimes called functional) strength are generally considered in epidemiological studies.

Analyses of the genetic determinants of strength provide information concerning the contribution of both genes and environmental factors. Interaction effects between genes and environment (the dependence of weight training response on genes) and the identification of genes or coding variants in relation to strength characteristics are also of interest.

Power and strength show normal variation in the general population, as is typical for quantitative, multifactorial phenotypes that are influenced by both multiple genes (polygenic) and environmental factors. The search for the genetic basis of muscular strength and power is based on two approaches: the unmeasured genotype approach (top down) and the measured genotype approach (bottom up).

When the measured genotype is not available, inferences concerning genetic influences on a phenotype are based on statistical analyses of the distributions of strength measures in related individuals and families based on the theoretical framework of biometrical genetics. Twin and family studies are the two major strategies used to identify genetic and environmental contributions to muscular strength. The heritability coefficient derived thereof is specific for the studied population and can be estimated using ANOVA or genetic modelling techniques.

Two major complementary strategies are available in humans to identify genes using the measured genotype approach. The first method is localisation and identification by quantitative …

https://bjsm.bmj.com/content/bjsports/40/10/822.full.pdf

Gene driven power athletes? Genetic variation in muscular strength and power

The purpose of this study was to determine whether the observed phenotypic stability in static strength during adolescence, as measured by interage correlations in arm pull, is mainly caused by gen...

https://www.physiology.org/doi/pdf/10.1152/japplphysiol.00021.2005

Genetic and environmental determination of tracking in static strength during adolescence

Purpose: To determine whether the observed phenotypic stability in explosive strength during adolescence, as measured by inter-age correlations in vertical jump (VTJ), is mainly caused by genetic and/or environmental factors Methods: Subjects are from the Leuven Longitudinal Twin Study (LLTS) (n = 105 pairs, equally divided over five zygosity groups) VTJ data were aligned on age at peak height velocity (APHV) to attenuate the temporal fluctuations in inter-age correlations caused by differences in timing of the adolescent growth spurt Simplex models were fitted using structural equation modelling Results: After aligning the data on APHV, the annual inter-age correlations show a clear simplex structure over a 4 year interval The best fitting models included additive genetic and unique environmental sources of variation Heritability estimates ranged between 608% (CI 377%–772%) and 873% (CI 742%–940%) for boys and between 765% (CI 567%–890%) and 886% (CI 778%–941%) for girls Up to 564% and 628% of the total variation at the last measurement occasion is explained by additive genetic factors that already explained a significant amount of variation at previous measurement occasions in boys and girls respectively It thus can be concluded that the observed stability of explosive strength during adolescence is mainly caused by a stable genetic influence in boys and girls Conclusions: Additive genetic factors seem to be the main cause of the observed phenotypic stability in VTJ performance in boys and girls during adolescence

Genetic and environmental causes of tracking in explosive strength during adolescence.

There is an apparent link between fetal and childhood growth and puberty and risk for several degenerative diseases in adulthood. It is also important to consider associations between birth weight and indicators of growth and biological maturation during childhood and adolescence as potential explanations for associations between fetal growth and adult risk for disease. The present study examines the association between birth weight and (1) size attained and rate of growth in body size and cortical bone area of the second metacarpal (M II), and (2) skeletal age and rate of skeletal maturation in children 6-11 years of age. The sample included 127 boys and 105 girls of European ancestry, divided into two age groups, 6-8 years and 9-11 years. The relationship between birth weight and attained size (stature, mass, and the BMI), M II cortical area and skeletal age (SA, Tanner-Whitehouse method) during childhood was examined with correlational analyses. Observations on children measured on two occasions were converted to annual velocities, and correlations between birth weight and annual velocities were also calculated. Birth weight is significantly associated with stature and mass in boys and only with stature in girls 6-11 years of age, but is not related to the BMI, M II cortical area, or skeletal maturity. Birth weight is not significantly related to annual velocities of growth in stature, mass, the BMI and M II cortical area; to the annual increment in SA; and to weight gain from birth to the time of measurement (intervals of 6 to 11 years). The results emphasize a role of other influences than birth weight on growth rate, cortical area of M II, and skeletal maturation during childhood. Am. J. Hum. Biol. 11:505-511, 1999. Copyright 1999 Wiley-Liss, Inc.

Relation between birth weight at term and growth rate, skeletal age, and cortical bone at 6-11 years.

UNLABELLED It is has been suggested that repetitive loading on the distal end of the radius in elite gymnasts may lead to epiphyseal changes, a premature closure (union) of the radius growth plate, and ulnar overgrowth. PURPOSE It is hypothesized that ulnar overgrowth in female gymnasts is associated with advanced maturity status and early onset of epiphyseal closure of the radius, and later maturity status and later onset of epiphyseal closure of the ulnar. METHODS Posterior-anterior radiographs of 201 female gymnasts, participants of the 1987 World Championships Artistic Gymnastics, were used to measure ulnar overgrowth, to determine skeletal maturation of the hand and wrist with the Tanner-Whitehouse technique, and to determine the maturity status of the radius and ulna separately, particularly with regard to the onset of epiphyseal closure. To test the hypothesis, extreme quintiles for ulnar overgrowth were contrasted for skeletal maturation of the hand and wrist and for maturity stages of the radius and ulna as defined by the Tanner-Whitehouse criteria. RESULTS Female gymnasts who demonstrate ulnar overgrowth are skeletally more advanced in maturity status of the entire hand-wrist compared with gymnasts who did not show ulnar overgrowth. There were, however, no differences between gymnasts in the extreme quintiles of ulnar overgrowth in the maturation of the radius, although gymnasts with ulnar overgrowth show more advanced maturity status of the ulna. CONCLUSIONS Ulnar overgrowth is thus not apparently associated with advanced maturity of the distal radial epiphysis as defined in protocols for assessing skeletal maturity and does not apparently lead to premature epiphyseal closure of the distal radius.

Gaston Beunen

Papers

Gene driven power athletes? Genetic variation in muscular strength and power

Genetic and environmental determination of tracking in static strength during adolescence

Genetic and environmental causes of tracking in explosive strength during adolescence.

Relation between birth weight at term and growth rate, skeletal age, and cortical bone at 6-11 years.

Ulnar variance and skeletal maturity of radius and ulna in female gymnasts