H.C.G. Kemper

A randomized trial investigating an exercise program to prevent reduction of bone mineral density and impairment of motor performance during treatment for childhood acute lymphoblastic leukemia

Reduced bone mineral density (BMD), altered body composition, impaired motor performance and passive ankle dorsiflexion are side effects of acute lymphoblastic leukemia (ALL) treatment. We performed a randomized study investigating whether an exercise program could prevent these side effects.

Body composition and physical fitness of undernourished South African rural primary school children

Objective:The purpose of this study was to determine the relationships between the body composition characteristics, body mass index (BMI), sum of skinfolds (SSF), % body fat (%BF), fat-free mass (FFM) and waist-to-hip ratio (WHR), and nine physical fitness items in undernourished rural primary school children in Ellisras, South Africa.Design:A cross-sectional study.Setting:The study consisted of 462 boys and 393 girls who were aged 7–14 y.Measurements:Five body composition measures were assessed: BMI, SSF, %BF, FFM and WHR. Nine physical fitness test items were assessed: standing long jump, bent arm hang, sit-ups, 10 × 5 m shuttle run, 50 m sprint, 1600 m run, flamingo balance, sit and reach, plate tapping.Results:BMI was highly correlated with FFM (r=0.7, P<0.001). In line with findings from Western countries, regression coefficients (B) showed that children with higher BMI or SSF performed worse in bent arm hang (girls, B=−0.84, P<0.001, and B=−0.06, P=0.02, respectively) and in 1600 m run (B=6.68, P<0.001). BMI was significantly associated with flamingo balance (B=0.26, P=0.04). WHR was positively associated with bent arm hang (B=9.37, P=0.03), and inversely with sit and reach (B=−7.48, P=0.01). In contrast, significant relationships were found between BMI and standing long jump (B=0.74, P=0.04), sit and reach (B=0.51, P<0.001), flamingo balance (B=0.26, P=0.04) and plate tapping (B=−19, P=0.01). SSF was significantly associated with sit and reach (B=0.04, P=0.03). Significant inverse associations were found between FFM and bent arm hang (girls, B=−0.06, P=0.05), 1600 m run (girls, B=−2.33, P=0.003) and 50 m run (boys, B=−0.11, P=0.006). FFM was significantly associated with standing long jump (boys, B=0.99, P<0.001; girls, B=0.73, P<0.001), flamingo balance (B=0.17, P<0.001), and with sit and reach (boys, B=0.59, P=0.03).Conclusion:In the present study in undernourished children, body composition was significantly related to physical fitness, but not always in the expected direction. It is therefore important to note that in this population, BMI should not be interpreted as a measure of fatness/overweight, but rather as an indicator of muscle mass.Sponsorship:Financial support was received from the Vrije Universiteit, Amsterdam, The Netherlands, and the University of the North, Sovenga, South Africa.

Current and adolescent levels of cardiopulmonary fitness are related to large artery properties at age 36: the Amsterdam Growth and Health Longitudinal Study

Background High levels of cardiopulmonary fitness (VO2max) are associated with reduced risk of cardiovascular morbidity and mortality, but little is known to what extent this is related to the effects of cardiopulmonary fitness on atherosclerosis and arterial stiffness. Moreover, the time course of these relationships needs to be elucidated. We sought to investigate (i) the cross‐sectional relationship between VO2max and carotid atherosclerosis and carotid and femoral arterial stiffness at age 36, as well as (ii) the relationship between VO2max during adolescence (13–16 years) and the same arterial properties at age 36 (prospective analyses).

Current and adolescent body fatness and body fat distribution are related to carotid atherosclerosis and large artery stiffness at age 36.

Objective Body fat and its distribution are determinants of cardiovascular disease but the underlying mechanisms of these adverse effects are poorly understood. We therefore investigated (1) the cross-sectional relationship between estimates of body fatness and its distribution on the one hand and carotid atherosclerosis and stiffness of the carotid, femoral and brachial arteries and the carotido-femoral segment on the other (336 subjects, 175 women); (2) the relationship between estimates of body fatness and its distribution during adolescence (13–16 years) and the same arterial properties at age 36– prospective analyses (subpopulation of 159 subjects, 84 girls). Design Cross-sectional and prospective analyses within an ongoing observational longitudinal study: The Amsterdam Growth and Health Longitudinal Study. Methods Body fatness and its distribution were assessed by anthropometry and dual-energy X-ray absorptiometry (DXA); arterial properties were assessed non-invasively by ultrasound imaging. Results Total adiposity and, in men, truncal subcutaneous fat accumulation during adolescence, were positively and independently associated with carotid intima–media thickness at age 36, a pre-clinical indicator of atherosclerosis. Adolescent truncal subcutaneous fat accumulation but not total adiposity was associated with increased arterial stiffness at age 36. At age 36, both abdominal and truncal subcutaneous fat were independently associated with arterial stiffness, while the associations between total adiposity and arterial stiffness appeared to be mediated by other cardiovascular risk factors. Conclusions Body fatness and body fat distribution are associated with large artery structural and functional properties at age 36 and the roots of these associations may already be present in adolescence.

Motor fitness in Dutch youth: Differences over a 26-year period (1980–2006)

This study aimed to compare neuromotor fitness test scores of 9-12-year-old Dutch youth in 2006 with scores of same aged children in 1980. Body height, body weight and performance on neuromotor fitness test items were measured in 2050 Dutch children from 9 to 12 years in 2006 and were compared with data of 2603 same aged Dutch children measured in 1980 with the same neuromotor fitness test battery. Dutch 9-12 year olds in 2006 were significantly taller and heavier than their peers in 1980. Age- and sex-specific performance on almost all neuromotor fitness test items was significantly worse in 2006. Thus, our data suggest that neuromotor fitness of Dutch youth has significantly decreased over the past 26 years.

Validation of a Physical Activity Questionnaire to Measure the Effect of Mechanical Strain on Bone Mass

Most of the questionnaires available to estimate the daily physical activity levels of humans are based on measuring the intensity of these activities as multiples of resting metabolic rate (METs). Metabolic intensity of physical activities is the most important component for evaluating effects on cardiopulmonary fitness. However, animal studies have indicated that for effects on bone mass the intensity in terms of energy expenditure (metabolic component) of physical activities is less important than the intensity of mechanical strain in terms of the forces by the skeletal muscles and/or the ground reaction forces. The physical activity questionnaire (PAQ) used in the Amsterdam Growth and Health Longitudinal Study (AGAHLS) was applied to investigate the long-term effects of habitual physical activity patterns during youth on health and fitness in later adulthood. The PAQ estimates both the metabolic components of physical activities (METPA) and the mechanical components of physical activities (MECHPA). Longitudinal measurements of METPA and MECHPA were made in a young population of males and females ranging in age from 13 to 32 years. This enabled evaluation of the differential effects of physical activities during adolescence (13-16 years), young adulthood (21-28 years), and the total period of 15 years (age 13-28 years) on bone mineral density (BMD) of the lumbar spine, as measured by dual-energy X-ray absorptiometry (DXA) in males (n = 139) and females (n = 163) at a mean age of 32 years. The PAQ used in the AGAHLS during adolescence (13-16 years) and young adulthood (21-28 years) has the ability to measure the physical activity patterns of both genders, which are important for the development of bone mass at the adult age. MECHPA is more important than METPA. The highest coefficient of 0.33 (p < 0.01) was between MECHPA measured over the total period of 15 years (13-28 years) and lumbar BMD at age 32 years. Only during adolescence (12-16 years) was METPA more important with regard to lumbar BMD at age 32 years, with a beta of 0.21 (p < 0.01). The relative validity of the PAQ was established by comparing PAQ scores during four annual measurements in 200 boys and girls with two other objective measures of physical activity: movement counters (pedometers) and heart rate monitoring. These showed significant (p < 0.01) correlations in both genders, varying between 0.16 and 0.20. The small variation indicates, however, that all three instruments measure different aspects of physical activity. The results from the PAQ, with respect to MECHPA, validated in humans the results from animal studies in which bone adaptation during skeletal growth and development continuously adjust skeletal mass and architecture to changing mechanical stimuli caused by physical activity.

Computerization of a dietary history interview in a running cohort; evaluation within the Amsterdam Growth and Health Longitudinal Study

Objective: In nutritional research, a growing interest in the use of computer-assisted cross-check dietary history interview methods exists in order to improve cost-effectiveness. The introduction of such a method in an ongoing longitudinal study was evaluated with special emphasis on the effect on interviewer bias.Design: A study for the interviewer bias within and the agreement between a previously used paper-based face-to-face cross-check dietary history interview method and a newly developed interviewer-administered computer-assisted version of this interview method.Subjects: The interviewer bias of 436 face-to-face interviews is compared with that of 352 computer-assisted interviews. A subset of 82 subjects underwent a face-to-face interview at the mean age of 27 and 32 y and a computer-assisted interview at their mean age of 36 y. Energy, three macronutrients (protein, fat and carbohydrate), two micronutrients (calcium and iron) and alcohol intakes obtained by these three measurements are compared to analyse the agreement between the two interview methods.Results: ANOVA showed no interviewer bias for all seven analysed nutrients within the data from the computer-assisted interview, while for the face-to-face interview method, several nutrients varied significantly among the interviewers. Five different measures, used to analyse the agreement (differences, Pearsons correlation, ICC, square weighted kappa and Bland–Altman plots), showed no relevant differences between the two cross-check dietary history interview methods.Conclusions: It is concluded that the computer-assisted interview caused a reduction of interviewer bias and is of similar quality to the face-to-face interview method. Computerization of a paper-based interview can be implemented in a running cohort if a change in method is unavoidable.

The association between dietary patterns and cardio vascular disease risk indicators in healthy youngsters: Results covering fifteen years of longitudinal development

Objective: To examine longitudinal relationships between nutrition and risk indicators for cardio vascular diseases (CVD) during adolescence and young adulthood. Design: A longitudinal study over fifteen years. Subjects: 98 females and 84 males, from 13 to 27 years. Methods: By means of six interviews dietary patterns were determined. Blood samples were analyzed for serum concentration of total cholesterol (TC), and high-density-lipoprotein (HDL), bloodpressure, body fat and maximal aerobic power (VO2max) were determined. The longitudinal relations were analyzed with generalized estimation equations (GEE), a statistical technique in which relations at different time-points are tested simultaneously. Results: Compared to Dutch recommendations six out of seven macro nutrients appear to be unfavorable with respect to CVD. Borderline or high CVD risk values are apparent at 27 y in more than 25% of the subjects with respect to percentage body fat and serum total cholesterol in both sexes. In males 40% or more show borderline hypertension. The ‘univariate’ longitudinal analyses showed significantly positive relations: (1) between the intake of animal protein, saturated fat (SFA), cholesterol (Chol) and TC, and HDL; (2) between total energy intake (EN) and systolic blood pressure, and VO2max. Significantly negative associations were found: (1) between EN, poly-unsaturated fat (PUFA) and TC concentrations; (2) between EN and sum of four skinfolds (SSF). Conclusions: With increasing age, over a period of 15 y in both sexes the SFA and Chol intake relate significantly to the development of a negative CVD risk profile. The intake of PUFA relates positive to a CVD risk profile. The significantly negative relation between EN intake and body fat (SSF) is partly explained by the relation between EN and VO2max.

Relation between the longitudinal development of lipoprotein levels and biological parameters during adolescence and young adulthood in Amsterdam, The Netherlands.

STUDY OBJECTIVES: To analyse the relation between the longitudinal development of total serum cholesterol (TC), high density lipoprotein cholesterol (HDL), and the TC/ HDL ratio and the longitudinal development of the biological parameters body fatness (SSF), lean body mass (LBM), and cardiopulmonary fitness (VO2-max). The relations were analysed with generalised estimating equations (GEE). SETTING: The relations were investigated with data from the Amsterdam growth and health study, a longitudinal study in which six measurements were carried out within a period of 15 years. PARTICIPANTS: Altogether 98 females and 84 males aged 13 years at the start of the study. MAIN RESULTS: Adjusted for lifestyle and other biological parameters, the longitudinal development of TC was inversely related to the development of LBM (standardised regression coefficient beta = -0.27; p < or = 0.01) and positively to SSF (beta males = 0.32; p < or = 0.01 and beta females = 0.15; p < or = 0.01). HDL was inversely related to LBM (beta = -0.26; p < or = 0.01) and positively to VO2-max (beta = 0.08; p < or = 0.05). The TC/HDL ratio was positively related to SSF (beta males = 0.39; p < or = 0.01 and beta females = 0.13; p < or = 0.01) and inversely to VO2-max (beta = -0.09; p < or = 0.05). CONCLUSIONS: The longitudinal analyses showed that body fatness was related to a high risk profile with respect to hypercholesterolaemia, and cardiopulmonary fitness to a low risk profile. Furthermore, it was shown that using body mass index as an indicator of body fatness in relation to lipoprotein values, has some important drawbacks.

The Relationship between Health (Malnutrition) and Educational Achievements (Maths and English) in the Rural Children of South Africa.

Abstract The purpose of this paper is to report the cross-sectional relationship between educational achievements and the ‘health status’ of the rural South African children in the Ellisras Longitudinal Study (ELS). The study followed a cohort design where 1033 children (569 boys and 464 girls) aged 7–14 were randomly sampled from 11 primary schools and one secondary school. Anthropometric measurements for height for age (HAZ), weight for age (WAZ), body mass index (BMI) and sum of skinfolds (SOS) were carried out to establish their ‘health status’. Educational achievement tests for Mathematics and English were administered to check their educational status. The results of the multilevel analysis showed that HAZ, WAZ and BMI were positively related to both English and Mathematics performance. HAZ was only positively related to mathematical performance and SOS was not related to educational achievement at all. Furthermore, age and gender only marginally influenced the observed relationships. The study recommends that other factors such as socio-economic status and learning environment should be looked into to find out whether these factors influence the observed relationships.