Bianca El-Naaman

Tracking of clustered cardiovascular disease risk factors from childhood to adolescence

Background:Clustering of cardiovascular disease (CVD) risk factors has been found in children as young as 9 y of age. However, the stability of this clustering over the course of childhood has yet to be determined. The purpose of this study was to determine the tracking of clustered CVD risk from young school age through adolescence and to examine differences in tracking between levels of overweight/obesity and cardiorespiratory fitness (VO2peak).Methods:Beginning at 6 y, children (n = 434) were measured three times in 7 y. Anthropometrics, blood pressure, and VO2peak were measured. Fasting blood samples were analyzed for CVD risk factors. A clustered risk score (z-score) was constructed by adding sex-specific z-scores for blood pressure, homeostatic model assessment (HOMA-IR), triglyceride (TG), skinfolds, and negative values of high-density lipoprotein cholesterol (HDLc) and VO2peak.Results:Significant tracking coefficients were found between clustered z-score at all time intervals (r = 0.514, 0.559, and 0.381 between ages 6–9, 9–13, and 6–13 y, respectively, all P < 0.0001). Tracking was higher for low-fit children, whereas no clear pattern was found for different levels of body fat.Conclusion:We found that clustered z-score is a fairly stable characteristic through childhood. Implementation of preventive strategies could therefore start at early school age.

The association between physical activity, physical fitness and development of metabolic disorders

BACKGROUND Cardiovascular (CVD) risk factors have been shown to cluster in some children. This has been shown in children from the age of nine years, but recently we found no clustering in six-year old children. It is uncertain when clustering develops and which parameters are related to the development of clustered CVD risk. METHODS A longitudinal study including 484 children aged six years. Three years later, 434 children participated in a follow-up. The main outcome was clustering of five CVD risk factors: homeostasis assessment insulin resistance (HOMA), total cholesterol:HDL ratio, triglyceride (TG), systolic blood pressure and sum of four skinfolds. Independent variables were physical activity and cardiorespiratory fitness. RESULTS CVD risk factors were independently distributed in the six-year-olds, and there was no association between composite risk factor score and physical fitness or activity even if there were obese and unfit children in the population. Clustering of CVD risk factors was found at the age of nine years, and the observed number with three or more CVD risk factors was 3.33 (95% CI: 1.41-7.87) times higher than expected if risk factors had been independently distributed. At the age of nine years, the lowest quartile of fitness had 34.9 (95% CI: 8.0-152.5) times higher risk of having clustered risk than the most fit quartile. CONCLUSION Clustering of CVD risk factors developed between the age of six and nine years. At nine years of age clustered CVD risk was highly associated with low fitness level.

Effects of a three-year intervention: the Copenhagen School Child Intervention Study.

INTRODUCTION This study assessed short-term and long-term effects of a 3-yr controlled school-based physical activity (PA) intervention on fatness, cardiorespiratory fitness (VO(2peak)) and CVD risk factors in children. METHODS The study involved 18 schools (10 intervention and 8 controls) and included a follow-up 4 yr after the end of intervention. The analyses included 696, 6- to 7-yr-old children at baseline, 612 postintervention (age 9.5 yr) and 441 at follow-up (age 13.4 yr). The intervention consisted of a doubling of the amount of physical education (PE; from 90 to 180 min·wk(-1)), training of PE teachers, and upgrading of PE and playing facilities. Anthropometrics and systolic blood pressure (SBP) were measured. VO(2peak) was directly measured, and PA was assessed using accelerometry. Fasting blood samples were analyzed for CVD risk factors. A composite risk score was computed from z-scores of SBP, triglycerides, total cholesterol-to-HDL cholesterol ratio, homeostatic model assessment (HOMA score), skinfolds, and inverse VO(2peak). RESULTS The HOMA score of the intervention group boys had a smaller increase from baseline to postintervention compared with control boys (P = 0.004). From baseline to follow-up intervention group boys had a smaller increase in SBP compared with control boys (P = 0.010). There were no other significant differences between groups. CONCLUSIONS This 3-yr school-based PA intervention caused positive changes in SBP and HOMA score in boys but not in girls, and no effects were seen in PA, VO(2peak), fatness, and the other measured CVD risk factors. Our results indicate that a doubling of PE and providing training and equipment may not be sufficient to induce major improvements in CVD risk factors in a normal population.

Association between sweet drink intake and adiposity in Danish children participating in a long‐term intervention study

In several studies direct associations between intake of sugar‐sweetened beverages and adiposity have been reported. However, most previous studies were conducted among Americans and assessed the intake in the sub‐categories of soft drinks and sugar‐sweetened beverages, only, rather than the total intake of sweet drinks.

Inflammatory Markers and Clustered Cardiovascular Disease Risk Factors in Danish Adolescents

Aims: To evaluate the associations between inflammatory markers and clustering of cardiovascular disease (CVD) risk factors, and to examine how inflammatory markers and CVD risk are related to fatness and cardiorespiratory fitness (VO2peak) in adolescents. Methods: Body mass and height, skinfolds and blood pressure of 413 adolescents (mean age 13.4 ± 0.3 years) were measured. Circulating fasting levels of glucose, insulin, lipids, adiponectin, C-reactive protein (CRP), tumor necrosis factor (TNF)α, soluble TNF receptor-1 (sTNFR1), interleukin (IL)-6 and IL-1 receptor antagonist (IL-1Ra) were measured. VO2peak was measured in progressive tests to exhaustion. CVD risk was expressed as a clustered z-score, summing standardized values of individual risk factors. Results: The clustered z-score was negatively associated with adiponectin and positively associated with CRP, IL-6 and TNFα (all p values <0.05). The associations with adiponectin, CRP and IL-6 were stronger for the fattest adolescents. VO2peak was negatively correlated with clustered z-score, adiponectin and IL-6 and positively related to systolic blood pressure. The sum of four skinfolds was inversely related to adiponectin and positively correlated to body mass index, systolic blood pressure, homeostasis model assessment, clustered z-score and CRP. Conclusion: In adolescents, CVD risk was associated with alternations in adiponectin, TNFα, CRP and IL-6, and related to both VO2peak and fatness.

Sex Differences in the Association between Level of Childhood Interleukin-6 and Insulin Resistance in Adolescence

The purpose of this study was to determine whether levels of interleukin-6 (IL-6) in childhood are related to insulin resistance in adolescence. Further, to explore how fatness and cardiorespiratory fitness (VO2peak) moderate this relationship. Methods. 292 nine-year-old children (n = 292) were followed for 4 years. Anthropometrics and VO2peak were measured. Fasting blood samples were analyzed for IL-6, insulin, and glucose. Homeostasis model assessment (HOMA-IR) was used as a measure of insulin resistance. Results. For girls but not boys, levels of IL-6 at age 9 yrs correlated with HOMA-IR at age 13 yrs: r = 0.223, P = 0.008. Girls with IL-6 levels within the highest quartile at age 9 yrs had an odds ratio of 3.68 (CI = 1.58–8.57) being in the highest quartile of HOMA-IR four years later. Conclusion. In this cohort, IL-6 levels in childhood were related to insulin resistance in adolescence, but only for girls.

Intervention effects on dietary intake among children by maternal education level: results of the Copenhagen School Child Intervention Study (CoSCIS).

Dietary intake among Danish children, in general, does not comply with the official recommendations. The objectives of the present study were to evaluate the 3-year effect of a multi-component school-based intervention on nutrient intake in children, and to examine whether an intervention effect depended on maternal education level. A total of 307 children (intervention group: n 184; comparison group: n 123) were included in the present study. All had information on dietary intake pre- and post-intervention (mean age 6·8 and 9·5 years for intervention and comparison groups, respectively) assessed by a 7-d food record. Analyses were conducted based on the daily intake of macronutrients (energy percentage (E%)), fatty acids (E%), added sugar (E%) and dietary fibre (g/d and g/MJ). Analyses were stratified by maternal education level into three categories. Changes in nutrient intake were observed in the intervention group, mainly among children of mothers with a short education ( < 10 years). Here, intake of dietary fibre increased (β = 2·1 g/d, 95 % CI 0·5, 3·6, P= 0·01). Intake of protein tended to increase (β = 0·6 E%, 95 % CI -0·01, 1·2, P= 0·05), while intake of fat (β = -1·7 E%, 95 % CI -3·8, 0·3, P= 0·09) and SFA (β = -0·9, 95 % CI -2·0, 0·2, P= 0·10) tended to decrease. Also, a significant intervention effect was observed on the intake of SFA among children of mothers with a long education (β = -0·8, 95 % CI -1·5, -0·03, P= 0·04). This multi-component school-based intervention resulted in changes in the dietary intake, particularly among children of mothers with a short education. As the dietary intake of this subgroup generally differs most from the recommendations, the results of the present study are particularly encouraging.

Dietary arginine and linear growth: the Copenhagen School Child Intervention Study

The amino acid arginine is a well-known growth hormone (GH) stimulator and GH is an important modulator of linear growth. The aim of the present study was to investigate the effect of dietary arginine on growth velocity in children between 7 and 13 years of age. Data from the Copenhagen School Child Intervention Study during 2001-2 (baseline), and at 3-year and 7-year follow-up, were used. Arginine intake was estimated via a 7 d precoded food diary at baseline and 3-year follow-up. Data were analysed in a multilevel structure in which children were embedded within schools. Random intercept and slopes were defined to estimate the association between arginine intake and growth velocity, including the following covariates: sex; age; baseline height; energy intake; puberty stage at 7-year follow-up and intervention/control group. The association between arginine intake and growth velocity was significant for the third and fourth quintile of arginine intake (2.5-2.8 and 2.8-3.2 g/d, respectively) compared with the first quintile ( < 2.2 g/d) (P for trend = 0.04). Protein intake (excluding arginine) was significantly associated with growth velocity; however, the association was weaker than the association between arginine intake and growth velocity (P for trend = 0.14). The results of the present study suggest a dose-dependent physiological role of habitual protein intake, and specifically arginine intake, on linear growth in normally growing children. However, since the study was designed in healthy children, we cannot firmly conclude whether arginine supplementation represents a relevant clinical strategy. Further research is needed to investigate whether dietary arginine may represent a nutritional strategy potentially advantageous for the prevention and treatment of short stature.