Idoia Labayen

Breakfast consumption and CVD risk factors in European adolescents: the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study

OBJECTIVEnTo examine the association between breakfast consumption and CVD risk factors in European adolescents.nnnDESIGNnCross-sectional. Breakfast consumption was assessed by the statement ‘I often skip breakfast’ and categorized into ‘consumer’, ‘occasional consumer’ and ‘skipper’. Blood pressure, weight, height, waist circumference, skinfold thickness, total cholesterol (TC), HDL cholesterol (HDL-C), LDL cholesterol (LDL-C), TAG, insulin and glucose were measured and BMI, TC:HDL-C, LDL-C:HDL-C and homeostasis model assessment–insulin resistance index (HOMA-IR) were calculated.nnnSETTINGnThe European Union-funded HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study.nnnSUBJECTSnEuropean adolescents, aged 12?50–17?49 years, from ten cities within the HELENA study (n 2929, n 925 with blood sample, 53% females).nnnRESULTSnIn males, significant differences across breakfast consumption category (‘consumer’, ‘occasional consumer’ and ‘skipper’) were seen for age, BMI, skinfold thickness, waist circumference, cardiorespiratory fitness, systolic and diastolic blood pressures, TC:HDL-C, LDL-C:HDL-C, glucose, insulin, HOMA-IR and LDL-C; in females, for cardiorespiratory fitness, skinfold thickness, BMI, insulin and HOMA-IR. In overweight/obese males significant differences were also seen for TC and LDL-C, whereas no differences were observed in non-overweight males or in females regardless of weight status.nnnCONCLUSIONSnOur findings among European adolescents confirm previous data indicating that adolescents who regularly consume breakfast have lower body fat content. The results also show that regular breakfast consumption is associated with higher cardiorespiratory fitness in adolescents, and with a healthier cardiovascular profile, especially in males. Eating breakfast regularly may also negate somewhat the effect of excess adiposity on TC and LDL-C, especially in male adolescents.

Sleep duration and activity levels in Estonian and Swedish children and adolescents

We aimed to examine the associations of sleep duration with time spent on sedentary, moderate and vigorous activities in children and adolescents. The sample consisted of 2,241 (53.5% girls) Estonian and Swedish children (9–10xa0years) and adolescents (15–16xa0years), from the European Youth Heart Study, in 1998–1999. Sleep duration was calculated by the difference between self-reported bedtime and time for getting up on a normal weekday. Sedentary time/physical activity was measured by accelerometry (valid data on 1,462 participants). Adolescents had lower odds than children, and Swedish higher odds than Estonian, of meeting the sleep recommendations (>9xa0h) (ORxa0=xa00.22, 95% CI 0.17–0.27; and 1.32, 1.07–1.61, respectively). Participants sleeping longer than 10xa0h spent more time on physical activities (all intensities) and less time on sedentary activities than those sleeping shorter durations (all Pxa0<xa00.001). The associations with physical activity became non-significant after additional adjustment for age or sexual maturation (Tanner stages), whereas the associations with sedentary time became borderline significant (Pxa0=xa00.09/0.03, for age and Tanner, respectively). In conclusion, these results do not suggest a link between sleep durations and activity in a relatively large sample of children and adolescents from two European countries. Consequently, the common assumption that physical activity is a mediator in the relationship between short sleep durations and obesity is not supported by our findings.

FADS1 Genetic Variability Interacts with Dietary α-Linolenic Acid Intake to Affect Serum Non-HDL–Cholesterol Concentrations in European Adolescents

Two rate-limiting enzymes in PUFA biosynthesis, Δ5- and Δ6-desaturases, are encoded by the FADS1 and FADS2 genes, respectively. Genetic variants in the FADS1-FADS2 gene cluster are associated with changes in plasma concentrations of PUFA, HDL- and LDL-cholesterol, and TG. However, little is known about whether dietary PUFA intake modulates these associations, especially in adolescents. We assessed whether dietary linoleic acid (LA) or α-linolenic acid (ALA) modulate the association between the FADS1 rs174546 polymorphism and concentrations of PUFA, other lipids, and lipoproteins in adolescents. Dietary intakes of LA and ALA, FADS1 rs174546 genotypes, PUFA levels in serum phospholipids, and serum concentrations of TG, cholesterol, and lipoproteins were determined in 573 European adolescents from the HELENA study. The sample was stratified according to the median dietary LA (≤9.4 and >9.4 g/d) and ALA (≤1.4 and >1.4 g/d) intakes. The associations between FADS1 rs174546 and concentrations of PUFA, TG, cholesterol, and lipoproteins were not affected by dietary LA intake (all P-interaction > 0.05). Similarly, the association between the FADS1 rs174546 polymorphism and serum phospholipid concentrations of ALA or EPA was not modified by dietary ALA intake (all P-interaction > 0.05). In contrast, the rs174546 minor allele was associated with lower total cholesterol concentrations (P = 0.01 under the dominant model) and non-HDL-cholesterol concentrations (P = 0.02 under the dominant model) in the high-ALA-intake group but not in the low-ALA-intake group (P-interaction = 0.01). These results suggest that dietary ALA intake modulates the association between FADS1 rs174546 and serum total and non-HDL-cholesterol concentrations at a young age.

Bicycling to school is associated with improvements in physical fitness over a 6-year follow-up period in Swedish children

OBJECTIVEnTo examine whether modes of commuting to school at baseline and changes in commuting were related to 6-year changes in cardiorespiratory fitness in youth.nnnMETHODSnA total of 262 (142 girls) Swedish children (9 years at entry) were measured at baseline (1998/9) and follow-up (2004/5). Mode of commuting to school was assessed by questionnaire and fitness by a maximal bicycle test.nnnRESULTSnAt baseline, 34% of children used passive modes of commuting (e.g., car, motorcycle, bus, train), 54% walked, and 12% bicycled to school. Six years later the percentage of bicyclists increased 19% and the percentage of walkers decreased 19%. On average, children who bicycled to school increased their fitness 13% (p=0.03) more than those who used passive modes and 20% (p=0.002) more than those who walked. Children who used passive modes or walked at baseline and bicycled to school at 6 years later increased their fitness 14% (p=0.001) more than those who remained using passive modes or walking at follow-up.nnnCONCLUSIONSnImplementing initiatives that encourage bicycling to school may be a useful strategy to increase cardiorespiratory fitness of children.

Breakfast habits among European adolescents and their association with sociodemographic factors: the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study

OBJECTIVEnTo describe breakfast habits at food group level in European adolescents and to investigate the associations between these habits and sociodemographic factors.nnnDESIGNnCross-sectional study.nnnSETTINGnSecondary schools from nine European cities participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) Study. Breakfast habits were assessed twice using a computer-based 24 h dietary recall. Adolescents who consumed breakfast on at least one recall day were classified as breakfast consumers and adolescents who did not have anything for breakfast on either of the two recall days were considered breakfast skippers. A breakfast quality index to describe breakfast quality was created based on the consumption or non-consumption of cereals/cereal products, dairy products and fruits/vegetables. The sociodemographic factors studied were sex, age, region of Europe, maternal and paternal education, family structure and family affluence.nnnSUBJECTSnAdolescents (n 2672, 53 % girls) aged 12-17 years.nnnRESULTSnThe majority of the adolescents reported a breakfast that scored poorly on the breakfast quality index. Older adolescents, adolescents from the southern part of Europe and adolescents from families with low socio-economic status were more likely to consume a low-quality breakfast.nnnCONCLUSIONSnThe study highlights the need to promote the consumption of a high-quality breakfast among adolescents, particularly in older adolescents, adolescents from southern Europe and adolescents from families with low socio-economic status, in order to improve public health.

Stability of the factorial structure of metabolic syndrome from childhood to adolescence: a 6- year follow-up study

BackgroundMetabolic syndrome (MS) is a clustering of cardiometabolic risk factors that is considered a predictor of cardiovascular disease, type 2 diabetes and mortality. There is no consistent evidence on whether the MS construct works in the same way in different populations and at different stages in life.MethodsWe used confirmatory factor analysis to examine if a single-factor-model including waist circumference, triglycerides/HDL-c, insulin and mean arterial pressure underlies metabolic syndrome from the childhood to adolescence in a 6-years follow-up study in 174 Swedish and 460 Estonian children aged 9 years at baseline. Indeed, we analyze the tracking of a previously validated MS index over this 6-years period.ResultsThe estimates of goodness-of-fit for the single-factor-model underlying MS were acceptable both in children and adolescents. The construct stability of a new model including the differences from baseline to the end of the follow-up in the components of the proposed model displayed good fit indexes for the change, supporting the hypothesis of a single factor underlying MS component trends.ConclusionsA single-factor-model underlying MS is stable across the puberty in both Estonian and Swedish young people. The MS index tracks acceptably from childhood to adolescence.

Validity of Resting Energy Expenditure Predictive Equations before and after an Energy-Restricted Diet Intervention in Obese Women

Background We investigated the validity of REE predictive equations before and after 12-week energy-restricted diet intervention in Spanish obese (30 kg/m2>BMI<40 kg/m2) women. Methods We measured REE (indirect calorimetry), body weight, height, and fat mass (FM) and fat free mass (FFM, dual X-ray absorptiometry) in 86 obese Caucasian premenopausal women aged 36.7±7.2 y, before and after (nu200a=u200a78 women) the intervention. We investigated the accuracy of ten REE predictive equations using weight, height, age, FFM and FM. Results At baseline, the most accurate equation was the Mifflin et al. (Am J Clin Nutr 1990; 51: 241–247) when using weight (bias:−0.2%, Pu200a=u200a0.982), 74% of accurate predictions. This level of accuracy was not reached after the diet intervention (24% accurate prediction). After the intervention, the lowest bias was found with the Owen et al. (Am J Clin Nutr 1986; 44: 1–19) equation when using weight (bias:−1.7%, Pu200a=u200a0.044), 81% accurate prediction, yet it provided 53% accurate predictions at baseline. Conclusions There is a wide variation in the accuracy of REE predictive equations before and after weight loss in non-morbid obese women. The results acquire especial relevance in the context of the challenging weight regain phenomenon for the overweight/obese population.

Birth weight and subsequent adiposity gain in Swedish children and adolescents: a 6-year follow-up study.

We examined whether birth weight (BW) predicts changes in body composition over a 6‐year period in Swedish children and adolescents. For this purpose, a total of 247 children (55.5% girls) and 162 adolescents (60.5% girls) were included in the study and were followed up 6 years later. BW was obtained from parental records. We measured weight, height, waist circumference, and the bicep, tricep, subscapular, suprailiac, and medial calf skinfolds, and we calculated BMI, fat‐free mass (FFM), and the sum of five skinfolds. Physical activity was assessed by accelerometry. Changes in pubertal status and baseline anthropometric estimates were used as confounders in all analysis. In the children cohort, we observed that BW was inversely associated with changes in BMI (β = −0.736, P = 0.002) and the sum of five skinfolds (β = −6.381, P = 0.009) regardless of confounders and physical activity, only in girls. We did not find any significant association between BW and adiposity gain estimates in the adolescent cohort. These findings give further support to the concept that low BW may have a programming effect of subsequent adiposity gain from childhood to adolescence. We also confirm the sex‐related differences in the programming effect of body composition.

Role of socio-cultural factors on changes in fitness and adiposity in youth: A 6-year follow-up study

BACKGROUND AND AIMSnOptimal cardio-respiratory fitness and adiposity levels are tightly related to health in youth. We analysed changes in fitness and adiposity in young individuals from two countries, and examined the role of maternal education in these changes.nnnMETHODS AND RESULTSnA 6-year follow-up study was conducted on 483 Estonian children (9 years) and 466 Swedish children (9-10 years) and adolescents (15 years). Fitness was assessed by a maximal bike test, and total and central adiposity were indirectly estimated by skinfolds (Slaughters equation for fat mass) and waist circumference. At follow-up, fitness and adiposity had increased in the children cohort (P ≤ 0.001), while small or no change occurred in the adolescent cohort. In the children cohort, Estonian participants had a lower increase in fitness and a higher increase in adiposity (total and central) than Swedish participants. Higher maternal education increased the odds of remaining fit (top quartile) by half and reduced the risk of remaining fat (top quartile) by half; odds ratios = 1.56 (1.00-2.43), 0.50 (0.32-0.77) and 0.61 (0.39-0.94) for fitness, total and central adiposity, respectively.nnnCONCLUSIONSnOur data suggest that the socioeconomic situation of a country might influence key cardiovascular risk factors (fitness and adiposity), being at higher risk for a low-middle income country (Estonia) than a higher income country (Sweden). The findings stress the role of socioeconomic status, particularly maternal education, in the maintenance of healthy fitness and adiposity levels from childhood into later life. Preventive efforts have to be taken from early age.

Insulin sensitivity at childhood predicts changes in total and central adiposity over a 6-year period

Objective:To examine the associations of insulin resistance at childhood with adiposity changes over a 6-year period (from 9 to 15 years) in a sample of 659 Swedish and Estonian children (52.7% girls) participating in the European Youth Heart Study.Research, Design and Methods:We measured weight, height, waist circumference, biceps, triceps, subscapular, suprailiac, and medial calf skinfolds, and we calculated body mass index (BMI), sum of five skinfolds, and body fat percentage. Fasting plasma glucose and insulin were measured and homeostasis model assessment of insulin resistance (HOMA-IR) was calculated. Changes in puberty stage, sex, centre and the corresponding baseline adiposity values were used as confounders in all analysis.Results:HOMA-IR at childhood was significantly and positively associated with changes in BMI (β=0.265; P=0.024), sum of five skinfolds (β=0.3445; P=0.003), body fat percentage (β=1.042; P=0.016) and waist circumference (β=0.806; P=0.002) from childhood to adolescence. These relationships persisted when overweight children were excluded from the analysis. BMI, sum of five skinfolds, body fat percentage and waist circumference at childhood were not significantly associated with changes in HOMA-IR (P for all >0.1).Conclusions:These results give further support to the concept that lower insulin sensitivity at childhood may predict subsequent total and central adiposity gain at adolescence. These findings enhance the role of insulin sensitivity as a target of obesity prevention already from the first decades of life.