Physical activity attenuates the negative effect of low birth weight on leptin levels in European adolescents; the HELENA study

We examined whether physical activity (PA) influences the association between birth weight and serum leptin in adolescents. The study comprised a total of 538 adolescents (315 girls), aged 12.5-17.49 years, born at term (≥ 37 weeks of gestation). We measured serum leptin levels and time engaged in moderate-vigorous PA (MVPA) by accelerometry. There was an interaction effect between birth weight and meeting the PA recommendations (60 min/day MVPA) on leptin levels in girls (P = 0.023) but not in boys (P = 0.809). Birth weight was negatively associated with leptin levels in girls not meeting the PA recommendations (i.e. more than 60 min/day of MVPA) (β = -0.096, P = 0.009), whereas no significant association was observed in those meeting the PA recommendations (β = -0.061, P = 0.433). In conclusion, meeting the PA recommendations may attenuate the negative effect of low birth weight on serum leptin levels in European female adolescents.

Combined influence of healthy diet and active lifestyle on cardiovascular disease risk factors in adolescents

To investigate the combined influence of diet quality and physical activity on cardiovascular disease (CVD) risk factors in adolescents, adolescents (n = 1513; 12.5-17.5 years) participating in the Healthy Lifestyle in Europe by Nutrition in Adolescence study were studied. Dietary intake was registered using a 24-h recall and a diet quality index was calculated. Physical activity was assessed by accelerometry. Lifestyle groups were computed as: healthy diet and active, unhealthy diet but active, healthy diet but inactive, and unhealthy diet and inactive. CVD risk factor measurements included cardiorespiratory fitness, adiposity indicators, blood lipid profile, blood pressure, and insulin resistance. A CVD risk score was computed. The healthy diet and active group had a healthier cardiorespiratory profile, fat mass index (FMI), triglycerides, and high-density lipoprotein cholesterol (HDL-C) levels and total cholesterol (TC)/HDL-C ratio (all P ≤ 0.05). Overall, active adolescents showed higher cardiorespiratory fitness, lower FMI, TC/HDL-C ratio, and homeostasis model assessment index and healthier blood pressure than their inactive peers with either healthy or unhealthy diet (all P ≤ 0.05). Healthy diet and active group had healthier CVD risk score compared with the inactive groups (all P ≤ 0.02). Thus, a combination of healthy diet and active lifestyle is associated with decreased CVD risk in adolescents. Moreover, an active lifestyle may reduce the adverse consequences of an unhealthy diet.

Differences in food consumption according to weight status and physical activity levels among Greek children between 1992/93 and 2006/07

BACKGROUND

There is a lack of data in Greece on trends in food intake according to weight status and physical activity (PA), despite the high prevalence of obesity. The present study aimed to examine differences in these parameters among first-grade children from Crete, Greece, over a 15-year period.

METHODS

Children (aged 5.9-7.6 years) from two representative cross-sectional studies participated during 1992/93 (n = 245) and 2006/07 (n = 257). Estimated 3-day food records were used to assess food consumption and energy-density (ED) [kJ g(-1) (kcal g(-1) )]. Moderate-to-vigorous-PA (MVPA) and cardiorespiratory-fitness were assessed by questionnaires and the 20-m shuttle-run test (20mSRT), respectively.

RESULTS

In 2006/07, compared to 1992/93, both sexes had a significantly higher intake of dairy products and snacks (P < 0.001), a lower intake of cereals (P < 0.001) and higher cardiorespiratory fitness levels (P < 0.001). Among girls, fruit/vegetable consumption was higher (P < 0.05), although legume intake was lower (P < 0.005). Among overweight/obese (OW/OB) children, ED significantly decreased (P < 0.05) and the mean consumption of fruits/vegetables was higher (P < 0.001). The percentage of OW/OB boys was significantly higher (P < 0.001); however, MVPA was significant higher in this group compared to 1992/93 (P < 0.001). During the two time-periods, active children in 2006/07 appeared to have a lower ED than active ones in 1992/93 (P < 0.001).

CONCLUSIONS

Several differences in food intake were observed among first-grade children of Crete between 1992/93 and 2006/07, as characterised by significant increases in the consumption of dairy products and snacks and a decrease in the intake of cereals, among both sexes. Future school-based interventions in this population should emphasise the need to increase fruit/vegetable, unrefined cereal and legume consumption.

Fatty acid composition of adipose tissue triglycerides after weight loss and weight maintenance: the DIOGENES study

Fatty acid composition of adipose tissue changes with weight loss. Palmitoleic acid as a possible marker of endogenous lipogenesis or its functions as a lipokine are under debate. Objective was to assess the predictive role of adipose triglycerides fatty acids in weight maintenance in participants of the DIOGENES dietary intervention study. After an 8-week low calorie diet (LCD) subjects with > 8 % weight loss were randomized to 5 ad libitum weight maintenance diets for 6 months: low protein (P)/low glycemic index (GI) (LP/LGI), low P/high GI (LP/HGI), high P/low GI (HP/LGI), high P/high GI (HP/HGI), and a control diet. Fatty acid composition in adipose tissue triglycerides was determined by gas chromatography in 195 subjects before the LCD (baseline), after LCD and weight maintenance. Weight change after the maintenance phase was positively correlated with baseline adipose palmitoleic (16:1n-7), myristoleic (14:1n-5) and trans-palmitoleic acid (16:1n-7t). Negative correlation was found with baseline oleic acid (18:1n-9). Lower baseline monounsaturated fatty acids (14:1n-5, 16:1n-7 and trans 16:1n-7) in adipose tissue triglycerides predict better weight maintenance. Lower oleic acid predicts lower weight decrease. These findings suggest a specific role of monounsaturated fatty acids in weight management and as weight change predictors.

Impact of REV-ERB alpha gene polymorphisms on obesity phenotypes in adult and adolescent samples

BACKGROUND

REV-ERBα has been shown to regulate adipogenesis and lipid metabolism as well as to link the circadian timing system to whole body metabolic homeostasis. We thus tested whether polymorphisms in REV-ERBα could be associated with metabolic phenotypes in human population samples.

METHODS

We analyzed the associations between 5 REV-ERBα polymorphisms and anthropometric (body weight, body mass index (BMI), waist and hip circumferences), biochemical (plasma lipid, glucose and insulin levels) and clinical (systolic and diastolic blood pressure) variables in three population-based studies (MONICA Lille n=1155 adults, MONA LISA Lille n=1170 adults and HELENA n=1155 adolescents). We assessed in vitro, the potential influence of one REV-ERBα polymorphism in transient transfection assays using two different cell lines.

RESULTS

We observed significant and consistent associations between the T minor allele of the REV-ERBα rs2071427 polymorphism (located in intron 1) and higher BMI (mean allele effect=+0.33 kg m(-2)) in the MONICA Lille (P=0.02), MONA LISA (P=0.02) and HELENA (P=0.03) studies. The odds ratios for obesity associated with this allele were 1.67 (1.00-2.79) (P=0.05) in MONICA Lille, 1.29 (1.01-1.65) (P=0.04) in MONA LISA Lille and the odds ratio for overweight was 1.48 (1.08-2.03) (P=0.01) in HELENA. In transfection experiments in human hepatocyte-derived cell lines, the REV-ERBα intron 1 directed the transcription of a luciferase reporter gene independently of the rs2071427 polymorphism.

CONCLUSION

Our results suggest that the REV-ERBα rs2071427 polymorphism modulates body fat mass in both adult and young people.

Risk factors of obesity in a cohort of 1001 Cypriot adults: An epidemiological study

BACKGROUND AND AIMS

To measure the prevalence of overweight and obesity in adults in the Republic of Cyprus, and to evaluate and relate possible obesity risk factors of the adult Cypriot population.

METHODS

This is an epidemiological cross-sectional study on a stratified random sample of 1001 (48.5% males-51.5% females) subjects, aged 18-80 years old. Anthropometric, biochemical, and dietary/lifestyle characteristics included in the study.

RESULTS

The prevalence of overweight (Ow) and obesity (Ob) was 46.9% and 28.8% for males and 26% and 27% for females, respectively. Overweight and obese subjects were found to have statistically significant higher levels of Body Mass Index (p<0.001), Waist circumference (p<0.001), Total serum cholesterol (p<0.001), Low density lipoprotein (p<0.005), Glucose (p<0.007) and Triglycerides (p<0.001) compared to normal peers. In addition, Ow and Ob participants consumed significantly lower levels of fruits and vegetables (p<0.001), exercised less time/d (p<0.001) and smoke more cigarettes/d (p<0.001), compared to normal subjects, respectively. In multiple regression analysis of factors associated with overweight and obesity, Waist Circumference (beta: 1.132, p<0.001), Glucose (beta: 0.892, p<0.045), alcohol consumption (beta: 0.563, p<0.001), and exercise levels (beta: -0.444, p<0.001), were the most significant ones.

CONCLUSION

The prevalence of overweight and obesity is very high in Cypriot adults. The current study also revealed a significant positive relation of Ow and Ob with waist circumference, high blood glucose levels and increased consumption of alcohol and a negative one with decreased levels of exercise.

Short sleep duration is associated with increased obesity markers in European adolescents: effect of physical activity and dietary habits. The HELENA study

BACKGROUND

Adequate sleep is a critical factor for adolescent's health and health-related behaviors.

OBJECTIVE

(a) to describe sleep duration in European adolescents from nine countries, (b) to assess the association of short sleep duration with excess adiposity and (c) to elucidate if physical activity (PA), sedentary behaviors and/or inadequate food habits underlie this association.

DESIGN

A sample of 3311 adolescents (1748 girls) aged 12.5-17.49 years from 10 European cities in Austria, Belgium, France, Germany, Greece, Hungary, Italy, Spain and Sweden was assessed in the Healthy Lifestyle in Europe by Nutrition in Adolescence Study between 2006 and 2008. We measured anthropometric data, sleep duration, PA (accelerometers and questionnaire), television watching and food habits (Food Frequency Questionnaire).

RESULTS

Average duration of daily sleep was 8 h. Shorter sleepers showed higher values of BMI, body fat, waist and hip circumferences and fat mass index (P<0.05), particularly in females. Adolescents who slept <8 h per day were more sedentary, as assessed by accelerometry, and spent more time watching TV (P<0.05). The proportion of adolescents who eat adequate amounts of fruits, vegetables and fish was lower in shorter sleepers than in adolescents who slept ≥8 h per day, and so was the probability of having adequate food habits (P<0.05). Correlation analysis indicated that short sleep is associated with higher obesity parameters.

CONCLUSIONS

In European adolescents, short sleep duration is associated with higher adiposity markers, particularly in female adolescents. This association seems to be related to both sides of the energy balance equation due to a combination of increased food intake and more sedentary habits.

Dietary strategy to manipulate ad libitum macronutrient intake, and glycaemic index, across eight European countries in the Diogenes Study

The aim of this study was to describe the development and implementation of a multifaceted, low-fat, weight-loss strategy for a Pan-European randomized controlled dietary intervention study, Diogenes. There were 891 families with at least one overweight/obese parent who underwent screening. Eligible, overweight/obese adults followed an 8-week weight-loss phase with a fixed low-energy diet (800 kcal). On attaining weight loss of > or = 8%, families were randomized to a 6- or 12-month low-fat (25-30%E) diet either based on national dietary guidelines or one of four interventions: low protein (LP)/low glycaemic index (LGI), LP/high GI (HGI), high protein (HP)/LGI and HP/HGI. The impact of each diet in preventing weight (re)gain was tested. A points-based system was used to manipulate dietary protein and carbohydrate. Manipulating carbohydrate composition involved substituting foods with a relatively high or low GI. A questionnaire was designed and completed by study investigators, providing feedback on the dietary intervention methods used to inform future interventions. The points system allowed macronutrient manipulations without compromising dietary flexibility or enforcing energy restrictions. Reported centre/participant differences in the ease of implementing the intervention may reflect dietary diversity and personal preferences for specific weight-management strategies. The points system provides a useful starting point for designing improved experimental paradigms for the manipulation of dietary intake in future trials.

The Diet, Obesity and Genes (Diogenes) Dietary Study in eight European countries - a comprehensive design for long-term intervention

Diogenes is a Pan-European, randomized, controlled dietary intervention study investigating the effects of dietary protein and glycaemic index on weight (re)gain, metabolic and cardiovascular risk factors in obese and overweight families in eight European centres. The article is methodological in character, and the presentation of 'results' will be limited to baseline characteristics of the study populations included. A total of 891 families with at least one overweight/obese parent underwent screening. The parents started an initial 8-week low-calorie diet and families with minimum one parent attaining a weight loss of > or = 8%, were randomized to one of five energy ad libitum, low-fat (25-30 E%) diets for 6 or 12 months: low protein/low glycaemic index, low protein/high glycaemic index, high protein/low glycaemic index, high protein/high glycaemic index or control (national dietary guidelines). At two centres the families were provided dietary instruction plus free foods for 6 months followed by 6-month dietary instruction only. At the remaining six centres the families received dietary instruction only for 6 months. The median weight loss during the low-calorie diet was 10.3 kg (inter-quartile range: 8.7-12.8 kg, n = 775). A total of 773 adults and 784 children were randomized to the 6-month weight (re)gain prevention phase. Despite major cultural and dietary regional differences in Europe, interventions addressing effects of dietary factors are feasible with a reasonable attrition.

Adipose tissue fatty acids in breast cancer patients versus healthy control women from Crete

BACKGROUND

Few studies have implemented biomarkers of fatty acid intake in relation to breast cancer.

AIMS

To examine possible differences in adipose tissue fatty acid composition between breast cancer patients and healthy control women. The relationship between tumor promotion and adipose tissue fatty acid synthesis was also investigated.

METHODS

The study was conducted at the University of Crete. Subjects included 94 women with clinically diagnosed cancer of the breast and 131 healthy control women. Histological tumor grading and breast cancer staging were assessed. Fatty acids were determined by gas chromatography in gluteal adipose tissue.

RESULTS

Conditional logistic regression analysis controlling for potential confounders indicated that elevated adipose monounsaturated fatty acids and oleic acid are associated with reduced odds of breast cancer [OR (T2 vs. T1) 0.15; 95% CI 0.03-0.64, and OR (T2 vs. T1) 0.18; 95% CI 0.04-0.71, respectively]. Adipose myristic acid was associated with an increase in breast cancer risk [OR (T3 vs. T1) 5.66; 95% CI 1.3-23.9].

CONCLUSIONS

Adipose oleic acid is inversely related, whereas adipose myristic acid is positively related to breast cancer risk. These relations could be mediated by Her-2/neu and FAS oncogenes.

Environmental tobacco smoke exposure as a risk factor for infections in infancy

AIM

This prospective observational study investigated the effect of environmental tobacco smoke (ETS) on frequency and severity of common infantile infections.

METHODS

In a representative sample of 926 infants, parental smoking was recorded at months 1 and 9 postpartum, and all infantile infectious episodes were recorded at 1, 3, 6, 9 and 12 months postpartum.

RESULTS

Both parents were regular smokers all through the first year in 107 (11.6%), at least one smoked regularly or occasionally in 492 (53.1%), and parents did not smoke at all in 327 (35.3%) families. Among mothers, 168 (18.1%) smoked perinatally. Infantile ETS exposure was associated with increased frequency of total infectious episodes (p = 0.025) and hospitalizations for infection (p = 0.007). In ETS exposed infants, birth in autumn and presence of siblings contributed to increased frequency of most infections and of hospital admissions for infection. By contrast, exclusive breastfeeding protected against the effect of ETS on total infantile infections (OR 0.982, 95% CI 0.965-0.999; p = 0.036), hospital admissions for infection (OR 0.980, 95% CI 0.961-0.999; p = 0.036) and thrush (OR 0.973, 95% CI 0.951-0.996; p = 0.022).

CONCLUSION

Our findings point to harmful effect of ETS on infantile health and further suggest that this effect may be enhanced or diminished by other factors. ETS should be regarded as a preventable risk factor for infections in infancy.

Design and implementation of the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study

OBJECTIVE

To provide an overview of the Healthy Lifestyle in Europe by Nutrition in Adolescence Cross-Sectional Study (HELENA-CSS) design, with particular attention to its quality control procedures. Other important methodological aspects are described in detail throughout this supplement.

DESIGN

Description of the HELENA-CSS sampling and recruitment approaches, standardization and harmonization processes, data collection and analysis strategies and quality control activities.

RESULTS

The HELENA-CSS is a multi-centre collaborative study conducted in European adolescents located in urban settings. The data management systems, quality assurance monitoring activities, standardized manuals of operating procedures and training and study management are addressed in this paper. Various quality controls to ensure collection of valid and reliable data will be discussed in this supplement, as well as quantitative estimates of measurement error.

CONCLUSION

The great advantage of the HELENA-CSS is the strict standardization of the fieldwork and the blood analyses, which precludes to a great extent the kind of immeasurable confounding bias that often interferes when comparing results from isolated studies.

Prevalence and independent predictors of insulin resistance in children from Crete, Greece: the Children Study

BACKGROUND

It has been proposed that insulin resistance (IR) is associated with the development of Type 2 diabetes mellitus and cardiovascular disease. The aim of this study is to determine the prevalence of IR in Greek schoolchildren and to investigate factors associated with IR.

METHODS

Between October 2005 and March 2006, 522 children were recruited from Crete. Physical activity and dietary habits, anthropometric and biochemical characteristics, as well as medical history of pupils' parents were recorded. IR was estimated using the homeostasis model assessment (HOMA-IR), fasting glucose-to-insulin ratio (FGIR) and quantitative insulin sensitivity check index (QUICKI). Multiple linear regression was used to determine independent predictors for IR.

RESULTS

Fasting insulin levels and HOMA-IR scores were higher in obese children and girls compared with their normal-weight peers (P < 0.001). Moreover, the former had lower values in FGIR and QUICKI indices compared with the latter, indicating that obese children and girls are more insulin resistant compared with their counterparts (P < 0.001). The prevalence of IR was 9.2% (2.9% in normal-weight, 10.5% in overweight and 31.0% in obese children), using as a threshold HOMA-IR > 2.10 97.5th percentile of normal-weight participants). Multiple linear regression revealed that central adiposity, female gender and intake of simple carbohydrates is associated positively with HOMA-IR values, even after controlling for many other factors.

CONCLUSION

These findings demonstrate that girls and obese children, particularly those with central adiposity, are at high risk of developing IR. Therefore, these groups should be targets of Type 2 diabetes mellitus and cardiovascular disease preventive interventions.

Stakeholder appraisal of policy options for tackling obesity in Greece

The study aimed to map stakeholders' evaluations of policy options to counter the rising prevalence of obesity in Greece, where the case for action on obesity is only now being made. The multi-criteria mapping method was used to capture and compare stakeholders' appraisals and to provide a policy analysis. Efficacy and practical feasibility were the issues most frequently used by stakeholders to evaluate options and were weighted more highly than cost criteria, which were often defined in terms of governmental costs. There was a broad favourable appraisal for downstream measures offering individuals the skills, information and opportunities to make healthier choices, rather than options to modify the obesogenic environment. Consistently, high rankings were given to educational options, for improving communal facilities and for some information-related options (food labelling, advertising), with particular support for policies targeting the young. There was also significant advocacy by a few for the creation of a new government body charged with intersectoral policy co-ordination. The Policy Options for Responding to the Growing Challenge of Obesity Research Project analyses thus point to support for a portfolio of measures to combat the problem of obesity in Greece as well as an appreciation that political will is an essential prerequisite.

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.