Physical activity as a preventive measure against overweight, obesity, infections, allergies and cardiovascular disease risk factors in adolescents: AFINOS Study protocol

Obesity Measures and Dietary Parameters as Predictors of Gut Microbiota Phyla in Healthy Individuals

The dynamics and diversity of human gut microbiota that can remarkably influence the wellbeing and health of the host are constantly changing through the host’s lifetime in response to various factors. The aim of the present study was to determine a set of parameters that could have a major impact on classifying subjects into a single cluster regarding gut bacteria composition. Therefore, a set of demographical, environmental, and clinical data of healthy adults aged 25–50 years (117 female and 83 men) was collected. Fecal microbiota composition was characterized using Illumina MiSeq 16S rRNA gene amplicon sequencing. Hierarchical clustering was performed to analyze the microbiota data set, and a supervised machine learning model (SVM; Support Vector Machines) was applied for classification. Seventy variables from collected data were included in machine learning analysis. The agglomerative clustering algorithm suggested the presence of four distinct community types of most abundant bacterial phyla. Each cluster harbored a statistically significant different proportion of bacterial phyla. Regarding prediction, the most important features classifying subjects into clusters were measures of obesity (waist to hip ratio, BMI, and visceral fat index), total body water, blood pressure, energy intake, total fat, olive oil intake, total fiber intake, and water intake. In conclusion, the SVM model was shown as a valuable tool to classify healthy individuals based on their gut microbiota composition.

The effects of a physical inactivity-related health risk message intervention on changes in risk perceptions and physical activity in middle-aged women

The study investigated the effects of the physical inactivity-related health risk message intervention on changes in risk perception for diseases. Forty-one women participated in the 16-week intervention. During this period, the study participants' physical activity, risk perceptions, and objective risk factors were measured. Results indicated that the intervention had a significant effect on improving perceived health risk of heart disease and obesity. Moreover, changes in perceived risk showed significant effect on changes in physical activity over the 16-week intervention. The study provided both theoretical and practical implications for perceived health risk as a predictor of physical activity.

Increased naive CD4+ and B lymphocyte subsets are associated with body mass loss and drive relative lymphocytosis in anorexia nervosa patients

Anorexia nervosa (AN) is an atypical form of malnutrition with peculiar changes in the immune system. We hypothesized that different lymphocyte subsets are differentially affected by malnutrition in AN, and thus, our aim was to investigate the influence of body mass loss on the variability of lymphocyte subsets in AN patients. A group of 66 adolescent female patients, aged 12-17 years, referred for their first episode of either AN or feeding or eating disorders not elsewhere classified were studied upon admission (46 AN-restricting subtype, 11 AN-binge/purging subtype, and 9 feeding or eating disorders not elsewhere classified). Ninety healthy adolescents served as controls. White blood cells and lymphocyte subsets were analyzed by flow cytometry. Relationships with the body mass index (BMI) z score were assessed in linear models adjusted by diagnostic subtype and age. Leukocyte numbers were lower in AN patients than in controls, and relative lymphocytosis was observed in AN-restricting subtype. Lower CD8⁺, NK, and memory CD8⁺ counts were found in eating disorder patients compared with controls. No differences were found for CD4⁺ counts or naive and memory CD4⁺ subsets between the groups. Negative associations between lymphocyte percentage and the BMI z score, as well as between the B cell counts, naive CD4⁺ percentage and counts, and the BMI z score, were found. In conclusion, increased naive CD4⁺ and B lymphocyte subsets associated with body mass loss drive the relative lymphocytosis observed in AN patients, which reflects an adaptive mechanism to preserve the adaptive immune response.

Television viewing time and risk of eating disorders in Spanish adolescents: AVENA and AFINOS studies

BACKGROUND

Effective preventive interventions for both eating disorders and obesity in adolescence should be focused on shared risk factors. We analyzed the association between television (TV) viewing time and the risk of eating disorders, as well as the potential role of obesity in this association.

METHODS

The sample consisted of a total of 3458 Spanish adolescents, aged 13-18.5 years, from the Food and Assessment of the Nutritional Status of Adolescents (AVENA) and Physical Activity as a Preventive Measure of the Development of Overweight, Obesity, Allergies, Infections, and Cardiovascular Risk Factors in Adolescents (AFINOS) studies. Adolescents' TV time was assessed by self-report. Body mass index was calculated and the adolescents were classified into non-overweight and overweight-obesity. The risk of eating disorders was evaluated using the SCOFF questionnaire.

RESULTS

Adolescents who watched TV >1 h/day had a higher risk for eating disorders, compared with those adolescents who watch TV <1 h/day. Also, overweight-obese adolescents had a higher risk for eating disorders than those who were non-overweight. Analyses across groups of TV viewing time and weight status showed similar trends, so that the higher the time spent in TV viewing, the higher the risk of eating disorders, regardless of weight status.

CONCLUSIONS

TV viewing time might be a focal point for prevention of both eating disorders and obesity in adolescence.

Cognition and the risk of eating disorders in Spanish adolescents: the AVENA and AFINOS studies

Eating disorders (ED) can arise from a combination of biological and psychological factors. Some studies suggest that intellectual factors might be important in the development of ED, although the evidence is still scarce. The aim of this study was to examine the association between cognition measurements (cognitive performance and academic achievement) and the risk of developing ED in adolescents considering their weight status. The sample consisted of 3,307 adolescents (1,756 girls), aged 13-18.5 years, who participated in the AVENA (n = 1,430; 783 girls) and AFINOS (n = 1,877; 973 girls) studies. Cognitive performance was measured by the TEA test in the AVENA study, and academic achievement was self-reported in the AFINOS study. ED risk was evaluated in both studies by using the SCOFF questionnaire. Body mass index was calculated to classify adolescents as non-overweight or overweight (including obesity). Overweight adolescents showed a higher risk of developing ED than non-overweight ones in both studies. In the AVENA study, overweight boys with low performance in reasoning ability showed increased risk of ED (p = 0.05). In the AFINOS study, overweight boys with low academic performance in physical education and non-overweight girls with low academic achievement in all the areas analyzed showed higher risk of ED than their peers (all p < 0.05).

CONCLUSION

No association between cognitive performance and ED risk was found in adolescents, while academic achievement was associated with ED risk, especially in non-overweight girls. The non-cognitive traits that accompany academic achievement could influence the likelihood of developing ED in these girls.

L-Carnitine supplementation impairs endothelium-dependent relaxation in mesenteric arteries from rats

L-Carnitine (L-Car) is taken as fat burner. The risks of L-Car supplementation for the cardiovascular system are unclear. We evaluated the relaxing responses of the mesenteric and aorta rings from rats after four weeks of L-Car supplementation and/or physical training. Concentration response curves to acetylcholine (ACh) and sodium nitroprusside (SNP), as well as cyclic GMP levels, superoxide dismutase (SOD) activity and malondialdehyde (MDA) were evaluated. Physical training decreased body weight gain that was potentiated by L-Car. In mesenteric rings, L-Car impaired endothelium-dependent relaxation whereas endothelium independent relaxation was increased. In aorta, exercise improved endothelium-dependent relaxation; however, it was partially inhibited by L-Car. SNP-induced relaxation was similar in aorta of all groups. Basal cGMP were increased in aorta of exercised rats. SOD activity and MDA levels were unaltered. In conclusion, L-Car and physical exercise promotes body weight loss; however, it impairs endothelium-dependent vaso-relaxation possibly involving alterations in muscarinic receptors/eNOS/NO signalling pathway in mesenteric artery.

Six-year trend in active commuting to school in Spanish adolescents. The AVENA and AFINOS Studies

BACKGROUND

Promoting daily routine activities, such as active commuting to school, may have important health implications for young people.

PURPOSE

The aim of the study was to examine the secular trend of active commuting to school in Spanish adolescents over a 6-year period (2001-2002 to 2006-2007). We also examined several factors that might explain this trend.

METHODS

Data comes from two separate cross-sectional studies, both representatives from the city of Madrid (Spain): AVENA and AFINOS studies. These took place in 2001-2002 and 2006-2007 and included 415 (198 girls) and 891 (448 girls) adolescents aged 13-17, respectively. Commuting to school was assessed using a standardized question about their habitual mode of transportation to school: walking, cycling, bus/subway, car, or motorcycle. Chi-square and binary logistic regression were used.

RESULTS

Percentage of active commuting girls decreased significantly from 61 % to 48 % (p = 0.002) from 2001-2002 to 2006-2007. Walking declined from 61 % to 46 % and the use of bus/subway increased from 25 % to 37 % in girls. Girls belonging to average/small families had lower odds of being active commuters than girls of large families (OR, 95 % CI: 0.69, 0.48 to 0.98). There were no significant differences in mode of commuting to school for boys (p = 0.269).

CONCLUSION

Spanish adolescent girls in 2007-2008 had lower levels of active commuting to school, mainly walking, than their counterparts 6 years before. Belonging to a large family was related with higher active commuting in girls.

Follow-up in healthy schoolchildren and in adolescents with Down syndrome: psycho-environmental and genetic determinants of physical activity and its impact on fitness, cardiovascular diseases, inflammatory biomarkers and mental health; the UP&DOWN study

Background

An objective diagnosis of sedentary behaviour as well as of the physical activity and fitness levels in youth and to better understand how lifestyle is associated with cardiovascular disease risk factors and other phenotypes is of clinical and public health interest, and might be informative for developing intervention studies focused on the promotion of physical activity in these population. The aim of this methodological paper is to describe the design and assessment in the UP&DOWN study.

Methods/Design

The UP&DOWN study is a multi-center follow-up design where 2225 Spanish primary and secondary schoolchildren from Cadiz and Madrid, respectively, as well as 110 Spanish adolescents with Down syndrome from Madrid and Toledo were recruited to be assessed. Nine main measurement categories are assessed: i) socio-demographic and early determinants; ii) environmental determinants; iii) physical activity and sedentary behaviour; iv) health-related fitness; v) blood pressure and resting heart rate; vi) mental health; vii) dietary patterns; viii) blood samples; and ix) genetic analysis. During the 3-yr follow-up study, socio-demographic and early determinants, and genetic analysis are only assessed in the first year. Blood sampling is assessed in the first year and the third year (2nd follow-up), and all the other measurements are assessed every year.

Discussion

The findings of the UP&DOWN study may help the Health Information Systems and policy makers to identify the target population for primary prevention and health promotion policies, and to develop and test preventive strategies. Moreover, these data will allow following the trends at population level, as well as to modify/adapt/create new evidence-based physical activity guidelines at national level. The findings will also serve as a scientific platform for interventional studies.

Physical fitness, overweight and the risk of eating disorders in adolescents. The AVENA and AFINOS studies

What is already known about this subject Eating disorders are among the public health issues facing adolescents. An excess of body fat has been associated with an increased risk of these disorders. The association of physical fitness with eating disorders has not yet been analysed in adolescents. What this study adds This study confirms that the overweight and obesity increase the risk of developing eating disorders. The present study shows that there is an inverse association between physical fitness levels and the risk of eating disorders. This study suggests that physical fitness might attenuate the influence of overweight on the development of eating disorders in adolescents.

BACKGROUND

Eating disorders together with the overweight and obesity are important health concerns in adolescents.

OBJECTIVE

To analyse the individual and combined influence of overweight and physical fitness on the risk of developing eating disorders in Spanish adolescents.

METHODS

The sample consisted of 3571 adolescents (1864 females), aged 13 to 18.5 years, from Spain who participated in the AVENA and AFINOS studies. The risk of eating disorders was evaluated using the SCOFF questionnaire. Body mass index was calculated and the adolescents were classified into two groups: overweight (including obesity) and non-overweight according to Cole's cut-off points. Cardiorespiratory fitness in the AVENA Study was assessed by the 20-m shuttle-run test and the overall physical fitness level was self-reported in the AFINOS Study.

RESULTS

Overweight adolescents had a higher risk of developing eating disorders than non-overweight adolescents (odds ratio [OR] = 4.91, 95% confidence interval [CI]: 3.63-6.61 in the AVENA Study and OR = 2.45, 95% CI: 1.83-3.22 in the AFINOS Study). Also, adolescents with medium and low levels of physical fitness had a higher risk of developing eating disorders (OR = 1.51, 95% CI: 1.05-2.16, and OR = 2.25, 95% CI: 1.60-3.19, respectively, in the AVENA Study, and OR = 1.73, 95% CI: 1.37-2.17, and OR = 4.11 95% CI: 2.98-5.65, respectively, in the AFINOS Study) than adolescents with high levels of physical fitness. In both studies, the combined influence of overweight and physical fitness showed that adolescents with lower levels of physical fitness had an increased risk of developing eating disorders in both non-overweight and overweight groups.

CONCLUSIONS

Physical fitness might attenuate the influence of overweight on the development of eating disorders in adolescents.

Influence of health behaviours on the incidence of infection and allergy in adolescents: the AFINOS cross-sectional study

BACKGROUND

Some health behaviours are liable to affect the incidence of allergies and/or common infections in young people; however, the extent and ways in which these might occur are mostly unknown. This study examines the association of health behaviours related to physical activity, sedentariness, diet and sleep with allergy and infection symptoms in adolescents, and also with biological markers that might mediate disease incidence.

METHODS

The study comprised a total of 2054 adolescents (50.7% girls) from the Madrid region of Spain. The incidence of infection and allergy symptoms three months prior to the study was obtained from a self-administered questionnaire. Physical and sedentary activities, height and weight, food habits and sleep duration were also self-reported and their influence on infection and allergy incidence was assessed by logistic regression analysis. Blood biomarkers (IgE, eosinophil percentage, leptin, interleukin (IL)-2, IL-4, IL-5 and IL-10) were evaluated in a subsample of 198 subjects.

RESULTS

Adequate sleep duration (OR = 0.79, 95%CI: 0.64 to 0.97) and unhealthy weight status (overweight/obesity) (OR = 1.35, 95%CI: 1.04-1.74) were independently associated with decreased and increased allergy incidence, respectively. No significant association was observed with infection incidence. IgE and leptin differed between adolescents with and without allergy symptoms. In regression models IgE was significantly associated with inadequate sleep duration and leptin with weight status.

CONCLUSION

Excess weight and inadequate sleep duration are independently associated with the incidence of allergy symptoms in adolescents. Adequate sleep duration and weight during adolescence might be relevant for a decreased risk of suffering allergy symptoms.

Protective role of resting heart rate on all-cause and cardiovascular disease mortality

OBJECTIVE

To study the protective role of lower resting heart rate (RHR) in cardiovascular disease (CVD) and all-cause mortality.

PATIENTS AND METHODS

Patients (n=53,322) who received a baseline medical examination between January 1, 1974, and December 31, 2002, were recruited from the Cooper Clinic, Dallas, Texas. They completed a medical questionnaire and underwent clinical evaluation. Patients with CVD or cancer or who had less than 1 year of mortality follow-up were excluded from the study. Relative risks and 95% CIs for all-cause and CVD mortality across RHR categories were estimated using Cox proportional hazards models.

RESULTS

Highest cardiorespiratory fitness with lower mortality was found in individuals with an RHR of less than 60 beats/min. Similarly, patients with a higher RHR (≥80 beats/min) were at greater risk for CVD and all-cause mortality compared with an RHR of less than 60 beats/min. This analysis was followed by stratification of the data by hypertension, where hypertensive individuals with high RHRs (≥80 beats/min) were found to be at greater risk for CVD and all-cause mortality compared with those with hypertension and lower RHRs (<60 beats/min). In addition, unfit individuals with high RHRs had the greatest risk of CVD and all-cause mortality. The unfit with low RHR group had a similar risk for CVD and all-cause mortality as the fit with high RHR group.

CONCLUSION

Lower cardiorespiratory fitness levels and higher RHRs are linked to greater CVD and all-cause mortality.

Patterns of sedentary behavior and compliance with public health recommendations in Spanish adolescents: the AFINOS study

The aims of the present study were: (i) describe patterns of sedentary behavior in Spanish adolescents; and (ii) determine the proportion of adolescents that do not meet the public health recommendations for sedentary behavior. This study comprised 1,724 Spanish adolescents (882 girls), aged 13 to 16 years. Patterns of sedentary behavior (TV viewing, use of computer games, console games and surfing the Internet) were assessed using the HELENA sedentary behavior questionnaire. The total proportion of adolescents watching TV, using computer and console games, and surfing the internet for more than two hours daily was 24%, 9%, 7%, and 17%, respectively, on weekdays, and 50%, 22%, 16%, and 35%, respectively, on weekends. Over 63% of the adolescents from the study did not meet the recommendation for sedentary behavior (< 2 hours daily screen time) on weekdays and 87% did not comply with this recommendation on weekends. Since sedentary behavior plays a key role in adolescent health, public health interventions in Spain that take these factors into consideration are needed.

Associations of physical activity and fitness with adipocytokines in adolescents: the AFINOS Study

BACKGROUND AND AIMS

Adipocytokines may have a key role in the development of atherosclerosis and type 2 diabetes. The purpose of this study was to examine the independent and joint associations of physical activity (PA), cardiorespiratory fitness (CRF) and muscular fitness (MF) with adiponectin and leptin in adolescents.

METHODS AND RESULTS

A sample of 198 adolescents (96 girls), aged 13-17-year, was selected. Participants completed anthropometric measurements (height, weight, and waist circumference) and percentage of body fat (%BF) was estimated by bioelectrical impedance. PA was measured by accelerometer for 7-day. The 20-m shuttle-run test was used to assess CRF and two MF tests (handgrip strength and standing broad jump) were used to create an MF score. A cluster score of health status (0-3 risks) was created. Serum adiponectin and plasma leptin were also determined. Regression analyses controlling for age, sex, pubertal status and waist circumference showed that PA was not significantly associated with adiponectin and vigorous PA showed a significant inverse association with leptin. Both CRF and MF were significantly and inversely associated with adiponectin and leptin. Further analyses revealed that the 'healthy' group (0 risks) had significantly lower adiponectin and leptin than 'medium-healthy' (1 risk) and 'unhealthy' (2-3 risks) status groups.

CONCLUSIONS

PA, CRF and MF are inversely and jointly associated with adiponectin and leptin concentrations in adolescents.

Sedentary behaviors and emerging cardiometabolic biomarkers in adolescents

OBJECTIVE

To examine the associations of objectively measured sedentary time and television (TV) viewing time with emerging inflammatory and endothelial function markers in adolescents.

STUDY DESIGN

This study comprised 183 adolescents (88 girls), aged 13 to 17 years. Sedentary time and moderate-to-vigorous physical activity was objectively measured with accelerometry, whereas TV viewing time was self-reported. White blood cell counts and levels of C-reactive protein, complement factors C3 and C4, interleukin-6, adiponectin, leptin, intercellular adhesion molecule 1, vascular cell adhesion molecule 1, E-selectin, L-selectin, and plasminogen activator inhibitor-1 were measured in fasted blood samples.

RESULTS

Sedentary time was not significantly associated with any of the examined cardiometabolic markers after controlling for potential confounders. However, TV viewing time was positively associated with soluble endothelial adhesion molecules intercellular adhesion molecule 1 (standardized β = 0.19, P = .008), vascular cell adhesion molecule 1 (β = 0.17, P = .020), L-selectin (β = 0.18, P = .013), and E-selectin (β = 0.16, P = .023) concentrations, after controlling for sex, age, pubertal status, moderate-to-vigorous physical activity, body mass index, and total sedentary time.

CONCLUSIONS

High TV viewing time may play a key role in cardiovascular and metabolic diseases through the cell adhesion molecules in adolescence.

Association between excessive body fat and eating-disorder risk in adolescents: the AFINOS Study

BACKGROUND AND OBJECTIVE

Overweight and obesity, together with eating disorders, are important public health concerns in adolescence. The aim of this study was to assess the association between excessive body fat and the risk of eating disorders.

SUBJECTS AND METHOD

The sample consisted of 195 adolescents (97 girls) aged 13 to 18 years. Eating-disorder risk was evaluated by applying the SCOFF questionnaire. Body mass index, sum of 6 skinfolds, waist and hip circumferences and waist-hip and waist-height ratios were used to assess body fat.

RESULTS

24.7% of girls and 17.3% of boys were at risk of eating disorders, and 31.6% of boys and 21.6% of girls presented overweight (including obesity) according to Cole's cut-off points. Those adolescents classified above the 85th percentile on all the anthropometric measurements, as well as overweight adolescents, were at increased risk of developing an eating disorder (OR: 2.8-4.30, all p < 0.01).

CONCLUSION

Regardless of the anthropometric measurements used, adolescents with excessive body fat showed a higher risk of having eating disorders than those with normal weight.

Behavioural correlates of active commuting to school in Spanish adolescents: the AFINOS (Physical Activity as a Preventive Measure Against Overweight, Obesity, Infections, Allergies, and Cardiovascular Disease Risk Factors in Adolescents) study

OBJECTIVE

To examine the associations between lifestyle factors and active commuting to school in Spanish adolescents.

DESIGN

Cross-sectional study. Lifestyle factors (overall/extracurricular physical activity, television viewing, reading as a hobby, sleep duration, breakfast/fruit intake, smoking and alcohol intake) as well as mode and duration of commuting to school were self-reported. Active commuters were defined as those adolescents who walked or cycled to school.

SETTING

Secondary schools in Madrid, Spain.

SUBJECTS

Adolescents (n 2029) aged 13 to 17 years.

RESULTS

Similar percentages of adolescent boys (57·6 %) and girls (56·1 %) were classified as active commuters to school (P = 0·491). The analysis showed that only adequate sleep duration (OR = 1·35, 95 % CI 1·11, 1·66; P = 0·003) and breakfast consumption (OR = 0·66, 95 % CI 0·49, 0·87; P = 0·004) were independently associated with active commuting to school.

CONCLUSIONS

Only those behaviours that occur immediately before commuting to school (sleep and breakfast) are associated with active commuting in Spanish adolescents.