Prevalence of overweight and obesity and associations with socioeconomic indicators: the study of health and activity among adolescents in Kuwait.

BACKGROUND: Kuwait is one of the Arab countries with the highest prevalence of overweight or obesity. However, few studies have described the prevalence of obesity in this country. The aim of this study is to describe the prevalence of overweight and obesity among Kuwaiti adolescents; and to examine the association of overweight and obesity status with familial socioeconomic status (SES). METHODS: Cross-sectional data from 591 adolescent students (47% boys, median age: 16 years) from the Study of Health and Activity among Adolescents in Kuwait in 2012 and 2013. Body weight status was determined using the International Obesity Task Force (IOTF) body mass index standards. SES was based on parental education. Odds ratio for overweight and obesity were calculated using multiple logistic regression. RESULTS: In our study, over half of the adolescents were overweight or obese 54.3% (95% CI: 49.9-58.4). The prevalence of overweight (including obesity) was higher in boys (59.8%, 95% CI: 54.3-66.3) than girls (49.2%, 95% CI: 43.5-54.8). No association between parental education and the risk of overweight/obesity was found. CONCLUSIONS: There is an alarmingly high rate of overweight/obesity among Kuwaiti adolescents, but we did not find evidence of a social gradient in obesity risk. Urgent actions are needed to reverse this epidemic across all social groups.

Physical Activity and Sedentary Behaviors Levels of Kuwaiti Adolescents: The Study of Health and Activity Among Adolescents in Kuwait.

BACKGROUND: There is only scarce number of studies available describing the lifestyle of adolescents living in Arab countries. Hence, we described physical activity (PA) and sedentary behaviors patterns among Kuwaiti adolescents and the associations with parental education. METHODS: Cross-sectional data from 435 adolescents (201 boys and 234 girls) were collected from the Study of Health and Activity among Adolescents in Kuwait conducted between 2012 and 2013. Outcome variables included PA (ActiGraph GT1M accelerometers) and sedentary behaviors. Exposure variable was parental education. Descriptive and multiple logistic regression analyses were used to examine the association between parental education and outcome variables. RESULTS: Total sedentary time (minutes per day) was higher in girls [568.2 (111.6)] than in boys [500.0 (102.0)], whereas boys accumulated more minutes in light, moderate, and vigorous PA (all Ps ≤ .001). In total, 3.4% of adolescents spent ≥60 minutes per day of moderate to vigorous PA (by accelerometry), while only 21% met the screen time guidelines. Low/medium maternal education was associated with a higher odds of exceeding screen time guidelines (odds ratio = 2.09; 95% confidence interval, 1.09-4.02). CONCLUSIONS: Most Kuwaiti adolescents in this sample were physically inactive and exceeded screen time guidelines. Objective PA was not socially patterned, yet an inverse association between maternal education and screen time behaviors was found.

Effects of Eight Months of Whole-Body Vibration Training on the Muscle Mass and Functional Capacity of Elderly Women.

Few intervention studies have used whole-body vibration (WBV) training in the elderly, and there is inconclusive evidence about its health benefits. We examined the effect of 8 months of WBV training on muscle mass and functional capacity in elderly women. A total of 37 women (aged 82.4 ± 5.7 years) voluntarily participated in this study. Subjects were randomly assigned to a vibration group (n = 19) or a control group (n = 18). The vibration group trained on a vertical vibration platform twice a week. The control group was requested not to change their habitual lifestyle. The quadriceps femoris muscle cross-sectional area was determined by magnetic resonance imaging. All participants were evaluated by a battery of tests (Senior Fitness Test) to determine their functional capacity, as well as handgrip strength and balance/gait. General linear repeated-measure analysis of variance (group by time) was performed to examine the effect of the intervention on the outcomes variables. After 8 months, nonstatistically significant differences in the quadriceps CSA (pre-training: 8,516.16 ± 1,271.78 mm² and post-training: 8,671.63 ± 1,389.03 mm²) (p > 0.05) were found in the WBV group (Cohen's d: -0.12), whereas the CON group significantly decreased muscle mass (pre-training: 9,756.18 ± 1,420.07 mm² and post-training: 9,326.82 ± 1,577.53 mm²), with moderate effect size evident (Cohen's d: 0.29). In both groups, no changes were observed in the functional capacity, handgrip strength and balance/gait. The WBV training could prevent the loss of quadriceps CSA in elderly women.

Sedentary behaviours and its association with bone mass in adolescents: the HELENA Cross-Sectional Study.

BACKGROUND: We aimed to examine whether time spent on different sedentary behaviours is associated with bone mineral content (BMC) in adolescents, after controlling for relevant confounders such as lean mass and objectively measured physical activity (PA), and if so, whether extra-curricular participation in osteogenic sports could have a role in this association. METHODS: Participants were 359 Spanish adolescents (12.5-17.5 yr, 178 boys,) from the HELENA-CSS (2006-07). Relationships of sedentary behaviours with bone variables were analysed by linear regression. The prevalence of low BMC (at least 1SD below the mean) and time spent on sedentary behaviours according to extracurricular sport participation was analysed by Chi-square tests. RESULTS: In boys, the use of internet for non-study was negatively associated with whole body BMC after adjustment for lean mass and moderate to vigorous PA (MVPA). In girls, the time spent studying was negatively associated with femoral neck BMC. Additional adjustment for lean mass slightly reduced the negative association between time spent studying and femoral neck BMC. The additional adjustment for MVPA did not change the results at this site. The percentage of girls having low femoral neck BMC was significantly smaller in those participating in osteogenic sports (≥ 3 h/week) than in the rest, independently of the cut-off selected for the time spent studying. CONCLUSIONS: The use of internet for non-study (in boys) and the time spent studying (in girls) are negatively associated with whole body and femoral neck BMC, respectively. In addition, at least 3 h/week of extra-curricular osteogenic sports may help to counteract the negative association of time spent studying on bone health in girls.

Reliability and intermethod agreement for body fat assessment among two field and two laboratory methods in adolescents.

To increase knowledge about reliability and intermethods agreement for body fat (BF) is of interest for assessment, interpretation, and comparison purposes. It was aimed to examine intra- and inter-rater reliability, interday variability, and degree of agreement for BF using air-displacement plethysmography (Bod-Pod), dual-energy X-ray absorptiometry (DXA), bioelectrical impedance analysis (BIA), and skinfold measurements in European adolescents. Fifty-four adolescents (25 females) from Zaragoza and 30 (14 females) from Stockholm, aged 13-17 years participated in this study. Two trained raters in each center assessed BF with Bod-Pod, DXA, BIA, and anthropometry (DXA only in Zaragoza). Intermethod agreement and reliability were studied using a 4-way ANOVA for the same rater on the first day and two additional measurements on a second day, one each rater. Technical error of measurement (TEM) and percentage coefficient of reliability (%R) were also reported. No significant intrarater, inter-rater, or interday effect was observed for %BF for any method in either of the cities. In Zaragoza, %BF was significantly different when measured by Bod-Pod and BIA in comparison with anthropometry and DXA (all P < 0.001). The same result was observed in Stockholm (P < 0.001), except that DXA was not measured. Bod-Pod, DXA, BIA, and anthropometry are reliable for %BF repeated assessment within the same day by the same or different raters or in consecutive days by the same rater. Bod-Pod showed close agreement with BIA as did DXA with anthropometry; however, Bod-Pod and BIA presented higher values of %BF than anthropometry and DXA.

Reliability and validity of a screen time-based sedentary behaviour questionnaire for adolescents: The HELENA study.

BACKGROUND: Although there is a growing interest in the epidemiology of sedentary behaviours, it is unknown whether sedentary behaviour questionnaires are broad markers of sedentary time. The aims of this study were to determine the: (i) reliability of the Healthy Lifestyle in Europe by Nutrition in Adolescence (HELENA) screen time-based sedentary behaviour questionnaire; and (ii) its validity, i.e. the ability of the questionnaire to correctly rank adolescents according to the objectively measured sedentary time. METHODS: A total of 183 adolescents (104 females aged 12.5-17.5 years) were involved in the reliability study. Participants completed the HELENA sedentary questionnaire twice (1 week apart). The validity study comprised 2048 (1212 females) adolescents (12.5-17.5 years of age) included in the HELENA cross-sectional study. Questions included television viewing, computer games, console games, Internet for study and non-study reasons and study during week and weekend days. We compared median values of sedentary time, using accelerometers, by tertiles of self-reported sedentary behaviours and their sum (composite sedentary score). RESULTS: Reliability study: κ-values showed a good agreement (>0.7), except for Internet for study reasons (0.46 weekdays, 0.33 weekend). The questionnaire correctly classified boys' sedentary time when analysed by specific behaviours and by a composite sedentary score. In girls, median values of objectively measured sedentary time were not different across tertiles of self-reported sedentary behaviours or the composite sedentary score. CONCLUSION: The HELENA sedentary questionnaire is reliable, yet only correctly classifies objectively measured sedentary time in boys.

Clustering patterns of physical activity, sedentary and dietary behavior among European adolescents: The HELENA study.

BACKGROUND: Evidence suggests possible synergetic effects of multiple lifestyle behaviors on health risks like obesity and other health outcomes. A better insight in the clustering of those behaviors, could help to identify groups who are at risk in developing chronic diseases. This study examines the prevalence and clustering of physical activity, sedentary and dietary patterns among European adolescents and investigates if the identified clusters could be characterized by socio-demographic factors. METHODS: The study comprised a total of 2084 adolescents (45.6% male), from eight European cities participating in the HELENA (Healthy Lifestyle in Europe by Nutrition in Adolescence) study. Physical activity and sedentary behavior were measured using self-reported questionnaires and diet quality was assessed based on dietary recall. Based on the results of those three indices, cluster analyses were performed. To identify gender differences and associations with socio-demographic variables, chi-square tests were executed. RESULTS: Five stable and meaningful clusters were found. Only 18% of the adolescents showed healthy and 21% unhealthy scores on all three included indices. Males were highly presented in the cluster with high levels of moderate to vigorous physical activity (MVPA) and low quality diets. The clusters with low levels of MVPA and high quality diets comprised more female adolescents. Adolescents with low educated parents had diets of lower quality and spent more time in sedentary activities. In addition, the clusters with high levels of MVPA comprised more adolescents of the younger age category. CONCLUSION: In order to develop effective primary prevention strategies, it would be important to consider multiple health indices when identifying high risk groups.

Interrater reliability and time measurement validity of speed-agility field tests in adolescents.

The aim of this study was to examine the interrater reliability (trained vs. untrained raters) and criterion-related validity (manual vs. automatic timing) of the 4 × 10-m shuttle run and 30-m running speed tests (times measured). The study comprised 85 adolescents (38 girls) aged 13.0-16.9 years from the Healthy Lifestyle in Europe by Nutrition in Adolescence study. The time required to complete the 4 × 10-m shuttle run and 30-m running tests was simultaneously measured (a) manually with a stopwatch by both trained and untrained raters (for interrater reliability analysis), and (b) by using photoelectric cells (for validity analysis). Systematic error, random error, and heteroscedasticity were studied with repeated-measured analysis of variance and Bland-Altman plots. The systematic error for untrained vs. trained raters and the untrained raters vs. photoelectric cells were in all cases ∼0.1 seconds (p < 0.01), that is, untrained raters recorded higher times. No systematic error was found between trained raters and photoelectric cells (p > 0.05). No heteroscedasticity was shown in any case (p > 0.05). The findings indicate that manual measurements by a trained rater, using a stopwatch, seem to be a valid method to assess speed and agility fitness testing in adolescents. Researchers must be trained to minimize the measurement error.

Sedentary behaviours and socio-economic status in Spanish adolescents: the AVENA study.

BACKGROUND: This study aimed to describe the influence of socio-economic status (SES) on the prevalence sedentary behaviours among Spanish adolescents. METHODS: Cross-sectional data from Spanish adolescents from the Alimentación y Valoración del Estado Nutricional de los Adolescentes (AVENA) Study (2002). A national representative sample of 1776 adolescents aged 13-18.5 years provided information about time spent watching television (TV), playing with computer or videogames and studying. Parental education and occupation were assessed as SES. Participants were categorized by gender, age, parental education and occupation. Logistic regression models were used. RESULTS: No gender differences were found for TV viewing. For computer and videogames use (weekdays), more boys played >3 h/day (P < 0.001), whereas a higher percentage of girls reported studying >3 h/day (P < 0.001). Among boys, parental education and occupation were inversely associated with TV viewing, parental occupation directly associated with study and maternal education inversely with computer and videogames use during weekdays (all P < 0.05). For girls, parental occupation was inversely associated with TV viewing. CONCLUSION: Spanish adolescents presented different sedentary patterns according to age, gender and SES. Boys reported more time engaged in electronic games, whereas girls reported more time studying. Parental occupation had more influence than parental education on the time spent in sedentary behaviours.

Extra-curricular participation in sports and socio-demographic factors in Spanish adolescents: the AVENA study.

The aims of this study were to identify differences between the sexes in extra-curricular participation in sports and to determine its association with body fat and socio-demographic factors in Spanish adolescents. A total of 2165 adolescents (1124 males and 1041 females) aged 13.0-18.5 years from the AVENA Study participated. Participants filled in an ad hoc questionnaire for extra-curricular participation in sports, which was the dependent variable. Independent variables were: age, percent body fat, and father's and mother's educational level and occupation. Chi-square tests and logistic regression were applied. Bivariate analysis showed for male adolescents that age and father's occupation were related to extra-curricular participation in sports. In addition, body fat and mother's education and occupation (all P < 0.05) were related to extra-curricular participation of in sports for female adolescents. Logistic regression analysis showed that the likelihood of involvement in extra-curricular participation in sports was 5.3-fold (3.86-7.38) higher for males than females. Age and father's education in both males and females were independently associated with extra-curricular participation in sports. In summary, Spanish male adolescents were shown to engage in more extra-curricular sports than females. In addition, age and father's education (in both sexes) were associated with the participation of their offspring in extra-curricular sports during adolescence.

Sedentary patterns and media availability in European adolescents: The HELENA study.

OBJECTIVE: To describe sedentary behaviors in adolescents and to examine the influence of media availability on TV viewing. METHOD: The study assessed 3278 adolescents (1537 males and 1741 females, 12.5-17.5 years) involved in the HELENA study (2007). Adolescents reported hours of TV viewing, computer games, console, internet for study and non-study reasons, and study, as well as availability of TVs, computers and consoles. RESULTS: Time spent in sedentary behaviors was higher during weekends (all p<0.001). Males spent more hours on TV viewing (for > or = 15 years at weekends), playing computer games and console games while females spent more time studying and surfing for non-study reasons. During weekdays, one third of adolescents exceeded the screen time guidelines (>2h/day) based solely on TV viewing, whereas around 60% exceeded it at weekends. Having a TV or a console in the bedroom was associated with higher TV viewing (OR=2.66; 95% CI 2.23-3.18; and OR=1.92; 95% CI 1.61-2.28, respectively) whereas the presence of computer reduced it (OR=0.57; 95% CI 0.48-0.68). CONCLUSION: Adolescents living in Europe are not meeting media recommendations, especially during weekend. The absence of a TV in the adolescents' bedroom might reduce TV viewing. Further studies are needed to confirm or contrast our findings.

Association of physical activity with muscular strength and fat-free mass in adolescents: the HELENA study.

The objective of this study is to analyse the association of objectively assessed physical activity (PA) with muscular strength and fat-free mass in adolescents, and to determine whether meeting the current PA recommendations is associated with higher levels of muscular strength and fat-free mass. The present cross-sectional study comprised 363 Spanish adolescents (180 females) aged 12.5-17.5 years. PA was assessed by accelerometry and expressed as average PA (counts/min), and min/day of inactive, light, moderate, vigorous and moderate to vigorous PA (MVPA). MVPA was dichotomized into < 60 min/day and > or = 60. Upper body muscular strength was measured with the handgrip strength test, and lower body muscular strength was measured with the standing broad jump, squat jump, counter movement jump and Abalakov tests. Fat-free mass was measured by DXA. We observed positive associations between vigorous PA and all the lower body muscular strength tests except for the counter movement jump in males. PA was not associated with fat-free mass in both males and females. Male adolescents engaged in at least 60 min/day MVPA performed better in the standing broad jump test. In conclusion, the findings of the present study suggest that only vigorous PA is associated with muscular strength, particularly lower-body muscular strength in male adolescents.

Influence of socioeconomic factors on fitness and fatness in Spanish adolescents: the AVENA study.

OBJECTIVE: This study was to examine the influence of socioeconomic status on fitness and fatness in Spanish adolescents. SUBJECTS AND METHODS: A total of 1 795 adolescents (833 boys) aged 12.5-18.5 years from the AVENA study participated in this study. The following physical fitness components were assessed: muscular strength (standing long jump), speed-agility (4 × 10 m shuttle run) and cardiorespiratory fitness (20 m shuttle run). Total and central body fat was assessed using skinfold thickness and waist circumference, respectively. Both parents reported their educational and professional level. RESULTS: Girls with higher paternal educational level and boys with higher either maternal or paternal professional level had higher muscular strength levels (all P<0.05). Speed-agility and cardiorespiratory fitness were not associated with parental educational or professional levels in boys. In contrast, girls with higher paternal educational level or higher parental professional level had higher levels in both fitness components (all P<0.05). A higher maternal educational level was associated with lower total and central body fat in boys (all P<0.05), but not in girls. We observed a small effect size (Cohen's d∼0.2) in most of these associations. CONCLUSIONS: Our results suggest modest associations of high socioeconomic status with better fitness and fatness levels in Spanish adolescents. These associations greatly depend on the socioeconomic status and fitness parameters studied.

Socio-economic factors and active commuting to school in urban Spanish adolescents: the AVENA study.

BACKGROUND: This study aimed: (i) to describe the patterns of commuting to school in urban Spanish adolescents; and (ii) to examine the associations between active commuting to school (ACS) and socio-economic factors. METHODS: From the AVENA Study, 2183 adolescents (1142 females) aged 13-18.5 years were gathered. Mode and time of transportation to school were self-reported by the adolescents. Parental education level (primary, secondary or university degree), parental professional level (managerial, skilled worker or unskilled worker/unemployed) and the type of school (public or private) were self-reported by the parents. The relationships between ACS and socio-economic factors were analysed by binary logistic regression. RESULTS: Nearly <65% of the adolescents reported ACS and 83% of them spent <15 min travelling to school. In male adolescents, maternal primary education level showed an odds ratio (OR) of 1.55 (95% confidence interval, 1.12-2.15), with respect to mothers with a university degree. In female adolescents, mothers with a primary education level showed an OR of 0.68 (0.50-0.92), with respect to mothers with a university degree. Low maternal professional level showed an OR of 1.70 (1.29-2.24), with respect to high maternal professional levels. Students attending public schools showed an OR of 3.47 (2.46-4.90), with respect to students from private schools. CONCLUSION: Most of the adolescents actively commuted to school, yet the time spent commuting was low. Socio-economic level seems to be inversely related to the ACS in adolescents. Type of school and maternal educational level were the main predictors of ACS.