Sandra Abreu

Metabolic syndrome, physical activity and cardiac autonomic function

Our primary aim was to investigate the associations that components of metabolic syndrome and physical activity have with cardiac autonomic nervous system activity as estimated by heart rate variability (HRV) in young adults free of metabolic abnormalities. We also aimed to identify predictors of 3‐year changes in HRV.

Muscle strength and soccer practice as major determinants of bone mineral density in adolescents

OBJECTIVES To analyse the relationship between isokinetic strength of the lower limb muscles and bone mineral density and content (BMD, BMC) of adolescent male soccer players and age-matched controls not involved in sport (12-15 years). METHODS A random sample of 151 young males was divided into soccer players (SG; n=117) and control subjects (CG; n=34). Peak torque of knee extensors (PTE) and flexors (PTF) was measured during isokinetic knee joint movement (90°/s) of the dominant and non-dominant lower limbs. BMD and BMC of the whole-body, lumbar spine, dominant/non-dominant lower limb were determined by dual-energy X-ray absorptiometry. Physical activity was monitored with accelerometers during 5 days. Estimated maturity offset was used as an indicator of biological maturity status. RESULTS Whole-body BMD (1.03±0.01 vs. 0.98±0.01 g/cm2, P=0.003) and dominant (1.09±0.01 vs. 1.02±0.01 g/cm2, P<0.001) and non-dominant (1.09±0.01 vs. 1.01±0.01 g/cm2, P<0.001) lower limb BMD was greater in SG compared to CG. No significant differences were found for BMC. Compared to CG, SG performed better in the YY-IE2 test (780±40 vs. 625±31 m), exhibited higher PTE (dominant limb: 155.2±30.3 vs. 123.4±37.0N m; non-dominant limb: 156.2±36.1 vs. 120.4±41.1 N m) and PTF muscles (dominant limb: 79.0±25.3 vs. 57.1±25.3 Nm; non-dominant limb: 73.3±20.7 vs. 57.0±24.2N m). Moreover, the PTE, soccer participation and maturity status were positively associated with the BMD at all body sites (r2=0.57-0.73, P<0.05). CONCLUSIONS Muscle strength of knee extensors is associated with BMD and BMC at all body sites. Muscle-skeletal structures respond positively to the weight-bearing and impact-loading imposed by soccer practice. Soccer seemed to be a multilateral balanced sport activity.

Impact of compliance with different guidelines on physical activity during pregnancy and perceived barriers to leisure physical activity

Abstract The aims of the this prospective study were to analyse physical activity (PA) engagement during the first and second trimesters, considering the different guidelines published on PA, to document the individual characteristics associated with the accomplishment of these guidelines and to examine pregnant women’s perceived barriers to leisure PA, using a socioecological framework. A sample of 133 pregnant women in two stages – at 10–12 weeks’ gestation (T1) and 20–22 weeks’ gestation (T2) – were evaluated. PA was assessed by accelerometry during the T1 and T2 evaluation stages. Socio-demographic characteristics, lifestyle factors and barriers to leisure PA were assessed via questionnaire. A large proportion of women (ranging from 32% to 96%) did not reach the levels of PA recommended by the guidelines. There were no significant differences between T1 and T2 with regard to compliance with PA recommendations. A decrease in PA levels from T1 to T2 was noted for all recommendations. No associations were found between participants’ characteristics and adherence to the recommendations in T1 and T2. No significant differences were found in barriers to leisure PA between T1 and T2. The most commonly reported barriers to leisure PA were intrapersonal, not health related. Our results indicate that there were no differences between trimesters regarding compliance of PA recommendations, and perceived barriers were similar in both trimesters.

Relationship of milk intake and physical activity to abdominal obesity among adolescents.

What is already known about this subject Diet and physical activity (PA) are recognized as important factors to prevent abdominal obesity (AO). Studies have found an inverse relationship between milk intake or milk products and body weight and/or body fat in children and adolescents. Evidence suggests that low levels of PA are associated with AO in youth.

Association between dairy product intake and abdominal obesity in Azorean adolescents

BACKGROUND:Some studies have reported an inverse association between dairy product (DP) consumption and weight or fat mass loss.OBJECTIVES:The objective of our study was to assess the association between DP intake and abdominal obesity (AO) among Azorean adolescents.SUBJECTS/METHODS:This study was a cross-sectional analysis. A total of 903 adolescents (370 boys) aged 15–16 years was evaluated. Anthropometric measurements were collected (weight, height and waist circumference (WC)) and McCarthys cut-points were used to categorize WC. AO was defined when WC was ⩾90th percentile. Adolescent food intake was assessed using a self-administered semiquantitative food frequency questionnaire and DP intake was categorized in <2 and ⩾2 servings/day. Data were analyzed separately for girls and boys, and logistical regression was used to estimate the association between DPs and AO adjusting for potential confounders.RESULTS:The prevalence of AO was 54.9% (boys: 32.1% and girls: 70.7%, P<0.001). For boys and girls, DP consumption was 2.3±1.9 and 2.1±1.6 servings/day (P=0.185), respectively. In both genders, the proportion of adolescents with WC <90th percentile was higher among individuals who reported a dairy intake of ⩾2 servings/day compared with those with an intake <2 servings/day (boys: 71% vs 65% and girls: 36% vs 24%, P<0.05). After adjustments for confounders, two or more DP servings per day were a negative predictor of AO (odds ratio, 0.217; 95% confidence interval, 0.075–0.633) only in boys.CONCLUSION:We found a protective association between DP intake and AO only in boys.

Ability of Different Measures of Adiposity to Identify High Metabolic Risk in Adolescents

Introduction. This study aimed to evaluate the screening performance of different measures of adiposity: body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR) for high metabolic risk in a sample of adolescents. Methods. A cross-sectional school-based study was conducted on 517 adolescents aged 15–18, from the Azorean Islands, Portugal. We measured fasting glucose, insulin, total cholesterol (TC), HDL-cholesterol, triglycerides, and systolic blood pressure. HOMA and TC/HDL-C ratio were calculated. For each of these variables, a Z-score was computed by age and sex. A metabolic risk score (MRS) was constructed by summing the Z-scores of all individual risk factors. High risk was considered when the individual had ≥1SD of this score. Receiver-operating characteristics (ROC) were used. Results. Linear regression analyses showed that, after adjusting for age and pubertal stage, all different measures of adiposity are positively and significantly associated with MRS in both sexes, with exception of WHtR for boys. BMI, WC, and WHtR performed well in detecting high MRS, indicated by areas under the curve (AUC), with slightly greater AUC for BMI than for WC and WHtR in both sexes. Conclusion. All measures of adiposity were significantly associated with metabolic risk factors in a sample of Portuguese adolescents.

Food consumption, physical activity and socio-economic status related to BMI, waist circumference and waist-to-height ratio in adolescents

OBJECTIVE To examine the association between obesity and food group intakes, physical activity and socio-economic status in adolescents. DESIGN A cross-sectional study was carried out in 2008. Coles cut-off points were used to categorize BMI. Abdominal obesity was defined by a waist circumference at or above the 90th percentile, as well as a waist-to-height ratio at or above 0·500. Diet was evaluated using an FFQ, and the food group consumption was categorized using sex-specific tertiles of each food group amount. Physical activity was assessed via a self-report questionnaire. Socio-economic status was assessed referring to parental education and employment status. Data were analysed separately for girls and boys and the associations among food consumption, physical activity, socio-economic status and BMI, waist circumference and waist-to-height ratio were evaluated using logistic regression analysis, adjusting the results for potential confounders. SETTING Public schools in the Azorean Archipelago, Portugal. SUBJECTS Adolescents (n 1209) aged 15-18 years. RESULTS After adjustment, in boys, higher intake of ready-to-eat cereals was a negative predictor while vegetables were a positive predictor of overweight/obesity and abdominal obesity. Active boys had lower odds of abdominal obesity compared with inactive boys. Boys whose mother showed a low education level had higher odds of abdominal obesity compared with boys whose mother presented a high education level. Concerning girls, higher intake of sweets and pastries was a negative predictor of overweight/obesity and abdominal obesity. Girls in tertile 2 of milk intake had lower odds of abdominal obesity than those in tertile 1. Girls whose father had no relationship with employment displayed higher odds of abdominal obesity compared with girls whose father had high employment status. CONCLUSIONS We have found that different measures of obesity have distinct associations with food group intakes, physical activity and socio-economic status.

Physical Activity, Obesity Status, and Blood Pressure in Preschool Children.

OBJECTIVE To examine the combined effects of physical activity and weight status on blood pressure (BP) in preschool-aged children. STUDY DESIGN The sample included 733 preschool-aged children (49% female). Physical activity was objectively assessed on 7 consecutive days by accelerometry. Children were categorized as sufficiently active if they met the recommendation of at least 60 minutes daily of moderate-to-vigorous physical activity (MVPA). Body mass index was used to categorize children as nonoverweight or overweight/obese, according to the International Obesity Task Force benchmarks. BP was measured using an automated BP monitor and categorized as elevated or normal using BP percentile-based cut-points for age, sex, and height. RESULTS The prevalence of elevated systolic BP (SBP) and diastolic BP was 7.7% and 3.0%, respectively. The prevalence of overweight/obese was 32%, and about 15% of children did not accomplish the recommended 60 minutes of daily MVPA. After controlling for age and sex, overweight/obese children who did not meet the daily MVPA recommendation were 3 times more likely (OR 3.8; CI 1.6-8.6) to have elevated SBP than nonoverweight children who met the daily MVPA recommendation. CONCLUSIONS Overweight or obese preschool-aged children with insufficient levels of MVPA are at significantly greater risk for elevated SBP than their nonoverweight and sufficiently active counterparts.

Muscular fitness and metabolic and inflammatory biomarkers in adolescents: Results from LabMed Physical Activity Study

This study aimed to evaluate the associations between muscular fitness and inflammatory biomarkers and to investigate the relationship between muscular fitness and selected clustered inflammatory biomarkers in adolescents. This is a cross‐sectional analysis with 529 adolescents (267 girls) aged 12‐18 years. Handgrip strength and standing long jump tests assessed MF. Continuous scores of clustered inflammatory biomarkers (sum of Z‐scores of C‐reactive protein [CRP], C3, C4, fibrinogen, and leptin); metabolic risk factor (MRF) score (sum of Z‐scores of SBP, triglycerides, ratio total cholesterol [TC]/HDL, HOMA‐IR, and waist circumference [WC]) were computed. Regression analyses showed an inverse association between muscular fitness score (β=−.204; P<.021) and clustered score of inflammatory biomarkers, adjusted for age, sex, pubertal stage, socioeconomic status, adherence to the Mediterranean diet, cardiorespiratory fitness (CRF), MRF score, and body fat. Analysis of covariance showed that adolescents with an adverse inflammatory profile with low levels of muscular fitness exhibit the poorest MRF score (F3,525=6.461; P<.001), adjusted for age, sex, pubertal stage, socioeconomic status, adherence to the Mediterranean diet, CRF, and body fatness. The inflammatory state seems to explain a significant part of the highest MRF score and in adolescents with high inflammatory status and low muscular strength.

Effects of 6-month soccer and traditional physical activity programmes on body composition, cardiometabolic risk factors, inflammatory, oxidative stress markers and cardiorespiratory fitness in obese boys

ABSTRACT Physical activity is important in obesity prevention, but the effectiveness of different physical activity modalities remains to be determined among children. The main purpose of this study was to compare the effects of a 6-month soccer programme and a traditional physical activity programme on changes in body composition, cardiometabolic risk factors, inflammatory and oxidative markers, cardiorespiratory fitness and perceived psychological status in obese boys. Eighty-eight boys (8–12 years; BMI > +2 standard deviations of WHO reference values) participated in one of three groups: soccer, traditional activity and control. Soccer and traditional activity programmes involved 3 sessions per week for 60–90 min at an average intensity of 70–80% of maximal heart rate. Control group participated in activities of normal daily living. All boys participated in school physical education, two sessions per week of 45–90-min. Measurements were taken at baseline and after 6 months, and included body size and composition, cardiometabolic risk factors, inflammatory and oxidative markers, cardiorespiratory fitness and perceived psychological status. Physical activity and dietary intake were assessed before and immediately following the intervention. The three groups had similar characteristics at baseline. After 6 months, both intervention groups had significantly lower relative fatness (% fat), waist circumference and total cholesterol, and higher cardiorespiratory fitness, self-esteem, perceived physical competence and attraction to physical activity compared with control group. In conclusion, physical activity interventions over 6 months positively influenced several indicators of health status among obese boys. The results also suggested that soccer has the potential as an effective tool for the prevention and reduction of childhood obesity and associated consequences.