LabMed Physical Activity Study Research Articles

IDEAL CARDIOVASCULAR HEALTH STATUS AND HEALTH-RELATED QUALITY OF LIFE IN ADOLESCENTS: THE LABMED PHYSICAL ACTIVITY STUDY.

ABSTRACTObjective: Adolescent’s ideal cardiovascular health index (ICVH) seems to be an important indicator of youth’s lifestyles and cardiometabolic health with potential positive consequences for their Health-Related Quality of Life (HRQoL). The purpose of this study was to examine the associations between the ICVH index and HRQoL in adolescents.Methods: This was a cross-sectional study based on secondary analyses from the LabMed Physical Activity Study (n=407 adolescents, 53% girls). ICVH, as defined by the American Heart Association, was determined as meeting ideal behaviors (physical activity, body mass index, smoking status, and diet intake) and health factors (blood pressure, total glucose, and cholesterol). HRQoL was measured with the Kidscreen-10 self-report questionnaire.Results: Analysis of covariance (ANCOVA) showed a significant association between the accumulation of ideal cardiovascular health metrics and HRQoL (F(4,403)=4.160; p=0.003). In addition, the higher the number of ideal health behaviors accumulated, the higher the mean values of HRQoL (p-value for trend=0.001), after adjustments for age, sex, socioeconomic status and pubertal stage.Conclusions: ICVH index was positively associated with HRQoL in adolescents. Ideal health behaviors metrics seem to have a stronger association with HRQoL than the ideal health factors metrics in adolescents.

Association of Adipocytokines and Inflammatory Biomarkers with Blood Pressure in Adolescents: A Longitudinal Analysis

Background and aimsSeveral cross-sectional, but few prospective, studies suggest that inflammation may be involved in the development of high blood pressure. We examined markers of inflammation for their associations with blood pressure levels over a two-year period in healthy adolescents. Methods and resultsThe sample comprised 406 adolescents (209 girls) aged 12–18 years in the LabMed Physical Activity Study were followed-up for 2 years. Anthropometric (weigh, height, BMI), markers of inflammation (high sensitivity C-reactive protein, complement factors C3 and C4, fibrinogen, leptin and adiponectin) and ambulatory blood pressure (BP) were collected. Socioeconomic status, pubertal development, adherence to Mediterranean diet and cardiorespiratory fitness were measured for adjustment for potential confounders. Adjusted linear regression models revealed a significant association of Leptin/Adiponectin (L/A) Ratio (baseline) with systolic BP (β = 0.120; p < 0.034) and with diastolic BP (β = 0.125; p < 0.036) at follow-up (full adjusted model). Leptin was associated with systolic BP at follow-up (β = 0.102; p < 0.038) after adjustment for systolic BP at baseline, height, pubertal stage, socioeconomic status, adherence to Mediterranean diet, cardiorespiratory fitness, however, not independently of BMI. ConclusionL/A ratio was positively associated with systolic BP and diastolic BP even after adjusting confounding variables. Therefore, a higher misbalance between leptin and adiponectin (higher L/A ratio) early adolescence may exert a negative effect BP levels in late adolescence regardless of several confounders factors.

Adiposity and attained height in adolescents: a longitudinal analysis from the LabMed Physical Activity Study.

Background To investigate the associations between adiposity and attained height over a 2-year period in healthy adolescents. Methods One thousand and seventeen adolescents aged 12-18 years participated in this cohort study; 893 (87.8%) were reevaluated 1 year later (T2) and 734 (72.2%) subjects 2 years later (T3). Body fat and anthropometry were measured according to standardized procedures. Socioeconomic status, pubertal stage and lifestyles determinants were gathered and used as confounders. Prospective associations between adiposity and height were examined using generalized linear models. Results Greater adiposity at T1 was significantly associated with a lower attained height over time, when adjusting for confounders, which varied between 0.03 and 1 cm in T2 and 0.1 and 1 cm in T3. Conclusions Excess of adiposity in early adolescence may exert an effect on attained height in late adolescence. This study supports future lifestyles intervention studies aiming at preventing overweight and obesity and improving attained height.

Cardiorespiratory fitness and health-related quality of life in adolescents: A longitudinal analysis from the LabMed Physical Activity Study.

The purpose of this study was to examine the longitudinal associations between cardiorespiratory fitness and health-related quality of life (HRQoL) in a sample of adolescents, and to determine whether changes in cardiorespiratory fitness were associated with HRQoL over a 2-year follow-up. This is a longitudinal analysis with 571 Portuguese adolescents (274 boys and 297 girls) aged 12-18 years. HRQoL was measured with the Kidscreen-10 questionnaire; the 20 m shuttle-run was used to estimate cardiorespiratory fitness; socioeconomic status was assessed with the Family Affluence Scale; and pubertal stage was assessed with Tanner stages. Linear regression and analysis of covariance (ancovas) were used to examine the associations between cardiorespiratory fitness and HRQoL. HRQoL decreased over a 2-year period both in boys and girls (P < .05). Moreover, girls at baseline and at follow-up reported significantly lower HRQoL values than boys (between subjects P < .001). After adjustments for potential confounders, regression analyses showed significant cross-sectional associations between cardiorespiratory fitness and HRQoL both at baseline (B = 0.095; P = .023) and at follow-up (B = 0.090; P = .012). ancova showed that adolescents whose cardiorespiratory fitness decreased over time exhibited lower scores of HRQoL at follow-up, compared to those with persistent high cardiorespiratory fitness; this held after adjustments for age, sex, socioeconomic status, and pubertal stage. Changes in cardiorespiratory fitness during adolescence were associated with HRQoL over a 2-year period. This study suggests that improving cardiorespiratory fitness could be an important strategy in improving the HRQoL of adolescents.

Longitudinal associations between motor competence and different physical activity intensities: LabMed physical activity study

ABSTRACTAn appropriated level of motor competence is essential for children´s healthy growth and development and a key factor in the promotion of lifelong active lifestyles and health.The purpose of this study was to examine associations between motor competence and different physical activity intensities (light, moderate, moderate-to-vigorous and vigorous physical activity), as well as total physical activity, over a two-year period, in adolescents. The sample comprised of 103 adolescents (13.49 ± 0.87 years, 53 girls), from the north of Portugal. Motor competence was evaluated with the body coordination test, Körperkoordination-Test-für-Kinder. Physical activity was objectively assessed with GT1M accelerometers (ActiGraph, Pensacola, FL, USA). Physical activity variables were expressed as proportions of accelerometer wear time. Regression analyses showed positive longitudinal associations between motor competence at baseline and moderate physical activity (B = 0.0033, p = 0.018), moderate-to-vigorous physical activity (B = 0.0052, p = 0.024) and total physical activity (B = 0.067, p = 0.040) at follow up, after adjustments for age, sex, the corresponding physical activity intensity at baseline, body mass index, pubertal stage and socioeconomic status. Our findings highlight the importance of motor competence development to promote moderate-to-vigorous physical activity during adolescence.

Fruit, vegetable consumption and blood pressure in healthy adolescents: A longitudinal analysis from the LabMed study

Background and aimsThe associations between fruit and vegetable consumption and high blood pressure among adults are well studied. Nonetheless, data on the influence of a low consumption of fruit and vegetables on cardiovascular disease risk, particularly blood pressure, among healthy adolescents are scarce. Therefore, we aim to analyse the associations between fruit and/or vegetable intake and blood pressure over a two-year period in healthy adolescents. Methods and resultsAs part of a cohort, 606 adolescents from the LabMed Physical Activity study were evaluated in 2011 (baseline) and 2013 (follow-up). Blood pressure was measured according to standardized procedures and fruit and vegetable consumption was assessed with a food frequency questionnaire. Anthropometric variables, socioeconomic status, pubertal stage and lifestyle determinants were gathered and used as confounders. Prospective associations between fruit and/or vegetable intake and blood pressure were examined using generalized linear models. Girls who consumed more fruit at baseline had a significant decrease in diastolic blood pressure at follow-up [unstandardized beta: −0.005 mmHg (95%CI: −0.01; −0.0002) (p = 0.038)]. ConclusionIn apparently healthy adolescents, fruit intake may already start to have an effect in blood pressure. Girls who consumed more fruit exhibited lower levels of diastolic blood pressure.

Longitudinal association between ideal cardiovascular health status and muscular fitness in adolescents: The LabMed Physical Activity Study

Background and aimsMuscular fitness is an emerging predictor for cardiovascular disease mortality. The ideal cardiovascular health metrics has been inversely related to a subsequent cardiometabolic health in adulthood. However, evidence regarding muscular fitness and ideal cardiovascular health in adolescents is scarce. This study aimed to examine the longitudinal association between ideal cardiovascular health index and muscular fitness. Methods and resultsThis study cohort consisted of 331 adolescents (183 girls) from the LabMed Physical Activity Study who were followed from 2011 to 2013. Ideal cardiovascular health, as defined by the American Heart Association, was determined as meeting ideal health factors (total cholesterol, blood pressure, and glucose) and behaviors (smoking status, body mass index, physical activity, and diet). Handgrip strength and standing long jump tests assessed muscular fitness and were transformed into standardized values according to age and sex. ANCOVA showed a significant association between the accumulation of ideal cardiovascular health metrics at baseline and muscular fitness indices at follow-up (F(4, 322) = 2.280, p = 0.04). In addition, the higher the number of ideal cardiovascular health metrics accumulated, the higher the likelihood of having a high muscular fitness over a two-year period (p for trend = 0.01), after adjustments for age, sex, pubertal stage and socioeconomic status and muscular fitness at baseline. ConclusionThe ideal cardiovascular health status during adolescence was associated with high muscular fitness levels over a two-year period.

Environmental perceptions and its associations with physical fitness and body composition in adolescents: longitudinal results from the LabMed Physical Activity Study.

Background The environmental correlates have been extensively studied in the last years, but most associations with physical fitness (PF) and body composition have been cross-sectional in nature. Objective This study aimed to determine if adolescents' environmental perceptions associated with PF and body composition in a 2-year follow-up. Subjects Participants were 583 adolescents aged 12-18 years (299 girls) from the LabMed Physical Activity Study. Methods PF and body composition were assessed with the protocols of the ALPHA health-related fitness battery and environmental perceptions with the ALPHA environmental questionnaire. Linear regression models were used to determine the associations between environmental perceptions at baseline and PF and anthropometric measures at follow-up. Results Results showed that perceptions of distant facilities at baseline were associated with lower fitness at follow-up in boys. Also, boys' lower study environment perceptions at baseline were associated with higher body composition at follow-up. Positive perceptions of a pleasant environment at baseline were associated with better fitness at follow-up in boys. Additionally, girls' positive bike lanes availability and esthetics perceptions at baseline were associated with better body composition at follow-up. Conclusion Positive environmental perceptions at baseline are associated with better PF and body composition at follow-up.

Associations between physical fitness and adherence to the Mediterranean diet with health-related quality of life in adolescents: results from the LabMed Physical Activity Study

Physical fitness (PF) and adherence to the Mediterranean diet are important indicators of healthy lifestyles. The purpose of this study is to analyze the independent and combined associations between PF and adherence to Mediterranean diet with health-related quality of life (HRQoL) in adolescents. This is a cross-sectional analysis with 956 Portuguese adolescents aged 12-18 years. HRQoL was measured with the Kidscreen-10 questionnaire. PF was assessed with the ALPHA health-related fitness battery. The 20-m shuttle run test was used for the estimation of cardiorespiratory fitness; handgrip strength and standing long jump tests were applied for the assessment of muscular fitness and the 4 × 10 m shuttle run test for the assessment of motor fitness (speed and agility). The results of the PF tests (cardiorespiratory fitness, muscular fitness and motor fitness) were transformed into standardized values (Z-scores) by age and sex. Adherence to the Mediterranean diet was assessed with the KIDMED index. Regression analysis and analysis of covariance were performed. PF (B = 0.228; P < 0.05) and adherence to the Mediterranean diet (B = 0.259; P < 0.05) were positively associated with HRQoL, after controlling for several variables. Participants classified as high PF and high adherence to Mediterranean diet had on average the highest HRQoL score compared with those with low PF and low adherence to Mediterranean diet (F(3, 939) = 4.270; P = 0.005), after adjustments for potential confounders. The combination of high PF levels and optimal adherence to Mediterranean diet is positively associated with HRQoL.

Associations between health-related quality of life and body mass index in Portuguese adolescents: LabMed physical activity study.

Background In adolescence there are several biological and physiological changes associated with overweight and obesity. Objective The purpose of this study was to analyze the associations between health-related quality of life (HRQoL) and body mass index (BMI) in adolescents. Methods This is a cross-sectional analysis of 957 Portuguese adolescents (446 girls and 511 boys) aged 12-18 years. A series of variables were collected: (a) HRQoL was assessed using the KIDSCREEN-10 questionnaire; (b) socioeconomic status (SES) was measured using the Family Affluence Scale; (c) body composition (weigh, height) were measured and BMI was calculated and, (d) pubertal stage was assessed with Tanner stages; (e) the 20-m shuttle-run was used to estimate cardiorespiratory fitness. Regression models and mediation analysis were performed to assess the association between HRQoL and BMI. Results HRQoL was significantly higher in boys than girls (p < 0.05). The prevalence of overweight and obesity was 23.5% and 6.7% in girls, and 21.3% and 5% in boys, respectively. HRQoL was inversely and significantly associated with BMI in boys (B = -0.130; p < 0.05) and girls (B = -0.148; p < 0.05) after controlling for age, pubertal stage and SES. Cardiorespiratory fitness act as a full mediator variable on the relationship between BMI and HRQoL in adolescents (p < 0.05). Conclusion Our results suggest that cardiorespiratory fitness acted as a full mediator in the relationship between BMI and HRQoL, in adolescents. Public health policies targeting a wealthy weight and an improved physical fitness level could be a strategy of particular interest for improving the HRQoL of adolescents.

Dietary inflammatory index and inflammatory biomarkers in adolescents from LabMed physical activity study.

The dietary inflammatory index (DII) is a tool to measure the diet's inflammatory potential and has been used with adults to predict low-grade inflammation. The present study aims to assess whether this dietary score predicts low-grade inflammation in adolescents. The sample comprises 329 adolescents (55.9% girls), aged 12-18 years, from LabMed Physical Activity Study. DII score was calculated based on a food-frequency questionnaire and categorized into tertiles. We collected blood samples to determine the follow inflammatory biomarkers: C-reactive protein (CRP), interleukin-6 (IL-6), complement component 3 (C3), and 4 (C4). In addition we calculated an overall inflammatory biomarker score. Odds ratios (OR) and 95% confidence intervals (95%CI) were computed from binary logistic regression models. DII score, comparing first with third tertile, was positively associated with IL-6 in crude model (OR = 1.88, 95%CI:1.09-3.24, p trend = 0.011) and in fully adjusted (for biological and lifestyle variables) (OR = 3.38, 95%CI:1.24-9.20, p trend = 0.023). Also, DII score was positively associated with C4, when fully adjusted (OR = 3.12, 95%CI:1.21-8.10, p trend = 0.016). DII score was negatively associated with C3 in crude model, comparing first with second but not with third tertile, and no significant associations in fully adjusted model were observed, although a trend was found (OR = 1.71, 95%CI:0.63-4.66, p trend = 0.044). No significant associations were observed between DII score and CRP. However, DII score was positively associated with the overall inflammatory biomarker score, when fully adjusted (OR = 5.61, 95%CI:2.00-15.78, p trend = 0.002). DII score can be useful to assess the diet's inflammatory potential and its association with low-grade inflammation in adolescents.

Cardiorespiratory Fitness and Blood Pressure: A Longitudinal Analysis

To examine the association between cardiorespiratory fitness and cardiovascular indices 2 years later, and to determine whether changes in cardiorespiratory fitness are associated with cardiovascular indices at a 2-year follow-up in adolescents. The sample comprised 734 adolescents (349 girls) aged 12-18 years followed for 3 years from the LabMed Physical Activity Study. Cardiorespiratory fitness was assessed by the 20-meter shuttle run test. Height, weight, waist circumference, and resting blood pressure (BP) were measured according to standard procedures. Regression analyses showed a significant inverse association between cardiorespiratory fitness at baseline and systolic BP (B = -0.126; P = .047) and rate pressure product (B = -29.94; P = .016), at follow-up after adjustments for age, sex, height, pubertal stage, socioeconomic status, and waist circumference. Significant differences were found between cardiorespiratory fitness groups (fit vs unfit) at baseline and systolic BP and rate pressure product at follow-up (P < .05 for all). Analysis of covariance showed a significant association between cardiorespiratory fitness changes and systolic BP (P = .024) and rate pressure product (P = .014), after adjustment for age, sex, height, pubertal status, socioeconomic status, and waist circumference. Changes in cardiorespiratory fitness during adolescence were associated with cardiovascular indices over a 2-year period. Adolescents with persistently low levels of cardiorespiratory fitness exhibited the highest levels of systolic BP and rate pressure product.

Low-grade inflammation and muscular fitness on insulin resistance in adolescents: Results from LabMed Physical Activity Study.

Low muscular fitness (MF) and low-grade inflammation has been linked to insulin resistance (IR). To evaluate the associations between MF and a clustered score of inflammatory biomarkers on IR and to investigate the combined impact of MF and inflammation on IR in adolescents. This is a cross-sectional analysis with 529 adolescents (267 girls) aged 12 to 18 years. Pubertal stage, socioeconomic status, adherence to the Mediterranean diet, cardiorespiratory fitness, and waist circumference were assessed. Standing long-jump and isometric handgrip dynamometry were used as indicators of MF. Continuous score of clustered inflammatory biomarkers (InflaScore) (sum of Z-scores of C-reactive protein, C3, C4, fibrinogen, and leptin) and IR (homeostasis model assessment of insulin resistance [HOMA-IR] estimated from fasting serum insulin and glucose) were assessed. HOMA-IR and fasting insulin were positively associated with InflaScore and negatively associated with MF, independently of age, sex, pubertal stage, socioeconomic status, adherence to the Mediterranean diet, cardiorespiratory fitness, and waist circumference. Adolescents classified as High InflaScore/Unfit showed significantly higher HOMA-IR when compared than those with High InflaScore/Fit and those with Low InflaScore/Fit (F(3,519) = 4.761, P < .003), after adjustments for potential confounders. Unfit adolescents with high InflaScore had the highest odds of expressing high HOMA-IR (odds ratio, OR = 2.40, 95% confidence interval [CI]: 1.2-5.6) and insulin risk (2.53 95% CI, 1.5-5.9) when compared to those of the Low InflaScore/Fit group, after adjustments for potential confounders. Higher levels of MF seem to minimize the deleterious effect of inflammation on IR.

Ability of Nontraditional Risk Factors and Inflammatory Biomarkers for Cardiovascular Disease to Identify High Cardiometabolic Risk in Adolescents: Results From the LabMed Physical Activity Study

PurposeThen objective of this study was to evaluate the ability of several nontraditional cardiometabolic and inflammatory biomarkers in identifying high cardiometabolic risk in adolescents. MethodsA cross-sectional study was conducted with 529 Portuguese adolescents (267 girls) aged 14.3 ± 1.7 years. A clustered cardiometabolic risk score (body fat percentage, systolic blood pressure, ratio of total cholesterol to high-density lipoprotein cholesterol, triglycerides, homeostatic model assessment of insulin resistance, and negative values of cardiorespiratory fitness) was computed. The nontraditional cardiometabolic biomarkers assessed were complement factors (C3 and C4), C-reactive protein (CRP), fibrinogen, leptin, white blood cells (WBCs), albumin, interleukin-6, and a clustered score of inflammatory biomarkers (InflaScore) (C3, C4, CRP, fibrinogen, and leptin). ResultsReceiver operating characteristic curves analyses showed that C3, C4, CRP, fibrinogen, leptin, and the InflaScore were able to present discriminatory ability in identifying an unfavorable cardiometabolic profile in both girls and boys (p < .01 for all). Logistic regression analyses showed that C3, C4, CRP, fibrinogen, leptin, the InflaScore (in both sexes), and WBC (boys) were associated with high cardiometabolic risk, independent of age, pubertal stage, socioeconomic status, or adherence to a Mediterranean diet (p < .05 for all). ConclusionsC3, C4, CRP, fibrinogen, and leptin were associated with high cardiometabolic risk in both sexes and WBC in boys. In addition, the clustered inflammatory biomarkers seem to have a better diagnostic accuracy in identifying an unfavorable cardiometabolic profile than single biomarkers. Such biomarkers may have utility in motivating health professionals, public health workers, and adolescents' families toward lifestyle changes, improving prevention efforts early in life.

Cardiorespiratory fitness and inflammatory profile on cardiometabolic risk in adolescents from the LabMed Physical Activity Study.

We investigated the combined effect of cardiorespiratory fitness and the clustered score of inflammatory biomarkers (InflaScore) on the cardiometabolic risk score in adolescents. This is a cross-sectional analysis with 529 adolescents (267 girls) aged 12-18years. The shuttle run test was used to assess cardiorespiratory fitness. Continuous scores of clustered inflammatory biomarkers (high sensitivity C-reactive protein, complement factors C3 and C4, fibrinogen and leptin); cardiometabolic risk score (systolic blood pressure, triglycerides, ratio total cholesterol/HDL, HOMA-IR and waist circumference) were computed. Adolescents with a higher inflammatory profile had the highest cardiometabolic risk score; adolescents with high InflaScore and low fitness had the highest odds of having a high cardiometabolic risk (OR 16.5; 95% CI 7.8-34.5), followed by adolescents with a higher InflaScore but fit (OR 7.5; 95% CI 3.7-8.4), and then by adolescents with a low InflaScore and unfit (OR 3.7; 95% CI 1.6-8.4) when compared to those with low InflaScore and fit, after adjustments for age, sex, pubertal stage, adherence to a Mediterranean dietary pattern and socioeconomic status. The findings of our study suggest that the combination of high inflammatory state and low cardiorespiratory fitness is synergistically associated with a significantly higher cardiometabolic risk score and thus supports the relevance of early targeted interventions to promote physical activity and preservation as part of primordial prevention.

Associations between fruit and vegetable variety and low-grade inflammation in Portuguese adolescents from LabMed Physical Activity Study.

The dietary guidelines for the consumption of a variety of fruits and vegetables have been recognized as an important factor for achieving healthy eating patterns to reduce the risk of chronic disease throughout the lifespan. Our aim is to assess the association between fruit and vegetable variety and low-grade inflammation in adolescents. This cross-sectional analysis was conducted with 412 adolescents (ages 14.4±1.7years; 52% girls). The consumption of a variety of fruits and vegetables was assessed with a food-frequency questionnaire, considering the number of individual/category of fruit or vegetable intake at least once month, and categorized into tertiles. Blood samples were collected to determine C-reactive protein (CRP), interleukin-6 (IL-6), complement component 3 (C3), and 4 (C4). We created categories of lower or higher (inflammatory state) for each biomarker, considering sex- and age-adjusted median values. Then, we computed an overall inflammatory score, by adding all points awarded wherein one point was assigned if biomarker was higher or zero if lower, and created categories of 0-1 or 2-4 biomarkers above the median. The odds ratio (OR) and 95% interval confidence (95% CI) were calculated from binary logistic regression to estimate the magnitude of association between fruit and vegetable variety and inflammatory biomarkers. Adolescents with a greater variety of vegetable consumption (≥13 categories/month) had lower odds of having a higher CRP (OR 0.31, 95% CI 0.15-0.64, p trend=0.004) when compared to those with lower variety consumption (≤6 categories/month), independent of vegetable quantity intake. However, a greater variety of fruit consumption (≥12 categories/month) had higher odds of having a higher IL-6 (OR 4.41, 95% CI 1.67-11.71, p trend=0.012), C3 (OR 3.30, 95% CI 1.23-8.86, p trend=0.047), and inflammatory score (OR 4.90, 95% CI 1.62-14.86, p trend=0.017), when compared to those with lower variety consumption (≤9 categories/month), independent of fruit quantity intake, only for girls. The consumption of a variety of vegetables is inversely associated with lower CRP. This finding supports the current dietary guidelines regarding the consumption of a variety of vegetables. The role of fruit variety in low-grade inflammation should be further studied.

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 12-18years. 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.

Association between serum adiponectin levels and muscular fitness in Portuguese adolescents: LabMed Physical Activity Study

Background and aimParadoxically, recent investigations have showed that adiponectin levels are inversely associated with muscle strength. However, to date, there is a lack of knowledge on the relationship between muscular fitness (MF) and adiponectin levels in adolescents. We aimed to examine the independent associations between MF and adiponectin levels in adolescents, controlling for several potential confounders. Methods and resultsThis is a cross-sectional analysis with 529 Portuguese adolescents aged 12–18 years. A MF score was computed as the mean of the handgrip strength and standing long jump standardized values by age and gender. We measured fasting glucose, insulin, HDL-cholesterol, C-reactive protein and adiponectin. Linear regression analysis showed a significant inverse association between adiponectin (Z-score by age and sex) and MF score, after adjustments for age, sex, pubertal stage, socioeconomic status, adherence to the Mediterranean diet, body mass index, HOMA-IR, HDL-cholesterol, C-reactive protein and cardiorespiratory fitness (unstandardized β = −0.176; p < 0.005). Analysis of covariance showed a significant difference between the Low MF/Non-overweight group and the High MF/Non-overweight Group (p < 0.05) and between the Low MF/Non-overweight and High MF/Overweight Group (p < 0.05) (F (5, 523) = 2.262, p = 0.047). ConclusionAdiponectin circulating levels are inversely and independently associated with MF. In non-overweight adolescents, those with high levels of MF presented lower levels of adiponectin compared to those with Low MF. Likewise, overweight adolescents with High MF presented lower levels of serum adiponectin than non-overweight adolescents with Low MF.