Association Between Typologies of Sedentary Behavior and Muscle Strength, Gait Speed, and Balance in Community-Dwelling Older Adults.

Knowledge of how the different types of sedentary behaviors (SB) are associated with functional limitations can guide professionals who work with older adults on better recommendations about the amount of daily time that should be encouraged in each type of SB. The objective was to estimate the associations between two SB typologies (SB television [TV] and SB computer/internet) and the presence of handgrip strength, lower limb strength, gait speed, and balance limitations in Brazilian community-dwelling older adults. This is a cross-sectional study with 1,298 community-dwelling older adults (≥60 years). SB was assessed by self-reporting daily time spent watching TV or using computer/internet (categorized into <2, 3-4, and ≥5 hr/day). Outcomes were handgrip strength, lower limb strength, gait speed, and balance limitations considering referenced cutoff points. Older adults in SB TV ≥5 hr/day had 1.75 (95% confidence interval [CI] [1.07, 2.86]) and 1.88 (95% CI [1.02, 3.46]) times more chances of handgrip strength and gait speed limitations, respectively. On the other hand, those who spent 3-4 and ≥5 hr/day in SB computer/internet had 0.45 (95% CI [0.20, 0.99]) and 0.37 (95% CI [0.15, 0.93]) had less chances of lower limb strength and balance limitations, respectively. In conclusion, functional limitations would be associated differently depending on the type of SB in the older adults sampled.

The neutrophil to lymphocyte ratio (NLR) positively correlates with the presence and severity of metabolic syndrome in obese adults, but not in obese children/adolescents.

Metabolic syndrome (MetS) associated with obesity is a pathological condition increasing worldwide. Recent studies have demonstrated that the neutrophil to lymphocyte ratio (NLR) can be successfully used to stage MetS in obese adults. The aim of the study was to evaluate NLR values in 552 children/adolescents (M 219, F 333; 14.8 [12.9-16.3] years) and 231 adults (M 88, F 143; 52.3 [36.4-63.3] years) with morbid obesity, subdivided into subgroups according with the presence or absence of MetS. Adult patients with obesity showed a higher prevalence of MetS compared to the pediatric population (71% vs 26%), associated with a greater number of subjects with 3 and 4-5 altered components for MetS. NLR was higher (P-value = 0.041) in adults with MetS compared with those without. NLR values also positively correlated with the severity grade of the syndrome (P-value = 0.032). By contrast, in pediatric subjects with obesity with MetS, NLR values were comparable with those recorded in subjects without MetS (P-value = 0.861), no correlation being found with MetS severity (P-value = 0.441). Our study confirms the importance of NLR as an inflammatory indicator associated with MetS in adult subjects with severe obesity, while it excludes a similar role in children/adolescents.

Association between biomarkers of redox status and cytokines with different patterns of habitual physical activity in eutrophic and overweight/obese preschoolers: multivariate analysis of a cross-sectional study.

BACKGROUND: Although it is well known that obesity is frequently associated with reduced levels of habitual physical activity (HPA), which contributes to determining severe oxidative stress and inflammatory state, this association is however unknown in preschoolers so far. This study aimed to investigate the association between biomarkers of redox status and cytokines with different patterns of HPA according to the adiposity of preschoolers. METHODS: A cross-sectional study was conducted in 50 preschoolers (25 overweight/obese, OW/OB and 25 eutrophic, EU), matched for age, sex, economic level, and maternal education. Total antioxidant capacity (TAC), superoxide dismutase (SOD) and catalase (CAT) activities, substances reactive to thiobarbituric acid (TBARS), soluble tumor necrosis factor receptors (sTNFRs), and leptin levels were evaluated. HPA levels were evaluated by accelerometry (ActiGraph GT9X accelerometer). Correlation, multiple linear regression, and partial least squares regression analysis were used to determine the association between redox status biomarkers and cytokines with different patterns of HPA (HPA level, bouts of moderate to vigorous physical activity [MVPA], and multivariate pattern of HPA) in EU and OW/OB preschoolers. RESULTS: OW/OB preschoolers had lower CAT activity, higher levels of TAC, TBARS, and cytokines, and similar levels of HPA to EU preschoolers. In EU preschoolers, SOD activity exhibited a stronger negative association with moderate intensity ranges of HPA (R2 = 0.18), and negative correlation with sTNFRs (r = -0.40 to -0.46). TBARS had a stronger positive association with ranges of light intensity in the multivariate pattern of HPA (R2 = 0.10). In OW/OB preschoolers, the HPA multivariate associative pattern was predominantly from vigorous intensity ranges. Thus, SOD activity had a positive association with the multivariate pattern of HPA (R2 = 0.38) and MVPA bouts (ß [95% CI] = 0.457 [0.0026. 0.0576]). TAC had a negative association with the multivariate pattern of HPA (R2 = 0.38) and MVPA bouts (ß [95% CI] = -0.718 [-0.0025. -0.0003]). Additionally, leptin levels were lower in OW/OB preschoolers engaged in vigorous physical activity (VPA) (8000-9999 counts/min) for longer periods of time. CONCLUSION: The results of this study indicate that OW/OB preschoolers have higher levels of oxidative stress biomarkers and pro-inflammatory cytokines compared to EU preschoolers. Moreover, VPA may exert antioxidative and anti-inflammatory effects in OW/OB preschoolers.

Ceramide Risk Score in the Evaluation of Metabolic Syndrome: An Additional or Substitutive Biochemical Marker in the Clinical Practice?

Ceramide risk score (CERT1, ceramide test 1), based on specific ceramides (Cers) and their corresponding ratios in the plasma, has been reported as a promising biochemical marker for primary and secondary prediction of cardiovascular disease (CVD) risk in different populations of patients. Thus far, limited attention has been paid to metabolic syndrome, a condition considered at high CVD risk. The aim of the present study was to evaluate CERT1 in a group of obese subjects without (OB-MetS-) and with (OB-MetS+) metabolic syndrome (according to the International Diabetes Federation (IDF) diagnostic criteria), compared to an age- and sex-matched normal-weight (NW) group. In all participants, plasma levels of Cer 16:0, Cer 18:0, Cer 24:1, and Cer 24:0 were measured, and the corresponding ratios Cer 16:0/24:0, Cer 18:0/24:0, and Cer 24:1/24:0 were calculated together with CERT1. Subjects with obesity showed higher CERT1 values than the NW group (p < 0.05), with no difference between OB-MetS- and OB-MetS+ groups. Waist circumference (WC), homeostatic model assessment of insulin-resistance (HOMA-IR) (surrogates of IDF diagnostic criteria for metabolic syndrome), and C reactive protein (CRP) (a marker of inflammation) were predictors of CERT1 (p < 0.05), with the contribution of the other IDF criteria such as arterial hypertension and dyslipidemia being negligible. Adjustment for WC resulted in a loss of the difference in CERT1 between OB-MetS- and NW subjects, with the combination of WC and HOMA-IR or CRP as covariates being necessary to yield the same effect for the difference in CERT1 between OB-MetS+ and NW subjects. Importantly, an association was found between CERT1 and vascular age (VA) (p < 0.05). Proportions of NW, OB-MetS- and OB-MetS+ subjects appeared to be distributed according to the CERT1-based risk groups (i.e., low, moderate, increased, and high risk; p < 0.05), with some OB-MetS- subjects included in the increased/high-risk group and some OB-MetS+ in the low/moderate-risk one. In conclusion, the clinical diagnosis of metabolic syndrome seems to be inaccurate to assess CVD risk in the obese population; however, further studies are needed before considering CERT1 as an additional or substitutive biochemical marker in clinical practice.

Identification of a Specific Plasma Sphingolipid Profile in a Group of Normal-Weight and Obese Subjects: A Novel Approach for a "Biochemical" Diagnosis of Metabolic Syndrome?

Metabolic syndrome is nosographically defined by using clinical diagnostic criteria such as those of the International Diabetes Federation (IDF) ones, including visceral adiposity, blood hypertension, insulin resistance and dyslipidemia. Due to the pathophysiological implications of the cardiometabolic risk of the obese subject, sphingolipids, measured in the plasma, might be used to biochemically support the diagnosis of metabolic syndrome. A total of 84 participants, including normal-weight (NW) and obese subjects without (OB-SIMET-) and with (OB-SIMET+) metabolic syndrome, were included in the study, and sphingolipidomics, including ceramides (Cer), dihydroceramides (DHCer), hexosyl-ceramides (HexCer), lactosyl-ceramides (LacCer), sphingomyelins (SM) and GM3 ganglosides families, and sphingosine-1-phosphate (S1P) and its congeners, was performed in plasma. Only total DHCers and S1P were significantly higher in OB-SIMET+ than NW subjects (p < 0.05), while total Cers decreased in both obese groups, though statistical significance was reached only in OB-SIMET- (vs. NW) subjects (p < 0.05). When considering the comparisons of the single sphingolipid species in the obese groups (OB-SIMET- or OB-SIMET+) vs. NW subjects, Cer 24:0 was significantly decreased (p < 0.05), while Cer 24:1, DHCer 16:0, 18:0, 18:1 and 24:1, and SM 18:0, 18:1 and 24:1 were significantly increased (p < 0.05). Furthermore, taking into account the same groups for comparison, HexCer 22:0 and 24:0, and GM3 22:0 and 24:0 were significantly decreased (p < 0.05), while HexCer 24:1 and S1P were significantly increased (p < 0.05). After having analyzed all data via a PLS-DA-based approach, the subsequent determination of the VIP scores evidenced the existence of a specific cluster of 15 sphingolipids endowed with a high discriminating performance (i.e., VIP score > 1.0) among the three groups, including DHCer 18:0, DHCer 24:1, Cer 18:0, HexCer 22:0, GM3 24:0, Cer C24:1, SM 18:1, SM 18:0, DHCer 18:1, HexCer 24:0, SM 24:1, S1P, SM 16:0, HexCer 24:1 and LacCer 22:0. After having run a series of multiple linear regressions, modeled by inserting each sphingolipid having a VIP score > 1.0 as a dependent variable, and waist circumference (WC), systolic/diastolic blood pressures (SBP/DBP), homeostasis model assessment-estimated insulin resistance (HOMA-IR), high-density lipoprotein (HDL), triglycerides (TG) (surrogates of IDF criteria) and C-reactive protein (CRP) (a marker of inflammation) as independent variables, WC was significantly associated with DHCer 18:0, DHCer 24:1, Cer 18:0, HexCer 22:0, Cer 24:1, SM 18:1, and LacCer 22:0 (p < 0.05); SBP with Cer 18:0, Cer 24:1, and SM 18:0 (p < 0.05); HOMA-IR with DHCer 18:0, DHCer 24:1, Cer 18:0, Cer 24:1, SM 18:1, and SM 18:0 (p < 0.05); HDL with HexCer 22:0, and HexCer 24:0 (p < 0.05); TG with DHCer 18:1, DHCer 24:1, SM 18:1, and SM 16:0 (p < 0.05); CRP with DHCer 18:1, and SP1 (p < 0.05). In conclusion, a cluster of 15 sphingolipid species is able to discriminate, with high performance, NW, OB-SIMET- and OB-SIMET+ groups. Although (surrogates of) the IDF diagnostic criteria seem to predict only partially, but congruently, the observed sphingolipid signature, sphingolipidomics might represent a promising "biochemical" support for the clinical diagnosis of metabolic syndrome.

Pediatric quality of life multidimensional fatigue scale (PedsQL-MFS) detects the effects of a 3-week Inpatient body weight reduction program for children and adolescents with obesity.

BACKGROUND: Fatigue is a frequent complaint amongst children and adolescents with obesity, and it interferes with adherence to dietary and exercise regimes that could reduce obesity. The present study evaluated the effect of an inpatient 3-week body weight reduction program on body weight and fatigue. METHOD: One hundred children and adolescents with obesity (64% female; aged 11-18 years) undertook an inpatient program of personalized diet, daily exercise, education, and counselling. RESULTS: The sample evidenced a mean reduction in body mass (females: ΔM = 4.3 (sd = 2.1) kg, p < .001), males: ΔM = 6.2 (sd = 2.6) kg, p < .001), BMI standard deviation score (females: ΔM = 0.17 (sd = 0.07), males: ΔM = 0.24 (sd = 0.08), p < .001) and fatigue (females: ΔM = 7.8 (sd = 9.7), males: ΔM = 5.0 (sd = 6.9), p < .001) as measured by the Pediatric Quality of Life Multidimensional Fatigue Scale (PedsQL-MFS) and improvements on the Attention problems subscale of the Youth Self Report (total sample: ΔM = 0.89 (sd = 2.44), p < .001). Reliable change analyses revealed fatigue changes were achieved by up to 34% females and 17% males, but the majority did not achieve reliable change and changes in fatigue were not correlated with changes in body mass. CONCLUSIONS: The program achieved clinically significant improvements in some children and adolescents. Future studies should explore predictors of treatment responsiveness. Trial registration Observational study. Not registered.

Association between executive functions and gross motor skills in overweight/obese and eutrophic preschoolers: cross-sectional study.

BACKGROUND: Preschool age (3-5 years old) is a crucial period for children to acquire gross motor skills and develop executive functions (EFs). However, the association between the qualitative gross motor skills and EFs remains unknown in preschoolers, especially among overweight and obese children. METHODS: This was a cross-sectional, exploratory, and quantitative study carried out on 49 preschool children, divided into two subgroups according to their body mass index (overweight/obese: 24; eutrophic [normal weight]: 25). The mean age was 4.59 years. More than half of the sample were boys (55%) and most of the mothers had completed high school (67%) and were class C socioeconomic level (63%). Gross motor skills were assessed using the Test of Gross Motor Development-2, while EFs were evaluated using Semantic verbal fluency (SVF), Tower of Hanoi (TH), Day/Night Stroop, and Delayed Gratification tests. Multiple linear regression models adjusted for sex, age, maternal education, socioeconomic status, quality of the home environment, and quality of the school environment using the stepwise method were executed, considering the cognitive tasks as independent variables and gross motor skills as dependent variable. RESULTS: The overweight/obese preschoolers showed worse locomotor skills than their eutrophic peers and below average gross motor quotient (GMQ). Overweight/obese girls performed worse in OC skills than boys with excess weight. SVF (number of errors) and TH (rule breaks) explained 57.8% of the variance in object control (OC) skills and 40.5% of the variance in GMQ (p < .05) in the overweight/obese children. Surprisingly, there was no significant association between any of the EF tasks and gross motor skills in the eutrophic children. CONCLUSION: A relationship between EF tasks (number of errors in SVF and rule breaks in TH) and gross motor skills (OC and GMQ) was demonstrated in the overweight/obese preschoolers, indicating that worse cognitive flexibility, working memory, planning, and problem solving are associated with worse gross motor skills in this population when compared to eutrophic children.

Factor structure, reliability, inter-rater agreement and convergent validity of the parent and child Italian versions of the paediatric quality of life inventory multidimensional fatigue scale for children and adolescents in paediatric inpatients with obesity and their parents.

OBJECTIVE: This study aimed to examine the factor structure, reliability, inter-rater agreement and convergent validity of the child and parent Italian versions of the paediatric quality of life inventory multidimensional fatigue scale (PedsQL-MFS) in paediatric inpatients with obesity and one of their parents. METHODS: 100 pairs of children/adolescents (64% female, mean age = 15.34) with obesity and one of their parents completed the PedsQL-MFS and the Child Behaviour Checklist (CBCL) or the Youth Self Report. RESULTS: Confirmatory Factor Analysis indicated that the three correlated first-order factors model corresponding to the published subscales demonstrated acceptable fit and achieved strict invariance across parent and child informants. Bifactor Analysis supported the multidimensionality and the reliability of the total and subscale scores as multidimensional composites. Parent-child agreement was low with latent means higher for parent reports. PedsQL-MFS total scores were strongly correlated with Somatic Complaints scores on the CBCL, and moderately associated with anxiety, depression, social problems and school problems. CONCLUSIONS: Total scores of the child and parent Italian versions of the PedsQL-MFS demonstrated good reliability and convergent validity in paediatric inpatients with obesity and their parents, and are complementary rather than interchangeable. LEVEL OF EVIDENCE: No level of evidence.

Risk factors, awareness of disease and use of medications in a deprived population: differences between indigent natives and undocumented migrants in Italy.

BACKGROUND: Undocumented migrants experience many health problems; a comparison with a suitable control group of natives living in the same socio-economic conditions is still lacking. METHODS: Demographic data and data on risk factors, chronic conditions and dietary habits were obtained for 6933 adults (2950 Italians and 3983 undocumented migrants) receiving medical assistance from 40 non-governmental organizations all over the country. RESULTS: Attributed to the fact that these were unselected groups, differences were found in their demographic features, the main ones being their marital status (singles: 50.5% among Italians and 42.8% among migrants; P < 0.001). Smokers were more frequent among Italians (45.3% versus 42.7% P = 0.03); the same happened with hypertension (40.5% versus 34.5% P < 0.001). Migrants were more often overweight (44.1% versus 40.5% P < 0.001) and reporting a chronic condition (20.2% versus 14.4% P < 0.001). Among those on medications (n = 1354), Italians were fewer (n = 425) and on different medications. Differences emerged also in dietary habits. CONCLUSIONS: Differences in health conditions exist between native-borns and undocumented migrants, not because of a bias related to socio-economic conditions. Further studies are needed to design sustainable health policies and tailored prevention plans.

Effects of an acute bout of exercise on circulating extracellular vesicles: tissue-, sex-, and BMI-related differences.

BACKGROUND: Exercise is recognized to evoke multisystemic adaptations that, particularly in obese subjects, reduce body weight, improve glucometabolic control, counteract sarcopenia, and lower the risk of cardiometabolic diseases. Understanding the molecular and cellular mechanisms of exercise-induced benefits is of great interest due to the therapeutic implications against obesity. OBJECTIVES AND METHODS: The aim of the present study was to evaluate time-related changes in size distribution and cell origin of extracellular vesicles (EVs) in obese and normal-weight subjects who underwent a moderate-intensity exercise on a treadmill (at 60% of their VO2max). Blood samples were drawn before, immediately at the end of the exercise and during the postexercise recovery period (3 and 24 h). Circulating EVs were analyzed by a nanoparticle tracking analysis and flow cytometry after labeling with the following cell-specific markers: CD14 (monocyte/macrophage), CD61 (platelet), CD62E (activated endothelium), CD105 (total endothelium), SCGA (skeletal muscle), and FABP (adipose tissue). RESULTS: In all subjects, acute exercise reduced the release of total (i.e., 30-700 nm) EVs in circulation, predominantly EVs in the microvesicle size range (i.e., 130-700 nm EVs). The postexercise release of microvesicles was higher in normal-weight than obese subjects; after exercise, circulating levels of exosomes (i.e., 30-130 nm EVs) and microvesicles were, respectively, lower and higher in females than males. In all experimental subgroups (males vs. females and obese vs. normal-weight subjects), acute exercise reduced and increased, respectively, CD61 + and SCGA + EVs, being the effect on CD61 + EVs prolonged up to 24 h after the end of the test with subjects in resting conditions. Total EVs, exosomes, and CD61 + EVs were associated with HOMA-IR. CONCLUSIONS: Though preliminary, the results of the present study show that a single bout of acute exercise modulates the release of EVs in circulation, which are tissue-, sex-, and BMI specific, suggesting that the exercise-related benefits might depend upon a complex interaction of tissue, endocrine, and metabolic factors.

Obesity-associated poor muscle quality: prevalence and association with age, sex, and body mass index.

BACKGROUND: Muscle quality (i.e., the expression of muscle function per unit of muscle mass) has been proposed as a clinically-relevant measure to detect individuals at risk of functional incapacity. Individuals with obesity might be at an increased risk of having poor muscle quality. Thus, we aimed to analyze the prevalence of poor muscle quality in obese individuals, to determine associated variables, and to provide normative values for this population. METHODS: 203 individuals with obesity (103 women, age: 18-75 years, body mass index (BMI): 35-64 kg·m- 2) participated in this cross-sectional study. Their muscle strength (handgrip dynamometry), muscle power (sit-to-stand test) and muscle mass (bioelectrical impedance analysis) were measured, and muscle quality (strength/power to muscle mass ratio) was compared with reference values obtained in young healthy individuals. Muscle quality was individually categorized as normal, low or poor based on specific muscle strength and power (i.e., strength and power per unit of muscle mass, respectively). Sex and age-specific normative values of specific muscle strength and power were computed for the whole cohort. RESULTS: Age and being a woman were inversely associated with specific muscle strength, with age being also inversely associated with specific muscle power. A small proportion of participants (6%) presented with an impaired (i.e., low/poor) specific muscle power while most of them (96%) had impaired specific muscle strength. Eventually, 84% of the participants were deemed to have poor muscle quality. Being a woman (odds ratio [OR]: 18.09, 95% confidence intervals [CI]: 4.07-80.38), age (OR: 1.06, 95%CI: 1.03-1.10) and BMI (OR: 1.22, 95%CI: 1.07-1.38) were independently associated with a higher risk of poor muscle quality in adjusted analyses. CONCLUSIONS: These findings show a high prevalence of poor muscle quality among individuals with obesity, with age, sex and BMI being independent predictors.

Whole-body vibration improves the functional parameters of individuals with metabolic syndrome: an exploratory study.

BACKGROUND: Metabolic syndrome (MetS) is a cluster of metabolic abnormalities that increases the cardiovascular risk. Regular physical exercise can promote benefits, but the MetS individuals are demotivated to perform it. Thus, new possibilities are important as an alternative intervention. The whole-body vibration can be considered an exercise modality and would be a safe and low-cost strategy to improve functional parameters of individuals in different clinical conditions. The aim of this exploratory study was to assess effects of whole-body vibration on functional parameters of MetS individuals. The hypothesis of this work was that the whole-body vibration could improve the functionality of MetS individuals. METHODS: Twenty-two individuals performed the intervention. The vibration frequency varied from 5 to 14 Hz and the peak-to-peak displacements, from 2.5 to 7.5 mm. Each session consisted of one minute-bout of working time followed by a one minute-bout of passive rest in each peak-to-peak displacement for three-times. The whole-body vibration protocol was applied twice per week for 5 weeks. Data from the trunk flexion, gait speed, sit-to-stand test and handgrip strength were collected. Physiological parameters (blood pressure and heart rate) were also evaluated. The Wilcoxon Rank test and Student t-test were used. RESULTS: No significant changes (p > 0.05) were observed in physiological parameters (arterial blood pressure and heart rate). Significant improvements were found in trunk flexion (p = 0.01), gait speed (p = 0.02), sit-to-stand test (p = 0.005) and handgrip strength (p = 0.04) after the whole-body vibration. CONCLUSIONS: In conclusion, whole-body vibration may induce biological responses that improve functional parameters in participants with MetS without interfering in physiological parameters, comparing before and after a 5-week whole-body vibration protocol. TRIAL REGISTRATION: Register in the Registro Brasileiro de Ensaios Clínicos (ReBEC) with the number RBR 2bghmh (June 6th, 2016) and UTN: U1111-1181-1177. (virgula).

Indexes of adiposity and body composition in the prediction of metabolic syndrome in obese children and adolescents: Which is the best?

BACKGROUND AND AIM: There is no agreement about which index of adiposity and/or body composition is the most accurate in identifying the metabolic syndrome (METS). The aim of our study was to compare the accuracy of the different indexes in order to recognize the most reliable. METHODS AND RESULTS: We evaluated 1332 obese children and adolescents (778 females and 554 males), aged 14.4 ± 1.8 yrs, Body Mass Index (BMI) standard deviation scores (SDS) 2.99 ± 0.55, followed at the Istituto Auxologico Italiano, a tertiary center for childhood obesity. For each subject the following indexes were assessed: BMI, BMI SDS, Fat-Free Mass Index (FFMI), Fat Mass Index (FMI), Tri-Ponderal Mass Index (TMI), Waist-to-Height ratio (WtHR) and a new one, the Body Mass Fat Index (BMFI), which normalizes the BMI for percentage of body fat and the waist circumference. Thereafter we calculated for each index a threshold value for age and sex, in order to compare their accuracy, sensitivity and specificity in identifying the METS. There was a good correlation among indexes (p < 0.0001 for all). However, when the area under the curve (AUC) was compared, some of them, in particular the BMFI and the BMI, performed better than the other ones, although the differences were small. CONCLUSIONS: BMI, which neither considers body composition nor fat distribution, performs as good as other indexes, and should therefore be the preferred one, also because of the easiness of its calculation.

Metabolic and muscular factors limiting aerobic exercise in obese subjects.

PURPOSE: The aim of the present study was to understand the role of central (cardiovascular O2 delivery) and peripheral factors (muscle level) in limiting the maximal aerobic performance in obese (OB) subjects. METHODS: Fifteen OB (mean age ± SD 25 ± 7 years; BMI 43 ± 7 kg/m2) and 13 lean sedentary subjects (CTRL, age 27 ± 7 years; BMI 22 ± 3 kg/m2) participated in this study. Oxygen uptake (VO2), hearth rate (HR) and cardiac output (CO) were measured during cycle ergometer (CE) and knee extension (KE) incremental tests. Maximal voluntary contractions (MVCs) of knee extensor muscles were performed before and immediately after the two tests. RESULTS: VO2peak, HR peak and CO peak were significantly higher in CE than KE (+ 126%, + 33% and + 46%, respectively, p < 0.001), both in OB and CTRL subjects, without differences between the two subgroups. Maximal work rate was lower in OB than CTRL (191 ± 38 vs 226 ± 39 W, p < 0.05) in CE, while it was similar between the two subgroups in KE. Although CE and KE determined a reduction of MVC in both subgroups, MVC resulted less decreased after CE than KE exercises (- 14 vs - 32%, p < 0.001) in OB, while MVC decrements were similar after the two exercises in CTRL (- 26% vs - 30%, p > 0.05, for CE and KE, respectively). CONCLUSIONS: The lower muscle fatigue observed in OB after CE compared to KE test suggests that central factors could be the most important limiting factor during cycling in OB.

Cardiometabolic risk factors differ among adolescents with obesity in three European countries - a cross-sectional study.

AIM: We aimed to compare modifiable cardiometabolic risk factors among treatment-seeking adolescents with obesity in Italy, Germany and Norway. METHODS: This retrospective, registry-based, cross-sectional cohort study included 2,327 (59% girls) 12-18 year-old adolescents with obesity from three tertiary care outpatient clinics in Europe, between 1999 and 2015. The prevalence of cardiometabolic risk factors was compared between clinics, and multivariate logistic regression models including gender, age, waist circumference and body mass index were used to assess the associations between population and cardiometabolic risk. RESULTS: In total, 1,396 adolescents (60% girls) from Italy, 654 (58% girls) from Germany and 277 (51% girls) from Norway were included. The mean ± SD age was 15.2 ± 1.6 years, body mass index 38.8 ± 6.5 kg/m2 and body mass index standard deviation score 3.21 ± 0.43. The prevalence of elevated nonhigh-density lipoprotein-cholesterol in Norway, Germany and Italy was 60%, 54% and 45%, while the prevalence of high systolic or diastolic blood pressure (≥130 or ≥85 mmHg) were 15%, 46% and 66%, respectively. CONCLUSION: Cardiometabolic risk factors among treatment-seeking adolescents with obesity from Italy, Germany and Norway differed across the populations in this study, which might imply that preventive clinical work should reflect such differences.

Symmetry of Gait in Underweight, Normal and Overweight Children and Adolescents.

Abnormal excess or lack of body mass can influence gait patterns, but in some cases such differences are subtle and not easy to detect, even with quantitative techniques for movement analysis. In these situations, the study of trunk accelerations may represent an effective way to detecting gait anomalies in terms of symmetry through the calculation of Harmonic Ratio (HR), a parameter obtained by processing trunk accelerations in the frequency domain. In the present study we used this technique to assess the existence of differences in HR during gait in a cohort of 75 healthy children and early adolescents (aged 7-14 years) stratified into 3 equally-sized age and gender-matched groups (Underweight: UW; Normal Weight: NW; Overweight: OW). The accelerometric signal, acquired using a single wearable inertial sensor, was processed to calculate stride length, speed, cadence and HR in antero-posterior, vertical and medio-lateral directions. No differences in spatio-temporal parameters were found among groups, while the HR in the medio-lateral direction was found significantly lower in UW children, while OW exhibited the highest values. On the basis of the results obtained, HR appears capable of discriminating gait symmetry in children with different body mass even when conventional gait parameters are unchanged.

Assessment of fat-free mass from bioelectrical impedance analysis in men and women with Prader-Willi syndrome: cross-sectional study.

We have recently shown that population-specific formulae are required to estimate fat-free mass (FFM) from bioelectrical impedance analysis (BIA) in obese women with Prader-Willi syndrome (PWS) matched by age and percent fat mass (FM) to non-PWS women. The present cross-sectional study was aimed at developing generalised BIA equations that could be used in PWS subjects independently of sex and FM. We used dual-energy X-ray absorptiometry to measure FFM and BIA to measure whole-body impedance at 50 kHz (Z50) in 34 women and 21 men with PWS. The impedance index, that is, height (cm)2/Z50 (Ω), explained 77% (BCa-bootstrapped 95% CI 65 to 85%) of the variance of FFM with a root mean squared error of the estimate of 3.7 kg (BCa-bootstrapped 95% CI 3.2 to 4.5 kg). BIA can be used to estimate FFM in obese and non-obese PWS men and women by means of population-specific equations.

Ergogenic effects of beetroot juice supplementation during severe-intensity exercise in obese adolescents.

Previous studies showed a higher O2 cost of exercise, and therefore, a reduced exercise tolerance in patients with obesity during constant work rate (CWR) exercise compared with healthy subjects. Among the ergogenic effects of dietary nitrate ([Formula: see text]) supplementation in sedentary healthy subjects, a reduced O2 cost and enhanced exercise tolerance have often been demonstrated. The aim of this study was to evaluate the effects of beetroot juice (BR) supplementation, rich in [Formula: see text], on physiological variables associated with exercise tolerance in adolescents with obesity. In a double-blind, randomized crossover study, 10 adolescents with obesity (8 girls, 2 boys; age = 16 ± 1 yr; body mass index = 35.2 ± 5.0 kg/m2) were tested after 6 days of supplementation with BR (5 mmol [Formula: see text] per day) or placebo (PLA). Following each supplementation period, patients carried out two repetitions of 6-min moderate-intensity CWR exercise and one severe-intensity CWR exercise until exhaustion. Plasma [Formula: see text] concentration was significantly higher in BR versus PLA (108 ± 37 vs. 15 ± 5 µM, P < 0.0001). The O2 cost of moderate-intensity exercise was not different in BR versus PLA (13.3 ± 1.7 vs. 12.9 ± 1.1 ml·min-1·W-1, P = 0.517). During severe-intensity exercise, signs of a reduced amplitude of the O2 uptake slow component were observed in BR, in association with a significantly longer time to exhaustion (561 ± 198 s in BR vs. 457 ± 101 s in PLA, P = 0.0143). In obese adolescents, short-term dietary [Formula: see text] supplementation is effective in improving exercise tolerance during severe-intensity exercise. This may prove to be useful in counteracting early fatigue and reduced physical activity in this at-risk population.

Structural, Functional, and Clinical Characterization of a Novel PTPN11 Mutation Cluster Underlying Noonan Syndrome.

Germline mutations in PTPN11, the gene encoding the Src-homology 2 (SH2) domain-containing protein tyrosine phosphatase (SHP2), cause Noonan syndrome (NS), a relatively common, clinically variable, multisystem disorder. Here, we report on the identification of five different PTPN11 missense changes affecting residues Leu261 , Leu262 , and Arg265 in 16 unrelated individuals with clinical diagnosis of NS or with features suggestive for this disorder, specifying a novel disease-causing mutation cluster. Expression of the mutant proteins in HEK293T cells documented their activating role on MAPK signaling. Structural data predicted a gain-of-function role of substitutions at residues Leu262 and Arg265 exerted by disruption of the N-SH2/PTP autoinhibitory interaction. Molecular dynamics simulations suggested a more complex behavior for changes affecting Leu261 , with possible impact on SHP2's catalytic activity/selectivity and proper interaction of the PTP domain with the regulatory SH2 domains. Consistent with that, biochemical data indicated that substitutions at codons 262 and 265 increased the catalytic activity of the phosphatase, while those affecting codon 261 were only moderately activating but impacted substrate specificity. Remarkably, these mutations underlie a relatively mild form of NS characterized by low prevalence of cardiac defects, short stature, and cognitive and behavioral issues, as well as less evident typical facial features.

Can whole body vibration exercises affect growth hormone concentration? A systematic review.

Whole body vibration (WBV) has been recognized as an effective alternative exercise modality to resistance exercise for its ability in enhancing force and power, generating capacity in skeletal muscle, increasing bone mass and improving cardiovascular function. Since the effect of WBV exercises on growth hormone (GH) levels has been never compared and discussed, the aim of this study was to review systematically the literature to verify the WBV effects on GH concentration. By using PubMed, Scopus and PEDRo databases with the keywords 'growth hormone' or GH and 'whole body vibration' or WBV, we found and analysed 12 papers (182 subjects recruited), verifying their level of evidence (National Health and Medical Research Council hierarchy of evidence) and the methodological quality (PEDRo scale). Although WBV induced GH responses in nine out of 12 publications, caution should be however taken when considering the results due to the markedly different methodologies among these publications.