Effect of a 24-Week Concurrent Exercise Intervention on Neck Adiposity and Its Distribution in Young Adults: The ACTIBATE Randomized Controlled Trial.

Neck adipose tissue (NAT) accumulation and neck circumference are independent predictors of cardiometabolic risk (CMR) and low-grade chronic inflammation in young adults. The present study examines whether a 24-week concurrent exercise intervention can reduce NAT volume and neck circumference in young adults, and whether any changes in these variables are related to changes in body composition, CMR, and the inflammatory profile. Seventy-four participants (51 women, age 22 ± 2 years) were included in the main analyses, after being randomly assigned to either a (a) control (n = 34), (b) moderate-intensity exercise (n = 19), or (c) vigorous-intensity exercise (n = 21) group. Participants in the exercise groups trained 3-4 days/week (endurance + resistance exercise training). NAT volume and NAT distribution across different depots were estimated using computed tomography before and after the intervention. Anthropometric variables, body composition (determined by dual-energy X-ray absorptiometry), and CMR/inflammatory markers were also recorded. The exercise intervention did not reduce the total NAT volume, nor was NAT distribution affected (p > .05). However, it did reduce neck circumference in the vigorous-intensity exercise group compared with the moderate-intensity exercise and control groups (by 0.8 and 1 cm, respectively, p ≤ .05). Changes in total NAT and neck circumference were positively, albeit weakly, related (adj. R2: .05-.21, all p ≤ .05) to changes in body weight and adiposity, leptin (only total NAT), and CMR (only neck circumference). Altogether 24 weeks of concurrent exercise does not appear to reduce NAT accumulation in young adults, but may slightly reduce neck circumference in those who partake in vigorous exercise.

Circulating concentrations of free triiodothyronine are associated with central adiposity and cardiometabolic risk factors in young euthyroid adults

Thyroid dysfunction is associated with classic cardiometabolic risk factors in humans. However, this relationship remains unclear in young euthyroid adults. The present work examines the associations of circulating thyroid hormones (THs) and thyroid-stimulating hormone (TSH) concentrations with body composition and cardiometabolic risk factors in young euthyroid adults. A total of 106 sedentary, euthyroid adults (72 women; 22 ± 2 years old) participated in this cross-sectional study. THs and TSH serum concentrations were determined in fasting conditions (6 h). Body composition (fat mass (FM), lean mass (LM), and visceral adipose tissue (VAT)) was determined by dual-energy X-ray absorptiometry, anthropometric parameters (weight, height, and waist circumference) were measured, and neck adipose tissue mass was quantified through computed tomography (CT) scanning. Cardiometabolic risk factors including fasting glucose and lipid metabolism markers, hepatic phosphatase and transaminases, and blood pressure were also assessed. Free triiodothyronine (FT3) concentration was positively associated with body mass index, LM, VAT, and waist circumference (all P ≤ 0.038). FT3 was also associated with glucose, insulin, HOMA-IR, fatty liver index, and blood pressure (all P < 0.024). All the associations were attenuated when adjusting for sex. In contrast, we found no associations of TSH or free thyroxine with any body composition parameter or cardiometabolic risk factors. In conclusion, FT3 is associated with central adiposity and cardiometabolic risk factors including insulin resistance, fatty liver index, and mean, systolic and diastolic blood pressure in young euthyroid adults. ClinicalTrials.gov identifier: NCT02365129. (AU)

Circulating concentrations of free triiodothyronine are associated with central adiposity and cardiometabolic risk factors in young euthyroid adults.

Thyroid dysfunction is associated with classic cardiometabolic risk factors in humans. However, this relationship remains unclear in young euthyroid adults. The present work examines the associations of circulating thyroid hormones (THs) and thyroid-stimulating hormone (TSH) concentrations with body composition and cardiometabolic risk factors in young euthyroid adults. A total of 106 sedentary, euthyroid adults (72 women; 22 ± 2 years old) participated in this cross-sectional study. THs and TSH serum concentrations were determined in fasting conditions (6 h). Body composition (fat mass (FM), lean mass (LM), and visceral adipose tissue (VAT)) was determined by dual-energy X-ray absorptiometry, anthropometric parameters (weight, height, and waist circumference) were measured, and neck adipose tissue mass was quantified through computed tomography (CT) scanning. Cardiometabolic risk factors including fasting glucose and lipid metabolism markers, hepatic phosphatase and transaminases, and blood pressure were also assessed. Free triiodothyronine (FT3) concentration was positively associated with body mass index, LM, VAT, and waist circumference (all P ≤ 0.038). FT3 was also associated with glucose, insulin, HOMA-IR, fatty liver index, and blood pressure (all P < 0.024). All the associations were attenuated when adjusting for sex. In contrast, we found no associations of TSH or free thyroxine with any body composition parameter or cardiometabolic risk factors. In conclusion, FT3 is associated with central adiposity and cardiometabolic risk factors including insulin resistance, fatty liver index, and mean, systolic and diastolic blood pressure in young euthyroid adults. ClinicalTrials.gov identifier: NCT02365129.

Higher Physical Activity Is Related to Lower Neck Adiposity in Young Men, but to Higher Neck Adiposity in Young Women: An Exploratory Study.

The role of lifestyle behaviors on neck adipose tissue (NAT), a fat depot that appears to be involved in the pathogenesis of different cardiometabolic diseases and in inflammatory status, is unknown. In this cross-sectional and exploratory study, the authors examined the relationship between sedentary time and physical activity (PA) with neck adiposity in young adults. A total of 134 subjects (69% women, 23 ± 2 years) were enrolled. The time spent in sedentary behavior and PA of different intensity were objectively measured for 7 consecutive days (24 hr/day), using a wrist (nondominant)-worn accelerometer. The NAT volume was assessed using computed tomography, and the compartmental (subcutaneous, intermuscular, and perivertebral) and total NAT volumes were determined at the level of vertebra C5. Anthropometric indicators and body composition (by dual-energy X-ray absorptiometry) were determined. The time spent in light physical activity and moderate physical activity (MPA) and the overall PA were inversely associated with the intermuscular NAT volume in men, as were the MPA and overall PA with total NAT volume (all ps ≤ .04). Sedentary time was directly related to the total NAT volume (p = .04). An opposite trend was observed in women, finding a direct relationship of MPA with the subcutaneous NAT; of light physical activity, MPA, and overall PA with the perivertebral NAT; and of light physical activity with total NAT volumes (all ps ≤ .05). The observed associations were weak, and after adjusting for multiplicity, the results became nonsignificant (p > .05). These findings suggest that the specific characteristics of PA (time and intensity) might have sex-dependent implications in the accumulation of NAT.

Performance Assessment for Rock Climbers: The International Rock Climbing Research Association Sport-Specific Test Battery.

PURPOSE: To examine the validity and reliability of a battery of 10 measures designed to assess the key physiological parameters for successful rock climbing performance. METHODS: In phase 1 of the research, an expert panel, using the Delphi method, established a 10-item test battery based on the key determinants of climbing performance. In phase 2, the tests were assessed for validity and reliability to examine their suitability as sport-specific measures of rock climbing performance. A total of 132 rock climbers, from 7 countries, volunteered to take part in the study. Each climber visited their nearest laboratory on 3 separate occasions in order to enable the required tests and retests to be completed. A minimum of 7 days was allowed between visits. RESULTS: The 10 tests established for phase 2 were designed as sport-specific measures of flexibility, strength, power, and endurance. Results indicated that, while reliable, the flexibility and strength tests were only partially successful in differentiating across climber abilities. The power and endurance tests, however, performed well with regard to validity and reliability, with the finger hang and powerslap tests being most strongly correlated with performance ability (P < .0005 to P < .002). CONCLUSION: The authors' data suggest that climbing may require a threshold level of flexibility and strength for successful performance, beyond which further improvements may not be required. In contrast, the finger hang and powerslap tests were not only reliable measures but also differentiated between climber abilities from lower grade to elite levels.

Association between dietary factors and brown adipose tissue volume/18F-FDG uptake in young adults.

OBJECTIVE: To study the association between usual dietary factors (dietary energy density, nutrient intake, food group consumption, and dietary pattern) and brown adipose tissue (BAT) volume/18F-fluorodeoxyglucose (18F-FDG) uptake after personalized cold exposure in young healthy adults. METHODS: A total of 122 young adults (n = 82 women; 22.0 ± 2.1 years old; 24.8 ± 4.8 kg/m2) took part in this cross-sectional study. Dietary factors were measured via a food frequency questionnaire and three non-consecutive 24 h recalls. Dietary energy density (foods and caloric beverages included) and macronutrient intakes were subsequently estimated using EvalFINUT® software, food group consumption was estimated from the food frequency questionnaire, and different dietary patterns and quality indices were determined according to the reference methods. BAT volume, BAT 18F-FDG uptake, and skeletal muscle 18F-FDG uptake were assessed by static 18F-FDG positron-emission tomography and computed tomography (PET-CT) scans after a 2 h personalized exposure to cold. RESULTS: A direct association was detected between dietary energy density and BAT Standardized Uptake Value (SUV)mean (ß = 0.215; R2 = 0.044; P = 0.022), and between ethanol consumption and BAT volume (ß = 0.215; R2 = 0.044; P = 0.022). The a priori Mediterranean dietary pattern was inversely associated with BAT SUVmean and SUVpeak (ß = -0.273; R2 = 0.075; P = 0.003 and ß = -0.255; R2 = 0.066; P = 0.005 respectively). In addition, the diet quality index for a Mediterranean diet and a pro-inflammatory dietary pattern (as determined via the dietary inflammatory index) were directly associated with BAT SUVmean and SUVpeak (SUVmean: ß = 0.238; R2 = 0.053; P = 0.013 and ß = 0.256; R2 = 0.052; P = 0.012 respectively; SUVpeak: ß = 0.278; R2 = 0.073; P = 0.003 and ß = 0.248; R2 = 0.049; P = 0.016 respectively). After controlling for multiplicity and possible confounders (sex, the evaluation wave and BMI), all the detected associations persisted. CONCLUSION: Dietary factors are slightly associated with BAT volume and/or 18F-FDG uptake after a personalized cold exposure in young adults. Our results provide an overall picture of the potential relationships between dietary factors and BAT-related variables in humans.

Neck adipose tissue accumulation is associated with higher overall and central adiposity, a higher cardiometabolic risk, and a pro-inflammatory profile in young adults.

OBJECTIVES: Neck adipose tissue (NAT) volume increases with general adiposity, with fat accumulating in different neck tissue compartments. In patients with certain malignant/benign tumours, the accumulation of NAT, and certain NAT distributions, have been associated with cardiometabolic risk (CMR). However, it is unknown whether the same relationships exist in healthy people, and whether NAT accumulation and distribution are related to the inflammatory status. METHODS: In this cross-sectional study, 139 young healthy adults (68% women) underwent a computed tomography scan to quantify the volume of compartmental (i.e., subcutaneous, intermuscular and perivertebral) and total NAT at the height of vertebra C5. Anthropometric indicators were measured, and body composition determined using dual energy X-ray absorptiometry. Information on CMR factors (i.e., blood glycaemic and lipid markers, blood pressure and physical fitness) was also gathered, and a CMR score calculated. Several plasma cytokines and serum components of the innate immune system were measured to determine the inflammatory status. RESULTS: Compartmental and total NAT volumes were directly related to body mass index (BMI), and lean, fat, and visceral adipose tissue (VAT) masses (all, P ≤ 0.05). Larger compartmental (especially intermuscular) and total NAT volumes were directly associated with the CMR score, several CMR factors (i.e., glycaemic and lipid markers and blood pressure), and the C3, C4 and leptin concentrations. They were, however, inversely correlated with the CMR factors high density lipoprotein-cholesterol (HDL-C) and physical fitness, and with the adiponectin concentration (all P ≤ 0.05). Several of these associations remained statistically significant (P ≤ 0.05) after adjustment for BMI, body fat percentage or VAT mass. Overall, results did not change after applying false discovery rate correction. CONCLUSIONS: NAT volume and its distribution among different tissue compartments is associated with the CMR and inflammatory profile of young healthy adults. Total NAT volume appears to be as valuable as VAT mass in terms of predicting CMR and inflammatory status.

Publisher Correction: Neck circumference is associated with adipose tissue content in thigh skeletal muscle in overweight and obese premenopausal women.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Neck circumference is associated with adipose tissue content in thigh skeletal muscle in overweight and obese premenopausal women.

Neck circumference (NC) has been proposed as a simple and practical tool, independently associated with cardiometabolic risk factors. However, the association of NC with inter-muscular adipose tissue (IMAT) is still to be determined. We aimed to examine the association of NC with thigh IMAT, and visceral adipose tissue (VAT) measured with computed tomography (CT) in overweight/obese women. 142 premenopausal overweight and obese Caucasian women participated in this cross-sectional study. NC was measured with an inextensible metallic tape above the thyroid cartilage according to International Society for Advancement of Kinanthropometry protocol. Thigh IMAT and VAT volumes were measured with a single cross-sectional CT. Regarding the covariates, fat mass (FM) was assessed with dual-energy x-ray absorptiometry and physical activity was objectively measured with accelerometry. NC was positively associated with thigh IMAT and VAT volumes (standardized ß coefficient: ß = 0.45, P-value = ≤0.001, ß = 0.60, P = ≤ 0.001; respectively), which persisted after adjusting for age, height, overall FM or moderate-to-vigorous physical activity. Our findings show that NC is associated with thigh IMAT volume in overweight and obese premenopausal Caucasian women, regardless of the amount of lower-body fatness. These results suggest underscoring the relevance of NC as a marker of adipose tissue content in thigh skeletal muscle.

Association of Neck Circumference with Anthropometric Indicators and Body Composition Measured by DXA in Young Spanish Adults.

BACKGROUND: Due to a clinical and public health interest of neck circumference (NC), a better understanding of this simple anthropometric measurement, as a valid marker of body composition is necessary. METHODS: A total of 119 young healthy adults participated in this study. NC was measured over the thyroid cartilage and perpendicular to the longitudinal axis of the neck. Body weight, height, waist circumference (WC), and hip circumference were measured. A Dual X-ray absorptiometry (DXA) scan was used to determine fat mass, lean mass, and visceral adipose tissue (VAT). Additionally, body mass index (BMI) and triponderal mass index (TMI), the waist to hip and waist to height ratios, and the fat mass and lean mass indexes (FMI and LMI, respectively) were calculated. RESULTS: NC was positively associated in women (W) and men (M), with BMI (rW = 0.70 and rM = 0.84, respectively), TMI (rW = 0.63 and rM = 0.80, respectively), WC (rW = 0.75 and rM = 0.86, respectively), VAT (rW = 0.74 and rM = 0.82, respectively), Waist/hip (rW = 0.51 and rM = 0.67, respectively), Waist/height (rW = 0.68 and rM = 0.83, respectively) and FMI (rW = 0.61 and rM = 0.81, respectively). The association between NC and indicators of body composition was however weaker than that observed by BMI, TMI, WC and Waist/height in both women and men. It is of note that in women, NC was associated with FMI, VAT and LMI independently of BMI. In men, adding NC to anthropometric variables did not improve the prediction of body composition, while slight improvements were observed in women. CONCLUSIONS: Taken together, the present study provides no indication for NC as a useful proxy of body composition parameters in young adults, yet future studies should explore its usefulness as a measure to use in combination with BMI, especially in women.

A comparison of body composition assessment methods in climbers: Which is better?

OBJECTIVE: To compare body composition estimations of field estimation methods: Durnin & Womersley anthropometry (DW-ANT), bioelectrical impedance analysis (BIA) and Deborah-Kerr anthropometry (DK-ANT) against dual-energy X-ray absorptiometry (DXA) in a male Chilean sport climbing sample. METHODS: 30 adult male climbers of different performance levels participated in the study. A DXA scan (Lunar Prodigy®) was used to determine fat mass, lean mass and total bone mineral content (BMC). Total muscle mass (MM, kg) was estimated through a validated prediction model. DW-ANT and BIA ("non-athletes" and "athletes" equations) were used to determinate fat mass percentage (FM %), while DK-ANT was utilized to estimate MM and BMC. RESULTS: A significant (p<0.01) inter-method difference was observed for all methods analyzed. When compared to DXA, DW-ANT and BIA underestimated FM% and DK-ANT overestimated MM and BMC (All p<0.01). The inter-method differences was lower for DW-ANT. DISCUSSION: We found that body composition estimation in climbers is highly method dependent. If DXA is not available, DW-ANT for FM% has a lower bias of estimation than BIA in young male Chilean climbers. For MM and BMC, further studies are needed to compare and estimate the DK-ANT bias level. For both methods, correction equations for specific climbing population should be considered.

[Carbohydrate and lipid consumption before a training session changed the fat mass in health-physically active adults: a controlled and randomized clinical trial]. / El consumo de hidratos de carbono y lípidos incluidos en una matriz alimentaria previo a una sesión de entrenamiento modifica la masa grasa en adultos sanos físicamente activos: un ensayo clínico controlado y aleatorizado.

INTRODUCTION: The effect of exercise on fat-acid oxidation depends on its intensity and duration. Pre-training ingest of carbohydrates (CH) decreases the rate of fat oxidation. In contrast, the effect of pre-consumption of monounsaturated fatty acids (MUFA) is less known. OBJECTIVE: the aim of this study was to compare the effect of pre-consumption of two isocaloric snacks in a standardized exercise session during a period of nine weeks and to quantify their impact in the fat oxidation and decrease of fat mass in healthy and physically active adults. METHODS: randomized, placebo-control clinical trial study. A total of 19 subjects between 20 and 39 years old were randomly distributed in three groups: CH group, with snack of high content of complex CH; FAT group, with snack of high content of MUFA; and control group, with a minimum fast for three hours before the training session. The measurements were rate of fat oxidation, body composition, and endurance training with continuing and intervallic modalities. RESULTS: the control group showed a tendency to fat mass decrease at the end of the intervention. The fat oxidation of group had a higher tendency than the CH and control group, before and after the intervention. Nevertheless, statistical differences of fat oxidation were not found between the groups. CONCLUSIONS: the fat oxidation and the decrease of fat mass may not be influenced by the type of food previously consumed before exercise.

Introducción: el efecto del ejercicio sobre la oxidación de los ácidos grasos depende de la intensidad y la duración. La ingesta de hidratos de carbono (HC) previo a una rutina de entrenamiento disminuye la tasa de oxidación de los ácidos grasos (FATmax). En contraste, el efecto del consumo de ácidos grasos monoinsaturados (AGMI) es poco concluyente.Objetivos: comparar el efecto de dos colaciones isocalóricas consumidas una hora antes de una sesión de ejercicio físico estandarizado durante nueve semanas sobre FATmax y la disminución de la masa grasa en adultos sanos físicamente activos.Metodología: ensayo clínico aleatorizado controlado. Un total de 19 sujetos entre 20 y 39 años fueron distribuidos al azar en tres grupos: grupo HC, con una colación alta en HC complejos; grupo lípidos, con una colación alta en AGMI; y grupo control, con ayuno mínimo de tres horas previo a la sesión de ejercicio. Se realizaron mediciones de FATmax, análisis de composición corporal y entrenamiento de resistencia aeróbica, con modalidades continuas e interválicas.Resultados: el grupo control mostró una tendencia a la disminución de masa grasa después de nueve semanas de entrenamiento. El FATmax fue mayor en los grupos HC y control en condiciones de pre y postintervención. Sin embargo, no se observaron diferencias signifi cativas para FATmax entre los grupos.Conclusiones: el FATmax y la disminución de masa grasa podrían no estar influenciados por el tipo de alimentos previamente consumidos antes del ejercicio.

El consumo de hidratos de carbono y lípidos incluidos en una matriz alimentaria previo a una sesión de entrenamiento modifica la masa grasa en adultos sanos físicamente activos: un ensayo clínico controlado y aleatorizado / Carbohydrate and lipid consumption before a training session changed the fat mass in health-physically active adults: a controlled and randomized clinical trial

Introducción: el efecto del ejercicio sobre la oxidación de los ácidos grasos depende de la intensidad y la duración. La ingesta de hidratos de carbono (HC) previo a una rutina de entrenamiento disminuye la tasa de oxidación de los ácidos grasos (FATmax). En contraste, el efecto del consumo de ácidos grasos monoinsaturados (AGMI) es poco concluyente. Objetivos: comparar el efecto de dos colaciones isocalóricas consumidas una hora antes de una sesión de ejercicio físico estandarizado durante nueve semanas sobre FATmax y la disminución de la masa grasa en adultos sanos físicamente activos. Metodología: ensayo clínico aleatorizado controlado. Un total de 19 sujetos entre 20 y 39 años fueron distribuidos al azar en tres grupos: grupo HC, con una colación alta en HC complejos; grupo lípidos, con una colación alta en AGMI; y grupo control, con ayuno mínimo de tres horas previo a la sesión de ejercicio. Se realizaron mediciones de FATmax, análisis de composición corporal y entrenamiento de resistencia aeróbica, con modalidades continuas e interválicas. Resultados: el grupo control mostró una tendencia a la disminución de masa grasa después de nueve semanas de entrenamiento. El FATmax fue mayor en los grupos HC y control en condiciones de pre y postintervención. Sin embargo, no se observaron diferencias significativas para FATmax entre los grupos. Conclusiones: el FATmax y la disminución de masa grasa podrían no estar influenciados por el tipo de alimentos previamente consumidos antes del ejercicio

Introduction: The effect of exercise on fat-acid oxidation depends on its intensity and duration. Pre-training ingest of carbohydrates (CH) decreases the rate of fat oxidation. In contrast, the effect of pre-consumption of monounsaturated fatty acids (MUFA) is less known. Objective: the aim of this study was to compare the effect of pre-consumption of two isocaloric snacks in a standardized exercise session during a period of nine weeks and to quantify their impact in the fat oxidation and decrease of fat mass in healthy and physically active adults. Methods: randomized, placebo-control clinical trial study. A total of 19 subjects between 20 and 39 years old were randomly distributed in three groups: CH group, with snack of high content of complex CH; FAT group, with snack of high content of MUFA; and control group, with a minimum fast for three hours before the training session. The measurements were rate of fat oxidation, body composition, and endurance training with continuing and intervallic modalities. Results: the control group showed a tendency to fat mass decrease at the end of the intervention. The fat oxidation of group had a higher tendency than the CH and control group, before and after the intervention. Nevertheless, statistical differences of fat oxidation were not found between the groups. Conclusions: the fat oxidation and the decrease of fat mass may not be influenced by the type of food previously consumed before exercise

[Validity of neck circumference as a marker of adiposity in children and adolescents, and in adults: a systematic review]. / Validez del perímetro del cuello como marcador de adiposidad en niños, adolescentes y adultos: una revisión sistemática.

The objective of this systematic review was doing a search of the validity of neck perimeter as a marker of adiposity in children and adolescents as well as in adults. A systematic search for articles published before June 30, 2017 was conducted using the PubMed and Web of Science databases. Original studies, in Spanish or English, were searched to analyze the association between neck circumference and any other marker of adiposity. MeSH (Medical Subject Heading) categories were used in PubMed. The search criteria used were: (("neck circumference" or "neck diameter") AND ("Body Composition" [Mesh] OR "Anthropometry" [Mesh])). This search was repeated in Web of Science. We identified 494 studies, of which 47 were finally selected for this review. From the total, 66% of studies (16 in children and adolescents and 15 in adults) only specify that there is a relationship between neck circumference and body mass index or waist circumference, waist/hip circumference ratio in children and adults. We also observed that neck circumference was directly associated with adiposity markers indirectly measured by reference methods such as computed tomography (CT) or dual-energy x-ray absorptiometry (DXA) in adults. Conversely, no studies were found in children and adolescents. In conclusion, neck circumference is associated with doubly-indirect markers of total and central fat mass in children and adolescents, while in adults it is associated with adiposity parameters measured with indirect and doubly-indirect methods. Further studies including methods that address the association between neck circumference and body composition analyzed using reference methods are required, especially in children and adolescents.

Validez del perímetro del cuello como marcador de adiposidad en niños, adolescentes y adultos: una revisión sistemática / Validity of neck circumference as a marker of adiposity in children and adolescents, and in adults: a systematic review

El objetivo de la presente revisión sistemática fue realizar una búsqueda acerca de la validez del perímetro de cuello como marcador de adiposidad en niños y adolescentes así como en población adulta. Se realizó una búsqueda sistemática de artículos publicados antes del 30 de junio de 2017, utilizando las bases de datos PubMed y Web of Science. Se buscaron estudios originales, en idioma español o inglés, que analizaran la asociación entre el perímetro del cuello y al menos un marcador de adiposidad. En PubMed se usaron las categorías MeSH (medical subject heading).El criterio de búsqueda utilizado fue: (("neck circumference" or "neck diameter") AND ("Body Composition"[Mesh] OR "Anthropometry"[Mesh])).Se repitió la búsqueda en Web of Science. Se identificó un total de 494 estudios, de los cuales 47 fueron finalmente seleccionados para esta revisión. El 66% de los estudios (16 en niños y adolescentes y 15 en adultos) solo especifican que existe relación entre perímetro del cuello e indicadores doblemente-indirectos tales como el índice de masa corporal, la circunferencia de cintura o ratio circunferencia cintura/cadera en niños y adultos. Además, se observó que el perímetro del cuello se asocia de forma directa con marcadores de adiposidad indirectos, medidos mediante métodos de referencia tales como la tomografía axial computarizada (TAC) o la absorciometría dual de rayos X (DXA) en adultos, mientras que no se encontraron estudios en niños. En conclusión, el perímetro del cuello se asocia a marcadores indirectos de masa grasa total y central en niños y adolescentes, mientras que en adultos el perímetro del cuello se asocia a parámetros de adiposidad medidos tanto con métodos indirectos como doblemente-indirectos. Se requieren nuevos estudios con métodos que analicen la asociación entre el perímetro del cuello y la composición corporal analizada mediante métodos de referencia, principalmente en niños y adolescentes

The objective of this systematic review was doing a search of the validity of neck perimeter as a marker of adiposity in children and adolescents as well as in adults. A systematic search for articles published before June 30, 2017 was conducted using the PubMed and Web of Science databases. Original studies, in Spanish or English, were searched to analyze the association between neck circumference and any other marker of adiposity. MeSH (Medical Subject Heading) categories were used in PubMed. The search criteria used were: (("neck circumference" or "neck diameter") AND ("Body Composition" [Mesh] OR "Anthropometry" [Mesh])). This search was repeated in Web of Science. We identified 494 studies, of which 47 were finally selected for this review. From the total, 66% of studies (16 in children and adolescents and 15 in adults) only specify that there is a relationship between neck circumference and body mass index or waist circumference, waist/hip circumference ratio in children and adults. We also observed that neck circumference was directly associated with adiposity markers indirectly measured by reference methods such as computed tomography (CT) or dual-energy x-ray absorptiometry (DXA) in adults. Conversely, no studies were found in children and adolescents. In conclusion, neck circumference is associated with doubly-indirect markers of total and central fat mass in children and adolescents, while in adults it is associated with adiposity parameters measured with indirect and doubly-indirect methods. Further studies including methods that address the association between neck circumference and body composition analyzed using reference methods are required, especially in children and adolescents

Physical fitness, cardiometabolic risk and heart rate recovery in Chilean children.

OBJECTIVE: To evaluate the association of physical fitness (PF) and cardiometabolic risk (CMR) with heart rate recovery time (ΔHRR) in Chilean school aged children. METHODS: Cross-sectional study in 478 6-9 years old children participants. We measured weight, height and abdominal circumference. Fitness was measured using the 6MWT, grip strength and leap forward without impulse tests; PF z-scores were calculated. Heart rate (HR) was monitored and recorded during the 6MWT. ΔHRR was calculated as the difference between HR before and one minute after test; blood glucose, insulin, triglycerides and HDL-cholesterol were measured. Waist circumference, CMR-z and HOMA were calculated. RESULTS: Absolute ΔHRR and CMR-z measures in normal weight children were lower than in obese children (p < 0.05 and p < 0.01, respectively). In obese children, ΔHRR was also associated with grip strength/weight (r = -0.6, p < 0.01) and PF-z (r = -0.6, p = 0.04). Insulin and HOMA were significantly related to ΔHRR (r = 0.3, p < 0.001), especially in overweight and obese children. ΔHRR values were not associated with CMR-z. CONCLUSIONS: A significant relationship between ΔHRR with fitness and insulin sensitivity in overweight and obese school children was found. We consider that these results support the need to measure these variables in overweight and obese children, in order to strengthen the need for early prevention.

Physical fitness, cardiometabolic risk and heart rate recovery in Chilean children / Condición física, riesgo cardiometabólico y frecuencia cardiaca de recuperación en escolares chilenos

Objective: To evaluate the association of physical fitness (PF) and cardiometabolic risk (CMR) with heart rate recovery time (DeltaHRR) in Chilean school aged children. Methods: Cross-sectional study in 478 6-9 years old children participants. We measured weight, height and abdominal circumference. Fitness was measured using the 6MWT, grip strength and leap forward without impulse tests; PF z-scores were calculated. Heart rate (HR) was monitored and recorded during the 6MWT. DeltaHRR was calculated as the difference between HR before and one minute after test; blood glucose, insulin, triglycerides and HDL-cholesterol were measured. Waist circumference, CMR-z and HOMA were calculated. Results: Absolute DeltaHRR and CMR-z measures in normal weight children were lower than in obese children (p < 0.05 and p < 0.01, respectively). In obese children, DeltaHRR was also associated with grip strength/weight (r = -0.6, p < 0.01) and PF-z (r = -0.6, p = 0.04). Insulin and HOMA were significantly related to DeltaHRR (r = 0.3, p < 0.001), especially in overweight and obese children. DeltaHRR values were not associated with CMR-z. Conclusions: A significant relationship between DeltaHRR with fitness and insulin sensitivity in overweight and obese school children was found. We consider that these results support the need to measure these variables in overweight and obese children, in order to strengthen the need for early prevention (AU)

Objetivo: establecer la asociación entre la condición física (CF) y el riesgo cardiometabolico (RCM) con el tiempo de recuperación de la frecuencia cardiaca (ΔFCR) en escolares chilenos. Métodos: estudio trasversal de 478 escolares de 6 a 9 años de ambos sexos. Se evaluó peso, talla y perímetro abdominal. Se midió CF global mediante T6M, fuerza de agarre y salto hacia adelante sin impulso; se calculó z-CF. Se midió frecuencia cardiaca (FC) con sensor durante el T6M. Calculamos DeltaFCRecup como la diferencia entre la FC en reposo y la FC al minuto de finalizado el test, glicemia, insulinemia, trigliceridemia y colesterol-HD. Perímetro de cintura, z-RCM y HOMA fueron calculados. Resultados: los escolares normopeso tuvieron menor DeltaFCRecup y z-RCM que los obesos (p < 0,05 and p < 0,01 respectivamente). En niños obesos, el DeltaFCRecup se asoció a fuerza de agarre/peso (r = -0,6, p < 0,01) y z-CF (r = -0,6, p = 0,04). Un menor DeltaFCRecup se relacionó con menores niveles de insulinemia y HOMA (r = 0,3, p < 0,001), especialmente en el grupo de escolares con sobrepeso y obesidad. El DeltaFCRecup no fue asociado a z-RCM. Conclusión: existe asociación entre el DeltaFCRecup y la condición física y sensibilidad insulinica en escolares con sobrepeso y/u obesidad, lo que refuerza la necesidad de la medición de esta variable en niños con sobrepeso y obesidad para una prevención temprana (AU)