Muscle strength, balance and upper extremity function are not predictors of cervical proprioception in healthy young subjects.

Purpose/Aim: The aim of this study is to examine the relationship between cervical proprioception sense and balance, hand grip strength, cervical region muscle strength and upper extremity functionality in healthy young subjects.Methods: A total of 200 people with a mean age of 20.8 ± 1.8 participated in the study. Cervical proprioception sense of the participants was evaluated with Cervical Joint Position Error Test (CJPET), balance with Biodex Stability System, hand grip strength with hand dynamometer, and upper extremity functionality with Perdue Pegboard test. The relationship of variables with cervical proprioception was evaluated with Pearson Correlation analysis.Results: According to this study results, there was no significant relationship between CJPET (extension, left rotation, right rotation) and sub-parameters of dynamic balance (anteroposterior, mediolateral, overall), cervical muscle strength and hand grip strength (p > 0.05). There was a significant correlation between CJPET flexion and static balance variables (p < 0.05).Conclusion: According to this study, there is no relationship between cervical proprioception and balance, hand grip muscle strength, cervical region muscle strength and upper extremity functionality in healthy young subjects.

Evenly Distributed Protein Intake over 3 Meals Augments Resistance Exercise-Induced Muscle Hypertrophy in Healthy Young Men.

BACKGROUND: Although daily protein intake (PI) has been reported to be essential for regulating muscle mass, the distribution of daily PI in individuals is typically the lowest at breakfast and skewed toward dinner. Skewed protein intake patterns and inadequate PI at breakfast were reported to be negative factors for muscle maintenance. OBJECTIVES: This study examined whether a protein-enriched meal at breakfast is more effective for muscle accretion compared with the typical skewed PI pattern. METHODS: This 12-wk, parallel-group, randomized clinical trial included 26 men (means ± SEs; age: 20.8 ± 0.4 y; BMI: 21.8 ± 0.4 kg/m2). The "high breakfast" (HBR) group (n = 12) consumed a protein-enriched meal at breakfast providing a PI of 0.33 g/kg body weight (BW); their PI at lunch (0.46 g/kg BW) and dinner (0.48 g/kg BW) provided an adequate overall daily PI (1.30 g/kg BW/d). The "low breakfast" (LBR) group (n = 14) consumed 0.12 g protein/kg BW at breakfast; intakes at lunch (0.45 g/kg BW) and dinner (0.83 g/kg BW) yielded the same daily PI as in the HBR group. The participants performed supervised resistance training (RT) 3 times per week (75-80% 1-repetition maximum; 3 sets × 10 repetitions). DXA was used to measure the primary outcome variable, that is, total lean soft tissue mass (LTM). RESULTS: The total LTM at baseline did not differ between the HBR (52.4 ± 1.3 kg) and LBR (53.4 ± 1.2 kg) groups. After the intervention, increases in total LTM were significant in both groups, with that in the HBR group (2.5 ± 0.3 kg) tending to be greater than that in the LBR group (1.8 ± 0.3 kg) (P = 0.06), with a large effect size (Cohen d = 0.795). CONCLUSIONS: For RT-induced muscle hypertrophy in healthy young men, consuming a protein-enriched meal at breakfast and less protein at dinner while achieving an adequate overall PI is more effective than consuming more protein at dinner.This study was registered at University hospital Medical Information Network (UMIN) Clinical Trials Registry as UMIN000037583 (https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000042763).

Cognitive performance during gait is worsened by overground but enhanced by treadmill walking.

PURPOSE: Walking is an attention-demanding task that affects and is affected by cognitive performance. Since treadmill walking (TW) assists gait automaticity, we have hypothesized that TW affects cognitive performance to a smaller extent than overground walking (OW). METHODS: Thirty young adults were recruited. Each subject walked overground over a 20-meter straight hallway at three different speeds (slow, normal and fast). Each task was repeated 3 times under Single Task (OW-ST) and Dual Task (OW-DT) condition, in a randomized sequence. DT was a serial subtraction by 7 starting from a different number (> 100) in each trial. Afterwards, each subject walked on the treadmill at the same three speeds as during OW-ST, while performing the dual task (TW-DT). The correct cognitive response (CCR), calculated from the number of correct responses and mistakes, was compared between rest, OW-DT and TW-DT. Dual-task cost (DTC) was calculated for speed and for CCR. RESULTS: Backward counting diminished normal and fast OW-DT speed by about 15 %. Slow OW-DT speed was not significantly reduced. In turn, OW affected the cognitive performance. DTC for speed during OW-DT increased during normal and fast speed. CCR significantly decreased, more at slower OW-DT speed. Conversely, CCR was not worsened by TW-DT. CCR did not decline at slow TW-DT speed and improved significantly from slow and normal to fast speeds. DTC for CCR resulted smaller in TW-DT than OW-DT. CONCLUSIONS: Decline in the cognitive performance during OW-DT is more prominent at slow speed, in keeping with higher demand of attentional resources for this unusual locomotor behaviour. Conversely, motorized TW improves the cognitive performance likely because it reduces the attentional cost of walking. Gait training by TW might improve automaticity in patients with movement disorders.

Association between breakfast skipping and postprandial hyperglycaemia after lunch in healthy young individuals.

Breakfast skipping has become an increasing trend in the modern lifestyle and may play a role in obesity and type 2 diabetes. In our previous studies in healthy young individuals, a single incident of breakfast skipping increased the overall 24-h blood glucose and elevated the postprandial glycaemic response after lunch; however, it was difficult to determine whether this response was due to breakfast omission or the extra energy (i.e. lunch plus breakfast contents). The present study aimed to assess the postprandial glycaemic response and to measure their hormone levels when healthy young individuals had identical lunch and dinner, and the 24-h average blood glucose as a secondary outcome. Nine healthy young men (19-24 years) participated in two-meal trials: with breakfast (three-meal condition) or without breakfast (breakfast skipping condition). During the meals, each individual's blood glucose was continuously monitored. Skipping breakfast resulted in a significantly higher (P < 0·001) glycaemic response after lunch as compared with the glycaemic response after an identical lunch when breakfast was consumed. Despite the difference in the total energy intake, the 24-h average blood glucose was similar between the two-meal conditions (P = 0·179). Plasma NEFA level was significantly higher (P < 0·05) after lunch when breakfast was omitted, and NEFA level positively correlated with the postprandial glycaemic response (r 0·631, P < 0·01). In conclusion, a single incident of breakfast skipping increases postprandial hyperglycaemia, and associated impaired insulin response, after lunch. The present study showed that skipping breakfast influences glucose regulation even in healthy young individuals.

Association of Protein Intake in Three Meals with Muscle Mass in Healthy Young Subjects: A Cross-Sectional Study.

Protein intake of >0.24 g/kg of body weight (BW) at a single meal is necessary to maximize muscle protein synthesis in a young population. However, the association between the protein intake rate for three meals and muscle mass in the young population has not been evaluated. We hypothesized that a protein intake of >0.24 g/kg BW at all three meals is effective for maintaining muscle mass. Therefore, we cross-sectionally examined the association between protein intake at all three meals with muscle mass in 266 healthy young subjects (aged 21.4 ± 2.4 years). Subjects were divided into the AP group, which achieved protein intake >0.24 g/kg BW at all three meals; and the NP group, which did not. We calculated total fat-free mass (FFM) and appendicular fat-free mass (AppFFM) with dual-energy X-ray absorptiometry, and the percentage of total FFM (TotalFFM%) and appendicular FFM (AppFFM%) were calculated as the percentage of BW (%BW). We demonstrated that TotalFFM% (77.0 ± 0.5 vs. 75.2 ± 0.4%, p = 0.008) and AppFFM% (34.7 ± 0.3 vs. 34.1 ± 0.2%, p = 0.058) were higher in the AP than in the NP group. This finding suggests that achieving protein intake of >0.24 g/kg BW at all three meals is important for muscle mass maintenance in young populations.

Skipping breakfast is associated with lower fat-free mass in healthy young subjects: a cross-sectional study.

Skipping breakfast has been reported to decrease daily energy and nutrient intake. We aimed to investigate whether habitual breakfast intake frequency is associated with fat-free mass (FFM) in healthy young subjects. We hypothesized that skipping breakfast and the subsequent negative energy balance may be risk factors for reduced muscle mass. This cross-sectional study included 270 healthy young subjects (152 men, 118 women). We collected information on habitual breakfast intake frequency, sleep quality according to the Pittsburgh Sleep Quality Index, circadian rhythm type using the Morningness-Eveningness Questionnaire, and physical activity using the International Physical Activity Questionnaire. According to the definition of National Health and Nutrition Examination Survey in Japan, the subjects were asked to report habitual breakfast intake frequency over the preceding month (excluding consumption of tablets, energy drinks, confectionary, fruits, dairy products, or sweetened beverages alone). FFM was assessed using dual-energy x-ray absorptiometry; then, appendicular FFM (AppFFM) was calculated. We also calculated appendicular skeletal muscle mass index (kg AppFFM/m2) and %AppFFM (% body weight) to adjust body size between individuals. Multiple regression analysis showed that habitual breakfast intake frequency was positively associated with appendicular skeletal muscle mass index (ß = .087, P = .031) and %AppFFM (ß = .086, P = .045) after adjusting for age, sex, living conditions, Pittsburgh Sleep Quality Index, Morningness-Eveningness Questionnaire, and International Physical Activity Questionnaire scores as covariates. These findings suggest that skipping breakfast is a risk factor for lower muscle mass in healthy young subjects, irrespective of strong confounders, such as age, sex, and physical activity.

Method comparison of two non-invasive dual-wavelength spectrophotometric retinal oximeters in healthy young subjects during normoxia.

PURPOSE: Spectrophotometric retinal oximetry is a non-invasive technology for measuring oxygen saturation in arterioles and venules (SaO2 , SvO2 ). We compared two commercially available systems: the Oxymap T1 (Oxymap ehf., Reykjavik, Iceland) and the Dynamic Vessel Analyzer (DVA, Imedos, Jena, Germany). METHODS: Twenty healthy adults were included after giving informed consent. Two measurement cycles 30 min apart, including Oxymap T1, DVA, arterialized capillary blood draw of the earlobe (ScO2 ) and peripheral oxygen saturation using finger pulse oximetry (SpO2 ) were scheduled. RESULTS: SaO2 (p > 0.0004) but not SvO2 (p < 0.05) was statistically significantly different between the retinal oximeters used. Agreement between devices using repeated SO2 measurements resulted in a standard deviation (SD) of differences of 3.5% in retinal arterioles and 4.8% in venules. Bland-Altman plot using the mean of a participant's two measurements from each device showed an average mean difference of 4.4% (95% confidence limits of agreement: -8.6 to 17.4) and -3.3% (95% confidence limits of agreement: -28.8 to 22.2) for SaO2 and SvO2 , respectively. Comparison of mean SaO2 and SvO2 with mean ScO2 and SpO2 indicated that SO2 measurements were generally higher in ScO2 and SpO2 . CONCLUSION: This study shows very good repeatability for both devices, which is consistent with the literature. However, it does not show sufficient concordance between SaO2 measurements from both devices, indicating that patients should be followed by one device only. Differences in absorbance wavelengths used and image post-processing may explain the differences.

Continuity of sleep problems from adolescence to young adulthood: results from a longitudinal study.

BACKGROUND: Considering the lack of evidence on incidence and continuity of sleep problems from adolescence to young adulthood, this study explores sleep problems' incidence and their continuation rates from 14 to 21 years. METHODS: Sleep data from the 14-year (n = 4,924) and 21-year (n = 3660) follow-up of the Mater-University of Queensland Study of Pregnancy cohort were used. Sociodemographic, lifestyle, and psychological conditions were explored for their role in sleep problems. Modified Poisson regression with a robust error variance was used to identify predictors. Inverse probability weights were used to account for attrition. RESULTS: Of all subjects, 26.0% of the subjects at 14 years and 28.3% of the subjects at 21 years reported "often" sleep problems, with 41.7% of adolescent sleep problems persisting at 21 years. Perinatal and early-life maternal factors, for example, drug abuse (incidence rate ratio (IRR), 1.32; 95% confidence interval [CI], 1.02-1.71), smoking, depression, and anxiety, were significant predictors of adolescent sleep problems. Female sex (IRR, 2.13; 95% CI, 1.55-2.94), advanced pubertal stages, and smoking were the important predictors of sleep problems at 21 years. Adolescent depression/anxiety supported the continuity of sleep problems (IRR, 1.21; 95% CI, 1.05-1.40), whereas exercise was seen to exert a protective effect. CONCLUSION: This study indicates high rates of sleep problems in young subjects, with around half of sleep problems originating in adolescence persisting in young adulthood. Therefore, early interventions are needed to manage sleep problems in young subjects and prevent further progression to other life stages. Future studies should explore if sleep problems in young adults also persist in later life stages and identify the factors supporting the continuity of sleep problems.

Aortic root dilatation in the children and young adults: prevalence, determinants, and association with target organ damage.

Aortic root dilatation is associated with increased cardiovascular risk in hypertensive adults. In the young, few data have been published evaluating the cardiovascular organ damage that may be present in patients with aortic dilatation. The objective was to evaluate the prevalence of proximal aorta dilatation, its possible determinants, and its relation with target organ damage in young subjects. The aorta was measured at the level of the sinus of valsalva and at its proximal ascending aorta (pAA) in a total of 177 young subjects (11-35 years). Linear regression analysis was used to assess the association between aortic size, clinical, and hemodynamic parameters. Prevalence of pAA and sinus of valsalva dilatation was 10.2% and 8.7%, respectively. No significant differences in prevalence were found in hypertensive, diabetic and obese subjects; aortic enlargement was less frequent in African-Americans. Age, sex, and central pulse pressure were the most important determinants of aortic size. Left ventricular mass was increased in patients with aortic enlargement, and aortic size showed an inverse relation with indices of local distensibility. The prevalence of aortic dilatation among young patients is high (10%). As in adults, age and body surface area are the main determinants of aortic size. Dilatation of the ascending aorta is associated with an increased left ventricular mass, as in adults, but not with increased arterial stiffness. Local distensibility is reduced in patients with pAA enlargement.

Evolution of Early Repolarization Patterns after 5 Years in a Military Population at Low Cardiovascular Risk and Practical Implications in Military Medical Expertise.

BACKGROUND: The French military population is a young and athletic population with a high prevalence of early repolarization patterns (ERP) compared to the general population. Screening of military officers at risk of sudden death (SD) is a priority in military medical expertise. The aim of our study was to evaluate the prevalence of ERP and its evolution over a period of 5 years in a specific asymptomatic population, free of heart disease and cardiovascular risk factors. METHODS: From March to December 2008, we prospectively collected the electrocardiograms (ECGs) of military officers enlisted into the submarine forces of France. For 5 years (until 2012), the military officers included in the study underwent a clinical examination twice per year. A new ECG was carried out 5 years after the initial one. RESULTS: A total of 250 male subjects were included (mean age 22.87 ± 0.5 years). The prevalence of ERP was 19.2%. The most common appearance was an elevation of a slurring type J point (31/48 or 64.5%) in inferolateral leads (18/48 or 37.8%). After 5 years, the prevalence of ERP was identical to that of the previous period (19.2%) with no change in appearance, distribution, and amplitude in 47 subjects (97.9%). Repolarization changed in two patients (one occurrence of ERP and one disappearance). During the 5 years of follow-up, the subjects remained asymptomatic CONCLUSION: ERP is common in our population of young, athletic, and asymptomatic military officers and changes little in 5 years.

Diastolic stress echocardiography in the young: a study in nonathletic and endurance-trained healthy subjects.

BACKGROUND: The response of diastolic Doppler indices to exercise is not well defined for young subjects. The aims of this study were to evaluate this in nonathletic and endurance-trained probands and to correlate echocardiographic data with maximal oxygen consumption. METHODS: In this prospective study, Doppler echocardiography was performed at rest and after exercise in 40 nonathletes (NAs) and 20 endurance-trained athletes (ETs) aged < 40 years, matched for age and gender. Diastolic function was assessed by mitral inflow and early diastolic velocities of the septal (e' septal) and lateral (e' lateral) mitral annulus. Maximal oxygen consumption quantification was performed simultaneously. RESULTS: All cardiac chambers were larger in ETs than NAs. ETs had higher e' lateral at rest (18.1 ± 2.7 vs 16.3 ± 3.3 cm/sec, P = .02) and higher mitral E (141 ± 15 vs 132 ± 15 cm/sec, P = .02) and e' lateral (23.5 ± 2.5 vs 21.4 ± 3.0 cm/sec, P = .01) with exercise than NAs. There was a slight increase in E/e' septal (overall, from 6.8 ± 1.3 to 7.2 ± 1.2; P = .02) and E/e' lateral (overall, from 5.0 ± 0.8 to 6.2 ± 0.9; P < .0001) with exercise. Changes in diastolic parameters with exercise were similar in ETs and NAs. Percentage of predicted maximal oxygen consumption was correlated with exertional E (r = 0.28, P = .03) and e' lateral (r = 0.32, P = .01), but the strongest predictor was indexed left ventricular end-diastolic volume (r = 0.66, P < .0001). CONCLUSIONS: During exercise, E/e' increases but remains within normal ranges in healthy young subjects, and the response to exercise does not differ between ETs and NAs. These data help define the normal diastolic stress echocardiographic response in the young. Exercise capacity shows a correlation with enhanced exertional early diastolic velocities but is more closely related to cardiac structural adaption to endurance training.

Diffusion tensor imaging and MR morphometry of the central auditory pathway and auditory cortex in aging.

Age-related hearing loss (presbycusis) is caused mainly by the hypofunction of the inner ear, but recent findings point also toward a central component of presbycusis. We used MR morphometry and diffusion tensor imaging (DTI) with a 3T MR system with the aim to study the state of the central auditory system in a group of elderly subjects (>65years) with mild presbycusis, in a group of elderly subjects with expressed presbycusis and in young controls. Cortical reconstruction, volumetric segmentation and auditory pathway tractography were performed. Three parameters were evaluated by morphometry: the volume of the gray matter, the surface area of the gyrus and the thickness of the cortex. In all experimental groups the surface area and gray matter volume were larger on the left side in Heschl's gyrus and planum temporale and slightly larger in the gyrus frontalis superior, whereas they were larger on the right side in the primary visual cortex. Almost all of the measured parameters were significantly smaller in the elderly subjects in Heschl's gyrus, planum temporale and gyrus frontalis superior. Aging did not change the side asymmetry (laterality) of the gyri. In the central part of the auditory pathway above the inferior colliculus, a trend toward an effect of aging was present in the axial vector of the diffusion (L1) variable of DTI, with increased values observed in elderly subjects. A trend toward a decrease of L1 on the left side, which was more pronounced in the elderly groups, was observed. The effect of hearing loss was present in subjects with expressed presbycusis as a trend toward an increase of the radial vectors (L2L3) in the white matter under Heschl's gyrus. These results suggest that in addition to peripheral changes, changes in the central part of the auditory system in elderly subjects are also present; however, the extent of hearing loss does not play a significant role in the central changes.

Metabolic changes in the auditory cortex in presbycusis demonstrated by MR spectroscopy.

In humans, aging is accompanied by the deterioration of the hearing function--presbycusis. The major etiology for presbycusis is the loss of hair cells in the inner ear; less well known are changes in the central auditory system. Therefore, we used 1H magnetic resonance spectroscopy at 3T tomograph to examine metabolite levels in the auditory cortex of three groups of subjects: young healthy subjects less than 30 years old and subjects older than 65 years either with mild presbycusis corresponding to their age or with expressed presbycusis. Hearing function in all subjects was examined by pure tone audiometry (125-16,000 Hz). Significant differences were found in the concentrations of glutamate and N-acetylaspartate, with lower levels in aged subjects. Lactate was particularly increased in subjects with expressed presbycusis. Significant differences were not found in other metabolites, including GABA, between young and elderly subjects. The results demonstrate that the age-related changes of the inner ear are accompanied by a decrease in the excitatory neurotransmitter glutamate as well as a lactate increase in the auditory cortex that is more expressed in elderly subjects with large hearing threshold shifts.

La ciudad, los jóvenes y el campo de las prácticas corporales / A cidade, os jovens e o campo das práticas corporais / Bodily practices, the youths and the city

La investigación abordó una reconstrucción del campo de las prácticas corporales en la ciudad de la Plata. Los referentes empíricos, sujetos juveniles, protagonistas de la resignificación de los espacios de la ciudad para el despliegue de prácticas corporales, del trazado de diversos territorios de interacción y rituales de la comunicación corporal. La estrategia involucra: a. Rastrillaje de prácticas, territorios y saberes corporales existentes en la ciudad, mediante censos y encuestas; b. aplicación de registros etnográficos; c. triangulación de los datos obtenidos; d. clasificación e inventariado de las propuestas corporales.

A investigação aborda uma reconstrução do campo das práticas corporais na cidade de La Plata. Os referentes empíricos, sujetos juvenis, protagonistas da ressignificação dos espaços da cidade para o desdobramento de práticas corporais, do traçado de diversos territórios de interação e rituais da comunicação corporal. A estratégia envolve: a. uma pesquisa das práticas, os territórios e saberes corporais existentes na cidade, mediante censos e enquetes; b. aplicação de registros etnográficos; c. triangulação dos dados obtidos; d. classificação e inventariado das propostas corporais.

The research approaches a reconstruction of the field of the bodily practices in the city of La Plata. The empirical modals are juvenile subjects, since they have a leading role in establishing bodily practices, generating different body expression rituals and interaction areas. The working strategy involves: a. a field study of the practices, areas and knowledge of bodily practices in the city, by means of censuses and surveys; b. using ethnographic records, c. triangulation of data obtained; d. classification and inventory of the different bodily options.