Accuracy of six minute walk test, stair test and spirometry using maximal oxygen uptake as gold standard

Step by Step: Evaluation of Cardiorespiratory Fitness in Healthy Children, Young Adults, and Patients with Congenital Heart Disease Using a Simple Standardized Stair Climbing Test

(1) Background: Cardiorespiratory fitness (CRF) is known to be a prognostic factor regarding long-term morbidity and mortality. This study aimed to develop a standardized Stair Climbing Test (SCT) with a reliable correlation to spiroergometry and the 6MWT which can be used in healthy children as well as patients with congenital heart disease (CHD) and a restricted exercise capacity. (2) Methods: A total of 28 healthy participants aged 10-18 years were included. We tested the individuals' CRF by cardiopulmonary exercise testing (CPET) on a treadmill, the 6MWT, and a newly developed Stair Climbing Test (SCT). For the SCT, we defined a standardized SCT protocol with a total height of 13.14 m to achieve maximal exercise effects while recording time and vital parameters. To compare the SCT, the 6 Min Walking Test, and CPET, we introduced an SCT-Index that included patient data (weight, height) and time. To assess the SCT's feasibility for clinical practice, we also tested our protocol with five adolescents with complex congenital heart disease (i.e., Fontan circulation). (3) Results: A strong correlation was observed between SCT-Index and O2 pulse (r = 0.921; p < 0.001). In addition, when comparing the time achieved during SCT (tSCT) with VO2max (mL/min/kg) and VO2max (mL/min), strong correlations were found (r = -0.672; p < 0.001 and r = -0.764; p < 0.001). Finally, we determined a very strong correlation between SCT-Index and VO2max (mL/min) (r = 0.927; p = <0.001). When comparing the 6MWD to tSCT, there was a moderate correlation (r = -0.544; p = 0.003). It appears to be feasible in patients with Fontan circulation. (4) Conclusions: We were able to demonstrate that there is a significant correlation between our standardized SCT and treadmill CPET. Therefore, we can say that the SCT can be used as an easy supplement to CPET and in certain contexts, it can also be used as a screening tool when CPET is not available. The advantages would be that the SCT is a simple, quick, cost-effective, and reliable standardized (sub)maximal exercise test to evaluate CRF in healthy children on a routine basis. We can even assume that it can be used in patients with congenital heart disease.

Impact of Energy and Protein Delivery to Critically Ill Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Optimal energy and protein delivery goals for critically ill patients remain unknown. The purpose of this systematic review and meta-analysis was to compare the impact of energy and protein delivery during the first 4 to 10 days of an ICU stay on physical impairments. We performed a systematic literature search of MEDLINE, CENTRAL, and ICHUSHI to identify randomized controlled trials (RCTs) that compared energy delivery at a cut-off of 20 kcal/kg/day or 70% of estimated energy expenditure or protein delivery at 1 g/kg/day achieved within 4 to 10 days after admission to the ICU. The primary outcome was activities of daily living (ADL). Secondary outcomes were physical functions, changes in muscle mass, quality of life, mortality, length of hospital stay, and adverse events. Fifteen RCTs on energy delivery and 14 on protein were included in the analysis. No significant differences were observed in any of the outcomes included for energy delivery. However, regarding protein delivery, there was a slight improvement in ADL (odds ratio 21.55, 95% confidence interval (CI) −1.30 to 44.40, p = 0.06) and significantly attenuated muscle loss (mean difference 0.47, 95% CI 0.24 to 0.71, p < 0.0001). Limited numbers of RCTs were available to analyze the effects of physical impairments. In contrast to energy delivery, protein delivery ≥1 g/kg/day achieved within 4 to 10 days after admission to the ICU significantly attenuated muscle loss and slightly improved ADL in critically ill patients. Further RCTs are needed to investigate their effects on physical impairments.

Chest three-dimensional-computed tomography imaging data analysis for the variation of exercise capacity after lung lobectomy

BACKGROUND

Postoperative loss of exercise capacity and pulmonary function is a major concern among lung cancer patients. In this study, the time for a stair-climbing to 12-m height was used to investigate whether preoperative chest 3D-computed tomography (CT) could be a useful tool for predicting postoperative variations in exercise capacity and pulmonary function.

METHODS

Seventy-eight patients undergoing lobectomy for suspected stage I lung cancer were prospectively enrolled. Preoperatively, lobe volume and low attenuation volume (LAV) were evaluated using the SYNAPSE VINCENT system. Preoperative data on stair-climbing time, spirometry, and diffusing capacity of the lung for carbon monoxide (DL_CO ) at baseline and 6-month postoperative data were used to evaluate variations in exercise capacity and pulmonary function. Maximal oxygen uptake (VO₂ t) was evaluated based on the stair-climbing time.

RESULTS

Significant differences in the variation of exercise capacity at 6 months postoperatively were found between the groups categorized by target lobe volume and LAV status: The large volume/LAV (+) group had a greater decline in VO₂ t. Mean loss of VO₂ t was -6.2%, -1.4%, -1.6%, and -0.1% in the large volume/LAV (+), large volume/LAV (-), small volume/LAV (+), and small volume/LAV (-) groups, respectively. The large volume/LAV (-) group had a greater decline in forced expiratory volume in 1 s. The small volume/LAV (+) group showed a reduced decline in the DL_CO .

CONCLUSIONS

Analysis of chest 3D-CT scans is a potential tool for predicting the loss of exercise capacity and pulmonary function after lung lobectomy. This article is protected by copyright. All rights reserved.

Effects of Central and Peripheral Fatigue on Impact Characteristics during Running

Fatigue and impact can represent an injury risk factor during running. The objective of this study was to compare the impact transmission along the locomotor system between the central and peripheral fatigued states during running. Tibial and head acceleration as well as shock attenuation in the time- and frequency-domain were analyzed during 2-min of treadmill running in the pre- and post-fatigue state in eighteen male popular runners (N = 18). The impact transmission was measured before and after a 30-min central fatigue protocol on the treadmill or a peripheral fatigue protocol in the quadricep and hamstring muscles using an isokinetic dynamometer. The time-domain acceleration variables were not modified either by peripheral or central fatigue (p > 0.05). Nevertheless, central fatigue increased the maximum (p = 0.006) and total (p = 0.007) signal power magnitude in the high-frequency range in the tibia, and the attenuation variable in the low- (p = 0.048) and high-frequency area (p = 0.000), while peripheral fatigue did not cause any modifications in the frequency-domain variables (p > 0.05). Furthermore, the attenuation in the low (p = 0.000)- and high-frequency area was higher with central fatigue than peripheral fatigue (p = 0.003). The results demonstrate that central fatigue increases the severity of impact during running as well as the attenuation of low and high components.

Accelerometer-Based Identification of Fatigue in the Lower Limbs during Cyclical Physical Exercise: A Systematic Review

Physical exercise (PE) is beneficial for both physical and psychological health aspects. However, excessive training can lead to physical fatigue and an increased risk of lower limb injuries. In order to tailor training loads and durations to the needs and capacities of an individual, physical fatigue must be estimated. Different measurement devices and techniques (i.e., ergospirometers, electromyography, and motion capture systems) can be used to identify physical fatigue. The field of biomechanics has succeeded in capturing changes in human movement with optical systems, as well as with accelerometers or inertial measurement units (IMUs), the latter being more user-friendly and adaptable to real-world scenarios due to its wearable nature. There is, however, still a lack of consensus regarding the possibility of using biomechanical parameters measured with accelerometers to identify physical fatigue states in PE. Nowadays, the field of biomechanics is beginning to open towards the possibility of identifying fatigue state using machine learning algorithms. Here, we selected and summarized accelerometer-based articles that either (a) performed analyses of biomechanical parameters that change due to fatigue in the lower limbs or (b) performed fatigue identification based on features including biomechanical parameters. We performed a systematic literature search and analysed 39 articles on running, jumping, walking, stair climbing, and other gym exercises. Peak tibial and sacral acceleration were the most common measured variables and were found to significantly increase with fatigue (respectively, in 6/13 running articles and 2/4 jumping articles). Fatigue classification was performed with an accuracy between 78% and 96% and Pearson’s correlation with an RPE (rate of perceived exertion) between r = 0.79 and r = 0.95. We recommend future effort toward the standardization of fatigue protocols and methods across articles in order to generalize fatigue identification results and increase the use of accelerometers to quantify physical fatigue in PE.

The Predictive Value of Stair Climbing Test on Postoperative Complications in Lung Cancer Patients with Limited Pulmonary Function

PURPOSE

To evaluate the predictive value of stair climbing test (SCT) on postoperative complications in lung cancer patients with limited pulmonary function.

METHODS

A total of 727 hospitalized lung cancer patients with limited pulmonary function were retrospectively reviewed. Included in the cohort were 424 patients who underwent SCT preoperatively. Patients were grouped according to general condition, past medical history, surgical approach, pulmonary function test, and SCT results. Comparison of the postoperative cardiopulmonary complication rates was made and independent risk factors were identified.

RESULTS

A total of 89 cardiopulmonary-related complications occurred in 69 cases, accounting for 16.3% of the entire cohort. The postoperative cardiopulmonary complication rates were significantly different between groups stratified by smoking index, percentage of forced expiratory volume in one second, percentage of diffusion capacity for carbon monoxide, SCT results, excision extension, and anesthetic duration (p <0.05). Multivariate analysis showed that only height achieved (p <0.001), changes in heart rate (∆HR; p <0.001), and excision extension (p = 0.006) were independent risk factors for postoperative cardiopulmonary complications.

CONCLUSIONS

The SCT could be used as a preoperative screening method for lung cancer patients with limited pulmonary function. For those patients who could only climb less than 6 floors or had ∆HR >30 bpm in the test, sublobar resection should be selected to reduce the postoperative cardiopulmonary complication rate.

Reliability and Accuracy of 2-Minute Step Test in Active and Sedentary Lean Adults

OBJECTIVE

The purpose of this study was to evaluate the intrarater and interrater reliability of the 2-minute step test (2MST) in active and sedentary lean adults and to identify the test cutoff point to differentiate active from sedentary individuals.

METHODS

This observational study involved 4 mixed-sex groups (each with 50 lean participants): group 1, sedentary and aged 18 to 24 years; group 2, active and aged 18 to 24 years; group 3, sedentary and aged 25 to 44 years; and group 4, active and aged 25 to 44 years. The 2MST was administered independently by 2 examiners (with 3 months' training) at 2 different times, with a 7-day interval. Habitual physical activity was evaluated by means of the Baecke Questionnaire (BQ). In statistical analysis, the Pearson correlation coefficient was used to verify the correlation between the 2MST and BQ; intraclass correlation coefficients (ICC_2,3) were used to determine the intrarater and interrater reliability of the 2MST; and the receiver operating characteristic curve was used to identify the accuracy of the 2MST.

RESULTS

Excellent intrarater and interrater reliability were found for all 4 groups (intraclass correlation coefficients ≥ 0.83). Correlating the 2MST score with the BQ score, a significant, positive, weak correlation was observed (r = 0.344, P < .001). For differentiating active from sedentary individuals, the 2MST showed low accuracy (area under the curve = 0.671), with 61% sensitivity and 67% specificity.

CONCLUSION

This study showed that the 2MST is a reliable test with a low amount of inherent error. There was a significant correlation between the 2MST and usual physical activity measured, and slight accuracy in differentiating active from sedentary individuals.

Factors associated with changes in the 12-m stair-climbing time after lung lobectomy

OBJECTIVE

Postoperative loss-of-exercise capacity is one of the main concerns for patients undergoing lung cancer surgery. This study was designed to identify the factors associated with loss-of-exercise capacity after lobectomy, using an easy surrogate measure: the 12-m stair-climbing time (SCt).

METHODS

Ninety-eight patients undergoing lobectomy for suspected stage I lung cancer were prospectively enrolled. SCt and pulmonary function test were evaluated preoperatively as baseline and at 6 months postoperatively. At 6 months postoperatively, 20 patients dropped out. Loss-of-exercise capacity was defined as at least a 3.3% decline (lower quartile) in the estimated maximal oxygen uptake (VO₂t: 43.06 - 0.4 × SCt). Factors associated with loss-of-exercise capacity were analyzed.

RESULTS

Median (interquartile range) baseline SCt was 31.5 (28.2-36.7) s. Baseline SCt was not significantly associated with complications. At 6 months postoperatively, SCt increased by + 4.4 (+ 3.2, + 6.8) s in patients with loss-of-exercise capacity. Sex, smoking status, lobe, procedure, and forced expiratory volume in 1 s showed no significant association with loss-of-exercise capacity. In the multivariable logistic regression, older age (≥ 73 years) (odds ratio: 5.25, 95% confidence interval: 1.50-18.43, p = 0.010) and lower baseline diffusing capacity of the lung for carbon monoxide (< 75%) (odds ratio: 9.23, 95% confidence interval: 1.94-43.93, p = 0.005) were significantly associated with loss-of-exercise capacity.

CONCLUSION

Age and the baseline diffusing capacity of the lung for carbon monoxide were identified as significant variables associated with variation of exercise capacity after lung cancer surgery, using pre- and postoperative SCt.

The Impact of Aerobic Exercise on Fronto-Parietal Network Connectivity and Its Relation to Mobility: An Exploratory Analysis of a 6-Month Randomized Controlled Trial

Impaired mobility is a major concern for older adults and has significant consequences. While the widely accepted belief is that improved physical function underlies the effectiveness of targeted exercise training in improving mobility and reducing falls, recent evidence suggests cognitive and neural benefits gained through exercise may also play an important role in promoting mobility. However, the underlying neural mechanisms of this relationship are currently unclear. Thus, we hypothesize that 6 months of progressive aerobic exercise training would alter frontoparietal network (FPN) connectivity during a motor task among older adults with mild subcortical ischemic vascular cognitive impairment (SIVCI)—and exercise-induced changes in FPN connectivity would correlate with changes in mobility. We focused on the FPN as it is involved in top-down attentional control as well as motor planning and motor execution. Participants were randomized either to usual-care (CON), which included monthly educational materials about VCI and healthy diet; or thrice-weekly aerobic training (AT), which was walking outdoors with progressive intensity. Functional magnetic resonance imaging was acquired at baseline and trial completion, where the participants were instructed to perform bilateral finger tapping task. At trial completion, compared with AT, CON showed significantly increased FPN connectivity strength during right finger tapping (p < 0.05). Across the participants, reduced FPN connectivity was associated with greater cardiovascular capacity (p = 0.05). In the AT group, reduced FPN connectivity was significantly associated with improved mobility performance, as measured by the Timed-Up-and-Go test (r = 0.67, p = 0.02). These results suggest progressive AT may improve mobility in older adults with SIVCI via maintaining intra-network connectivity of the FPN.

Insulin Sensitivity and Inflammation Mediate the Impact of Fitness on Cerebrovascular Health in Adolescents

BACKGROUND/OBJECTIVES

To investigate in adolescents the relationships between retinal vessel diameter, physical fitness, insulin sensitivity, and systemic inflammation.

METHODS

We evaluated 157 adolescents, 112 with excessive weight and 45 lean, all without type 2 diabetes mellitus. All received detailed evaluations, including measurements of retinal vessel diameter, insulin sensitivity, levels of inflammation, and physical fitness.

RESULTS

Overweight/obese adolescents had significantly narrower retinal arteriolar and wider venular diameters, significantly lower insulin sensitivity, and physical fitness. They also had decreased levels of anti-inflammatory and increased levels of proinflammatory markers as well as an overall higher inflammation balance score. Fitness was associated with larger retinal arteriolar and narrower venular diameters and these relationships were mediated by insulin sensitivity. We demonstrate that inflammation also mediates the relationship between fitness and retinal venular, but not arterial diameter; insulin sensitivity and inflammation balance score jointly mediate this relationship with little overlap in their effects.

CONCLUSIONS

Increasing fitness and insulin sensitivity and reducing inflammation among adolescents carrying excess weight may improve microvascular integrity. Interventions to improve physical fitness and insulin function and reduce inflammation in adolescents, a group likely to benefit from such interventions, may reduce not only cardiovascular disease in middle age, but also improve cerebrovascular function later in life.

Aerobic exercise promotes executive functions and impacts functional neural activity among older adults with vascular cognitive impairment

BACKGROUND

Vascular cognitive impairment (VCI) results from cerebrovascular disease, and worldwide, it is the second most common type of cognitive dysfunction. While targeted aerobic training is a promising approach to delay the progression of VCI by reducing cardiometabolic risk factors, few randomised controlled trials to date have specifically assessed the efficacy of aerobic training on cognitive and brain outcomes in this group at risk for functional decline.

AIM

To examine the effect of moderate-intensity aerobic training on executive functions and functional neural activity among older adults with mild subcortical ischaemic VCI (SIVCI).

METHODS

Older adults with mild SIVCI were randomly assigned to: (1) 6-month, 3×/week aerobic training (n=10) or (2) usual care (control; n=11). Participants completed functional MRI (fMRI) at baseline and trial completion. During the fMRI sessions, behavioural performance on the Eriksen flanker task and task-evoked neural activity were assessed.

RESULTS

At trial completion, after adjusting for baseline general cognition, total white matter lesion volume and flanker performance, compared with the control group, the aerobic training group significantly improved flanker task reaction time. Moreover, compared with the controls, the aerobic training group demonstrated reduced activation in the left lateral occipital cortex and right superior temporal gyrus. Reduced activity in these brain regions was significantly associated with improved (ie, faster) flanker task performance at trial completion.

SUMMARY

Aerobic training among older adults with mild SIVCI can improve executive functions and neural efficiency of associated brain areas. Future studies with greater sample size should be completed to replicate and extend these findings.

Long-term cost reduction of routine medications following a residential programme combining physical activity and nutrition in the treatment of type 2 diabetes: a prospective cohort study

OBJECTIVES

To demonstrate that lifestyle modifications will reduce the cost of routine medications in individuals with type 2 diabetes (T2D), through a mechanism involving glycaemic control.

DESIGN

A within-trial cost-medication analysis with a 1-year time horizon.

SETTING

Controlled environment within the spa resort of Chatel-Guyon, France.

PARTICIPANTS

Twenty-nine participants (aged 50-70 years) with T2D.

INTERVENTIONS

A 1-year follow-up intervention, beginning with a 3-week residential programme combining high exercise volume (15-20 hours/week), restrictive diet (-500 kcal/day) and education. Participants continued their routine medication, independently managed by their general practitioner.

MAIN OUTCOME MEASURES

Number of medications, number of pills, cost of medications and health-related outcomes.

RESULTS

Twenty-six participants completed the 1-year intervention. At 1 year, 14 patients out of 26 (54%) stopped/decreased their medications whereas only 5 (19%) increased or introduced new drugs (χ²=6.3, p=0.02). The number of pills per day decreased by 1.3±0.3 at 12 months (p<0.001). The annual cost of medications for T2D were lower at 1 year (€135.1±43.9) versus baseline (€212.6±35.8) (p=0.03). The regression coefficients on costs of routine medication were 0.507 (95% CI 0.056 to 0.959, p=0.027) for HbA1c and 0.156 (95% CI -0.010 to 0.322, p=0.06) for blood glucose levels. Diabetics patients with HbA1c >6.5% in the highest (last) quartile doubled their routine medication costs (66% vs 33%, p=0.037).

CONCLUSIONS

Individuals with T2D reduced routine medication costs following a long-term lifestyle intervention that started with a 3-week residential programme. Combining high exercise volume, restrictive diet and education effectively supported the health of T2D. The main factor explaining reduced medication costs was better glycaemic control, independent of weight changes. Despite limitations precluding generalisability, cost-effective results of reduced medication should contribute to the evidence base required to promote lifestyle interventions for individuals with T2D.

TRIAL REGISTRATION NUMBER

NCT00917917; Post-results.

Paradoxical dissociation between heart rate and heart rate variability following different modalities of exercise in individuals with metabolic syndrome: The RESOLVE study

Aims To analyse the effects of different modalities of exercise training on heart rate variability (HRV) in individuals with metabolic syndrome (MetS). Methods and results Eighty MetS participants (aged 50-70 years) were housed and managed in an inpatient medical centre for 21 days, including weekends. Physical activity and food intake/diet were intensively monitored. Participants were randomly assigned into three training groups, differing only by intensity of exercise: moderate-endurance-moderate-resistance ( re), high-resistance-moderate-endurance ( Re), and moderate-resistance-high-endurance ( rE). HRV was recorded before and after the intervention by 24-hour Holter electrocardiogram. Although mean 24-hour heart rate decreased more in Re than re (-11.6 ± 1.6 vs. -4.8 ± 2.1%; P = 0.010), low frequency/high frequency decreased more in re than Re (-20.4 ± 5.5% vs. + 20.4 ± 9.1%; P = 0.002) and rE (-20.4 ± 5.5% vs. -0.3 ± 11.1%; P = 0.003). Very low frequency increased more in Re than re (+121.2 ± 35.7 vs. 42.9 ± 11.3%; P = 0.004). For all HRV parameters, rE ranged between re and Re values. Low frequency/high frequency changes were linked with visceral fat loss only in re (coefficient 5.9, 95% CI 1.9-10.0; P = 0.004). By day 21, HRV parameters of MetS groups (heart rate -8.6 ± 1.0%, standard deviation of R-R intervals + 34.0 ± 6.6%, total power + 63.3 ± 11.1%; P < 0.001) became closer to values of 50 aged-matched healthy controls. Conclusions A 3-week residential programme with intensive volumes of physical activity (15-20 hours per week) enhanced HRV in individuals with MetS. Participants with moderate intensity of training had greater improvements in sympathovagal balance, whereas those with high intensity in resistance training had greater decreases in heart rate and greater increases in very low frequency. Modality-specific relationships were observed between enhanced HRV and visceral fat loss. Clinical Trial Registration URL: http://www.clinicaltrials.gov . Unique identifier: NCT00917917.

Fitness, insulin sensitivity, and frontal lobe integrity in adults with overweight and obesity

OBJECTIVE

To formally test whether insulin sensitivity mediates the relationship between fitness and brain integrity.

METHODS

Eighty-four middle-aged participants without diabetes received a 6-min walk test from which maximal oxygen uptake (VO2 max) was derived, a structural magnetic resonance scan, and a medical evaluation including fasting glucose and insulin levels.

RESULTS

This study showed significant associations between fitness, abdominal obesity, and insulin sensitivity and anterior cingulate cortex (ACC) volume as well as between ACC thickness and quantitative insulin-sensitivity check index (QUICKI). The relationship between ACC volume and VO2 max was completely mediated through QUICKI. Further, this strong association was confirmed by a single and very significant cluster on the ACC linking gray matter volume and QUICKI in a voxel-based morphometry analysis.

CONCLUSIONS

As expected, increased abdominal obesity was associated with reductions in fitness, ACC volumes, and insulin sensitivity. Importantly, this study demonstrated a significant mediation of the relationship between VO2 max and ACC volume by QUICKI. This suggests that the links between impaired insulin sensitivity and brain abnormalities in adults carrying excess weight could be alleviated through increased physical activity and fitness.

Preoperative Evaluation: Estimation of Pulmonary Risk

Postoperative pulmonary complications (PPCs) are common after major non-thoracic surgery and associated with significant morbidity and high cost of care. A number of risk factors are strong predictors of PPCs. The overall goal of the preoperative pulmonary evaluation is to identify these potential, patient and procedure-related risks and optimize the health of the patients before surgery. A thorough clinical examination supported by appropriate laboratory tests will help guide the clinician to provide optimal perioperative care.

Prediction of Cardiorespiratory Fitness by the Six-Minute Step Test and Its Association with Muscle Strength and Power in Sedentary Obese and Lean Young Women: A Cross-Sectional Study

Impaired cardiorespiratory fitness (CRF) is a hallmark characteristic in obese and lean sedentary young women. Peak oxygen consumption (VO_2peak) prediction from the six-minute step test (6MST) has not been established for sedentary females. It is recognized that lower-limb muscle strength and power play a key role during functional activities. The aim of this study was to investigate cardiorespiratory responses during the 6MST and CPX and to develop a predictive equation to estimate VO_2peak in both lean and obese subjects. Additionally we aim to investigate how muscle function impacts functional performance. Lean (LN = 13) and obese (OB = 18) women, aged 20–45, underwent a CPX, two 6MSTs, and isokinetic and isometric knee extensor strength and power evaluations. Regression analysis assessed the ability to predict VO_2peak from the 6MST, age and body mass index (BMI). CPX and 6MST main outcomes were compared between LN and OB and correlated with strength and power variables. CRF, functional capacity, and muscle strength and power were lower in the OB compared to LN (<0.05). During the 6MST, LN and OB reached ~90% of predicted maximal heart rate and ~80% of the VO_2peak obtained during CPX. BMI, age and number of step cycles (NSC) explained 83% of the total variance in VO_2peak. Moderate to strong correlations between VO_2peak at CPX and VO_2peak at 6MST (r = 0.86), VO_2peak at CPX and NSC (r = 0.80), as well as between VO_2peak, NSC and muscle strength and power variables were found (p<0.05). These findings indicate the 6MST, BMI and age accurately predict VO_2peak in both lean and obese young sedentary women. Muscle strength and power were related to measures of aerobic and functional performance.

Obesity, fitness, and brain integrity in adolescence

OBJECTIVE

We set out to ascertain the relationship between insulin resistance, fitness, and brain structure and function in adolescents.

DESIGN AND METHODS

We studied 79 obese and 51 non-obese participants who were recruited from the community, all without type 2 diabetes mellitus. All participants received medical, endocrine, neuropsychological, and MRI evaluations as well as a 6-minute walk test that was used to estimate fitness (maximal oxygen consumption).

RESULTS

Obese adolescents had significantly thinner orbitofrontal cortices and performed significantly worse on Visual Working Memory tasks and the Digit Vigilance task. Insulin sensitivity and maximal oxygen consumption (VO2 max) were both highly correlated with central obesity and orbitofrontal cortical thickness, although insulin sensitivity was the stronger predictor for orbitofrontal cortical thickness. We also found that VO2 max was the only significant physiological variable related to visual working memory.

CONCLUSIONS

This is the first study to report positive associations between insulin resistance, VO2 max, and frontal lobe brain integrity in adolescents. Given the importance of brain health for learning and school performance, we conclude that schools should also emphasize physical fitness in order to maintain structural and functional brain integrity and facilitate academic achievement.

Cardiorespiratory evaluation in pre and post operative moments of laparoscopic cholecystectomy

PURPOSE

To analyze the changes in both respiratory function and cardiopulmonary exercise tests results in patients subjected to laparoscopic cholecystectomy.

METHODS

Fifty patients were evaluated (76% women) and the average age was 47.8 ± 14.2 years. All individuals underwent the measurement of spirometry, manovacuometry, 6-minute walk test (6MWT) and stair-climbing test (SCT). All tests were performed at the first (PO1), fifth (PO5) and thirtieth (PO30) postoperative days.

RESULTS

BMI average was 28.8 ± 4.8 kg/m(2). Sample comprised 68% non-smokers, 20% current smokers, and 12% former smokers. There was no incidence of postoperative complication whatsoever. There was a significant decrease in spirometric values at PO1, but values were similar to the ones of PRE at PO30. Manovacuometry showed alterations at PO1 displaying values that were similar to the ones of PRE at PO30. 6MWT was significantly shorter at until PO5, but at PO30 values were similar to ones of PRE. As for SCT, values were significantly compromised at PO5 and PO30 since they were similar to the ones of PRE.

CONCLUSION

Patients submitted to laparoscopic cholecystectomy present a decrease in cardiorespiratory function on the first postoperative moments but there is a rapid return to preoperative conditions.

Six-minute walking distance correlated with memory and brain volume in older adults with mild cognitive impairment: a voxel-based morphometry study

Background/Aims

High fitness levels play an important role in maintaining memory function and delaying the progression of structural brain changes in older people at risk of developing dementia. However, it is unclear which specific regions of the brain volume are associated with exercise capacity. We investigated whether exercise capacity, determined by a 6-min walking distance (6MWD), is associated with measures of logical and visual memory and where gray matter regions correlate with exercise capacity in older adults with mild cognitive impairment (MCI).

Methods

Ninety-one community-dwelling older adults with MCI completed a 6-min walking test, structural magnetic resonance imaging scanning, and memory tests. The Wechsler Memory Scale-Revised Logical Memory and Rey-Osterrieth Complex Figure Tests were used to assess logical and visual memory, respectively.

Results

The logical and visual memory tests were positively correlated with the 6MWD (p < 0.01). Poor performance in the 6MWD was correlated with a reduced cerebral gray matter volume in the left middle temporal gyrus, middle occipital gyrus, and hippocampus in older adults with MCI.

Conclusions

These results suggest that a better 6MWD performance may be related to better memory function and the maintenance of gray matter volume in older adults with MCI.

Efeitos do estímulo verbal sobre o desempenho no teste de escada e ajustes cardiorrespiratórios em sujeitos saudáveis

Esta pesquisa teve o objetivo de avaliar os efeitos do estímulo verbal (EV) no tempo do teste de escada (TEsc) e nas variáveis cardiorrespiratórias de adultos saudáveis. Trinta e um adultos saudáveis realizaram dois TEsc (com EV e sem EV). Antes e depois de cada teste, foram avaliados os sinais vitais e a Escala de Borg. Os tempos nos TEsc foram comparados por meio do Teste t de Student para amostras pareadas e as diferenças, de acordo com a ordem de realização dos testes utilizando o Teste de Mann-Whitney. Os sinais vitais e a Escala de Borg foram comparados por meio do Teste de Friedman ou ANOVA com post hoc do Teste de Tukey. As variações foram comparadas utilizando o Teste t Student para amostras independentes ou Teste de Mann-Whitney (p<0,05). O tempo no TEsc sem EV foi de 23,48±8,28 segundos, significativamente maior que o teste com EV, que foi de 21,60±7,18 segundos (p<0,05). Todas as variáveis aumentaram após os testes, e a Escala de Borg foi a única que teve maior variação no TEsc com EV, variando 2,5±1,4 no teste sem estímulo e 3,0±1,8 pontos no com estímulo (p<0,05). O estímulo verbal melhora o desempenho no TEsc e leva à maior sensação de esforço.

Study on functional cardiorespiratory changes after laparoscopic Nissen fundoplication

PURPOSE: To analyze the behavior of cardiopulmonary function in postoperative of laparoscopic Nissen fundoplication. METHODS: Thirty-two patients, 13 males (41%) and 19 females (59%), were evaluated. Their age ranged from 25 to 67 years, with a mean of 44.4 ± 10.9. Pulmonary volumes, respiratory pressures and exercise tests were performed in the preoperative period (PRE) and in the first (PO1), second (PO2), fifth (PO5) and thirtieth (PO30) postoperative periods. RESULTS: Thirty-two patients were evaluated, of whom 59% were females. Mean age was 44.4 ± 10.9 years. Lung volumes had significant decrease at PO1 and PO2 and were similar to PRE values at PO5. Respiratory pressures were altered only at PO1. The distance covered in the 6-minute walk test had significant reduction until PO2, and climbing time in the stair-climbing test significantly increased at PO2. CONCLUSION: Patients submitted to LNF surgery have decreased cardiorespiratory function in the early postoperative period; however, they soon return to preoperative conditions.

Comparison between actual and predicted postoperative stair-climbing test, walk test and spirometric values in patients undergoing lung resection

PURPOSE

To assess whether the tests - Forced Expiratory Volume at one second (FEV₁), 6-minute walk test (6MWT) and stair-climbing test (SCT) showed proportional changes after the resection of functioning lung.

METHODS

Candidates for pulmonary resection were included. Spirometry, 6MWT and SCT were performed preoperatively (pre) and at least 3 months after surgery (pos). SCT was performed on a staircase with a total ascent height of 12.16m. The time taken to climb the total height the fastest possible was defined as stair-climbing time (SCt). Number of functioning segments lost, was used to calculated predicted postoperative (ppo) tests values. Pre, ppo and pos values for each test were compared. Data were analyzed by repeated-measure ANOVA with significance level set at 5%.

RESULTS

A total of 40 patients were enrolled. Pulmonary resection results ranged from gain of 2 functioning segments to loss of 9. Pre, ppo and pos values were the following: preFEV₁ = 2.6±0.8L, ppo FEV₁ =2.3±0.8L, and pos FEV₁=2.3±0.8L, (pre FEV₁ > ppo FEV₁ = pos FEV₁); pre6MWT = 604±63m, ppo6MWT= 529±103m, pos6MWT= 599±74m (pre6MWT = pos6MWT > ppo6MWT); preSCt = 32.9±7.6s, ppoSCt = 37.8±12.1s, posSCt = 33.7±8.5s (preSCt = posSCt < ppoSCt).

CONCLUSION

In our group of patients, pulmonary resection led to loss of lung function measured by spirometry, but not to exercise capacity measured by stair-climbing and walk tests.