Exercise Capacity and Quality of Life in Patients with Schizophrenia

The aim of this study was to resolve the relationship between physical capacity (PC) and quality of life (Qol) in schizophrenic patients and healthy controls. 31 patients (PG: 18 male, 13 female) and a control group (CG) of 50 healthy subjects (15 male, 35 female) were involved. PC was assessed as peak oxygen uptake [VO₂peak, (ml (min kg_KG)^?1)] and power output expressed as watts per kilogram (W kg^?1). Qol was assessed using the SF-36 questionnaire. Patients with schizophrenia showed reduced VO₂peak (male: PG 29 ± 5 vs. CG 44 ± 10; female: PG 21 ± 4 vs. CG 30 ± 8) and power output (male: PG 2.04 ± 0.47 vs. CG 3.43 ± 0.70; female PG 1.40 ± 0.28 vs. CG 2.43 ± 0.52). Scales of the SF-36 questionnaire were lower in the PG. While in the CG correlations were found between PC and several subscales of Qol, this was not the case in the PG. The restricted PC seen in the PG showed no relation to their subjectively assessed worsened Qol, which would indicate that schizophrenic patients evaluate limitations arising from this differently than healthy control subjects.     

Cardiovascular fitness after stroke: Role of muscle mass and gait deficit severity

Functional disability after hemiparetic stroke may be compounded by physical deconditioning and muscular wasting, factors related to disuse and advancing age. However, the role of body composition, severity, and chronicity of gait deficits as determinants of exercise fitness after stroke is unknown. The purpose of this study was to determine whether oxygen consumption during peak exercise (VO₂ peak) is associated with body composition, the severity, or duration of gait deficits in chronic (>6 months) hemiparetic stroke patients. Twenty-six patients (22 men, 4 women), aged 66 ± 9 years (mean ± standard deviation [SD]), completed a progressive graded treadmill test until fatigue to measure VO₂ peak (1.3 ± 0.4 L/minute). Timed 30-foot walks were used to determine self-selected floor walking velocity (0.63 ± 0.31 m/s), an index of gait deficit severity. Percent body fat (30.4% ± 10.6%), total lean mass (52.0 ± 9.3 kg), lean mass of the paretic and nonaffected legs (17.2 ± 3.7 kg), and lean mass of the paretic and nonaffected thighs (13.2 ± 2.7 kg) were determined by dual-energy x-ray absorptiometry. Total lean mass (r = 0.60), lean mass of both legs (r = 0.58), paretic leg lean mass (r = 0.55), lean mass of both thighs (r = 0.64), and self-selected floor walking velocity (r = 0.53, all P < .01) correlated with VO₂ peak. In contrast, percent body fat and latency since index stroke were unrelated to VO₂ peak. In a stepwise regression analysis, lean mass of both thighs (r = 0.64, P < .001) and self-selected walking velocity (cumulative r = 0.78, P < .001) were independent predictors of VO₂ peak and explained 61% of the variance. These results suggest that hemiparetic stroke patients are profoundly deconditioned, regardless of the latency since stroke, and that lower lean thigh mass and greater gait deficit severity predict even poorer peak exercise capacity.     

Arterial stiffness response to exercise in persons with and without Down syndrome

This study compared arterial stiffness and wave reflection at rest and following maximal exercise between individuals with and without Down syndrome (DS), and the influence of body mass index (BMI), peak oxygen uptake (VO₂peak) on changes in arterial stiffness. Twelve people with DS (26.6 ± 2.6 yr) and 15 healthy controls (26.2 ± 0.6 yr) completed this study. Intima-media thickness (IMT) and stiffness of common carotid artery was examined. Hemodynamic and arterial variables were measured before and 3-min after exercise. Persons with DS had higher BMI and lower VO₂peak than controls. IMT did not differ between groups. At rest, carotid β stiffness was significantly higher in persons with DS (P < 0.05) but there was no difference in between groups for any of the other arterial stiffness measures. After exercise, persons with DS exhibited attenuated arterial stiffness responses in AIx-75, carotid β stiffness and Ep in contrast with controls (significant group-by-time interactions). When controlling for BMI and VO₂peak, the interactions disappeared. In both groups combined, BMI was correlated significantly with carotid Ep and β at rest. VO₂peak correlated significantly with AIx-75 and its pre-post change (r = ?0.45, P = 0.029; r = 0.47, P = 0.033, respectively). The arterial stiffness responses to maximal exercise in persons with DS were blunted, potentially reflecting diminished vascular reserve. Obesity and particularly VO₂peak influenced these findings. These results suggest impaired vascular function in people with DS.     

Heart rate recovery and variability following combined aerobic and resistance exercise training in adults with and without Down syndrome

Persons with Down syndrome (DS) are at high risk for cardiovascular morbidity and mortality, and there is compelling evidence of autonomic dysfunction in these individuals. The main purpose of this study was to determine whether a combined aerobic and resistance exercise intervention produces similar results in cardiac autonomic function between adults with and without DS. Twenty-five participants (13 DS; 12 non-DS), aged 27–50 years, were included. Aerobic training was performed 3 days/week for 30 min at 65–85% of peak oxygen uptake (VO_2peak). Resistance training was prescribed for 2 days/week and consisted of two rotations in a circuit of 9 exercises at 12-repetition-maximum. There was a significant improvement in the VO_2peak and muscle strength of participants with and without DS after training. Heart rate recovery improved at 1 min post-exercise, but only in participants with DS. Both groups of participants exhibited a similar increase in normalized high frequency power and of decrease in normalized low frequency power after training. Therefore, 12 weeks of exercise training enhanced the heart rate recovery in adults with DS, but not in those without DS. Contrasting, the intervention elicited similar gains between groups for cardiovagal modulation.     

Reliability and validity of the 6-min walk test in adults and seniors with intellectual disabilities

IntroductionAdults with intellectual disabilities (ID) have significantly lower rates of physical activity and fitness than adults without ID. The 6-min walk test (6MWT) is an inexpensive and simple way to test mobility and submaximal work capacity.PurposeTo evaluate the test–retest reliability and validity of the 6MWT in adults and seniors with ID and explore factors contributing to the 6MWT distance (6MWD).Methods46 participants with mild, moderate and severe ID levels (age = 41 ± 11 years) performed the 6MWT three times (T1; T2; T3) to determine test–retest reliability. To test validity, peak oxygen uptake (VO₂ peak) was measured using a treadmill protocol. To analyze factors contributing to the 6MWD, sex, height, fat mass % and fat free mass %, ID level, isometric leg strength and relative VO₂ peak were also measured.ResultsThe walking distances for T1, T2 and T3 were 460.3 ± 76.9; 489.4 ± 81.2 and 491.4 ± 77.9 m, respectively. The 6MWDs between T1–T2 and T1–T3 were significantly different (p < 0.001), but T2 and T3 were not different. The intraclass correlation coefficient between T2 and T3 was 0.96 indicating high reliability. Relative VO₂ peak and isometric leg strength significantly contributed to the 6MWD (R² = 0.55).ConclusionsThe 6MWT is an easy, inexpensive, reliable and valid test in adults and seniors with ID. Familiarization is necessary to obtain reliable values. Relative VO₂ peak and leg strength have significant impact on the distance walked.     

Central nervous system effects of bombesin on the cardiovascular response to cold exposure

The effects of cold exposure on mean arterial pressure (MAP), heart rate (HR) and oxygen consumption (VO₂) were examined in conscious, unrestrained rats receiving intracerebroventricular (i.c.v.) injections of bombesin or appropriate control solutions. Cold exposure elicited significant elevations of MAP, HR and VO₂ in control-treated rats. I.c.v. administration of bombesin produced dose-related suppressions of cold-induced elevations of HR and VO₂, but not MAP. The central nervous system (CNS)-selective somatostasin analog, ODT8-SS, injected i.c.v., reversed the effects of bombesin on HR and VO₂ during cold exposure. Intravenous administration of atropine methyl nitrate did not antagonize the effects of bombesin on HR and VO₂ during cold exposure. HR and VO₂ were strongly correlated in bombesin-treated rats suggesting that this peptide may prevent cold-induced elevations of VO₂ through a CNS action on cardiac function.     

Corpus callosum in schizophrenia with deficit and non-deficit syndrome: a statistical shape analysis

BackgroundThe corpus callosum (CC) is the most targeted region in the cerebrum that integrates cognitive data between homologous areas in the right and left hemispheres.AimsOur study used statistical analysis to determine whether there was a correlation between shape changes in the CC in patients with schizophrenia (SZ) (deficit syndrome (DS) and non-deficit syndrome (NDS)) and healthy control (HC) subjects.MethodsThis study consisted of 27 HC subjects and 50 schizophrenic patients (20 with DS and 30 with NDS). 3 patients with DS and 4 patients with NDS were excluded. Three-dimensional, sagittal, T1-spoiled, gradient-echo imaging was used. Standard anatomical landmarks were selected and marked on each image using specific software.ResultsAs to comparing the Procrustes mean shapes of the CC, statistically significant differences were observed between HC and SZ (DS+NDS) (p=0.017, James’s F_j=73.732), HC and DS (p<0.001, James’s F_j=140.843), HC and NDS (p=0.006, James’s F_j=89.178) and also DS and NDS (p<0.001, James’s F_j=152.967). Shape variability in the form of CC was 0.131, 0.085, 0.082 and 0.086 in the HC, SZ (DS+NDS), DS and NDS groups, respectively.ConclusionsThis study reveals callosal shape variations in patients with SZ and their DS and NDS subgroups that take into account the CC’s topographic distribution.     

Aerobic training in patients with anoctamin 5 myopathy and hyperckemia

Introduction: Anoctamin 5 deficiency has recently been defined to cause limb‐girdle muscular dystrophy type 2L (LGMD2L) with pronounced hyperCKemia. No treatment interventions have been made so far in this condition. Methods: In 6 patients with LGMD2L, we studied the effect of home‐based, pulse‐watch monitored, moderate‐intensity exercise on a cycle ergometer for 30 minutes, 3 times weekly, for 10 weeks. Plasma creatine kinase (CK) was assessed before, during, and after the program as a marker of muscle damage. Primary outcome measures were maximum oxygen uptake (VO_2max) and time in the 5‐repetitions‐sit‐to‐stand test (FRSTST). Results: Training resulted in improvements in VO_2max (27 ± 7%; P = 0.0001) and FRSTST time (35 ± 12%; P = 0.007). Improvements in physiologic and functional muscle testing were accompanied by stable CK levels and no reports of adverse effects. Conclusions: These findings suggest that supervised aerobic exercise training is safe and effective in improving oxidative capacity and muscle function in patients with anoctamin 5 deficiency. Muscle Nerve 50 : 119–123, 2014     

How to Score the Peak Oxygen Consumption Obtained Through Cardiopulmonary Exercise Test in Individuals after Stroke?

ObjectivesTo compare five distinct methods to score the peak of oxygen consumption (VO2peak) obtained through the cardiopulmonary exercise testing (CPET) in individuals after stroke.Materials and methodsThe VO_2peak was obtained through the CPET with five methods: method-1: the highest value of the test; method-2: the highest value of the last 30 seconds at peak exercise; method-3: the mean of the last 30 seconds at peak exercise; method-4: the mean of the last 20 seconds at peak exercise; method-5: the highest value averaged of the 3 last blocks of 10 seconds at peak exercise. The coefficient of variance (CV) and the mean differences with 95% confidence interval (CI) between the scoring methods were calculated. A post-hoc test (Tukey HSD) was performed to calculate the adjusted 95%CI.ResultsFifty-nine individuals were included (54±12 years, 56±60 months after stroke). The CV of the methods 1-to-5 were, respectively: 27.91%, 25.77%, 23.38%, 23.83%, and 23.33%. There was no difference between method-1 and method-2 (95%CI: -1.10 to 4.69) and between methods 3 to 5: method-3 and method-4 (95%CI: -2.97 to 2.82); method-3 and method-5 (95%CI: -3.57 to 2.22); method-4 and method-5 (95%CI: -3.49 to 2.30). However, method-1 and -2 provided VO_2peak values different from that of methods 3-to-5.ConclusionsThe scoring method of obtaining the VO_2peak has an influence on its magnitude. Since methods 3-to-5 showed lower CV and provided similar values, they should be used to calculate the VO_2peak obtained through the CPET in individuals after stroke.     

Blunted endogenous GABA-mediated inhibition in the hypothalamic paraventricular nucleus of rats with streptozotocin-induced diabetes

The hypothalamic paraventricular nucleus (PVN) is involved in the regulation of sympathetic outflow and particularly affects the heart. This study sets out to determine the role of GABA of the paraventricular nucleus (PVN) in cardiovascular regulation in streptozotocin-induced diabetic rats. Pharmacological stimulation of glutamatergic receptors with DL-Homocysteic acid (200 mM in 100 nL) in the PVN region showed a significant depression in both mean arterial pressure (MAP) and heart rate (HR) of diabetic rats (Diabetic vs. non-diabetic: MAP 15.0 ± 1.5 vs. 35.8 ± 2.8 mmHg; HR 3.0 ± 2.0 vs. 30.0 ± 6.0 bpm, P < 0.05). Microinjection of bicuculline methiodide (1 mM in 100 nL), a GABA_A receptor antagonist, produced an increase in baseline MAP and HR in both non-diabetic and diabetic rats. In the diabetic rats, bicuculline injection into the PVN reduced the pressor and HR responses (Diabetic vs. non-diabetic: MAP 6.2 ± 0.8 vs. 25.1 ± 2.2 mmHg; HR 1.8 ± 1.1 vs. 25.4 ± 6.2 bpm, P < 0.05). A microinjection of muscimol (2 mM in 100 nL), which is a GABA_A receptor agonist, in the PVN elicited decreases in MAP and HR in both groups. The diabetic group showed a significantly blunted reduction in HR, but not MAP (Diabetic vs. non-diabetic: MAP ?15.7 ± 4.0 vs. ?25.0 ± 3.8 mmHg; HR ?5.2 ± 2.1 vs. ?39.1 ± 7.9 bpm). The blunted vasopressor and tachycardic responses to bicuculline microinjection in the diabetic rats are likely to result from decreased GABAergic inputs, attenuated release of endogenous GABA or alterations in GABA_A receptors within the PVN.     

Cardiorespiratory fitness and white matter integrity in Alzheimer’s disease

The objective of this study was to investigate the relationship between cardiorespiratory (CR) fitness and the brain’s white matter tract integrity using diffusion tensor imaging (DTI) in the Alzheimer’s disease (AD) population. We recruited older adults in the early stages of AD (n?=?37; CDR?=?0.5 and 1) and collected cross-sectional fitness and diffusion imaging data. We examined the association between CR fitness (peak oxygen consumption [VO₂peak]) and fractional anisotropy (FA) in AD-related white matter tracts using two processing methodologies: a tract-of-interest approach and tract-based spatial statistic (TBSS). Subsequent diffusivity metrics (radial diffusivity [RD], mean diffusivity [MD], and axial diffusivity [A?×?D]) were also correlated with VO₂peak. The tract-of-interest approach showed that higher VO₂peak was associated with preserved white matter integrity as measured by increased FA in the right inferior fronto-occipital fasciculus (p?=?0.035, r?=?0.36). We did not find a significant correlation using TBSS, though there was a trend for a positive association between white matter integrity and higher VO₂peak measures (p?<?0.01 uncorrected). Our findings indicate that higher CR fitness levels in early AD participants may be related to preserved white matter integrity. However to draw stronger conclusions, further study on the relationship between fitness and white matter deterioration in AD is necessary.     

非关键部位脑梗死患者的认知功能损伤研究

目的 研究单次或两次非关键部位脑梗死（包括皮质下梗死和脑干小脑梗死）的患者其认知功能表现与正常对照之间的差异,了解非关键部位脑梗死患者认知功能受损情况。方法 选取符合入组标准的、性别、年龄和受教育年数一一匹配的单次或两次发病的非关键部位脑梗死后3～6个月的患者和正常对照各30例,进行日常生活自理能力量表（ADL）、Hamilton抑郁量表17项评分（HAMD-17）、简易精神状态检查法（MMSE）、加利福尼亚词语学习（CVLT）、逻辑记忆（LM）、复杂图形（FC）、词语流畅性（VF）、结构实例（CP）、数字广度（DS）的评定。结果 卒中组患者MMSE总分显著低于对照组（27.8±2.4 vs 28.9±0.9,P＝0.021）;在CVLT总分、VF、认知总分方面与对照组相比存在统计学差异（38.2±7.0 vs 43.1±8.0,P＝0.016;43.8±10.6 vs 53.6±11.3,P＝0.001;168.3±24.0 vs 188.8±25.4,P＝0.002）,而在FC、LM、CP、DS方面两组相比没有统计学差异（41.2±7.1 vs 43.4±5.5,P＝0.185;21.6±5.6 vs 24.1±5.1,P＝0.078;11.0 vs 11.0,P＝0.775;13.0±2.4 vs 13.9±2.8,P＝0.171）。另外卒中组ADL和HAMD－17的得分显著高于对照组（26±9 vs 20±0,P＝0.001;2.00 vs 0.00,P＝0.000）。结论 单次或两次非关键部位脑梗死的患者存在一定的认知功能障碍,主要表现为词语记忆和执行功能方面,尤其以执行功能为著。     

Resistance training and aerobic training improve muscle strength and aerobic capacity in chronic inflammatory demyelinating polyneuropathy

Introduction: We investigated the effects of aerobic and resistance exercise in patients with chronic inflammatory demyelinating polyneuropathy (CIDP). Methods: Eighteen CIDP patients treated with subcutaneous immunoglobulin performed 12 weeks of aerobic exercise and 12 weeks of resistance exercise after a run‐in period of 12 weeks without exercise. Three times weekly the participants performed aerobic exercise on an ergometer bike or resistance exercise with unilateral training of knee and elbow flexion/extension. Primary outcomes were maximal oxygen consumption velocity (VO₂‐max) and maximal combined isokinetic muscle strength (cIKS) of knee and elbow flexion/extension. Results: VO₂‐max and muscle strength were unchanged during run‐in (?4.9% ± 10.3%, P = 0.80 and ?3.7% ± 10.1%, P = 0.17, respectively). Aerobic exercise increased VO₂‐max by 11.0% ± 14.7% (P = 0.02). Resistance exercise resulted in an increase of 13.8% ± 16.0% (P = 0.0004) in cIKS. Discussion: Aerobic exercise training and resistance exercise training improve fitness and strength in CIDP patients. Muscle Nerve 57 : 70–76, 2018     

Norepinephrine and cardiovascular responses to maximal exercise in Parkinson's disease on and off medication

The aim of this experiment is to understand how Parkinson's disease (PD) medication affects the autonomic responses of individuals during an acute exercise stress test. Fourteen people with PD and fifteen healthy individuals age‐matched between 50 and 80 years performed a modified Bruce protocol. Subjects with PD performed the test once off medication (PD‐off) and then 1 week later on medication (PD‐on). Heart rate (HR), blood pressure (BP), VO₂, and norepinephrine (NE) levels were taken at rest and at peak exercise. At peak exercise HR, BP, and NE values for the PD‐on and PD‐off group were all significantly lower than healthy controls, regardless of whether subjects were on their medication. Autonomic abnormalities during exercise in this population appear to be disease manifested and not impactedby medications used to treat PD. We can assume, both on and off medication, this population will show markedly lower BP, HR, and NE responses. © 2009 Movement Disorder Society     

Effects of exercise induced oxidative stress on glutathione levels in Parkinson’s disease on and off medication

Resting plasma glutathione (GSH) levels are lower in individuals with Parkinson’s disease (PD) than any other neurological condition. Medications used to treat PD have also been shown to further decrease this depletion. Acute exercise has been shown to be an effective tool to produce oxidative stress in other populations as reflected in lowering levels of GSH. The purpose of this study was to determine how PD responds to acute exercise stress and how medication affects these responses. Fourteen men with PD and 14 men without PD underwent an exercise stress test. Subjects with PD performed the test once off PD medication (PD-Off-med) for 12 h then again 1 week later on PD medication (PD-On-med). GSH and glutathione disulfide (GSSG), were collected via blood draws at rest and after peak exercise along with peak VO₂. At rest and at peak exercise GSH levels and the GSH:GSSG ratio were significantly lower in the PD-On-med and PD-Off-med as compared to controls. GSSG levels were significantly higher in both medication conditions at rest and peak exercise compared to controls. When comparing PD-On-med vs. PD-Off-med at rest and peak exercise, the PD-On-med had lower GSH levels, a lower GSH:GSSG ratio and higher GSSG levels. VO₂ correlated positively with GSH levels. Subjects with PD have lower plasma GSH levels than healthy controls at rest and at peak exercise.     

Relationships between vascular dysfunction, circulating endothelial progenitor cells, and psychological status in healthy subjects

Background: Although the mechanisms remain unclear, depression and mental stress are associated with endothelial dysfunction and increases risk of cardiovascular disease (CVD). Recent studies suggest that circulating endothelial progenitor cells (EPC) play an important role in endothelial repair and correlate with endothelial function. Methods: We studied the relationship between the level of circulating CD34/KDR⁺ EPCs and CD133/KDR⁺ EPCs, brachial artery flow‐mediated dilation (FMD), Depression Anxiety Stress Scales in 129 normal individuals (54 ± 10 years, 54 men) without prior CVD or diabetes. Results: Their median depression score (DS) and stress score (SS) was 4 (range 0–34) and 6 (range 0–32), respectively. As defined by the ≥75th percentile, 41 subjects (32%) had high DS (≥8) and 31 (24%) had high SS (≥14). Subjects with high DS had significantly lower FMD (5.4 ± 2.7 versus 8.0 ± 4.0%, P<0.001) and percentage of CD34/KDR⁺ EPC (1.2 ± 1.3 versus 2.0 ± 2.4%, P = 0.037), but not CD133/KDR⁺ EPC (0.56 ± 0.42 versus 0.68 ± 0.76%, P = 0.44), than those with normal DS. In contrast, there were no significant difference in FMD (6.8 ± 3.5 versus 7.3 ± 3.9%, P = 0.46), percentages of circulating CD34/KDR⁺ EPC (1.20 ± 1.28 versus 1.95 ± 2.34%, P = 0.052) and CD133/KDR⁺ EPC (0.55 ± 0.41 versus 0.67 ± 0.73%, P = 0.52) between subjects with high and normal SS. Multivariate regression analysis revealed that high DS (OR 1.08, 95% CI: 1.02–1.15, P = 0.010) and old age (OR 1.05, 95% CI: 1.01–1.10, P = 0.019), but not SS or percentage of circulating EPC, were independent predictors for decreased FMD. Conclusions: Our results demonstrated that, in subjects without significant CVD, a high DS was associated with impaired brachial FMD and depletion of circulating EPC. However, only DS, but not SS or EPC count, was an independent predictor for impaired brachial FMD. Depression and Anxiety, 2011. © 2011 Wiley‐Liss, Inc.     

Violence in a Finnish forensic psychiatric hospital

Background: Patients with schizophrenia have a high risk of cardiovascular disease (CVD). High aerobic intensity training (HIT) improve peak oxygen uptake (VO_2peak), net mechanical efficiency of walking and risk factors for CVD but has not been investigated in patients with schizophrenia. Aims: To investigate effects from HIT on VO_2peak, net mechanical efficiency of walking and risk factors for CVD in patients with schizophrenia. Methods: 25 inpatients (F20–29, ICD-10) were allocated to either HIT or playing computer games (CG), 3 days per week for 8 weeks. HIT consisted of 4 × 4-min intervals with 3-min break periods, at 85–95% and 70% of peak heart rate, respectively. Results: 12 and seven patients completed HIT and CG, respectively. The baseline VO_2peak in both groups combined (n = 19) was 36.8 ± 8.2 ml/kg/min and 3.12 ± 0.55 l/min. The HIT group improved VO_2peak by 12% from 3.17 ± 0.59 to 3.56 ± 0.68 l/min (P < 0.001), more than the CG group (P = 0.014). Net mechanical efficiency of walking improved by 12% in the HIT group from 19.8 ± 3.0% to 22.2 ± 4.5% (P = 0.005), more than the CG group (P = 0.031). The psychiatric symptoms, expressed as the Positive and Negative Syndrome Scale (PANSS) and the Calgary Depression Scale for Schizophrenia (CDSS), did not improve in either group. Conclusions: VO_2peak and net mechanical efficiency of walking improved significantly by 8 weeks of HIT. HIT should be included in rehabilitation in order to improve physical capacity and contribute risk reduction of CVD.     

Cardiac autonomic function during submaximal treadmill exercise in adults with Down syndrome

This study determined whether the cardiac autonomic function of adults with Down syndrome (DS) differs from that of nondisabled persons during submaximal dynamic exercise. Thirteen participants with DS and 12 nondisabled individuals performed maximal and submaximal treadmill tests with metabolic and heart rate (HR) measurements. Spectral analysis of HR variability was performed on the last 256 consecutive R-R intervals obtained under the following conditions: (1) rest, (2) submaximal treadmill exercise (at constant relative intensity below the ventilatory threshold) and (3) recovery. Participants with DS presented lower chronotropic response than those without DS to peak and submaximal exercise (p < 0.05). Nevertheless, the fractional utilization of peak HR during treadmill walking was similar between groups (∼60% peak HR). Even though there were no between-group differences at rest or during recovery, the participants with DS showed a higher LF/HF ratio during exercise (p < 0.05). Similarly, the LF power of participants with DS during exercise was greater than that of nondisabled participants (p < 0.05). In contrast, both groups exhibited similar HF power at each physiological condition. In conclusion, these findings suggest that adults with DS demonstrate appropriate vagal withdrawal, but heightened sympathetic modulation of HR variability at ∼60% of their peak HR. Despite this, the absolute change in HR from rest to exercise was attenuated in these individuals compared to persons without disabilities. This indicates that DS may be associated with poor cardiac responsiveness to changes in autonomic modulation during exercise at intensities below the ventilatory threshold.     

Submaximal oxygen cost during incremental exercise in children with developmental coordination disorder

There has been minimal evidence examining the differences in submaximal aerobic power between children with and without probable developmental coordination disorder (pDCD). This is important as most activities of daily living are performed at submaximal levels. The aim of this study was to examine the oxygen cost of work (VO₂) performed during an incremental exercise protocol on a cycle ergometer. Subjects with pDCD (n = 63) were matched for age and gender to 63 typically developing controls (12–13 years of age) using a nested case–control design. Motor coordination was assessed using the Movement Assessment Battery for Children. Children with pDCD had significantly lower VO2 peak values relative to controls (35.0 vs. 42.9 ml/kg/min, p < 0.0001). At the submaximal level, mixed effects modeling demonstrated that, after controlling for relative body fat, and VO₂ peak, children with pDCD had consistently greater oxygen cost (VO₂ ml/kg/min) compared to controls at any given exercise intensity (p = 0.0006). A significant interaction between pDCD and workload indicated that the difference in VO₂ at higher workloads is greater than that at lower workloads (p = 0.0004). Children with pDCD utilize more oxygen to sustain the same submaximal workload. The implication of these findings is that children with pDCD may experience earlier fatigue than well coordinated individuals when engaging in physical activity.     

Using actigraphy to assess sleep and wake rhythms of narcolepsy type 1 patients: a comparison with primary insomniacs and healthy controls

Objective/backgroundIt has been shown that actigraphy may have a discriminant function (DS) for the diagnosis of narcolepsy type 1 patients (NT1), based on a combination of nighttime and daytime parameters. Here, we aimed to test those findings using another actigraph model with a different clinical sample as control (ie, primary insomniacs, PI), carrying out a secondary analysis of previously collected data.Patients/methodsThe study sample consisted of 13 NT1 (nine females; mean age 39.38 ± 11.48), 13 PI (nine females; mean age 38.69 ± 10.72) and 13 Healthy Controls (HC) (nine females; mean age 38 ± 10.77). Participants wore the Actiwatch AW64 (Cambridge Neurotechnology Ltd, Cambridge, UK) around the non-dominant wrist for seven consecutive days.ResultsSignificant differences between groups were observed with a higher number of episodes of wakefulness (wake bouts, WB) in PI than HC, a higher fragmentation index (FI) in NT1 than HC and PI, a higher duration of the longest nap (LNAP) in NT1 than HC and PI and higher DS in PI and NT1 than HC. A new DS (NDS), with LNAP and FI as independent variables, was proposed; which was higher in NT1 than HC and PI.ConclusionsThe present study confirms that actigraphy discriminates NT1 from HC. However, considering PI, a new discriminant function NDS which takes into account LNAP and FI is better for this actigraph model.