运动训练对慢性心力衰竭患者运动耐量的影响

目的　探讨运动训练对慢性心力衰竭患者运动耐量的影响。方法　 70例患者随机分为 2组 ,A组 (n =3 4)运动培训 3周 ,B组 (n =3 6)限制活动 3周 ,然后比较 2组 6min内步行的距离、左室射血分数(超声心动图测定 )、血白介素 6(双抗体夹心法 )及去甲肾上腺素浓度 (荧光法测定 )的变化。结果　运动训练组患者试验后 6min步行距离 ( 3 85± 3 0 .12 )m ,血IL 6( 0 .86± 0 .2 5 ) pmol/L ,NE( 2 .0 5± 0 .48)nmol/L ,LVEF( 43± 5 .2 3 ) % ,上述各指标与对照组相比 ,差异均有显著性意义 (P <0 .0 5 ) ,而且运动试验组试验前、后各指标的差异也有显著性意义 (P <0 .0 5 ) ,但对照组试验前、后差异无显著性意义 (P >0 .0 5 )。结论　运动训练能改善慢性心力衰竭患者的运动能力及心功能 ,对慢性心力衰竭患者的康复治疗是有益的。     

Exaggerated blood pressure response to exercise: importance of resting blood pressure

Normotensive individuals who exhibit an exaggerated blood pressure (BP) response to exercise have an increased risk of future hypertension. However, previous studies failed to control for resting BP despite the fact that an elevated resting BP in the normotensive range is also a strong predictor of future hypertension. Therefore, we determined whether maximal systolic BP is associated with resting BP. Resting BP was measured in 68 healthy normotensive men on three separate days. The subjects then performed a graded, maximal exercise test on a Monark cycle ergometer. Maximal systolic BP was strongly correlated with resting systolic BP (r = 0·64, P<0·0001). Subjects with elevations in systolic BP during maximal exercise (>220 mmHg) also had higher (P<0·005) resting BP than those without (<220 mmHg). When stepwise regression analyses were performed, systolic BP at rest was a significant independent predictor of maximal systolic BP, explaining over 40% of the variability. These results suggest that exaggerated BP response as a predictor of future hypertension reported in previous studies may be little more than a simple reflection of elevated resting BP. Specifically, these studies should not be interpreted as demonstrating that exercise BP is a better predictor of future hypertension than resting BP alone. In the future, defining the BP `response' to exercise as a change score (i.e. maximal BP minus resting BP) may be advantageous as it permits the effects of exercise to be examined independently of the level of resting BP.     

Exercise capacity and cardiovascular changes in patients with beta-thalassaemia major

Despite the introduction of deferoxamine, 50% of thalassaemia major patients die before the age of 35 years predominantly from iron induced heart failure. Indeed, the assessment of myocardial performance may be of particular interest since it can reveal an early myocardial dysfunction. By using impedance cardiography and mass spectrometry, we studied the cardiac function and the oxygen extraction ratio (O(2)ER) of 14 thalassaemic patients and 15 control healthy subjects during an incremental cycle-ergometer test. The achieved mechanical power output and the relative O(2) uptake did not reach any significant difference between groups. At the highest workload, O(2)ER reached significantly higher values in thalassaemic patients versus control subjects while the relationship between cardiac index (CI) and O(2)ER (CI/O(2)ER) decreased showing a lower contribution of cardiovascular system to maintain O(2) uptake. Results of this study imply that CI/O(2)ER allows an early diagnosis of the iron induced myocardial dysfunction, whereas it is not clinically patent yet. To our knowledge, this is the first study revealing an O(2)ER pivotal role as compensatory mechanism to maintain a normal working capacity in subjects suffering from thalassaemia major.     

The effect of trunk training on muscle thickness and muscle activity: a systematic review

Objective: A systematic review to examine the effect of static or dynamic trunk training compared to standard care or control therapy on muscle activity and muscle thickness of the trunk and lower limb muscles in stroke survivors.

Materials and methods: This review was registered on PROSPERO (no: CRD42017063771) and was written according to the PRISMA guidelines. The search strategy included studies from the first indexed article until September 2017 and was performed in the electronical databases PubMed, Web of Science, Cochrane Library, Ovid Medline and PEDro. Two independent reviewers screened, assessed risk of bias by means of the PEDro scale and extracted data.

Results: Eight studies were included of which three investigated the effects of trunk training on muscle thickness, the remaining five investigated muscle activity. The following muscles were investigated: erector spinae, multifidi, paravertebralis, transversus abdominis, internal and external oblique abdominis, rectus abdominis, quadriceps femoris, hamstrings, soleus and tibialis anterior. Trunk exercises significantly improved the muscle activity of the internal oblique abdominis and increased muscle thickness of transversus abdominis.

Conclusions: Trunk training is effective in restoring symmetry in muscle thickness to improve muscle strength. The gain in muscle thickness is specific to the applied exercise program, suggesting that therapeutic goal setting is of great importance. However, no conclusion could be made concerning changes in muscle activity due to a high risk of bias.

• Implications for rehabilitation:

• Trunk training seems to be effective in restoring symmetry in trunk muscle thickness.

• Not all muscle groups benefit from specific trunk exercises.

• Patients suffering from chronic stroke are still capable of restoring muscle function.

     

Morphological and functional relationships with ultrasound measured muscle thickness of the upper extremity and trunk

Unless a subject’s muscle is relatively small, a single image from a standard ultrasound can only measure muscle thickness (MT). Thus, it is important to know whether MT is related to morphological and functional characteristics of individual muscles of the extremity and trunk. In this review, we summarize previously published articles in the upper extremity and trunk demonstrating the relationships between ultrasound-measured MT and muscle morphology (cross-sectional area, CSA and muscle volume, MV) and muscular or respiratory function. The linear relationship between MT and muscle CSA or MV has been observed in biceps brachii, triceps brachii, pectoralis major, psoas major, and supraspinatus muscles. Previous studies suggest that MT in the upper arm and trunk may reflect muscle CSA and MV for the individual muscles. Unfortunately, few studies exist regarding the functional relationship with ultrasound MT in the upper extremity and trunk. Future research is needed to investigate these findings further.     

Reproducibility and sensitivity of muscle reoxygenation and oxygen uptake recovery kinetics following running exercise in the field

The purpose of this study was to assess the reliability of postexercise near‐infrared spectroscopy (NIRS)‐derived measurements and their sensitivity to different exercise intensities in the field. Seventeen athletes (24·1 ± 5·6 year) repeated, on three occasions, two 2‐min submaximal shuttle‐runs at 40% and 60% of V_IFT (final speed of the 30–15 intermittent fitness test) and a 50‐m shuttle‐run sprint (Sprint), with (OCC) or without (CON) repeated transient arterial occlusions of the medial gastrocnemius during the postexercise period. NIRS variables (i.e. oxyhaemoglobin [HbO₂], deoxyhaemoglobin [HHb] and their difference [Hb_diff]) were measured continuously for 3 min after each exercise. Half‐recovery (½Rec) and mean response (MRT; monoexponential curve fitting) times of muscle reoxygenation and muscle oxygen uptake () recovery were calculated. Reliability was assessed using the typical error of measurement, expressed as a coefficient of variation (CV). Postexercise recovery of muscle reoxygenation revealed CVs ranging from 16·8% to 37·3%; CV for recovery ranged from 6·2% to 20·9%, with no substantial differences shown between NIRS variables and exercise intensities. While running, intensity did not affect MRT or ½Rec for muscle reoxygenation, and differences were found for recovery (e.g. [Hb_diff]‐ MRT = 28·7 ± 5·2, 34·2 ± 5·1 and 37·3 ± 6·2 s for 40%, 60% and Sprint, respectively, P<0·01). To conclude, the kinetics of postexercise NIRS measurements showed CV values ranging from 6% to 37%, with no substantial differences between exercise intensities or NIRS‐derived variables. However, exercise intensity did influence recovery kinetics, but not that of muscle reoxygenation in an occlusion‐free condition.     

Growth hormone (GH) treatment in GH-deficient adults: effects on muscle size,strength and neural activation

Summary. The effects of 6 months of recombinant growth hormone (GH) treatment (0–5 IU kg^-1 per week) on muscle size, strength and neural activation (EMG) was studied in eight adults with childhood onset GH deficiency (GHD). Before treatment, height, body mass (BM) and lean body mass (LBM) 6f the GHD subjects were significantly lower (P<0–01) from those recorded in eight healthy controls, while no significant differences were found between the body mass index (BMI) of the two populations. Thigh muscle + bone cross-sectional area (CSA_M+B) and lower limb muscle plus bone volume (LLV_M+B) of the GHD patients were 66–1 ± 13–7% and 47–6 ± 6–8% of those recorded in the controls (P<0–01), whereas no difference in CSA/height² was found between the two groups. By contrast, LLV_M+B/height³ was 82–0 ± 19–0% that of the controls (P<0–05). Similarly, quadriceps muscle strength (MVC) of the GHD patients was 63–2 ± 12–4% that of controls (P<0–01), while no significant differences in the force per unit area (F/CSA) and per body mass (F/BM) were found. After 6 months of GH treatment LBM increased by 6–0 ± 4–2% (P<0.02), CSA_M+B by 14–5 ± 12–7% (P<0.01) and LLV_M+B by 10-l ± 7–3% (P<0.01), absolute differences from the normals still persisting. However, the LLV_M+B/height³ of the GHD patients after treatment was no longer significantly different from that of the controls. Quadriceps MVC increased by 9–8 ± 12–0% (P<0–02), differences from the controls being still significant, whereas the F/CSA and F/BM did not change. A right shift of the integrated EMG/Force relation, with no change in the maximal integrated EMG (iEMG) activity, was observed in the patients after treatment. In conclusion, the current study shows that adults with childhood onset GHD have a reduced skeletal muscle mass and strength which seem to be positively influenced by 6 months of GH treatment.     

In vivo quantitative near-infrared spectroscopy in skeletal muscle during incremental isometric handgrip exercise

The aim of this study was to investigate the performance of in vivo quantitative near-infrared spectroscopy (NIRS) in skeletal muscle at various workloads. NIRS was used for the quantitative measurement of O2 consumption (mVO2) in the human flexor digitorum superficialis muscle at rest and during rhythmic isometric handgrip exercise in a broad range of work intensities (10-90% MVC=maximum voluntary contraction force). Six subjects were tested on three separate days. No significant differences were found in mVO2 measured over different days with the exception of the highest workload. The within-subject variability for each workload measured over the three measurements days ranged from 15.7 to 25.6% and did not increase at the high workloads. The mVO2 was 0.14 +/- 0.01 mlO2 min-1 100 g-1 at rest and increased roughly 19 times to 2.68 +/- 0.58 mlO2 min-1 100 g-1 at 72% MVC. These results show that local muscle oxygen consumption at rest as well as during exercise at a broad range of work intensities can be measured reliably by NIRS, applied to a uniform selected subject population. This is of great importance as direct local measurement of mVO2 during exercise is not possible with the conventional techniques. The method is robust enough to measure over separate days and at various workloads and can therefore contribute to a better understanding of human physiology in both the normal and pathological state of the muscle.     

不同损伤平面脊髓损伤患者运动试验中心肺功能的变化

目的探讨不同损伤平面脊髓损伤患者运动试验中心肺功能的变化。方法将15例脊髓损伤患者分为高位截瘫组(8例)和低位截瘫组(7例),均在轮椅跑台上进行极量递增负荷运动试验,测量心肺功能指标。结果低位截瘫患者的心肺功能优于高位截瘫(P<0.05~0.01)。结论脊髓损伤平面越高,心肺功能越低,即损伤平面与心肺功能成反比。     

Key metabolite kinetics in human skeletal muscle during ischaemia and reperfusion: measurement by microdialysis

Abstract. The tissue kinetics of key metabolites of ischaemic and postischaemic tissue damage were studied in the intercellular space of human skeletal muscle by microdialysis. In vivo microdialysis calibration experiments ( n = 5) yielded the basal intercellular concentration of glucose in human skeletal muscle (3.6±0.6mM; mean±SD). The corresponding mean plasma glucose concentration was 4.3 ± 0.2 mM which was significantly higher. The time vs. concentration profiles of intercellular glucose ( n = 7), lactate ( n = 5), TxB₂ ( n = 6) and urea ( n = 8) were characterized during a 20 min period of leg constriction. TxB₂ increased exclusively during reperfusion in comparison to baseline ( n = 6). Administration of 500 mg acetylsalicylic acid, 5–10min after onset of ischaemia blunted TxB₂-response to reperfusion ( n = 4). It is concluded that intercellular muscle glucose concentration is less than that in plasma. Glucose uptake in skeletal muscle is rapid even under ischaemic conditions. Synthesis and release of TxB₂ is not evident during ischaemia. TxB₂ mediated reperfusion injury might be reduced by acetylsalicylic acid, even if administered after onset of ischaemia.     

Intact skeletal muscle mitochondrial enzyme activity but diminished exercise capacity in advanced heart failure patients on optimal medical and device therapy

Background

A skeletal myopathy, perhaps attributable to neuro-endocrine excitation or disuse, has been described in heart failure (HF) patients, and is thought to contribute to their exercise limitation. Our purpose was to assess biochemical and morphometric characteristics of skeletal muscles of HF patients on optimal HF therapy. A secondary purpose was to explore the effects of clonidine, which interrupts the neuro-endocrine excitation, on these same muscle characteristics.

Methods and results

Eleven HF patients (50.8 ± 3.4 years, peak VO₂ 11.6 ± 2.5 ml/kg/min) underwent two vastus lateralis biopsies (pre/post clonidine). Baseline values were compared to biopsies in 11 age-matched, healthy controls. Scatter plots of individual values for each mitochondrial enzyme revealed almost complete overlap between HF and control groups; mean values, although tending to be greater in controls versus HF patients, were not significantly different. The proportion of type 1 fibers was diminished in 10 of 11 patients. There was no difference in any of the variables after 3 months clonidine versus placebo.

Conclusion

In HF patients treated with optimal medical and device therapy, characteristic abnormalities of mitochondrial enzyme activity are not found, but muscle fiber type shifts are present. The remaining severe impairment in exercise capacity cannot be attributed to mitochondrial abnormalities.     

Oxygen Uptake to Work Rate Relation Throughout Peak Exercise in Normal Subjects: Relevance for Rate Adaptive Pacemaker Programming

The oxygen uptake to work rate (VO2/WR) relationship observed throughout peak exercise testing is already being applied for rate adaptive pacemaker programming. However, the detailed curve design of VO2/WR with respect to the anaerobic threshold (AT) has not yet been investigated. It was the purpose of this study to determine the VO2/WR slope below and above the AT in a healthy control group. Seventy-eight healthy control subjects (45.9 +/- 17.4 years; 34 women: 49.9 +/- 18.6 years 44 men: 43.6 +/- 16.6 years) were exercised on a treadmill with "breath-by-breath" gas exchange monitoring using the symptom limited "ramping incremental treadmill exercise" (RITE) protocol. The slope of the VO2/WR relationship from rest to peak exercise (r-p), rest to AT (slope A), and AT to peak exercise (slope B) in mL oxygen uptake per watt of external treadmill work was determined by linear regression analysis. [table: see text] The oxygen uptake to work rate relationship throughout peak exercise in the entire study group generated a significant slope change at the AT (31%, P < 0.0001) with a decreasing slope during higher work load intensities. Female subjects demonstrated a greater percentage of slope change at AT (43%), as compared to men (22%, P < 0.01). When using the oxygen uptake to work rate relationship for the programming of the pacemaker's rate response to exercise, the significant slope change at the AT should be considered to more appropriately pace during higher work intensities supported by anaerobic metabolism. Female pacemaker patients should be programmed to generate a steeper VO2/WR slope below AT with a greater slope change at AT, as compared to men. Abnormally high oxygen uptake to work rate ratios above the AT may be possibly used as an indicator of overpacing.     

The importance of lower-extremity muscle strength for lower-limb functional capacity in multiple sclerosis: Systematic review

BackgroundLower-limb functional capacity is impaired in most people with multiple sclerosis (PwMS). Reductions in lower-extremity muscle mechanical function (e.g., muscle strength) appear to have critical implications for lower-limb functional capacity. However, no review has summarized the current knowledge about the importance of muscle strength for functional tasks in PwMS. Expanding the current knowledge would advance the design of both clinical and research interventions aiming to improve functional capacity in PwMS.Objectives(1) To identify studies that measured lower-extremity muscle mechanical function and lower-limb functional capacity outcomes in PwMS, and (2) to map associations between muscle strength and functional capacity.MethodsThis review was based on a literature search (databases: PubMed, Embase). Included studies had to report data on lower-extremity muscle mechanical function and lower-limb functional capacity outcomes in PwMS. The associations between muscle strength and functional capacity were analyzed by using the reported correlation coefficients (R) recalculated to the determination coefficient R². Randomized trials and observational studies were included.ResultsA total of 59 articles were reviewed; 17 (773 participants) reported associations between muscle strength and functional capacity. Lower-extremity muscle mechanical function explained a significant part of the variance in most lower-limb functional capacity tests (approximately 20–30%). This was particularly evident in muscle strength from the weakest leg. Muscle strength was predominantly tested on knee extensors and knee flexors by using isokinetic dynamometry during maximal isometric (0°/s) and dynamic (30–60°/s) contractions. Walking tests such as the timed 25-Foot Walk Test and 10-Min, 2-Min and 6-Min Walk Test were the most frequently performed functional capacity tests.ConclusionsIn PwMS, muscle strength of particularly the weakest limb explains 20% to 30% of the variance across a number of lower-limb functional capacity tests. Thus, exercise programs should focus on increasing lower-extremity muscle mechanical function in PwMS and minimizing strength asymmetry between limbs.     

Isometric muscle strength and mobility capacity in children with cerebral palsy

Purpose: To determine the relationship between isometric leg muscle strength and mobility capacity in children with cerebral palsy (CP) compared to typically developing (TD) peers. Method: Participants were 62 children with CP (6–13 years), able to walk with (n?=?10) or without (n?=?52) walking aids, and 47 TD children. Isometric muscle strength of five muscle groups of the leg was measured using hand-held dynamometry. Mobility capacity was assessed with the 1-min walk, the 10-m walk, sit-to-stand, lateral-step-up and timed-stair tests. Results: Isometric strength of children with CP was reduced to 36–82% of TD. When adjusted for age and height, the percentage of variance in mobility capacity that was explained by isometric strength of the leg muscles was 21–24% (walking speed), 25% (sit-to-stand), 28% (lateral-step-up) and 35% (timed-stair) in children with CP. Hip abductors and knee flexors had the largest contribution to the explained variance, while knee extensors showed the weakest correlation. Weak or no associations were found between strength and mobility capacity in TD children. Conclusion: Isometric strength, especially hip abductor and knee flexor strength, is moderately related to mobility capacity in children with CP, but not in TD children. To what extent training of these muscle groups will lead to better mobility capacity needs further study.

• Implications for Rehabilitation

• Strength training in children with cerebral palsy (CP) may be targeted more specifically at hip abductors and knee flexors.

• The moderate associations imply that large improvements in mobility capacity may not be expected when strength increases.

     

综合监测联合个体化运动处方改善糖尿病患者有氧能力研究

［］ 目的:探讨综合监测联合个体化运动处方改善糖尿病患者有氧能力效果研究。方法:收集在我科室住院无运动禁忌的糖尿病患者124例作为研究对象,将其随机分为对照组(n=62)和干预组(n=62); 两组患者均实施常规糖尿病健康教育,对照组提供常规运动建议,干预组在此基础上,利用科学的专业运动监测设备,进行有氧能力和肌氧曲线测量,根据监测结果推荐适宜的运动强度,针对性进行个性化运动干预,并对患者进行定期的随访;观察两组患者有氧能力是否改善。结果 : 未按要求完成运动量和未完成规定的运动测试者,作为脱落病例处理。其中对照组脱落5例、干预组脱落3例,最终对照组57例、干预组59例,纳入后续研究分析。对照组相比,干预组患者有氧能力值、糖化血红蛋白、空腹血糖还有甘油三酯以及胆固醇等指标均有改善,且优于对照组, 差异有统计学意义(P<0.05)。结论 :通过联合有氧能力和肌氧曲线综合测量可以精准的进行个体化运动指导,可有效改善糖尿病患者的有氧能力,达到有效与安全的科学运动,提高糖尿病患者的运动治疗效果。     

抗阻训练对高血压病人血压及自主神经功能影响的Meta分析

目的:系统评价抗阻训练对高血压病人血压、自主神经功能及最大摄氧量的影响。方法:计算机检索PubMed、Web of Science、EMbase、the Cochrane Library、中国知网、万方数据库、维普数据库、中国生物医学文献数据库关于抗阻训练对高血压病人影响的随机对照试验,检索时限为各数据库建库至2021年3月20日。由2名研究者按纳入与排除标准独立筛选文献、提取资料、评价文献质量,并采用RevMan 5.3软件进行Meta分析。结果:共纳入12篇文献,涉及621例高血压病人。Meta分析结果显示,抗阻训练能有效降低高血压病人的收缩压[MD=-8.85,95%CI(-12.83,-4.87),P<0.000 1]及舒张压[MD=-4.85,95%CI(-6.77,-2.94),P<0.000 1];增加最大摄氧量[MD=2.00,95%CI(0.39,3.60),P=0.01];对心脏自主神经功能调节的影响尚不能确定。结论:现有证据表明,与不进行任何有规律运动的对照组相比,试验组能有效降低高血压病人的收缩压及舒张压,增加最大摄氧量,但对心脏自主神经功能调节的影...     

Exercise in elderly patients with chronic heart failure in primary care: Effects on physical capacity and health-related quality of life

Introduction

Chronic heart failure (CHF) limits exercise capacity which influences physical fitness and health-related quality of life (HRQoL).

Aim

The aim was to determine the effects on physical capacity and HRQoL of an exercise programme in elderly patients with CHF in primary care.

Methods

An exercise intervention was conducted as a prospective, longitudinal and controlled clinical study in primary care in elderly patients with CHF. Endurance exercise and resistance training were conducted as group-training at the primary care centre and as home training. Follow-up on physical capacity and HRQoL was done at 3, 6 and 12 months.

Results

Exercise significantly improved muscle endurance in the intervention group (n = 29, mean age 76.2 years) compared to the control group (n = 31, mean age 74.4 years) at all follow-ups except for shoulder flexion right at 12 months (shoulder abduction p = 0.006, p = 0.048, p = 0.029; shoulder flexion right p = 0.002, p = 0.032, p = 0.585; shoulder flexion left p = 0.000, p = 0.046, p = 0.004). Six minute walk test improved in the intervention group at 3 months (p = 0.013) compared to the control group. HRQoL measured by EQ5D-VAS significantly improved in the intervention group at 3 and 12 months (p = 0.016 and p = 0.034) and SF-36, general health (p = 0.048) and physical component scale (p = 0.026) significantly improved at 3 months compared to the control group.

Conclusion

This study shows that exercise conducted in groups in primary care and in the patients' homes could be used in elderly patients with CHF. The combination of endurance exercise and resistance training has positive effects on physical capacity. However, the minor effects in HRQoL need further verification in a study with a larger study population.     

Histochemical demonstration of skeletal muscle fibre types and capillaries on the same transverse section

Summary. Serial transverse sections of m. vastus lateralis biopsies from six healthy men were reacted:

• 1 for myofibrillar adenosine triphosphatase (mATPase) to identify fibre types;
• 2 with α-amylase, periodic acid-Schiff (αPAS) to visualize capillaries. Sections were also processed with a new histochemical method for identification of fibre types and capillaries on the same skeletal muscle slice (mATPase/αPAS). Fibre type composition using either method was 41% type I, 37% type IIA and 22% type IIB. Types I, HA and IIB least diameter areas (mean±SE, μm²) were similar in sections processed for mATPase/αPAS or mATPase (3976±338, 5187±373 and 4389±514 vs. 4092±345, 5100±360 and 4289±474, respectively). The number of capillaries per mm² and per fibre did not differ in sections processed using the αPAS (315±29 and 1·48 ±0·12) or mATPase/αPAS (317±25 and 1·43±0·10) method. The number of capillaries was greater (P<0·05) around types I or IIA than type IIB fibres whether a section was processed for mATPase/αPAS (4·5±0·2 or 4·6±0·2 vs. 3·4±0·3) or when fibre profiles of serial sections reacted for mATPase or αPAS were ‘matched’ (4·5±0·2 or 4·4±0·2 vs. 3·4±0·3). The results indicate that histochemical and morphometric measures can be made on the same transverse section using the new method with substantial savings of time, cost and energy.