Increased Skeletal Muscle Capillarization Independently Enhances Insulin Sensitivity in Older Adults After Exercise Training and Detraining

Intramuscular signaling and glucose transport mechanisms contribute to improvements in insulin sensitivity after aerobic exercise training. This study tested the hypothesis that increases in skeletal muscle capillary density (CD) also contribute to exercise-induced improvements in whole-body insulin sensitivity (insulin-stimulated glucose uptake per unit plasma insulin [M/I]) independent of other mechanisms. The study design included a 6-month aerobic exercise training period followed by a 2-week detraining period to eliminate short-term effects of exercise on intramuscular signaling and glucose transport. Before and after exercise training and detraining, 12 previously sedentary older (65 ± 3 years) men and women underwent research tests, including hyperinsulinemic-euglycemic clamps and vastus lateralis biopsies. Exercise training increased Vo_2max (2.2 ± 0.2 vs. 2.5 ± 0.2 L/min), CD (313 ± 13 vs. 349 ± 18 capillaries/mm²), and M/I (0.041 ± 0.005 vs. 0.051 ± 0.007 μmol/kg fat-free mass/min) (P < 0.05 for all). Exercise training also increased the insulin activation of glycogen synthase by 60%, GLUT4 expression by 16%, and 5′ AMPK-α1 expression by 21%, but these reverted to baseline levels after detraining. Conversely, CD and M/I remained 15% and 18% higher after detraining, respectively (P < 0.05), and the changes in M/I (detraining minus baseline) correlated directly with changes in CD in regression analysis (partial r = 0.70; P = 0.02). These results suggest that an increase in CD is one mechanism contributing to sustained improvements in glucose metabolism after aerobic exercise training.     

Physical Activity After Surgery for Severe Obesity: The Role of Exercise Cognitions

Background  

Physical activity after bariatric surgery is associated with sustained weight loss and improved quality of life. Some bariatric patients engage insufficiently in physical activity. This may be due to exercise cognitions, i.e., specific beliefs about benefits of and barriers to physical exercise. The aim of this study was to examine whether and to what extent both physical activity and exercise cognitions changed at 1 and 2 years post-surgery and whether exercise cognitions predict physical activity.     

运动平板试验Duke评分对冠心病诊断价值

目的:评价运动平板试验Duke评分(DTS)对冠心病的诊断价值.方法:选择124例胸痛患者行运动平板试验和冠状动脉造影检查,将其结果进行比较.结果:依据DTS进行冠心病诊断的敏感度为93.4％,特异度为68.3％,Duke评分和SYNTAX评分呈明显负相关.结论:DTS可以作为诊断冠心病提供参考并可对冠心病严重程度进行评估.     

Comparison of Supervised Exercise and Home Exercise After Ankle Fracture

Ankle fractures are common fractures of the lower extremities that have an incidence rate of 101 fractures per 100.000 person-years. It is not clear which rehabilitation intervention should be performed after an ankle fracture. The aims of this study are to compare the effectiveness of a supervised exercise program with that of a home exercise program and to determine and compare the costs of these programs. A supervised exercise program and a home exercise program were performed for 8 weeks. The supervised exercise group consisted of 35 patients (mean age 39.23 years), and the home exercise group consisted of 73 patients (mean age 41.78 years). The average follow-up was 27.86 ± 9.88 months. Demographic information, injury details, type and classification of fracture, pain severity, and ankle range of motion were recorded. The clinical outcomes were determined by using the Pain Disability Index, the American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Score, and the Short-Form 36 Health Survey. Surgical and rehabilitation satisfaction was evaluated with the use of a numeric scale. American Orthopaedic Foot and Ankle Society Ankle-Hindfoot Scores were statistically significantly higher in the home exercise group (p = .036), and rehabilitation satisfaction of the supervised exercise group was statistically significantly better (p = .047). The total rehabilitation crude cost of a patient in the supervised exercise group is 1113.63 Turkish lira (310.25 U.S. dollars) versus 182.31 Turkish lira (50.79 U.S. dollars) in the home exercise group. Considering that the crude cost of the home exercise program is very low and clinical outcomes are satisfactory, we recommend that patients with surgically treated isolated ankle fractures be followed up with a postoperative home exercise program.     

Exercise and Weight Loss Improve Muscle Mitochondrial Respiration,Lipid Partitioning,and Insulin Sensitivity After Gastric Bypass Surgery

Both Roux-en-Y gastric bypass (RYGB) surgery and exercise can improve insulin sensitivity in individuals with severe obesity. However, the impact of RYGB with or without exercise on skeletal muscle mitochondria, intramyocellular lipids, and insulin sensitivity index (S_I) is unknown. We conducted a randomized exercise trial in patients (n = 101) who underwent RYGB surgery and completed either a 6-month moderate exercise (EX) or a health education control (CON) intervention. S_I was determined by intravenous glucose tolerance test. Mitochondrial respiration and intramyocellular triglyceride, sphingolipid, and diacylglycerol content were measured in vastus lateralis biopsy specimens. We found that EX provided additional improvements in S_I and that only EX improved cardiorespiratory fitness, mitochondrial respiration and enzyme activities, and cardiolipin profile with no change in mitochondrial content. Muscle triglycerides were reduced in type I fibers in CON, and sphingolipids decreased in both groups, with EX showing a further reduction in a number of ceramide species. In conclusion, exercise superimposed on bariatric surgery–induced weight loss enhances mitochondrial respiration, induces cardiolipin remodeling, reduces specific sphingolipids, and provides additional improvements in insulin sensitivity.     

Near-Infrared Spectroscopy with Treadmill Exercise to Assess Lower Limb Ischemia in Patients with Atherosclerotic Occlusive Disease

Purpose We used near-infrared spectroscopy (NIRS) to measure exercise-induced ischemia in patients with intermittent claudication, and compared these results with those obtained by ankle-brachial pressure index (ABPI) analysis.Methods Sixty-two patients with intermittent claudication caused by atherosclerotic occlusive disease exercised on a treadmill until reaching the maximal tolerated walking distance. We measured the ABPI at rest and after exercise until it returned to the baseline value. A NIRS probe was positioned on the patients calf, which allowed the continuous monitoring of oxygen saturation (StO₂), oxygenated hemoglobin (Oxy Hb), and deoxygenated hemoglobin (Deoxy Hb) in the calf muscles before, during, and after exercise. During exercise, the StO₂ and Oxy Hb decreased, and the Deoxy Hb increased. The time taken for each measurement to return to the baseline value was defined as the recovery time. The recovery times obtained by NIRS and ABPI were compared.Results The recovery time for ABPI correlated well with that for StO₂ (_s = 0.73), Oxy Hb (_s = 0.63), and Deoxy Hb (_s = 0.65); however, the recovery times measured by NIRS were shorter than the recovery time for the ABPI.Conclusions Near-infrared spectroscopy is a reliable method for monitoring peripheral circulation during and after exercise, although the data generated provided slightly different information than the results obtained by ABPI.     

Changes in Pain Perception in Women During and Following an Exhaustive Incremental Cycling Exercise

Exercise has been found to alter pain sensitivity with a hypoalgesic response (i.e., diminished sensitivity to pain) typically reported during and/or following high intensity exercise. Most of this research, however, has involved the testing of men. Thus, the purpose of the following investigation was to examine changes in pain perception in women during and following exercise. Seventeen healthy female subjects (age 20.47±.87; VO₂ peak 36.77± 4.95) volunteered to undergo pain assessment prior to, during, and after a graded exhaustive VO₂ peak cycling challenge. Heart Rate (HR) and Oxygen Uptake (VO₂) were monitored along with electro-diagnostic assessments of Pain Threshold (PT) and Pain Tolerance (PTOL) at: 1) baseline (B), 2) during exercise (i.e., 120 Watts), 3) at exhaustive intensity (VO₂ peak), and 4) 10 minutes into recovery (R). Data were analyzed using repeated measures ANOVA to determine differences across trials. Significant differences in PT and PTOL were found across trials (PT, p = 0.0043; PTOL p = 0.0001). Post hoc analyses revealed that PT were significantly elevated at VO₂ peak in comparison to B (p = 0.007), 120 Watts (p = 0.0178) and R (p = 0.0072). PTOL were found to be significantly elevated at 120 Watts (p = 0.0247), VO₂ peak (p < 0.001), and R (p = 0.0001) in comparison to B. In addition, PTOL were found to be significantly elevated at VO₂ peak in comparison to 120 Watts (p = 0.0045). It is concluded that exercise-induced hypoalgesia occurs in women during and following exercise, with the hypoalgesic response being most pronounced following exhaustive exercise.

Key Points

• Exercise-induced hypoalgesia (i.e., elevated PT and PTOL) was found to occur in women during and following exercise, with the hypoalgesic response being most pronounced during exhaustive exercise.

Key Words: Nociception, cycling, hypoalgesia, pain tolerance threshold     

Exercise Training After Lung Transplantation Improves Participation in Daily Activity: A Randomized Controlled Trial

The effects of exercise training after lung transplantation have not been studied in a randomized controlled trial so far. We investigated whether 3 months of supervised training, initiated immediately after hospital discharge, improve functional recovery and cardiovascular morbidity of patients up to 1 year after lung transplantation. Patients older than 40 years, who experienced an uncomplicated postoperative period, were eligible for this single blind, parallel group study. Sealed envelopes were used to randomly allocate patients to 3 months of exercise training (n = 21) or a control intervention (n = 19). Minutes of daily walking time (primary outcome), physical fitness, quality of life and cardiovascular morbidity were compared between groups adjusting for baseline assessments in a mixed models analysis. After 1 year daily walking time in the treated patients (n = 18) was 85 ± 27 min and in the control group (n = 16) 54 ± 30 min (adjusted difference 26 min [95%CI 8–45 min, p = 0.006]). Quadriceps force (p = 0.001), 6‐minute walking distance (p = 0.002) and self‐reported physical functioning (p = 0.039) were significantly higher in the intervention group. Average 24 h ambulatory blood pressures were significantly lower in the treated patients (p ≤ 0.01). Based on these results patients should be strongly encouraged to participate in an exercise training intervention after lung transplantation.     

Platelet Counts and Liver Enzymes After Gastric Bypass Surgery

Background

Obesity is associated with chronic inflammation, liver steatosis and increased liver enzymes such as gamma-glutamyltransferase (GGT) and alanine aminotransferase (ALT), markers for non-alcoholic fatty liver disease (NAFLD) and liver fat content. Increased platelet counts (PCs) are a biomarker reflecting inflammation and the degree of fibrosis in NAFLD. We investigated alterations in PCs, GGT, ALT, C-reactive protein (CRP) and ferritin after Roux-en-Y gastric bypass (RYGBP).

Methods

One hundred twenty-four morbidly obese non-diabetic patients were evaluated before (baseline) and 12 months after (follow-up) RYGBP.

Results

Body mass index (BMI) was reduced from 43.5 kg/m² (baseline) to 31.1 kg/m² (follow-up), and p?<?0.001 and weight declined from 126.2 to 89.0 kg. PCs decreased from 303?×?10⁹ to 260?×?10⁹/l, p?<?0.001. GGT was reduced from 0.63 to 0.38 μkat/l, p?<?0.001. ALT decreased from 0.69 to 0.59 μkat/l, p?=?0.006. CRP was lowered from 7.3 to 5.4 mg/l p?<?0.001 and ferritin from 106 to 84 μg/l p?<?0.001. The alterations in PCs correlated with the changes in CRP (r?=?0.38, p?=?0.001), BMI (r?=?0.25, p?=?0.012), weight (r?=?0.24, p?=?0.015) and inversely correlated with ferritin (r?=?21, p?=?0.036).

Conclusions

PCs, GGT and ALT (markers for NAFLD), and CRP and ferritin (markers for inflammation) decreased in morbidly obese after RYGBP. The decrease in PCs correlated with alterations in CRP, BMI, weight and ferritin. The lowering of liver enzymes may reflect a lowered liver fat content and decreased general inflammation.

     

Recovery to Usual Activity After Outpatient Anorectal Surgery

World Journal of Surgery - Most elective anorectal procedures are performed in an outpatient setting, and the supposed recovery time is short. The aim of the present study was to assess return to...     

Lactate Kinetics After Intermittent and Continuous Exercise Training

The purpose of this study was to assess, the effects of continuous and intermittent exercise training on lactate kinetic parameters and maximal aerobic speed (MAS) using field tests. Twenty-four male sport students were equally divided into continuous (CT) and intermittent (IT) physically trained groups. Another six participants acted as non-trained controls (CG). The trained participants practiced 6-days per week for 6 weeks. Before and after training, all participants completed an incremental exercise test to assess their MAS, and a 30- second supra-maximal exercise followed by 30 minutes of active recovery to determine the individual blood lactate recovery curve. It was found that exercise training has significantly increased MAS (p < 0.001), the lactate exchange and removal abilities as well as the lactate concentrations at the beginning of the recovery ([La]-(0)); for both CT and IT groups; this was accompanied by a significant reduction of the time to lactate-peak. Nevertheless, the improvement in MAS was significantly higher (p < 0.001) post-intermittent (15.1 % ± 2.4) than post-continuous (10.3 % ± 3.2) training. The lactate-exchange and removal abilities were also significantly higher for IT than for CT-group (P<0.05). Moreover, IT-group showed a significantly shorter half-time of the blood lactate (t-½-[La]) than CT-group (7.2 ± 0.5 min vs 7.7 ± 0.3 min, respectively) (p < 0.05). However, no significant differences were observed in peak blood lactate concentration ([La]_peak), time to reach [La]_peak (t-[La]_peak), and [La]-(0) between the two physically-trained groups. We conclude that both continuous and intermittent training exercises were equally effective in improving t-[La]_peak and [La]_peak, although intermittent training was more beneficial in elevating MAS and in raising the lactate exchange (γ₁) and removal (γ₂) indexes.

Key points

• Coaches and athletes need to be aware of the potentiality positive effects of exercise intensity.
• Improvements in physical fitness are associated with a concomitant increase in the lactate removal ability.
• In order to reduce lactate accumulation and increase maximal aerobic speed maximally, interval training method, with work speeds equal to 90% - 100% of MAS, may be the effective way when compared with continuous training method.

Key words: Biexponential mathematical model, recovery, supra-maximal exercise.     

Effect of Exercise Intensity on Differentiated and Undifferentiated Ratings of Perceived Exertion During Cycle and Treadmill Exercise in Recreationally Active and Trained Women

The purpose of the study is to examine the effect of aerobic exercise intensity on components of the differentiated perceived exertion model in young women performing weight bearing and non-weight bearing aerobic exercise. Subjects were 18-25 yr old women who were recreationally active (n = 19; VO₂max = 33.40 ml·kg^-1·min^-1) and trained (N = 22; VO₂max = 43.3 ml·kg^-1·min^-1). Subjects underwent two graded exercise tests (GXT) on a treadmill and bike which were separated by 48 hours. RPE-Overall, -Legs, and -Chest, as well as oxygen uptake (VO₂) and heart rate were recorded each minute. Individual regression analyses were used to identify RPE-Overall,-Legs, and -Chest at 40, 60, 80% VO_2max/peak. Separate two factor (site (3) x intensity (3)) ANOVAs with repeated measures on site and intensity were computed for each training status. Furthermore, RPE responses were also examined with a one factor (site (3)) within subject ANOVA with repeated measure on site at the ventilatory breakpoint. For both the recreationally active and trained groups no significant differences were observed for RPE-Overall, -Legs, and -Chest during treadmill exercise. However, for cycling exercise results indicated that RPE-Legs was significantly greater at all exercise intensities than RPE-Overall and RPE-Chest for trained subjects while for recreationally active subjects RPE-Legs was only significantly higher at the highest exercise intensity. Responses at the ventilatory breakpoint during cycle exercise indicated that RPE-Legs was significantly greater than RPE-Chest and RPE-Overall for trained subjects but not for recreationally active subjects. Signal dominance was not observed at an intensity equivalent to the ventilatory breakpoint during treadmill exercise in either of the groups. In recreationally active and trained females signal dominance was demonstrated only during cycling exercise, but not during treadmill exercise. Signal integration could not be demonstrated during cycling and treadmill exercise at various intensities.

Key points

• RPE is a valid tool to track relative exercise intensity and can be applied as differentiated and undifferentiated responses regardless of training status.
• RPE-Legs dominated the signal response in trained women during cycling exercise.
• RPE-Legs, -Chest, and -Overall did not differ significantly in trained and recreationally active women during treadmill exercise.
• RPE-Legs and -Chest contribute equally to the formation of RPE-Overall during cycling and treadmill exercise.

Key words: Aerobic exercise, physical exertion, oxygen consumption, physical fitness     

Relationship Between Platelet Activation and Acute Rejection After Renal Transplantation

Objective

To provide an earlier diagnosis and efficiently treat acute rejection episodes (ARE) after renal transplantation, we studied its relationship to platelet activation.

Patients and Methods

The peripheral blood levels of platelet surface glycoprotein (CD61), platelet activation-dependent granule membrane protein (CD62p), lysosomal enzyme glycoprotein (CD63), macula densa granule membrane glycoprotein (CD42a), and fibrinogen receptor monoclonal antibody (PAC-1) among 203 patients with uremia in various stages before and after transplantation were assayed by flow cytometry. The patients with ARE were prospectively and randomly assigned to either a treatment group with an antiplatelet activation agent or a control group.

Results

The incidence of ARE was remarkably increased among patients with greater expression levels of platelet activation markers in peripheral blood preoperatively. The values of platelet activation markers were significantly higher among patients with ARE compared with those showing either normal graft function or acute tubular necrosis. The greater the increase in CD63, the worse the ARE. The expression levels of platelet activation markers decreased remarkably among the group treated with a platelet activation inhibitor in addition to antirejection therapy: the rejection reversal time shortened and the dose of antihuman thymocyte globulin (ATG) was lower. The sensitivity of platelet activation markers was better than its specificity.

Conclusions

Our studies demonstrated an association between platelet activation and ARE after renal transplantation. Platelet activation before transplantation can predict the occurrence of ARE. Platelet activation inhibitor therapy after transplantation improved ARE reversal.     

Platelet Transfusion can be Related to Liver Regeneration After Living Donor Liver Transplantation

Background  

Although liver regeneration is a fundamental aspect of living donor liver transplantation (LDLT), the factors that affect liver regeneration during the early post-transplantation period have not been thoroughly investigated. Recently it was suggested that platelets contribute to liver regeneration. The aim of the present study was to identify the major factors that affect liver graft regeneration during the early post-transplantation period.     

Heart Rate Variability Before and After Cycle Exercise in Relation to Different Body Positions

The purpose of this study was to assess the effect of three different body positions on HRV measures following short-term submaximal exercise. Thirty young healthy males performed submaximal cycling for five minutes on three different occasions. Measures of HRV were obtained from 5-min R to R wave intervals before the exercise (baseline) and during the last five minutes of a 15 min recovery (post-exercise) in three different body positions (seated, supine, supine with elevated legs). Measures of the mean RR normal-to-normal intervals (RRNN), the standard deviation of normal-to-normal intervals (SDNN), the root mean square of successive differences (RMSSD) and the low-frequency (LF) and the high-frequency (HF) spectral power were analyzed. Post-exercise RRNN, RMSSD were significantly higher in the two supine positions (p < 0. 01) compared with seated body position. Post-exercise ln LF was significantly lower in the supine position with elevated legs than in the seated body position (p < 0.05). No significant difference was found among the three different body positions for post-exercise ln HF (p > 0.05). Post-exercise time domain measures of HRV (RRNN, SDNN, RMSSD) were significantly lower compared with baseline values (p < 0.01) regardless body position. Post-exercise ln LF and ln HF in all three positions remained significantly reduced during recovery compared to baseline values (p < 0.01). The present study suggests that 15 minutes following short-term submaximal exercise most of the time and frequency domain HRV measures have not returned to pre-exercise values. Modifications in autonomic cardiac regulation induced by body posture present at rest remained after exercise, but the post-exercise differences among the three positions did not resemble the ones established at rest.

Key points

• Whether different body positions may enhance post-exercise recovery of autonomic regulation remains unclear.
• The absence of restoration of HRV measures after 15 minutes of recovery favor the existence of modifying effects of exercise on mechanisms underlying heart regulation.
• On the basis of discrepancies in HRV measures in different body positions pre- and post-exercise we argue that the pace of recovery of cardiac autonomic regulation is dependent on body posture.

Key words: Heart rate variability, recovery, exercise     

Breast Sensitivity Before and After the L Short-Scar Mammaplasty

Background  

Breast sensitivity preservation is among the aims of modern breast surgery. Large-volume resection, extensive undermining, and resections at the breast base have been associated with breast sensitivity alterations. The L short-scar mammaplasty technique is designed to preserve breast sensitivity by resection of tissue in the middle and inferior portions of the breast, but specifically dissection and preservation of the breast lateral neurovascular pedicle. Using this technique, a prospective study was designed for measurement of breast sensitivity quantitatively and subjectively to determine whether different resection volumes of the breast correlate with alteration of sensitivity postoperatively.     

Effects of Alprazolam Supplementation on Vertebral and Femoral Bone Mass in Rats on Strenuous Treadmill Training Exercise

The ability of alprazolam to diminish cortisol response and favor ovarian function could make it useful in the prevention of osteopenia in athletes in selected cases. A sample of 45 female Wistar rats, all 93 days old and with a mean initial weight of 267 ± 17 g, were studied. Rats were exposed to a high-performance level of exercise and were divided into two groups—one group received an alprazolam supplement and one did not—and compared with controls to determine the effect of alprazolam on bone mass as measured by dual-energy X-ray absorptiometry (DKA). Exercise consisted of treadmill running on 5 out of 7 days during a period of 11 weeks. A steep grade treadmill inclination was used to stimulate high-intensity muscle activity. Final inclination was 17.5° and treadmill speed was 45 cm/second. Upon completion of the experiment, all the rats were killed and the femur and 5th lumbar vertebra were dissected and cleaned. Length, weight, bone mineral content (BMC), and density (BMD) of the whole right femur and 5th lumbar vertebra were measured. In the exercise only group (no alprazolam), the length, weight, BMC, BMD, and femur BMC/final rat weight ratio of the femur, and the vertebral weight, vertebral BMD and BMC, and vertebral BMC/final rat weight ratio were lower than in the control and the exercise-alprazolam groups (P < 0.0167 – < 0.0001). Alprazolam preserves bone mass in rats exposed to intense exercise. Received: 1 June 1998 / Accepted: 15 December 1998     

Platelet Activating Factor and Thromboxane B2 Production After Cardiopulmonary Bypass

Platelet-activating factor (PAF) is believed to have a central role in the pathogenesis of ischemia-reperfision injury. The purpose of this study was to investigate the relationships among production of PAF, thromboxane B₂ (T_αB2), and cardiopulmonary sequelae in patients undergoing coronary artery bypass graft surgery (CABGS). Venous blood from nine patients (eight men, one woman) undergoing scheduled CABGS, was sampled from central venous catheters before anesthetic induction, pre-cardiopulmonary bypass (CPB), 10 and 30 minutes post-CPB, 10 and 30 minutes post-aortic declamping, and 120 minutes and 24 hours after the conclusion of CPB. Plasma levels of PAF and T_αB2 were determined by radioimmunoassay kits (Amersham Canada Ltd.). PAF and T_αB2 were significantly different between high-risk patients (group I; Canadian Cardiovascular Society class 3-4; n = 4) and low-risk patients (group II; Canadian Cardiovascular Society class 2; n = 5): group I PAF = 960 pg/mL, group II PAF = 159 pg/mL (P = 0.0029); group I T_αB2 = 320 pg/mL, group II T_αB2 = 229 pg/mL (P = 0.0262). Group I PAF was significantly greater than group II PAF: before CPB = 825 pg/mL (group I), 138 pg/mL (group II); during initiation of CPB = 1600-2015 pg/mL (group I), 158-200 pg/mL (group II) (P = 0.0143). Correlations between duration of CPB and peak PAF (r = 0.7049, P = 0.0339), peak PAF level, and time to extubation (r = 0.8863, P = 0.0079) were significant. PAF levels were different in patients requiring postoperative epinephrine (2124 ± 700 pg/mL) or dopamine (667 ± 266 pg/mL) (P = 0.0042). The production of PAF is determined by preoperative patient characteristics and duration of CPB. Increased levels of PAF in patients with unstable angina, left main coronary artery disease, or recent myocardial infarction are associated with the need for increased inotropy and prolonged ventilatory support following CABGS. The degree of PAF production during CPB may be a factor in postoperative instability in high-risk patients.