Exercise performance and ventilatory efficiency in patients with mild and moderate liver cirrhosis

The Acute Effect of Hyperoxia on Onset of Blood Lactate Accumulation (OBLA) and Performance in Female Runners during the Maximal Treadmill Test

The objective of this study was to analyze the acute effect of hyperoxia during the maximal treadmill test (MTT) of runners. Participants included 10 female street runners who performed the MTT under two different conditions: hyperoxia (HYPX), inhaling oxygen (60% O₂) every 3 min; and normoxia (NORM), without additional oxygen inhalation. Both groups performed the MTT with increases in the slope of the run every 3 min until voluntary exhaustion. The variables of lactate concentration, the onset of blood lactate accumulation (OBLA), peripheral oxygen saturation (SpO₂), heart rate (HR), and Borg scale were evaluated. It was verified after the comparison (HYPX vs. NORM) that stage 3 (p = 0.012, Cohen’s d = 1.76) and stage 4 (p < 0.001; Cohen’s d = 5.69) showed a reduction in lactate under the HYPX condition. OBLA under the HYPX condition was identified at a later stage than NORM. There were no differences in Borg scale, SpO₂, and HR between the different conditions. It was concluded that the HYPX condition contributed to a reduction in lactate concentration and delayed OBLA in runners.

Sarcopenic Obesity in Liver Cirrhosis: Possible Mechanism and Clinical Impact

The picture of chronic liver diseases (CLDs) has changed considerably in recent years. One of them is the increase of non-alcoholic fatty liver disease. More and more CLD patients, even those with liver cirrhosis (LC), tend to be presenting with obesity these days. The annual rate of muscle loss increases with worsening liver reserve, and thus LC patients are more likely to complicate with sarcopenia. LC is also characterized by protein-energy malnutrition (PEM). Since the PEM in LC can be invariable, the patients probably present with sarcopenic obesity (Sa-O), which involves both sarcopenia and obesity. Currently, there is no mention of Sa-O in the guidelines; however, the rapidly increasing prevalence and poorer clinical consequences of Sa-O are recognized as an important public health problem, and the diagnostic value of Sa-O is expected to increase in the future. Sa-O involves a complex interplay of physiological mechanisms, including increased inflammatory cytokines, oxidative stress, insulin resistance, hormonal disorders, and decline of physical activity. The pathogenesis of Sa-O in LC is diverse, with a lot of perturbations in the muscle-liver-adipose tissue axis. Here, we overview the current knowledge of Sa-O, especially focusing on LC.

Exercise and physical activity in cirrhosis: opportunities or perils

Reduced exercise capacity and impaired physical performance are observed in nearly all patients with liver cirrhosis. Physical activity and exercise are physiological anabolic stimuli that can reverse dysregulated protein homeostasis or proteostasis and potentially increase muscle mass and contractile function in healthy subjects. Cirrhosis is a state of anabolic resistance, and unlike the beneficial responses to exercise reported in physiological states, there are few systematic studies evaluating the response to exercise in cirrhosis. Hyperammonemia is a mediator of the liver-muscle axis with net skeletal muscle ammonia uptake in cirrhosis causing signaling perturbations, mitochondrial dysfunction with decreased ATP content, modifications of contractile proteins, and impaired ribosomal function, all of which contribute to anabolic resistance in cirrhosis and have the potential to impair the beneficial responses to exercise. English language-publications in peer-reviewed journals that specifically evaluated the impact of exercise in cirrhosis were reviewed. Most studies evaluated responses to endurance exercise, and readouts included peak or maximum oxygen utilization, grip strength, and functional capacity. Endurance exercise for up to 12 wk is clinically tolerated in well-compensated cirrhosis. Data on the safety of resistance exercise are conflicting. Nutritional supplements enhance the benefits of exercise in healthy subjects but have not been evaluated in cirrhosis. Whether the beneficial physiological responses with endurance exercise and increase in muscle mass with resistance exercise that occur in healthy subjects also occur in cirrhotics is not known. Specific organ-system responses, changes in body composition, or improved long-term clinical outcomes with exercise in cirrhosis need evaluation.

Preoperative optimization for major hepatic resection

PURPOSE

Major hepatic resections are performed for primary hepatobiliary malignancies, metastatic disease, and benign lesions. Patients with chronic liver disease, including cirrhosis and steatosis, are at an elevated risk of malnutrition and impaired strength and exercise capacity, deficits which cause increased risk of postoperative complications and mortality. The aims of this report are to discuss the pathophysiology of changes in nutrition, exercise capacity, and muscle strength in patient populations likely to require major hepatectomy, and review recommendations for preoperative evaluation and optimization.

METHODS

Nutritional and functional impairment in preoperative hepatectomy patients, especially those with underlying liver disease, have a complex and multifactorial physiologic basis that is not completely understood.

RESULTS

Recognition of malnutrition and compromised strength and exercise tolerance preoperatively can be difficult, but is critical in providing the opportunity to intervene prior to major hepatic resection and potentially improve postoperative outcomes. There is promising data on a variety of nutritional strategies to ensure adequate intake of calories, proteins, vitamins, and minerals in patients with cirrhosis and reduce liver size and degree of fatty infiltration in patients with hepatic steatosis. Emerging evidence supports structured exercise programs to improve exercise tolerance and counteract muscle wasting.

CONCLUSIONS

The importance of nutrition and functional status in patients indicated for major liver resection is apparent, and emerging evidence supports structured preoperative preparation programs involving nutritional intervention and exercise training. Further research is needed in this field to develop optimal protocols to evaluate and treat this heterogeneous cohort of patients.

Pre-Transplant Aerobic Capacity and Prolonged Hospitalization After Liver Transplantation

Introduction

Patients with end stage liver disease (ESLD) referred for liver transplantation (LT) are forwarded to pulmonary evaluation before being operated. ESLD is associated with muscle wasting, reduced exercise tolerance and aerobic capacity.

Objectives

We assessed the association between aerobic capacity (AC), liver disease severity and postoperative LT outcomes in a series of LT candidates in a university affiliated hospital in Brazil.

Methods

Pre-LT oxygen uptake at peak (pre-VO_2peak), liver disease severity, and early pos-LT outcomes such as length of intensive care unit (ICU) stay, <5 and ≥5 days and hospitalization, <20 and ≥20 days and postoperative mortality were compared. Pre-VO_2peak was measured through the cardiopulmonary exercise testing (CPET). Severity of liver disease was estimated by the Model for End-Stage Liver Disease (MELD) categorization into MELD < 18 and MELD ≥ 18 groups. Student's t-test was used to compare these groups. A logistic regression model was built to verify the effect of those variables on the length of ICU stay, length of hospitalization and postoperative mortality.

Results

A total of 47 patients were include in analysis. Pre-VO_2peak was similar to that of healthy sedentary individuals (75 ± 18%) and worse in the MELD ≥ 18 group as compared to the MELD < 18 group (19.51 ± 7.87 vs 25.21 ± 8.76 mL/kg/min, respectively; p = 0.048). According to the multivariate analysis, only a lower pre-VO_2peak (<20.09 ± 4.83 mL/kg/min) was associated to a greater length of hospitalization (p = 0.01).

Conclusions

In LT candidates, a reduced pre-VO_2peak may predict a higher risk of greater pos-LT length of hospitalization. The length of ICU stay and postoperative mortality were not associated with variables studied. This finding should be evaluated in other studies before making specific recommendations about a routine use of CPET in LT candidates.

Nutrition and exercise in the management of liver cirrhosis

Liver cirrhosis (LC) patients often have protein-energy malnutrition (PEM) and decreased physical activity. These conditions often lead to sarcopenia, which is the loss of skeletal muscle volume and increased muscle weakness. Recent studies have demonstrated that PEM and sarcopenia are predictors for poor survival in LC patients. Nutrition and exercise management can improve PEM and sarcopenia in those patients. Nutrition management includes sufficient dietary intake and improved nutrient metabolism. With the current high prevalence of obesity, the number of obese LC patients has increased, and restriction of excessive caloric intake without the exacerbation of impaired nutrient metabolism is required for such patients. Branched chain amino acids are good candidates for supplemental nutrients for both obese and non-obese LC patients. Exercise management can increase skeletal muscle volume and strength and improve insulin resistance; however, nutritional status and LC complications should be assessed before an exercise management regimen is implemented in LC patients. The establishment of optimal exercise regimens for LC patients is currently required. In this review, we describe nutritional status and its clinical impact on the outcomes of LC patients and discuss general nutrition and exercise management in LC patients.