Summary Background: Patients with advanced liver disease may develop portal hypertensionthat can result in variceal haemorrhage. Beta-blockers reduce portal pressure andminimise haemorrhage risk. These medications may attenuate measures of car-diopulmonary performance, such as the ventilatory threshold and peak oxygenuptake measured via cardiopulmonary exercise testing. Aim: To determine the effect of beta-blockers on cardiopulmonary exercise testingvariables in patients with advanced liver disease. Methods: This was a cross-sectional analysis of 72 participants who completed acardiopulmonary exercise test before liver transplantation. All participants remainedon their usual beta-blocker dose and timing prior to the test. Variables measuredduring cardiopulmonary exercise testing included the ventilatory threshold, peakoxygen uptake, heart rate, oxygen pulse, the oxygen uptake efficiency slope and theventilatory equivalents for carbon dioxide slope. Results: Participants taking beta-blockers (n = 28) had a lower ventilatory threshold(P <.01) and peak oxygen uptake (P = .02), compared to participants not takingbeta-blockers. After adjusting for age, the model of end-stage liver-disease score,liver-disease aetiology, presence of refractory ascites and ventilatory thresholdremained significantly lower in the beta-blocker group (P = .04). The oxygen uptakeefficiency slope was not impacted by beta-blocker use. Conclusions: Ventilatory threshold is reduced in patients with advanced liver dis-ease taking beta-blockers compared to those not taking the medication. This mayincorrectly risk stratify patients on beta-blockers and has implications for patientmanagement before and after liver transplantation. The oxygen uptake efficiencyslope was not influenced by beta-blockers and may therefore be a better measureof cardiopulmonary performance in this patient population.
BACKGROUND: High-intensity interval training (HIIT) is superior to moderate-intensity continuous training (MICT) at improving cardiometabolic risk. However, the optimal volume of HIIT to reduce the severity of the metabolic syndrome (MetS) has yet to be investigated. The aim of this study was to examine the impact of different volumes of HIIT and MICT on MetS severity (MetS z-score). METHODS: This was a substudy of the "Exercise in prevention of Metabolic Syndrome" (EX-MET) multicenter trial, reporting data collected at the Brisbane site. Ninety-nine adults diagnosed with MetS were randomized to one of the following 16-week interventions: (1) MICT [n = 34, 30 min at 60%-70% heart rate (HR) peak/session, 150 min/week]; (2) 4HIIT (n = 34, 4 × 4 min bouts at 85%-95% HR peak, interspersed with 3 min active recovery at 50%-70% HR peak, 114 min/week); or (3) 1HIIT (n = 31, 1 × 4 min bout at 85%-95% HR peak, 51 min/week). Z-scores were derived from levels of MetS risk factors before and after the intervention. RESULTS: Eighty-one participants completed post-testing (MICT, n = 26; 4HIIT, n = 28, 1HIIT, n = 27). After excluding 16 participants who had a change in medication dosage or type during the intervention, a total of 65 participants were included in the analysis [MICT, n = 22, age 55 ± 10 years, body mass index (BMI) 32 ± 6 kg/m; 4HIIT, n = 22, 56 ± 10 years, 35 ± 9 kg/m2; 1HIIT, n = 21, 57 ± 8 years, 32 ± 5 kg/m). MetS severity reduced following all interventions (pre- to post-MetS z-score: MICT, 1.80 ± 1.93 to 0.90 ± 1.93; 4HIIT, 2.75 ± 2.56 to 2.17 ± 2.71; 1HIIT, 2.48 ± 3.38 to 0.84 ± 2.98), with no significant differences between groups. There were no reported adverse events that were directly related to the exercise interventions. CONCLUSIONS: Low-volume HIIT (51 min/week) was as effective as high-volume HIIT (114 min/week) and MICT (150 min/week) in ameliorating MetS severity.