Background & Aim: Liver function plays a main role in determining aerobic capacity, which is impaired in patients with liver cirrhosis in point of protein-energy malnutrition, poor liver glycogen stores, and reduced hepatic glucose production as well. The aim was to investigate the relationship between respiratory muscle strength and endurance capacity in patients with cirrhosis.

Methods: Fourteen patients who had liver cirrhosis at least five years (7 men, 7 women, 53±11.65 years), and ?pre-frail? according to Liver Frailty Index have been included in the study. Maximal inspiratory pressure (MIP), and maximal expiratory pressure (MEP) were measured. Cardiopulmonary exercise testing (CPET) was applied on the treadmill with Modified Bruce Protocol, and anaerobic and maximum parts of measured CPET?s ventilatory and metabolic parameters were recorded.

Results: MIP significantly correlated with the VO2 max (r= 0.564, p=0.036), VE max (r=0.685, p=0.007), VT max (r= 0.707, p=0.005), O2pulse max (r= 0.650, p=0.012), MEP was correlated O2pulse max (r= 0.622, p=0.018) as well, but not with other CPET parameters at maximal load (p> 0.10 for all). At the anaerobic threshold MIP significantly correlated with VeVO2 (r= 0.557, p=0.038), and MEP was correlated with VeVO2 (r= 0.559, p=0.038).

Conclusion: CPET by measuring maximal oxygen consumption gives a gold standard approach to health status and aerobic capacity in liver cirrhosis. The pilot study?s findings show that respiratory muscle strength had a correlation with endurance capacity. Our findings will help design the exercise training programs for patients with liver cirrhosis.