Internal dysregulation of the renin system in patients with stable liver cirrhosis

Oxidative Mechanisms and Cardiovascular Abnormalities of Cirrhosis and Portal Hypertension

In patients with portal hypertension, there are many complications including cardiovascular abnormalities, hepatorenal syndrome, ascites, variceal bleeding, and hepatic encephalopathy. The underlying mechanisms are not yet completely clarified. It is well known that portal hypertension causes mesenteric congestion which produces reactive oxygen species (ROS). ROS has been associated with intestinal mucosal injury, increased intestinal permeability, enhanced gut bacterial overgrowth, and translocation; all these changes result in increased endotoxin and inflammation. Portal hypertension also results in the development of collateral circulation and reduces liver mass resulting in an overall increase in endotoxin/bacteria bypassing detoxication and immune clearance in the liver. Endotoxemia can in turn aggravate oxidative stress and inflammation, leading to a cycle of gut barrier dysfunction → endotoxemia → organ injury. The phenotype of cardiovascular abnormalities includes hyperdynamic circulation and cirrhotic cardiomyopathy. Oxidative stress is often accompanied by inflammation; thus, blocking oxidative stress can minimize the systemic inflammatory response and alleviate the severity of cardiovascular diseases. The present review aims to elucidate the role of oxidative stress in cirrhosis-associated cardiovascular abnormalities and discusses possible therapeutic effects of antioxidants on cardiovascular complications of cirrhosis including hyperdynamic circulation, cirrhotic cardiomyopathy, and hepatorenal syndrome.

Dysregulated Calcium Handling in Cirrhotic Cardiomyopathy

Cirrhotic cardiomyopathy is a syndrome of blunted cardiac systolic and diastolic function in patients with cirrhosis. However, the mechanisms remain incompletely known. Since contractility and relaxation depend on cardiomyocyte calcium transients, any factors that impact cardiac contractile and relaxation functions act eventually through calcium transients. In addition, calcium transients play an important role in cardiac arrhythmias. The present review summarizes the calcium handling system and its role in cardiac function in cirrhotic cardiomyopathy and its mechanisms. The calcium handling system includes calcium channels on the sarcolemmal plasma membrane of cardiomyocytes, the intracellular calcium-regulatory apparatus, and pertinent proteins in the cytosol. L-type calcium channels, the main calcium channel in the plasma membrane of cardiomyocytes, are decreased in the cirrhotic heart, and the calcium current is decreased during the action potential both at baseline and under stimulation of beta-adrenergic receptors, which reduces the signal to calcium-induced calcium release. The study of sarcomere length fluctuations and calcium transients demonstrated that calcium leakage exists in cirrhotic cardiomyocytes, which decreases the amount of calcium storage in the sarcoplasmic reticulum (SR). The decreased storage of calcium in the SR underlies the reduced calcium released from the SR, which results in decreased cardiac contractility. Based on studies of heart failure with non-cirrhotic cardiomyopathy, it is believed that the calcium leakage is due to the destabilization of interdomain interactions (dispersion) of ryanodine receptors (RyRs). A similar dispersion of RyRs may also play an important role in reduced contractility. Multiple defects in calcium handling thus contribute to the pathogenesis of cirrhotic cardiomyopathy.

Dobutamine reverses the cardio-suppressive effects of terlipressin without improving renal function in cirrhosis and ascites: a randomized controlled trial

Acute kidney injury and hepatorenal syndrome (HRS) are frequent complications in patients with cirrhosis and ascites. First-line treatment is terlipressin, which reverses HRS in ~40% of patients but also lowers cardiac output (CO). We aimed to investigate whether reversing the cardio-suppressive effect of terlipressin with the β-adrenoceptor agonist dobutamine would increase CO and thereby increase the glomerular filtration rate (GFR). We randomized 25 patients with cirrhosis, ascites, and impaired renal function (2:2:1): group A received terlipressin followed by the addition of dobutamine; group B received dobutamine and terlipressin as monotherapies; and group C received placebo. Renal and cardiac functions were assessed during 8 clearance periods of 30 min, and concentrations of vasoactive hormones were measured. Dobutamine as a monotherapy increased CO (1.03 L/min, P < 0.01) but had no significant effects on GFR. Renin (P < 0.05), angiotensin II (P < 0.005), and aldosterone (P < 0.05) increased after dobutamine infusion. Terlipressin as a monotherapy improved GFR (18.9 mL·min^-1·m^-2, P = 0.005) and mean arterial pressure (MAP) (14 mmHg, P = 0.001) but reduced CO (-0.92 L/min, P < 0.005) and renin (P < .005). A combined treatment of dobutamine and terlipressin had a positive effect on CO (1.19 L/min, P < 0.05) and increased renin (P < 0.005), angiotensin II (P < 0.005), and aldosterone (P < 0.05), but it had no significant effects on MAP or GFR. Dobutamine reversed the cardio-suppressive effect of terlipressin in cirrhosis, ascites, and impaired renal function. However, dobutamine reduced peripheral vascular resistance, activated renin-angiotensin-aldosterone system, and did not improve GFR compared with terlipressin as a monotherapy. Therefore, dobutamine cannot be recommended in cirrhosis and ascites.NEW & NOTEWORTHY This study shows that the cardio-suppressive effects of the vasopressin receptor agonist terlipressin can be reversed by dobutamine. This is a novel observation in patients with decompensated cirrhosis. Furthermore, we show that dobutamine reduced the peripheral vascular resistance and activated the renin-angiotensin system, whereas renal function was not further improved by terlipressin alone.

Eating Patterns in Patients with Compensated Cirrhosis: A Case-Control Study

Background: There is growing evidence suggesting that maintaining an adequate nutritional status for patients with liver cirrhosis (LC) is relevant to prevent complications. The present study aimed to describe dietary behaviours of patients with compensated and non-complicated LC and comparing them with those of subjects from the general population. Methods: In this case-control study, patients were volunteers enrolled in the ALICIR (ALImentation et CIRrhose) study, an observational survey nested in two French prospective cohorts of patients with biopsy-proven compensated cirrhosis related either to excessive alcohol consumption (CIRRAL) or to hepatitis B or C virus infection (CirVir). Controls were selected from the NutriNet-Santé cohort. Dietary data were collected through a semi quantitative food frequency questionnaire. Dietary and nutritional data were compared using multi-adjusted paired Student’s tests. Results: Between June 2014 and February 2016, 174 patients of CirVir (N = 97) or CIRRAL (N = 77) were matched with 348 controls from the NutriNet-Santé cohort, according to gender, age, BMI and educational level. Compared to controls, patients (mean ± SD) consumed more sodas (236.0 ± 29.8 mL vs. 83.0 ± 33.0 mL) and water (1787.6 ± 80.6 mL vs. 933.6 ± 85.3 mL), and lower amounts of salty snacks (4.2 ± 1.42 g vs. 9.0 ± 1.6 g) and alcoholic beverages (71.8 ± 23.4 g vs. 151.2 ± 25.9 g), with all p values < 0.0001. Dietary behaviours differed according to LC aetiology. Conclusions: Dietary behaviour of patients significantly differed from subjects from the general population.