Clinical Implications, Evaluation, and Management of Hyponatremia in Cirrhosis

Hyponatremia is the most common electrolyte abnormality in patients with decompensated cirrhosis on Liver Transplantation (LT) waiting list. Most of these patients have dilutional or hypervolemic hyponatremia secondary to splanchnic vasodilatation. Excessive secretion of the antidiuretic hormone also plays an important role. Hypervolemic hyponatremia is commonly associated with refractory ascites, spontaneous bacterial peritonitis, and hepatic encephalopathy. Although uncommon, the use of diuretics and laxatives can cause hypovolemic hyponatremia that is characterized by the striking absence of ascites or pedal edema. Clinical features are often nonspecific and depend on the acuity of onset rather than the absolute value of serum sodium. Symptoms may be subtle, including nausea, lethargy, weakness, or anorexia. However, rarely patients may present with confusion, seizures, psychosis, or coma. Treatment includes discontinuation of diuretics, beta-blockers, and albumin infusion. Hypertonic saline (3%) infusion may be used in patients with very low serum sodium (<110 mmol/L) or when patients present with seizures or coma. Short-term use of Vasopressin (V₂) receptor antagonists may also be used to normalize sodium levels prior to LT. However, all these measures may be futile, and LT remains the definite treatment in these patients to improve survival. In this review, we describe the classification, pathogenesis of hyponatremia, and its clinical implications in patients with cirrhosis. Approach to these patients along with management will also be discussed briefly.

Adipose tissue (P)RR regulates insulin sensitivity, fat mass and body weight

OBJECTIVE

We previously demonstrated that the handle-region peptide, a prorenin/renin receptor [(P)RR] blocker, reduces body weight and fat mass and may improve insulin sensitivity in high-fat fed mice. We hypothesized that knocking out the adipose tissue (P)RR gene would prevent weight gain and insulin resistance.

METHODS

An adipose tissue-specific (P)RR knockout (KO) mouse was created by Cre-loxP technology using AP2-Cre recombinase mice. Because the (P)RR gene is located on the X chromosome, hemizygous males were complete KO and had a more pronounced phenotype on a normal diet (ND) diet compared to heterozygous KO females. Therefore, we challenged the female mice with a high-fat diet (HFD) to uncover certain phenotypes. Mice were maintained on either diet for 9 weeks.

RESULTS

KO mice had lower body weights compared to wild-types (WT). Only hemizygous male KO mice presented with lower total fat mass, higher total lean mass as well as smaller adipocytes compared to WT mice. Although food intake was similar between genotypes, locomotor activity during the active period was increased in both male and female KO mice. Interestingly, only male KO mice had increased O2 consumption and CO2 production during the entire 24-hour period, suggesting an increased basal metabolic rate. Although glycemia during a glucose tolerance test was similar, KO males as well as HFD-fed females had lower plasma insulin and C-peptide levels compared to WT mice, suggesting improved insulin sensitivity. Remarkably, all KO animals exhibited higher circulating adiponectin levels, suggesting that this phenotype can occur even in the absence of a significant reduction in adipose tissue weight, as observed in females and, thus, may be a specific effect related to the (P)RR.

CONCLUSIONS

(P)RR may be an important therapeutic target for the treatment of obesity and its associated complications such as type 2 diabetes.

Randomized Controlled Trial Comparing the Efficacy of Terlipressin and Albumin with a Combination of Concurrent Dopamine, Furosemide, and Albumin in Hepatorenal Syndrome

BACKGROUND

Terlipressin with albumin is recommended in hepatorenal syndrome (HRS). Terlipressin is expensive and not licensed in many countries. Alternative therapy is necessary. We compared the efficacy of terlipressin and albumin with concurrent low-dose dopamine, furosemide, and albumin in HRS.

METHODS

In an open-label, randomized trial, forty consecutive patients each with HRS type I and HRS type II received either concurrent infusion of terlipressin 0.5 mg for every 6 hr and albumin 20 g/day for 5 days (n = 20) or a combination of dopamine 2 μg/kg/min, furosemide 0.01 mg/kg/hr, and albumin 20 g/day (triple therapy), in one of two therapeutic arms. Twenty-four-hour urine output, urinary sodium, and plasma renin activity (PRA) were assessed before and after treatment.

RESULTS

The two groups were comparable at baseline in both HRS-I and II. In HRS-I, 24 hr urine output and urine sodium at the end of 5 days increased in both treatment groups (terlipressin, urine output 278 ± 136 to 765 ± 699 ml/day, P < 0.01; urine sodium 28 ± 25.1 to 39 ± 32.1 meq/l, P = 0.05. Triple therapy: urine output 219 ± 134 to 706 ± 595 ml/day, P < 0.01; urine sodium 25 ± 18.3 to 41 ± 27.5 meq/l, P < 0.01). PRA (ng/ml/hr) decreased from 28.1 ± 9.76 to 24.2 ± 9.5 (P = 0.01) and from 29.5 ± 15.8 to 27.3 ± 17.1 (P = 0.02) in the terlipressin and triple therapy groups, respectively. In HRS-II, similar significant improvement (P < 0.01) was seen in 24 hr urine output and urine sodium; decrease in PRA (P < 0.05) was documented after treatment in both the arms. Post-treatment changes in parameters were comparable between the two arms, in both HRS-I and HRS-II cases.

CONCLUSIONS

Concurrent triple therapy improved renal function in HRS and was less expensive than terlipressin (Registration: CTRI/2011/07/001860; www.ctri.nic.in).