European Working Group on Sarcopenia in Older People (EWGSOP2) Criteria With Population-Based Skeletal Muscle Index Best Predicts Mortality in Asians With Cirrhosis

BACKGROUND/AIMS

Multiple definitions of sarcopenia exist and the acceptable criterion that best predicts outcome is lacking. We estimated the prevalence of sarcopenia based on four criteria and assessed their utility in predicting mortality in cirrhotics.

METHODS

In a prospective observational study, consecutive Asian patients with cirrhosis underwent testing for handgrip strength (HGS) and estimation of skeletal muscle index (SMI) using computed tomography at the third lumbar vertebra. Sarcopenia was defined based on the Western cut-off (WC; SMI < 50 cm²/m² for men and <39 cm²/m² for women), Asian cut-off (AC; SMI < 36.5 cm²/m² for men and 30.2 cm²/m² for women), European Working Group on Sarcopenia in Older People-2nd meeting (EWGSOP2) definition incorporating low HGS (<27 kg for men and <16 kg for women) with low SMI (defined by the WC), and EWGSOP2 definition with low HGS and low SMI (defined by AC). Risk factors for mortality were assessed using multivariate Cox-proportional hazards.

RESULTS

We included 219 patients with cirrhosis (168 men; mean age 42.6 years) with 50.2% patients having decompensation. Alcohol was the commonest aetiology (33.3%). The prevalence of sarcopenia was highest with the WC (men: 82.1%; women: 62.7%). There was a weak concordance among all criteria (Fleiss' kappa 0.23, 95% confidence interval [CI] 0.10-0.37). Overall, 12-month survival was 86.1% (81.1-91.3%) over a median (interquartile range) follow-up of 12 (6-15) months. Ascites (hazards ratio [HR] 6.27 [95% CI 1.6-24.1]; P < 0.007) and SMI (HR 0.92 [0.85-0.98]; P = 0.021) were independent predictors of mortality. The 12-month mortality rate was higher in patients with sarcopenia, irrespective of criteria (log rank P < 0.05). Low HGS and low SMI (defined by AC) was the best for predicting mortality (HR 3.04 [1.43-6.43]; P = 0.004).

CONCLUSION

A weak concordance exists amongst various diagnostic definitions of sarcopenia. Sarcopenia diagnosed by a combination of low HGS and population-specific SMI cut-off (AC) best predicts mortality.

Volatile Biomarkers in Breath Associated With Liver Cirrhosis - Comparisons of Pre- and Post-liver Transplant Breath Samples

Background

The burden of liver disease in the UK has risen dramatically and there is a need for improved diagnostics.

Aims

To determine which breath volatiles are associated with the cirrhotic liver and hence diagnostically useful.

Methods

A two-stage biomarker discovery procedure was used. Alveolar breath samples of 31 patients with cirrhosis and 30 healthy controls were mass spectrometrically analysed and compared (stage 1). 12 of these patients had their breath analysed after liver transplant (stage 2). Five patients were followed longitudinally as in-patients in the post-transplant period.

Results

Seven volatiles were elevated in the breath of patients versus controls. Of these, five showed statistically significant decrease post-transplant: limonene, methanol, 2-pentanone, 2-butanone and carbon disulfide. On an individual basis limonene has the best diagnostic capability (the area under a receiver operating characteristic curve (AUROC) is 0.91), but this is improved by combining methanol, 2-pentanone and limonene (AUROC curve 0.95). Following transplant, limonene shows wash-out characteristics.

Conclusions

Limonene, methanol and 2-pentanone are breath markers for a cirrhotic liver. This study raises the potential to investigate these volatiles as markers for early-stage liver disease. By monitoring the wash-out of limonene following transplant, graft liver function can be non-invasively assessed.

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Breath volatiles were compared for cirrhotic patients and controls and pre- and post-liver transplant.

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Three volatiles (limonene, methanol, 2-pentanone) have been found to have excellent diagnostic capabilities.

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Limonene shows washout characteristics following transplant supporting a hypothesis that it accumulates in fat.

There are numerous previous studies investigating breath volatiles in patients with liver disease but with conflicting results. It is impossible to tell which volatiles from previous studies may be false discoveries, and which are actually associated with the disease. We measured breath samples in patients and controls and in patients after transplant. Methanol, 2-pentanone and limonene show differences not only between patients and controls but also in cases pre- and post-transplant and have excellent diagnostic capabilities. We show evidence that limonene accumulates in the body, probably because the cirrhotic liver fails to metabolise dietary limonene.

Molecular biology of the hepatitis B virus for clinicians

Hepatitis B virus (HBV) infection is one of the major global health problems, especially in economically under-developed or developing countries. HBV infection can lead to a number of clinical outcomes including chronic infection, cirrhosis and liver cancer. It ranks among the top 10 causes of death, being responsible for around 1 million deaths every year. Despite the availability of a highly efficient vaccine and potent antiviral agents, HBV infection still remains a significant clinical problem, particularly in those high endemicity areas where vaccination of large populations has not been possible due to economic reasons. Although HBV is among the smallest viruses in terms of virion and genome size, it has numerous unique features that make it completely distinct from other DNA viruses. It has a partially double stranded DNA with highly complex genome organization, life cycle and natural history. Remarkably distinct from other DNA viruses, it uses an RNA intermediate called pregenomic RNA (pgRNA) and reverse transcriptase for its genome replication. Genome replication is accomplished by a complex mechanism of primer shifting facilitated by direct repeat sequences encoded in the genome. Further, the genome has evolved in such a manner that every single nucleotide of the genome is used for either coding viral proteins or used as regulatory regions or both. Moreover, it utilizes internal in-frame translation initiation codons, as well as different reading frames from the same RNA to generate different proteins with diverse functions. HBV also shows considerable genetic variability which has been related with clinical outcomes, replication potential, therapeutic response etc. This review aims at reviewing fundamental events of the viral life cycle including viral replication, transcription and translation, from the molecular standpoint, as well as, highlights the clinical relevance of genetic variability of HBV.