Muscle strength, Na,K-pumps, magnesium and potassium in patients with alcoholic liver cirrhosis -- relation to spironolactone

Renin angiotensin system-induced muscle wasting: putative mechanisms and implications for clinicians

Renin angiotensin system (RAS) alters various mechanisms related to muscle wasting. The RAS system consists of classical and non-classical pathways, which mostly function differently. Classical RAS pathway, operates through angiotensin II (AngII) and angiotensin type 1 receptors, is associated with muscle wasting and sarcopenia. On the other hand, the non-classical RAS pathway, which operates through angiotensin 1-7 and Mas receptor, is protective against sarcopenia. The classical RAS pathway might induce muscle wasting by variety of mechanisms. AngII reduces body weight, via reduction in food intake, possibly by decreasing hypothalamic expression of orexin and neuropeptide Y, insulin like growth factor-1 (IGF-1) and mammalian target of rapamycin (mTOR), signaling, AngII increases skeletal muscle proteolysis by forkhead box transcription factors (FOXO), caspase activation and muscle RING-finger protein-1 transcription. Furthermore, AngII infusion in skeletal muscle reduces phospho-Bad (Ser136) expression and induces apoptosis through increased cytochrome c release and DNA fragmentation. Additionally, Renin angiotensin system activation through AT1R and AngII stimulates tumor necrosis factor-α, and interleukin-6 which induces muscle wasting, Last but not least classical RAS pathway, induce oxidative stress, disturb mitochondrial energy metabolism, and muscle satellite cells which all lead to muscle wasting and decrease muscle regeneration. On the contrary, the non-classical RAS pathway functions oppositely to mitigate these mechanisms and protects against muscle wasting. In this review, we summarize the mechanisms of RAS-induced muscle wasting and putative implications for clinical practice. We also emphasize the areas of uncertainties and suggest potential research areas.

Severity of Hepatocyte Damage and Prognosis in Cirrhotic Patients Correlate with Hepatocyte Magnesium Depletion

We aimed to evaluate the magnesium content in human cirrhotic liver and its correlation with serum AST levels, expression of hepatocellular injury, and MELDNa prognostic score. In liver biopsies obtained at liver transplantation, we measured the magnesium content in liver tissue in 27 cirrhotic patients (CIRs) and 16 deceased donors with healthy liver (CTRLs) by atomic absorption spectrometry and within hepatocytes of 15 CIRs using synchrotron-based X-ray fluorescence microscopy. In 31 CIRs and 10 CTRLs, we evaluated the immunohistochemical expression in hepatocytes of the transient receptor potential melastatin 7 (TRPM7), a magnesium influx chanzyme also involved in inflammation. CIRs showed a lower hepatic magnesium content (117.2 (IQR 110.5-132.9) vs. 162.8 (IQR 155.9-169.8) μg/g; p < 0.001) and a higher percentage of TRPM7 positive hepatocytes (53.0 (IQR 36.8-62.0) vs. 20.7 (10.7-32.8)%; p < 0.001) than CTRLs. In CIRs, MELDNa and serum AST at transplant correlated: (a) inversely with the magnesium content both in liver tissue and hepatocytes; and (b) directly with the percentage of hepatocytes stained intensely for TRPM7. The latter also directly correlated with the worsening of MELDNa at transplant compared to waitlisting. Magnesium depletion and overexpression of its influx chanzyme TRPM7 in hepatocytes are associated with severity of hepatocyte injury and prognosis in cirrhosis. These data represent the pathophysiological basis for a possible beneficial effect of magnesium supplementation in cirrhotic patients.

Drinking and laboratory biomarkers, and nutritional status characterize the clinical presentation of early-stage alcohol-associated liver disease

Chronic and heavy alcohol consumption is commonly observed in alcohol use disorder (AUD). AUD often leads to alcohol-associated organ injury, including alcohol-associated liver disease (ALD). Approximately 10-20% of patients with AUD progress to ALD. Progression of ALD from the development phase to more advanced states involve the interplay of several pathways, including nutritional alterations. Multiple pathologic processes have been identified in the progression and severity of ALD. However, there are major gaps in the characterization and understanding of the clinical presentation of early-stage ALD as assessed by clinical markers and laboratory measures. Several Institutions and Universities, including the University of Louisville, in collaboration with the National Institutes of Health, have published a series of manuscripts describing early-stage ALD over the past decade. Here, we comprehensively describe early-stage ALD using the liver injury and drinking history markers, and the laboratory biomarkers (with a focus on nutrition status) that are uniquely involved in the development and progression of early-stage ALD.

Sarcopenia and Frailty in Cirrhosis

Sarcopenia and frailty are frequent in cirrhosis, and both contribute to increased morbidity and mortality. The complex pathogenesis of sarcopenia in cirrhosis is mainly determined by hyperammonemia and malnutrition. Sarcopenia/frailty screening and reevaluation should be undertaken in all cirrhotic patients. Frailty tests are useful in the ambulatory setting, whereas the computed tomography scan is the diagnostic gold standard for sarcopenia. To manage sarcopenia/frailty, a multidisciplinary team should develop a personalized comprehensive care plan that includes patient education, protein/calorie intake goals, late evening meals, exercise programs, and micronutrient replenishment. In selected patients, branched-chain amino acid and testosterone supplements may also be beneficial.

Association of Hypomagnesemia and Liver Injury, Role of Gut-Barrier Dysfunction and Inflammation: Efficacy of Abstinence, and 2-Week Medical Management in Alcohol Use Disorder Patients

(1) We investigated the involvement of serum magnesium level in early alcoholic liver disease (ALD), gut barrier dysfunction, and inflammation in alcohol use disorder (AUD) patients; and lastly, the efficacy of 2-week abstinence and medical management to alleviate hypomagnesemia. (2) Forty-eight heavy drinking AUD patients (34 males (M)/14 females (F)) participated in this study. Patients were grouped by serum alanine aminotransferase (ALT) level (a marker of liver injury) as group 1 (Group 1 (Gr.1); ALT ≤ 40 U/L, 7M/8F, without any indication of early-stage ALD) and group 2 (Group 2 (Gr.2); ALT > 40 U/L, 27M/6F or early-stage ALD). These patients were sub-divided within each group into patients with normal magnesium (0.85 and more mmol/L) and deficient magnesium (less than 0.85 mmol/L) levels. All participants were assessed at baseline (BL) and received standard medical management for 2 weeks with reassessment at the treatment end (2w). (3) Female participants of this study showed a significantly lower baseline level of magnesium than their male counterparts. Gr.2 patients showed a greater propensity in the necrotic type of liver cell death, who reported higher chronic and recent heavy drinking. Magnesium level improved to the normal range in Gr.2 post-treatment, especially in the hypomagnesemia sub-group (0.77 ± 0.06 mmol/L (BL) vs. 0.85 ± 0.05 mmol/L (2w), p = 0.02). In Gr.2, both apoptotic (K18M30) and necrotic (K18M65) responses were significantly and independently associated with inflammasome activity comprising of LBP (Lipopolysaccharide binding-protein) and TNFα (Tumor necrosis factor -α), along with serum magnesium. (4) In AUD patients with liver injury, 2-week medical management seems to improve magnesium to a normal level. This group exhibited inflammatory activity (LBP and TNFα) contributing to clinically significant hypomagnesemia. In this group, the level of magnesium, along with the unique inflammatory activity, seems to significantly predict apoptotic and necrotic types of hepatocyte death.

Elevated Myoglobin in Patients With Primary Aldosteronism: A Cross-Sectional Study

OBJECTIVES

Primary aldosteronism (PA) is characterized by the autonomous excessive production of aldosterone in the adrenal cortex. Aldosterone is associated with damages to heart muscle and skeletal muscle. The purpose of this study was to evaluate serum levels of muscle injury markers and their associated factors in patients with primary aldosteronism.

METHODS

We retrospectively enrolled subjects with PA and essential hypertension (EH) who had completed testing for serum high sensitivity troponin T (hs-TnT), creatine kinase isoenzyme MB (CK-MB) and myoglobin from the database of the Chongqing Primary Aldosteronism Study (CONPASS). Univariate and multivariate linear regression analyses were performed to analyze the influencing factors of myocardial injury markers.

RESULTS

In total, 278 patients with PA and 445 patients with EH were enrolled in this study. Compared with EH patients, serum concentrations of hs-TnT [7.0 (4.0-12.0) vs. 6.0 (3.0-11.0) ng/L; p=0.005] and myoglobin [24.2 (21.0-38.1) vs. 21.8 (21.0-31.9) μg/L; p=0.023] were significantly higher among PA patients, while no significant difference of CK-MB was found between two groups [1.4 (1.0-2.0) vs. 1.3 (0.9-1.9) μg/L; p=0.154]. Univariate linear regression analysis showed that myoglobin was negatively correlated with serum potassium (β=-0.31; p<0.01) and positively correlated with plasma aldosterone concentration (β=0.40; p<0.01) in the PA group, while no significant correlation was found between hs-TnT and biochemical parameters. After adjusting for multiple confounders, myoglobin was negatively correlated with serum potassium (β=-0.15; p<0.05) and positively correlated with plasma aldosterone concentration (β=0.34; p<0.01) in the PA group.

CONCLUSIONS

The serum level of myoglobin was significantly increased in PA patients, and myoglobin was independently correlated with plasma aldosterone concentration.

Aldosterone Inhibits In Vitro Myogenesis by Increasing Intracellular Oxidative Stress via Mineralocorticoid Receptor

BACKGROUND

Despite clinical evidence indicating poor muscle health in subjects with primary aldosteronism (PA), it is still unclear whether the role of aldosterone in muscle metabolism is direct or mediated indirectly via factors, such as electrolyte imbalance or impaired glucose uptake. As one approach to clarify this issue, we investigated the effect of aldosterone on in vitro myogenesis and the potential mechanism explaining it.

METHODS

Myogenesis was induced in mouse C2C12 myoblasts with 2% horse serum. Immunofluorescence, quantitative reversetranscription polymerase chain reaction, Western blot, viability, and migration analyses were performed for experimental research.

RESULTS

Recombinant aldosterone treatment suppressed muscle differentiation from mouse C2C12 myoblasts in a dose-dependent manner, and consistently reduced the expression of myogenic differentiation markers. Furthermore, aldosterone significantly increased intracellular reactive oxygen species (ROS) levels in myotubes, and treatment with N-acetyl cysteine, a potent biological thiol antioxidant, reversed the decrease of myotube area, myotube area per myotube, nucleus number per myotube, and fusion index due to aldosterone through decreasing oxidative stress. A binding enzyme-linked immunosorbent assay confirmed that mineralocorticoid receptor (MR) interacted with aldosterone in C2C12 myoblasts, while eplerenone, an MR inhibitor, blocked aldosterone-stimulated intracellular ROS generation during myogenesis and markedly attenuated the suppression of in vitro myogenesis by aldosterone.

CONCLUSION

These findings support the hypothesis that hypersecretion of aldosterone, like PA, directly contributes to muscular deterioration and suggest that antioxidants and/or MR antagonists could be effective therapeutic options to reduce the risk of sarcopenia in these patients.

Magnesium deficiency in liver cirrhosis: a retrospective study

BACKGROUND

Magnesium, known as "the forgotten electrolyte", is an essential element of life. Magnesium deficiency is implicated in many diseases, including liver cirrhosis. This study aimed to explore the prevalence of magnesium deficiency in liver cirrhosis and investigate the relationship between magnesium levels and complication of liver cirrhosis and clinical outcomes.

PATIENTS AND METHODS

Cirrhotic patients with serum magnesium levels measured were retrospectively identified from 2016 to 2017. Demographics, laboratory parameters, complications were collected. The Child-Pugh class, MELD score, and ALBI score were calculated.

RESULTS

The mean serum magnesium level of all 152 patients was lower than the normal, including 92 patients diagnosed with magnesium deficiency. Compared to Child-Pugh class A, magnesium levels were significantly lower in the patients with Child-Pugh class B or C (F = 10.26, p < .05). Magnesium levels were also considerably lower in the group with MELD score ≥21, compared to the other two groups with MELD score < 15 or 15-20 (F = 6.59, p < .05). Similarly, magnesium levels were significantly lower in the group with ALBI score > -1.39 (grade 3), compared to the other two groups with ALBI with score ≤ -2.6 (grade 1) or > -2.6, ≤ -1.39 (grade 2) (F = 8.44, p<.001). Furthermore, magnesium levels were lower in cirrhotic patients with infection. Magnesium-deficient patients had lower transplant-free survival rates than non-deficient patients.

CONCLUSION

Magnesium deficiency is highly prevalent in cirrhotic patients. Magnesium deficiency is related to worse transplant-free survival, infection and the severity of liver cirrhosis.

Lower Serum Magnesium Concentrations are associated With Specific Heavy Drinking Markers, Pro-Inflammatory Response and Early-Stage Alcohol-associated Liver Injury§

AIM

Chronic heavy alcohol intake frequently causes liver inflammation/injury, and altered mineral metabolism may be involved in this liver pathology. In this study, we evaluated the association of heavy drinking, changes in serum magnesium levels and biochemical evidence of liver injury in alcohol-use-disorder (AUD) patients who had no clinical signs or symptoms of liver injury. We also aimed to identify any sex-based differences in patients with mild or no biochemical evidence of liver injury induced by heavy drinking.

METHODS

114 heavy drinking alcohol-dependent (AD) female and male patients aged 21-65 years without clinical manifestations of liver injury, who were admitted to an alcohol treatment program, were grouped by alanine aminotransaminase (ALT) levels: ≤ 40 IU/L, as no liver injury (GR.1), and ALT>40 IU/L as mild liver injury (GR.2). Patients were actively drinking until the day of admission. Comprehensive metabolic biochemistry results, fatty acid panel, serum magnesium and drinking history data were collected at admission; and study-specific measures were evaluated.

RESULTS

In all AD patients, lower magnesium was significantly associated with the heavy drinking marker and heavy drinking days past 90 days (HDD90). A lower serum magnesium concentration was observed in AD patients with mild liver injury. Females of both groups had mean levels of magnesium in the deficient range. A clinically significant drop in magnesium levels was observed only in the GR.2 (mild liver injury) male AD patients. Females showed a significant association between low magnesium levels and the ω6:ω3 polyunsaturated fatty acids (PUFAs) ratio.

CONCLUSIONS

Specific heavy drinking markers showed an association with lower magnesium levels. Low serum magnesium levels are common in subjects with AUD and appear to be associated with the onset of liver injury.

Magnesium, Calcium, Potassium, Sodium, Phosphorus, Selenium, Zinc, and Chromium Levels in Alcohol Use Disorder: A Review

Macronutrients and trace elements are important components of living tissues that have different metabolic properties and functions. Trace elements participate in the regulation of immunity through humoral and cellular mechanisms, nerve conduction, muscle spasms, membrane potential regulation as well as mitochondrial activity and enzymatic reactions. Excessive alcohol consumption disrupts the concentrations of crucial trace elements, also increasing the risk of enhanced oxidative stress and alcohol-related liver diseases. In this review, we present the status of selected macroelements and trace elements in the serum and plasma of people chronically consuming alcohol. Such knowledge helps to understand the mechanisms of chronic alcohol-use disorder and to progress and prevent withdrawal effects, also improving treatment strategies.

Resistance Training Increases Muscle Strength and Muscle Size in Patients With Liver Cirrhosis

BACKGROUND & AIMS

Cirrhosis is often complicated by reduced muscle mass and strength, which limits the ability to perform daily activities and affects quality of life. Resistance training can increase muscle strength and mass in elderly and chronically ill patients. We performed a randomized controlled trial to investigate whether resistance training increases muscle strength and size in patients with compensated cirrhosis.

METHODS

We performed a prospective study of 39 patients with cirrhosis (Child-Pugh class A or B) seen at an outpatient clinic in Denmark from January 2015 through March 2017. Participants protein intake and activity levels were registered daily. Participants were randomly assigned (1:1) to a group that performed 36 1-hour sessions of physical exercise (supervised progressive resistance training for 1 hour, 3 times weekly for 12 weeks) or a control group (no change in daily activity level). Maximal muscle strength was measured as the peak torque in isokinetic knee extension and muscle size was measured as the cross-sectional area of the quadriceps muscle, assessed by magnetic resonance imaging of the thigh.

RESULTS

The exercise group increased their muscle strength by 13% (from a mean 119 Nm to 134 Nm)-an 11 Nm greater gain in mean strength than that of the control group (P = .05). The exercise group increased their quadriceps cross-sectional area by 10% (from a mean 58.5 cm² to 64.6 cm²)-a 4.4 cm² greater gain than that of the control group (P < .01). The exercise group had significant increases in whole-body lean mass and body cell mass, and significant increases in 6-minute walking distance and the mental component summary of the short form-36 questionnaire. Adverse events were minor and equal between groups.

CONCLUSIONS

In a randomized trial of patients with compensated cirrhosis, we found that 12 weeks of supervised progressive resistance training increased muscle strength and size and had beneficial effects on general performance measures, compared with patients who did not change their daily activity routine (control subjects). ClinicalTrials.gov no: NCT02343653.

Emerging Noninvasive Biomarkers, and Medical Management Strategies for Alcoholic Hepatitis: Present Understanding and Scope

Alcohol use disorder is associated with a wide array of hepatic pathologies ranging from steatosis to alcoholic-related cirrhosis (AC), alcoholic hepatitis (AH), or hepatocellular carcinoma (HCC). Biomarkers are categorized into two main categories: biomarkers associated with alcohol consumption and biomarkers of alcoholic liver disease (ALD). No ideal biomarker has been identified to quantify the degree of hepatocyte death or severity of AH, even though numerous biomarkers have been associated with AH. This review provides information of some of the novel and latest biomarkers that are being investigated and have shown a substantial association with the degree and severity of liver injury and inflammation. Importantly, they can be measured noninvasively. In this manuscript, we consolidate the present understanding and prospects of these biomarkers; and their application in assessing the severity and progression of the alcoholic liver disease (ALD). We also review current and upcoming management options for AH.

The Differential Effect of Excess Aldosterone on Skeletal Muscle Mass by Sex

The effects of excess aldosterone on skeletal muscle in individuals with primary aldosteronism (PA) are unknown. To examine the effects of aldosterone on skeletal muscle mass in patients with PA, by sex, 309 consecutive patients were enrolled. Skeletal muscle and fat mass of 62 patients with PA were compared with those of 247 controls with non-functioning adrenal incidentaloma (NFAI). Body composition parameters were measured using bioelectrical impedance analysis, and plasma aldosterone concentration (PAC) was measured using radioimmunoassay. The PAC in all women, but not in men, showed an inverse association with both appendicular skeletal muscle mass (ASM) (β = -0.197, P = 0.016) and height-adjusted ASM (HA-ASM) (β = -0.207, P = 0.009). HA-ASM in women (but not in men) with PA was 5.0% lower than that in women with NFAI (P = 0.036). Furthermore, women with PA had a lower HA-ASM than 1:1 age- and sex-matched controls with NFAI by 5.7% (P = 0.049) and tended to have a lower HA-ASM than 1:3 age-, sex-, and menopausal status-matched controls without adrenal incidentaloma (AI) by 7.3% (P = 0.053). The odds ratio (OR), per quartile increase in PAC, of low HA-ASM in women was 1.18 [95% confidence interval (CI), 1.01-1.39; P = 0.035]. The odds of HA-ASM in subjects with PA were 10.63-fold (95% CI: 0.83-135.50) higher, with marginal significance (P = 0.069) than in those with NFAI. Skeletal muscle mass in women with PA was lower than that in women with NFAI; suggesting that excess aldosterone has adverse effects on skeletal muscle metabolism.

Ionized magnesium in plasma and erythrocytes for the assessment of low magnesium status in alcohol dependent patients

BACKGROUND

Studies on the homeostasis of magnesium in alcohol-dependent patients have often been characterized by low hypomagnesemia detection rates. This may be due to the fact that the content of magnesium in blood serum constitutes only 1% of the average magnesium level within the human body. However, the concentration of ionized magnesium is more physiologically important and makes up 67% of the total magnesium within a human organism. There are no data concerning the determination of the ionized fraction of magnesium in patients addicted to alcohol and its influence on mental health status.

METHODS

This study included 100 alcohol-dependent patients and 50 healthy subjects. The free magnesium fraction was determined using the potentiometric method by means of using ion-selective electrodes. The total magnesium level was determined by using a biochemical Indiko Plus analyzer. In this study, different psychometric scales were applied.

RESULTS

Our results confirm the usefulness of ionized magnesium concentrations in erythrocytes and plasma as a diagnostic parameter of low magnesium status in alcohol-dependent patients.

CONCLUSIONS

The lower the concentration of ionized magnesium, the worse the quality of life an alcohol-dependent person might experience. In the case of total magnesium, no such correlation was determined.

Hyponatremia effect in patients with alcohol dependence on their physical and mental health status

Hyponatremia, i.e. reduction of sodium level in the blood plasma below 135 mmol/L, is one of the most common electrolyte disorders occurring in people addicted to alcohol. Numerous psychopathological symptoms may be significantly associated with its occurrence. Since sodium is one of the main bioelements, which is responsible for proper neuromuscular excitability maintenance and contributes in nerve impulses conduction, sodium balance disorders may be related to a risk to basic life functions. The tested group included 100 alcohol dependent patients (M = 90, F = 10). Sodium was determined using biochemical Indiko Plus analyzer. Analysis of sodium concentration demonstrated that 64% of people with alcohol dependence had low (<135 mmol/L) plasma sodium level, of which: 7% had severe hyponatremia (<120 mmol/L), 13% had moderate hyponatremia (120-130 mmol/L) and 44% had mild hyponatremia (130-135 mmol/L). The analysis showed an occurrence of significant differences in terms of: impulsivity, quality of life, clinical symptoms occurrence, maximum amount of alcohol consumed and general health state. The lower concentration of sodium in blood plasma in alcohol dependent people, the worse psychical and psychological quality of their life.

Effects of Age on Na(+),K(+)-ATPase Expression in Human and Rodent Skeletal Muscle

The maintenance of transmembrane Na(+) and K(+) concentration gradients and membrane potential is vital for the production of force in skeletal muscle. In aging an inability to maintain ion regulation and membrane potential would have adverse consequences on the capacity for performing repeated muscle contractions, which are critical for everyday activities and functional independence. This short review focusses on the effects of aging on one major and vital component affecting muscle Na(+) and K(+) concentrations, membrane potential and excitability in skeletal muscle, the Na(+),K(+)-ATPase (Na(+),K(+)-pump, NKA) protein. The review examines the effects of age on NKA in both human and rodent models and highlights a distant lack of research in NKA with aging. In rodents, the muscle NKA measured by [(3)H]ouabain binding site content, declines with advanced age from peak values in early life. In human skeletal muscle, however, there appears to be no age effect on [(3)H]ouabain binding site content in physically active older adults between 55 and 76 years compared to those aged between 18 and 30 years of age. Analysis of the NKA isoforms reveal differential changes with age in fiber-types in both rat and humans. The data show considerable disparities, suggesting different regulation of NKA isoforms between rodents and humans. Finally we review the importance of physical activity on NKA content in older humans. Findings suggest that physical activity levels of an individual may have a greater effect on regulating the NKA content in skeletal muscle rather than aging per se, at least up until 80 years of age.

Gender-specific association between urinary sodium excretion and body composition: Analysis of the 2008-2010 Korean National Health and Nutrition Examination Surveys

OBJECTIVE

Few studies have reported the relationship between sarcopenia and the estimated amount of sodium excreted in 24 h, as measured by the spot urine test (E24UNA), in a community-dwelling cohort. We investigated the gender specific association between E24UNA values and body composition indices.

MATERIALS AND METHODS

Data from a total of 7162 participants (3545 men and 3617 postmenopausal women) aged 45 years or older were obtained from multiple Korea National Health and Nutrition Examination Surveys (2008-2010) and analyzed. The total amount of sodium excreted in the urine in a 24-h period was estimated with spot urine specimens. Sarcopenia was defined as an appendicular skeletal muscle mass divided by body weight (ASM/Wt) that was less than 1 standard deviation below the sex-specific mean for young adults.

RESULTS

E24UNA values were positively correlated with body mass index, waist circumference, total fat mass, and blood pressure; in contrast, E24UNA values were negatively correlated with ASM/Wt in both sexes. Compared with those in the lowest E24UNA tertile, participants in the highest E24UNA tertile were at higher risk for sarcopenia (men: odds ratio (OR)=1.3 [95% confidence interval (CI)=1.07-1.59]; women: OR=1.41 [95% CI=1.16-1.73]). Further classification of subjects with sarcopenia into sarcopenic obese and sarcopenic nonobese groups revealed that the highest E24UNA values were found in the sarcopenic obese group; this difference was statistically significant. The next highest levels were found in the sarcopenic nonobese group, followed by the nonsarcopenic group. This trend was observed in both sexes.

CONCLUSION

High E24UNA values were independently associated with both sarcopenia and obesity in Korean individuals older than 45 years. These results suggest that high salt intake may have a deleterious effect on body composition.

Impact of nutrition and obesity on chronic liver disease

Undernutrition and obesity are at opposite ends of a spectrum that has an enormous impact on all aspects of liver diseases. The myriad effects of the opposing ends of the nutrition spectrum have led to a wealth of research aimed at elucidating the exact mechanisms of how they cause liver damage. In this article, the role of the liver in nutrient and energy metabolism is discussed, as well as the known and possible effects of specific nutrient deficiencies and obesity.

Effect of spironolactone on physical performance in older people with self-reported physical disability

BACKGROUND

Interventions that improve muscle function may slow decline in physical function and disability in later life. Recent evidence suggests that inhibition of the renin-angiotensin-aldosterone system may maintain muscle function. We evaluated the effect of aldosterone blockade on physical performance in functionally impaired older people without heart failure.

METHODS

In this parallel-group, double-blind, randomized, placebo-controlled trial, community-dwelling participants aged ≥65 years with self-reported problems with activities of daily living were randomized to receive 25 mg spironolactone or identical placebo daily for 20 weeks. The primary outcome was change in 6-minute walking distance over 20 weeks. Secondary outcomes were changes in Timed Up and Go test, Incremental Shuttle Walk Test, Functional Limitation Profile, EuroQol EQ-5D, and Hospital Anxiety and Depression Scale over 20 weeks.

RESULTS

Participants' mean (standard deviation) age was 75 (6) years. Of the 93% of participants (112/120) who completed the study, 106 remained on medication at 20 weeks. There was no significant difference in change in 6-minute walking distance at 20 weeks between the spironolactone and placebo groups (mean change, -3.2 m; 95% confidence interval, -28.9 to 22.5; P = .81). Quality of life improved significantly at 20 weeks, with an increase in EuroQol EQ-5D score of 0.10 (95% confidence interval, 0.03-0.18; P < .01) in the spironolactone group relative to the placebo group. There were no significant differences in between-group change for other secondary outcomes.

CONCLUSIONS

Spironolactone was well tolerated but did not improve physical function in older people without heart failure. Quality of life improved significantly, and the possible mechanisms for this require further study.

Mineralocorticoid antagonism: a novel way to treat sarcopenia and physical impairment in older people?

Dysregulation of the renin-angiotensin-aldosterone system has been associated with a number of age-related pathologies including hypertension, heart failure and chronic kidney disease. More recently, it has been suggested that alterations within the RAAS may contribute to the development of sarcopenia and subsequent decline in physical function. There is growing interest in developing interventions to prevent age-associated decline in muscle function. We postulate that inhibition of the RAAS with the mineralocorticoid antagonist spironolactone may have a role in countering the effects of physical impairment in older people by improving skeletal muscle function. Spironolactone may prevent skeletal myocyte apoptosis, improve vascular endothelial function and enhance muscle contractility by increasing muscle magnesium and sodium-potassium pumps. This article will review the literature underpinning the hypothesis that spironolactone may have a role in maintaining muscle function in older people.

Changes of activities of erythrocyte membrane Na+-K+-ATPase and Ca2+-Mg2+-ATPase and concentrations of Na+, K+, Ca2+ and Mg2+ in erythrocytes of patients with liver cirrhosis

AIM: To probe the activity changes of erythro-cyte membrane Na⁺-K⁺-ATPase (NKA) and Ca²⁺-Mg²⁺-ATPase (CMA) and their effects on the concentrations of intracellular sodium, potassi-um, calcium and magnesium in patients with liver cirrhosis.

METHODS: The erythrocyte membrane NKA and CMA activities, and the erythrocyte and serum sodium, potassium, calcium and magnesium (RNa, RK, RCa, RMg; SNa, SK, SCa, SMg) concentrations were measured in 52 patients with decompensated cirrhosis (group A), 36 patients with compensated cirrhosis (group B) and 36 healthy individuals (controls).

RESULTS: Compared with those in control group, the activities of NKA, CMA and the concentrations of RK and RMg in both group A (t = 5.92, P < 0.001; t = 7.21, P < 0.001; t = 2.32, P < 0.02; t = 4.79, P < 0.001) and group B (t = 3.83, P < 0.001; t = 2.53, P < 0.02; t = 2.03, P < 0.05; t = 3.33, P < 0.002) were decreased significantly. Compared with those in group B, the activities of NKA and CMA in group A (t = 2.29, P < 0.05; t = 4.14, P < 0.005) were decreased significantly. The concentrations of RNa and RCa did not differ between among the three groups. In comparison with those in control group, the concentrations of SNa, SK, SCa and SMg were lowered significantly in group A (t = 8.25, P < 0.001; t = 5.73, P < 0.001; t = 9.82, P < 0.001; t = 6.15, P < 0.001); and in comparison with those in group B, the concentrations of SNa, SK, SCa and SMg were also lowered significantly in group A (t = 6.94, P < 0.001; t = 5.00, P < 0.001; t = 5.57, P < 0.001; t = 5.73, P < 0.001). The activities of NKA and CMA and the concentrations of RK, RMg, SNa, SK, SCa and SMg were markedly lower in patients at Child C stage than those at Child B stage (P < 0.01 or P < 0.05). The activities of NKA and CMA and the concentrations of RK, RMg, SNa, SK and SMg were also markedly lower in patients with hepatoencephalopathy than those without hepatoencephalopathy (P < 0.01 or P < 0.05). In group A, the activities of NKA and CMA in patients with decreased SMg concentration were lower than those with normal SMg concentration (16.87 ± 3.19 vs 19.04 ± 3.25; 109.83 ± 13.51 vs 120.13 ± 13.27; both P < 0.05).

CONCLUSION: The deficiencies of potassium and magnesium exist in the patients with liver cirrhosis, deteriorating with advanced disease condition. The decreased NKA and CMA activities lead to a decrease of intracellular potassium and magnesium and increase of sodium and calcium. Magnesium deficiency is one of the reasons for decreased NKA and CMA activities in advanced cirrhosis.

Magnesium supplementation and muscle function in patients with alcoholic liver disease: a randomized, placebo-controlled trial

OBJECTIVE

The study was undertaken in order to evaluate the effect of magnesium (Mg) supplementation on muscle contents of Mg, muscle strength, muscle mass and sodium, potassium pumps (Na,K-pumps) in patients with alcoholic liver disease. Retrospectively, patients were also stratified according to spironolactone treatment.

MATERIAL AND METHODS

The study comprised a placebo-controlled, randomized trial in which 59 consecutive patients with alcoholic liver disease were treated with Mg intravenously and orally (12.5 mmol daily) or placebo for 6 weeks. Muscle content of Mg, maximum isokinetic muscle strength, skeletal muscle mass and muscle content of Na,K-pumps were measured before and after Mg supplementation.

RESULTS

Muscle Mg did not increase during the trial (paired t-test), but Mg supplementation and the duration of pre-study spironolactone treatment were independent predictors of muscle Mg (multiple regression). Muscle strength increased by 14% during the trial (p<0.001) and muscle mass increased by 11% (p=0.05), but with no difference between placebo and Mg treatment. Spironolactone treatment was associated with a 33% increase in the content of Na,K-pumps (p<0.001).

CONCLUSIONS

Six weeks of Mg supplementation did not increase muscle Mg, although Mg supplementation and spironolactone treatment were independent predictors of muscle Mg. The intervention had no effect on muscle strength and mass, but both increased during the study, probably owing to the general care and attendance to the patients.

Long-term management of alcoholic liver disease

Despite the epidemics of viral hepatitis C and nonalcoholic fatty liver disease, alcohol remains one of the major causes of liver disease. Commonly, hepatitis C and other liver diseases are found in association with alcohol consumption. This association in many instances is noted to accelerate the progression of liver disease. In many respects, the long-term management of alcoholic liver disease is not dissimilar from the long-term management of patients with cirrhosis from other etiologies. One major element is the abstinence of alcohol use. The ability to maintain sobriety has a major impact on the outcome of patients with alcoholic cirrhosis because maintaining abstinence can lead to significant regression of fibrosis and possibly early cirrhosis. Similarities in managing patients with cirrhosis due to alcohol or cirrhosis from other causes include vaccination to prevent superimposed viral hepatitis and screening for esophageal varices and hepatocellular carcinoma with subsequent appropriate therapy.

Decreased muscle strength and contents of Mg and Na,K-pumps in chronic alcoholics occur independently of liver cirrhosis

OBJECTIVES

To evaluate the influence of established liver cirrhosis on muscle strength and muscle contents of magnesium (Mg), potassium (K) and sodium, potassium pumps (Na,K-pumps) in chronic alcoholic patients.

DESIGN

An open cross-sectional study.

SETTING AND SUBJECTS

Forty consecutive chronic alcoholics (18 with cirrhosis and 22 without cirrhosis) admitted to the Department of Hepatology, Aarhus University Hospital, Denmark, or to a collaborating alcoholism treatment centre, and 36 healthy control subjects.

MAIN OUTCOME MEASURES

Evaluation of participant's subjective physical ability and measurement of maximum isokinetic muscle strength and muscle mass, as well as measurements of Mg, K and Na,K-pumps in skeletal muscle.

RESULTS

Maximum isokinetic muscle strength and muscle mass were equally reduced in patients with and without cirrhosis (P < 0.01 all). In keeping with this, both groups of patients felt equally physically restricted. Muscle Mg was reduced to the same extent in the two groups of patients (by 12 and 9%, P < 0.001, both), whereas the muscle K content was only significantly lower in the cirrhotic patients (10%, P < 0.001). The muscle content of Na,K-pumps was reduced by 14%, (P < 0.01) in the cirrhotic patients and by 8% (P < 0.05) in the noncirrhotic patients.

CONCLUSION

Our alcoholic patients complained of physical disability, had reduced skeletal muscle mass, isokinetic muscle strength, content of muscle Mg and content of Na,K-pumps. There was no difference between patients with and without cirrhosis. It appears that it is the heavy alcohol intake, and not the cirrhosis per se, that is responsible for the observed defects.