Neurohormonal factors in the development of catabolic/anabolic imbalance and cachexia

The complex pathophysiology of cardiac cachexia: A review of current pathophysiology and implications for clinical practice

Cardiac cachexia is a muscle wasting process that often develops in those with chronic heart failure resulting in weight loss, low levels of physical activity, reduced quality of life, and is associated with a poor prognosis. The pathology of cardiac cachexia is complex with new evidence emerging that implicates several body systems. This review describes the pathophysiology associated with cardiac cachexia and addresses: 1) hormonal changes- neurohormonal abnormalities and metabolic hormone imbalance; 2) mechanisms of muscle wasting in cardiac cachexia, and the integral mechanisms between changed hormones due to cardiac cachexia and muscle wasting processes, and 3) associated abnormalities of gastrointestinal system that contribute to cardiac cachexia. These pleiotropic mechanisms demonstrate the intricate interplay between the affected systems and account for why cardiac cachexia is difficult to manage clinically. This review summarises current pathophysiology of cardiac cachexia and highlights symptoms of cardiac cachexia, implications for clinical practice and research gaps.

[Malnutrition management of hospitalized patients with diabetes/hyperglycemia and heart failure]

Introduction

Heart failure (HF) is one of the leading causes of morbidity and mortality among older people, making it a major public health problem. Cardiovascular diseases in general, and HF in particular, are common comorbidities in people with type 2 diabetes (DM2). The concurrence of DM2 and HF is associated with more severe clinical symptoms and signs, and poorer quality of life and prognosis. Furthermore, due to the hypercatabolic state and nutrient absorption disorders, malnutrition is present in many HF cases. This article describes the results of the expert consensus and the responses of the panelists on the nutritional management in routine clinical practice of patients with diabetes/hyperglycemia hospitalized (non-critically ill) with HF.

The prevalence of malnutrition and its effects on the all-cause mortality among patients with heart failure: A systematic review and meta-analysis

OBJECTIVE

Malnutrition has a high occurrence in patients with chronic heart failure (CHF). The prevalence of malnutrition and its impact on all-cause mortality in patients with CHF were assessed using a meta-analysis.

METHODS

PubMed, Embase, the Cochrane Library, Web of Science, Medline, CBM, CNKI, WANFANG DATA, and VIP databases were searched to collect cross-sectional and cohort studies on malnutrition, and the prevalence and all-cause mortality of patients with CHF were determined. The time of retrieval was from the database establishment to May 2021. Two researchers independently performed screening of the literature, data extraction and assessed the risk of bias in the included studies. Then Stata 16.0 software was used for meta-analysis.

RESULTS

A total of 10 cross-sectional and 21 cohort studies were included, including 12537 patients with CHF. A meta-analysis demonstrated that the total prevalence of malnutrition in patients with heart failure was 46% (95% confidence interval [CI]: 0.43, 0.49). Compared to patients with non-malnutrition, malnutrition increased the risk of all-cause mortality in patients with CHF (hazard ratio = 2.15, 95% CI [1.89, 2.45], P < 0.05).

DISCUSSION

Current evidence suggests that the prevalence of malnutrition is high among patients with CHF. The risk of all-cause mortality in such patients can be increased by malnutrition. Therefore, the risk of malnutrition in patients with CHF should be considered to reduce the occurrence of adverse clinical outcomes.

Nutritional interventions for heart failure patients who are malnourished or at risk of malnutrition or cachexia: a systematic review and meta-analysis

Malnutrition is common in heart failure (HF), and it is associated with higher hospital readmission and mortality rates. This review aims to answer the question whether nutritional interventions aiming to increase protein and energy intake are effective at improving outcomes for patients with HF who are malnourished or at risk of malnutrition or cachexia. Systematic searches of four databases (Medline, Embase, CINAHL and Cochrane Central Register of Controlled Trials (CENTRAL)) were conducted on 21 June 2019. Randomized controlled trials (RCTs) or other interventional studies using protein or energy supplementation for adult HF patients who are malnourished or at risk of malnutrition or cachexia were included. Two independent reviewers assessed study eligibility and risk of bias. Five studies (four RCTs and one pilot RCT) met the inclusion criteria. The majority of studies were small and of limited quality. The pooled weighted mean difference (WMD) for body weight showed a benefit from the nutritional intervention by 3.83 kg (95% confidence interval (CI) 0.17 to 7.50, P = 0.04) from three trials with no significant benefit for triceps skinfold thickness (WMD = - 2.14 mm, 95% CI - 9.07 to 4.79, P = 0.55) from two trials. The combination of personalized nutrition intervention with conventional treatment led to a decrease in all-cause mortality and hospital readmission in one study. Findings of this review suggest that nutritional interventions could potentially improve outcomes in HF patients who are malnourished or at risk of malnutrition. However, the strength of the evidence is poor, and more robust studies with a larger number of participants are needed.

Does nutritional intervention maintain its prognostic benefit in the long term for malnourished patients hospitalised for heart failure?

OBJECTIVE

To assess the long-term effect of nutritional intervention on malnourished, hospitalised patients with heart failure (HF).

METHODS

A total of 120 malnourished patients hospitalized for HF were randomised to undergo (or not) an individual nutritional intervention for 6 months. The primary event was the combination of all-cause death and readmission for HF. We performed an intent-to-treat analysis and assessed the effect of the intervention at 24 months.

RESULTS

The combined event occurred in 47.5% of the intervention group and in 73.8% of the control group (hazard ratio: 0.45; 95% confidence interval: 0.28-0.72; P=.001). Thirty-nine percent of the intervention group and 59% of the control group died (hazard ratio: 0.53; 95% confidence interval: 0.31-0.89; P=.017).

CONCLUSION

A nutritional intervention for malnourished patients hospitalised for HF maintains its prognostic benefit in the long-term follow-up.

Nutritional Intervention in Malnourished Hospitalized Patients with Heart Failure

BACKGROUND AND AIMS

Hospitalized patients with heart failure who are malnourished present a worse prognosis than those with an adequate nutritional status. We undertook this study to assess whether a nutritional intervention in malnourished hospitalized patients with heart failure benefits morbidity and mortality.

METHODS

A multicenter, randomized, controlled clinical trial was conducted. A total of 120 malnourished hospitalized patients due to acute heart failure were randomised to conventional heart failure treatment or conventional heart failure treatment combined with an individualized nutritional intervention. The primary endpoint of this study was a composite of all-cause death or readmission for worsening of HF, with a maximum follow-up of 12 months. Analysis was by intention to treat.

RESULTS

Recruitment was stopped early according to the study protocol after completing the follow-up of the first 120 patients enrolled (59 in the intervention group and 61 in the control group). Both groups were homogeneous in baseline characteristics. At 12 months, the primary outcome occurred in 27.1% of patients in the intervention group and in 60.7% of patients in the control group (hazard ratio 0.45; 95% confidence interval [CI], 0.19-0.62, p = 0.0004). In total, 20.3% of patients died in the intervention group and 47.5% in the control group (hazard ratio 0.37, 95% CI, 0.19-0.72, p = 0.003). Readmission due to heart failure was also lower in the intervention group (10.2 vs. 36.1%, p = 0.001).

CONCLUSION

Nutritional intervention in malnourished hospitalized patients with heart failure reduces the risk of death from any cause and the risk of readmission for worsening of heart failure (ClinicalTrial.govNCT01472237).

Cardiac cachexia: hic et nunc

Cardiac cachexia (CC) is the clinical entity at the end of the chronic natural course of heart failure (HF). Despite the efforts, even the most recent definition of cardiac cachexia has been challenged, more precisely, the addition of new criteria on top of obligatory weight loss. The pathophysiology of CC is complex and multifactorial. A better understanding of pathophysiological pathways in body wasting will contribute to establish potentially novel treatment strategies. The complex biochemical network related with CC and HF pathophysiology underlines that a single biomarker cannot reflect all of the features of the disease. Biomarkers that could pick up the changes in body composition before they convey into clinical manifestations of CC would be of great importance. The development of preventive and therapeutic strategies against cachexia, sarcopenia, and wasting disorders is perceived as an urgent need by healthcare professionals. The treatment of body wasting remains an unresolved challenge to this day. As CC is a multifactorial disorder, it is unlikely that any single agent will be completely effective in treating this condition. Among all investigated therapeutic strategies, aerobic exercise training in HF patients is the most proved to counteract skeletal muscle wasting and is recommended by treatment guidelines for HF.

Cardiac cachexia: hic et nunc: "hic et nunc" - here and now

Cardiac cachexia (CC) is the clinical entity at the end of chronic natural course of heart failure (HF). Despite the efforts, even the most recent definition of cardiac cachexia has been challenged, more precisely the addition of new criteria on top of obligatory weight loss. The pathophysiology of CC is complex and multifactorial. Better understanding of pathophysiological pathways in body wasting will contribute to establish potentially novel treatment strategies. The complex biochemical network related with CC and HF pathophysiology underlines that a single biomarker cannot reflect all of the features of the disease. Biomarkers that could pick-up the changes in body composition before they convey into clinical manifestations of CC would be of great importance. The development of preventive and therapeutic strategies against cachexia, sarcopenia and wasting disorders is perceived as an urgent need by healthcare professionals. The treatment of body wasting remains an unresolved challenge to this day. As CC is a multifactorial disorder, it is unlikely that any single agent will be completely effective in treating this condition. Among all investigated therapeutic strategies, aerobic exercise training in HF patients is the most proved to counteract skeletal muscle wasting and is recommended by treatment guidelines for HF.

Cachexia in chronic heart failure: endocrine determinants and treatment perspectives

It is well documented in the current literature that chronic heart failure is often associated with cachexia, defined as involuntary weight loss of 5 % in 12 month or less. Clinical studies unraveled that the presence of cachexia decreases significantly mean survival of the patient. At the molecular level mainly myofibrillar proteins are degraded, although a reduced protein synthesis may also contribute to the loss of muscle mass. Endocrine factors clearly regulate muscle mass and function by influencing the normally precisely controlled balance between protein breakdown and protein synthesis The aim of the present article is to review the knowledge in the field with respect to the role of endocrine factors for the regulation of cachexia in patients with CHF and deduce treatment perspectives.

Insulin resistance and muscle metabolism in chronic kidney disease

Insulin resistance is a common finding in chronic kidney disease (CKD) and is manifested by mild fasting hyperglycemia and abnormal glucose tolerance testing. Circulating levels of glucocorticoids are high. In muscle, changes in the insulin signaling pathway occur. An increase in the regulatory p85 subunit of Class I phosphatidylinositol 3-Kinase enzyme leads to decreased activation of the downstream effector protein kinase B (Akt). Mechanisms promoting muscle proteolysis and atrophy are unleashed. The link of Akt to the ubiquitin proteasome pathway, a major degradation pathway in muscle, is discussed. Another factor associated with insulin resistance in CKD is angiotensin II (Ang II) which appears to induce its intracellular effects through inflammatory cytokines or reactive oxygen species. Skeletal muscle ATP is depleted and the ability of AMP-activated protein kinase (AMPK) to replenish energy stores is blocked. How this can be reversed is discussed. Interleukin-6 (IL-6) levels are elevated in CKD and impair insulin signaling at the level of IRS-1. With exercise, IL-6 levels are reduced; glucose uptake and utilization are increased. For patients with CKD, exercise may improve insulin signaling and build up muscle. Treatment strategies for preventing muscle atrophy are discussed.

Angiotensin II upregulates protein phosphatase 2Cα and inhibits AMP-activated protein kinase signaling and energy balance leading to skeletal muscle wasting

Congestive heart failure and chronic kidney disease are characterized by chronically elevated angiotensin II (Ang II) and muscle wasting. Ang II causes skeletal muscle wasting by reducing appetite and by enhancing catabolism. The serine/threonine kinase AMP-activated protein kinase (AMPK) functions mainly as a sensor of cellular energy status. It is energy sparing and favors ATP generation. We hypothesized that Ang II induces muscle wasting in part by inhibiting AMPK signaling and altering cellular energy balance. Our results show that Ang II infusion in mice reduced gastrocnemius muscle weight by 26% and depleted ATP by 74%. In addition, Ang II upregulated protein phosphatase 2Cα by 2.6-fold and reduced AMPK phosphorylation and signaling in muscle. Importantly, the pharmacological AMPK activator 5-aminoimidazole-4-carboxamide ribonucleoside restored AMPK activity to levels of pair-fed controls and reversed Ang II-mediated ATP depletion and muscle wasting. Moreover, 5-aminoimidazole-4-carboxamide ribonucleoside activated Akt and inhibited Ang II-induced increases in E3 ubiquitin ligase expression. These novel results demonstrate critical roles for energy depletion and AMPK inhibition in Ang II-induced skeletal muscle wasting and suggest a therapeutic potential for AMPK activators in diseases characterized by muscle wasting.

Angiotensin II-induced reduction in body mass is Ang II receptor mediated in association with elevated corticosterone

The mechanisms by which elevated glucocorticoids contribute to decreased body mass via angiotensin II (Ang II) infusion are not completely described. This study addressed the hypothesis that chronic Ang II infusion suppresses hepatic growth hormone receptor (GHr) and IGF1 expressions via an Ang II receptor (AT1)-mediated pathway associated with elevated glucocorticoids. Sprague-Dawley rats were assigned to three groups: 1) Control, 2) Ang II-infused (80 ng/min x 28d) and 3) Ang II+angiotensin receptor blocker (ARB; 10 mg losartan/kg/d x 21d). After 28d, Ang II decreased body mass by 14% (407+/-8 vs 350+/-17 g) and hepatic AT1a, GHr, and IGF1 mRNA expressions by 45%, 44%, and 44%, respectively. ARB treatment completely prevented the loss in body mass (409+/-9 g) and AT1a and GHr expressions and partially recovered the loss of hepatic IGF1. Ang II increased plasma corticosterone (B) 3-fold (173+/-28 vs 555+/-42 ng/mL) and ARB treatment prevented the response (150+/-47 ng/mL). Food consumption did not change suggesting that the decrease in body mass resulted from the catabolic actions of the Ang II-induced increase in systemic B and not from reduced caloric intake. The prevention by ARB treatment of the Ang II-induced decrease in body mass and downregulation of AT1a, GHr and IGF1 coinciding with suppression of plasma B suggests that the Ang II-induced decrease in body mass is AT1 receptor mediated in conjunction with elevated B. These data suggest that alleviating the Ang II-induced cachexia requires targeting AT1 and suppressing glucocorticoid secretion.

Integrin-linked kinase is involved in TNF-alpha-induced inducible nitric-oxide synthase expression in myoblasts

Tumor necrosis factor-alpha (TNF-alpha) is a pleiotropic cytokine produced by activated macrophages. Nitric oxide (NO) is a highly reactive nitrogen radical implicated in inflammatory responses. We investigated the signaling pathway involved in inducible nitric oxide synthase (iNOS) expression and NO production stimulated by TNF-alpha in cultured myoblasts. TNF-alpha stimulation caused iNOS expression and NO production in myoblasts (G7 cells). TNF-alpha-mediated iNOS expression was attenuated by integrin-linked kinase (ILK) inhibitor (KP392) and siRNA. Pretreatment with Akt inhibitor, mammalian target of rapamycin (mTOR) inhibitor (rapamycin), NF-kappaB inhibitor (PDTC), and IkappaB protease inhibitor (TPCK) also inhibited the potentiating action of TNF-alpha. Stimulation of cells with TNF-alpha increased ILK kinase activity. TNF-alpha also increased the Akt and mTOR phosphorylation. TNF-alpha mediated an increase of NF-kappaB-specific DNA-protein complex formation, p65 translocation into nucleus, NF-kappaB-luciferase activity was inhibited by KP392, Akt inhibitor, and rapamycin. Our results suggest that TNF-alpha increased iNOS expression and NO production in myoblasts via the ILK/Akt/mTOR and NF-kappaB signaling pathway.

FAK activation is required for TNF-alpha-induced IL-6 production in myoblasts

Tumor necrosis factor-alpha (TNF-alpha) is a pleiotropic cytokine produced by activated macrophages. IL-6 is a multifunctional cytokine that plays a central role in both innate and acquired immune responses. We investigated the signaling pathway involved in IL-6 production stimulated by TNF-alpha in cultured myoblasts. TNF-alpha caused concentration-dependent increases in IL-6 production. TNF-alpha-mediated IL-6 production was attenuated by focal adhesion kinase (FAK) mutant and siRNA. Pretreatment with phosphatidylinositol 3-kinase inhibitor (PI3K; Ly294002 and wortmannin), Akt inhibitor, NF-kappaB inhibitor (pyrrolidine dithiocarbamate, PDTC), and IkappaB protease inhibitor (L-1-tosylamido-2-phenyl phenylethyl chloromethyl ketone, TPCK) also inhibited the potentiating action of TNF-alpha. TNF-alpha increased the FAK, PI3K, and Akt phosphorylation. Stimulation of myoblasts with TNF-alpha activated IkappaB kinase alpha/beta (IKKalpha/beta), IkappaBalpha phosphorylation, p65 phosphorylation, and kappaB-luciferase activity. TNF-alpha mediated an increase of kappaB-luciferase activity which was inhibited by Ly294002, wortmannin, Akt inhibitor, PDTC and TPCK or FAK, PI3K, and Akt mutant. Our results suggest that TNF-alpha increased IL-6 production in myoblasts via the FAK/PI3K/Akt and NF-kappaB signaling pathway.

TNF-alpha increases protein content in C2C12 and primary myotubes by enhancing protein translation via the TNF-R1, PI3K, and MEK

Recent evidence supports that TNF-alpha, long considered a catabolic factor, may also have a physiological function in skeletal muscle. The catabolic view, mainly based on correlative studies in human and in vivo animal models, was challenged by experiments with myoblasts, in which TNF-alpha induced differentiation. The biological effects of TNF-alpha in differentiated muscle, however, remain poorly understood. In the present study, we tested whether TNF-alpha has growth-promoting effects in myotubes, and we characterized the mechanisms leading to these effects. Treatment of C(2)C(12) myotubes with TNF-alpha for 24 h increased protein synthesis (PS) and enhanced cellular dehydrogenase activity by 22 and 26%, respectively, without changing cell numbers. These effects were confirmed in myotubes differentiated from primary rat myoblasts. TNF-alpha activated two signaling cascades: 1) ERK1/2 and its target eIF4E and 2) Akt and its downstream effectors GSK-3, p70(S6K), and 4E-BP1. TNF-alpha-induced phosphorylation of Akt, and ERK1/2 was inhibited by an antibody against TNF-alpha receptor 1 (TNF-R1). PD-98059 pretreatment abolished TNF-alpha-induced phosphorylation of ERK1/2 and eIF4E, whereas PS was only partially inhibited. LY-294002 completely abolished TNF-alpha-induced stimulation of PS as well as phosphorylation of Akt and its downstream targets GSK-3, p70(S6K), and 4E-BP1. Rapamycin inhibited TNF-alpha-induced phosphorylation of the mTOR C1 target p70(S6K) without altering TNF-alpha-induced PS and 4E-BP1 phosphorylation. In conclusion, our results provide evidence that TNF-alpha enhances PS in myotubes and that this is based on enhanced protein translation mediated by the TNF-R1 and PI3K-Akt and MEK-ERK signaling cascades.

A phase II study with antioxidants, both in the diet and supplemented, pharmaconutritional support, progestagen, and anti-cyclooxygenase-2 showing efficacy and safety in patients with cancer-related anorexia/cachexia and oxidative stress

PURPOSE

To test the efficacy and safety of an integrated treatment based on a pharmaconutritional support, antioxidants, and drugs, all given orally, in a population of advanced cancer patients with cancer-related anorexia/cachexia and oxidative stress.

PATIENTS AND METHODS

An open early-phase II study was designed according to the Simon two-stage design. The integrated treatment consisted of diet with high polyphenols content (400 mg), antioxidant treatment (300 mg/d alpha-lipoic acid + 2.7 g/d carbocysteine lysine salt + 400 mg/d vitamin E + 30,000 IU/d vitamin A + 500 mg/d vitamin C), and pharmaconutritional support enriched with 2 cans per day (n-3)-PUFA (eicosapentaenoic acid and docosahexaenoic acid), 500 mg/d medroxyprogesterone acetate, and 200 mg/d selective cyclooxygenase-2 inhibitor celecoxib. The treatment duration was 4 months. The following variables were evaluated: (a) clinical (Eastern Cooperative Oncology Group performance status); (b) nutritional [lean body mass (LBM), appetite, and resting energy expenditure]; (c) laboratory [proinflammatory cytokines and leptin, reactive oxygen species (ROS) and antioxidant enzymes]; (d) quality of life (European Organization for Research and Treatment of Cancer QLQ-C30, Euro QL-5D, and MFSI-SF).

RESULTS

From July 2002 to January 2005, 44 patients were enrolled. Of these, 39 completed the treatment and were assessable. Body weight increased significantly from baseline as did LBM and appetite. There was an important decrease of proinflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor-alpha, and a negative relationship worthy of note was only found between LBM and IL-6 changes. As for quality of life evaluation, there was a marked improvement in the European Organization for Research and Treatment of Cancer QLQ-C30, Euro QL-5D(VAS), and multidimensional fatigue symptom inventory-short form scores. At the end of the study, 22 of the 39 patients were "responders" or "high responders." The minimum required was 21; therefore, the treatment was effective and more importantly was shown to be safe.

CONCLUSION

The efficacy and safety of the treatment have been shown by the study; therefore, a randomized phase III study is warranted.

Neonatal immune challenge exacerbates experimental colitis in adult rats: potential role for TNF-alpha

Early life events and childhood infections have been associated with the development and onset of inflammatory bowel disease in adulthood. However, the consequences of neonatal infection in the development and severity of colitis are not established. We investigated the effects of a neonatal (postnatal day 14) or juvenile (postnatal day 28) immune challenge with LPS on 2,4,6-trinitrobenzenesulfonic acid (TNBS)-induced damage and weight loss, as well as on food intake and body temperature in adult rats. Neonatally (n)LPS-treated rats developed more severe colitis than control animals, reflected in a greater loss of weight and a significantly increased macroscopic tissue damage score. These findings were associated with a hypothermic response after TNBS treatment in nLPS rats, but not in neonatally saline-treated rats receiving TNBS. These differences were not seen after TNBS in rats that had received LPS on postnatal day 28. Plasma corticosterone was measured as an index of adult hypothalamic-pituitary-adrenal (HPA) axis activation as was TNF-alpha, a proinflammatory cytokine associated with inflammatory bowel disease. Four days after TNBS treatment, plasma corticosterone was unaltered in all groups; however, TNF-alpha was significantly increased in adult TNBS-treated rats that had LPS as neonates compared with all other groups. In conclusion, neonatal, but not later, exposure to LPS produces long-term exacerbations in the development of colitis in adults. This change is independent of HPA axis activation 4 days after TNBS treatment but is associated with increased circulating TNF-alpha, suggestive of an exaggerated immune response in adults exposed to neonatal infection.

Anti-TNF antibody treatment improves glucocorticoid induced insulin-like growth factor 1 (IGF1) resistance without influencing myoglobin and IGF1 binding proteins 1 and 3

BACKGROUND

Insulin-like growth factor 1 (IGF1) is an important determinant of muscle mass because it promotes growth and suppresses protein degradation. IGF1 is decreased in rheumatoid arthritis and juvenile idiopathic arthritis because its synthesis is inhibited by inflammation. In parallel, glucocorticoids induce IGF1 resistance and add to muscle degradation.

OBJECTIVE

To investigate the influence of anti-tumour necrosis factor antibody treatment (anti-TNF) with adalimumab on levels of myoglobin (degradation marker) and IGF1 in patients with rheumatoid arthritis with and without prednisolone treatment.

METHODS

Subcutaneous adalimumab was given to 32 patients with longstanding rheumatoid arthritis (16 with and 16 without prednisolone) in a longitudinal study. IGF1, IGF1 binding protein 1 (IGFBP-1), IGFBP-3, and myoglobin were measured by enzyme linked immunosorbent assay.

RESULTS

Rheumatoid patients had normal serum myoglobin. Patients on prednisolone had higher myoglobin than patients not receiving prednisolone, indicating increased muscle degradation. On treatment with anti-TNF, myoglobin levels did not change in either patient group. Serum IGF1 was increased in patients with v without prednisolone, indicating IGF1 resistance (mean (SEM): 221 (23) v 122 (14) microg/l, p<0.001). Adalimumab treatment decreased the raised IGF1 levels in patients with prednisolone, so that after 12 weeks of treatment they reached the level of patients without prednisolone. Serum IGFBP-1 and IGFBP-3 did not differ in the two groups, and anti-TNF did not change these concentrations.

CONCLUSIONS

Anti-TNF antibody treatment over 12 weeks improved glucocorticoid induced IGF1 resistance without influencing myoglobin and IGF1 binding proteins. Thus, in rheumatoid patients on glucocorticoids with generally decreased muscle mass anti-TNF treatment with adalimumab has favourable effects.

Effect of intracerebroventricular angiotensin II on body weight and food intake in adult rats

We recently reported that intracerebroventricular infusions of ANG II decreased food intake and increased energy expenditure in young rats. The aim of the present study was to determine if intracerebroventricular ANG II has similar effects in adult rats. The time course of the effect was also investigated with the idea that at earlier time points, a potential role for increased hypothalamic expression of corticotropin-releasing hormone (CRH) in the anorexia could be established. Finally, the contribution of ANG II-induced water drinking to the decrease in food intake was directly investigated. Rats received intracerebroventricular saline or ANG II using osmotic minipumps. Food intake, water intake, and body weight were measured daily. Experiments were terminated 2, 5, or 11 days after the beginning of the infusions. ANG II (approximately 32 ng.kg(-1).min(-1)) produced a transient decrease in food intake that lasted for 4-5 days although body weight continued to be decreased for the entire experiment most likely due to increased energy expenditure as evidenced by increased uncoupling protein-1 mRNA expression in brown adipose tissue. At 11 and 5 days, the expression of CRH mRNA was decreased. At 2 days, CRH expression was not suppressed even though body weight was decreased. The decrease in food intake and body weight was identical whether or not rats were allowed to increase water consumption. These data suggest that in adult rats ANG II acts within the brain to affect food intake and energy expenditure in a manner that is not related to water intake.

The influence of patient- and facility-specific factors on nutritional status and survival in hemodialysis

BACKGROUND

Parameters of nutritional status, including serum albumin, serum creatinine, and body mass index (BMI), are powerful predictors of mortality and hospitalization in patients with end stage renal disease (ESRD). Patient-specific characteristics and facility-related practice patterns modify certain parameters of nutritional status. We aimed to determine whether patient and facility characteristics modify the risk profiles associated with malnutrition in hemodialysis patients.

METHODS

We analyzed data on 5,234 prevalent hemodialysis patients from the Dialysis Morbidity and Mortality Study (DMMS) Wave 1 for whom information on demographic, clinical, nutritional, and facility-related characteristics were available. We evaluated the associations among facility characteristics and serum albumin, serum creatinine, and BMI, adjusting for the effects of age, sex, race/ethnicity, diabetes, and dialysis vintage. We determined correlates of mortality and hospitalization, focusing on nutritional parameters, facility effects, and the interactions among patient-specific and facility-specific characteristics, albumin, creatinine, and BMI.

RESULTS

Serum albumin was lower with older age, diabetes, nonblack race, and hemodialysis using a catheter. Serum albumin was higher with annual vascular access surveillance, higher BMI among women, higher urea reduction ratio, among patients in whom dialyzers were reprocessed (particularly with bleach), among dialysis units in which water purification was used, and when vascular access blood flow rates were > or =350 mL/min. Overall survival was decreased with lower albumin, creatinine, and BMI. There were interactions among albumin, age, and vintage. Whereas lower serum albumin concentrations consistently were associated with an increased risk of death, the differences were attenuated among older patients and accentuated among patients of longer vintage.

CONCLUSION

Some facility-specific factors are associated with nutritional parameters including serum albumin, serum creatinine, and BMI. The associations of nutritional parameters with mortality and hospitalization vary by age, sex, and vintage but not by facility-specific factors, including those associated with the nutritional parameters themselves.

Partial reversal of cachexia by beta-adrenergic receptor blocker therapy in patients with chronic heart failure

BACKGROUND

Cachexia is a common problem in chronic heart failure (CHF) that may be partly mediated by activation of the sympathetic nervous system. The effects of beta-adrenergic receptor blocker (BB) therapy on body weight in cachectic and noncachectic subjects with CHF has not been previously reported.

METHODS AND RESULTS

Body weight and plasma norepinephrine, leptin, and insulin levels were measured in 27 subjects with CHF before and after 6 months of beta-adrenergic receptor blockade with carvedilol or long-acting metoprolol. Before BB therapy, baseline weight, plasma leptin, and plasma insulin levels did not differ between cachectic and noncachectic subjects. Baseline plasma norepinephrine levels were increased in cachectic subjects when compared with noncachectic subjects (930+/-248 pg/mL versus 503+/-109 pg/mL, P=.063). After 6 months of BB therapy, subjects with baseline cachexia demonstrated significantly greater weight gain (+5.2+/-9.6 versus +0.8+/-5.0 kg, P=.027), greater increase in plasma leptin levels (+3.7+/-3.9 versus +1.2+/-4.3 ng/mL, P=.030), and greater decrease in plasma norepinephrine levels (-374+/-261 versus -41+/-122 pg/mL, P=.012) when compared with noncachectic subjects.

CONCLUSIONS

Six months of BB therapy with carvedilol or long-acting metoprolol is associated with differential effects on body weight and hormonal levels in cachectic and noncachectic subjects with CHF. Further work is needed to determine the role the sympathetic nervous system in the pathogenesis of cachexia in patients with CHF.