Contribution of anorexia to tissue wasting in cachexia

Changes of gene expression in peripheral blood mononuclear cells of lung cancer patients with or without anorexia

BACKGROUND & AIMS

Anorexia is a disabling symptom in cancer and we aimed at investigating the role of changes in gene expression in lung cancer patients presenting with anorexia.

METHODS

Genome-wide transcriptomic profiling was assessed in PBMCs RNA from newly diagnosed lung cancer patients and in a control group. RT-qPCR was used for selected genes.

RESULTS

RNA-Seq analysis revealed among groups a large number of differentially expressed genes mainly implicated in immune system regulation, oxidative stress and cytokine-mediated inflammation signaling pathways. In particular, we identified a total of 983 DEGs (843 up-regulated; 140 down-regulated) in anorexic cancer compared to controls. A selected number of DEGs including ADAM8, SMAD4, CCR4 and CLU were differentially expressed within cancer group according to the presence/absence of anorexia. In terms of RT-qPCR, ADAM8 was less expressed in cancer patients than controls (p < 0.001), and in anorexic patients vs controls (p = 0.001). The expression of SMAD4 was lower in cancer vs controls (p = 0.005), and in anorexic patients vs controls (p = 0.009). We observed lower CCR4 expression in both anorexic and non-anorexic vs control (p = 0.004, p = 0.011, respectively) and a similar trend was present for CLU.

CONCLUSIONS

Our data shed new light on the role of specific genes and their associated molecular pathways as potential key mechanisms for the development of anorexia and may represent a novel landmark for understanding the complex pathophysiology of impaired appetite in cancer.

Evaluation of Browning Markers in Subcutaneous Adipose Tissue of Newly Diagnosed Gastrointestinal Cancer Patients with and without Cachexia

Simple Summary

Cachexia occurs frequently in cancer patients with deep metabolic derangements. The browning of adipose tissue promotes thermogenesis and energy expenditure and, in cancer, has been considered a major determinant of adipose tissue atrophy. We evaluated the molecular phenotype of this phenomenon in the subcutaneous adipose tissue (SAT) of newly diagnosed gastrointestinal cancer patients compared to controls. We observed that the modulation of different markers of the browning of SAT in gastrointestinal cancer and, in particular, pancreatic cancer showed significant changes in UCP1 and PGC1α; PGC1α was highly expressed in cachectic patients. Our study highlights the relevance of browning in patients with cancer, in particular in those with pancreatic cancer. Understanding the browning phenomenon may allow us to counteract these metabolic alterations before the development of severe cachexia, which is characterized by deep adipose and muscle depletion, negatively affecting survival and quality of life.

Abstract

We assessed the molecular phenotype of the browning of white adipose tissue in newly diagnosed cancer patients and controls undergoing surgery for gastrointestinal tumors and for non-malignant diseases, respectively. We collected subcutaneous adipose tissue (SAT) samples and using RT-PCR, we analyzed the expression of markers of browning and using Western blot the protein levels of UCP1 and PGC1α. The Ucp1 mRNA levels were lower in cancer patients vs. controls (p = 0.01), whereas Cidea and Tmem26 mRNA levels were higher in cancer patients. We found higher PGC1α protein levels in patients vs. controls, while no differences were seen for UCP1. The Ucp1 expression was lower in cachectic and non-cachectic patients vs. controls, whereas Cidea expression was higher in cachectic and non-cachectic patients vs. controls. Pgc1α mRNA levels were higher in cachectic vs. non-cachectic patients (p = 0.03) vs. controls (p = 0.016). According to type of tumors, we did not observe differences in Cidea expression, whereas Pgc1α was higher in pancreatic cancer vs. colorectal and vs. controls. We observed the lower expression of Ucp1 in pancreatic and colorectal cancer vs. controls. We documented higher UCP1 protein levels in pancreatic cancer patients vs. colorectal (p = 0.002) and vs. controls (p = 0.031). PGC1α protein levels were higher in pancreatic cancer patients vs. controls. Different markers of the browning of SAT are modulated, and pancreatic cancer showed changes in UCP1 and PGC1α; PGC1α was highly expressed in cachectic patients, with clinical implications that should be further clarified.

Current Screening Methods for the Risk or Presence of Malnutrition in Cancer Patients

Malnutrition is highly common among cancer patients and is associated with a poor quality of life, increased treatment toxicities and decreased survival. The screening of malnutrition should be performed in an early stage of cancer disease and should be rapid, not expensive and highly sensitive to identify the risk of developing malnutrition. Importantly, international clinical guidelines suggest to perform screening for malnutrition in all cancer patients and if the risk is present, they recommend to perform a full nutritional assessment. During the screening phase, different nutritional parameters are considered including the loss of appetite, low food intake, body weight loss and burden of the disease. These items are present in several screening tools, such as the Nutrition Risk Screening (NRS)-2002, the Malnutrition Universal Screening Tool (MUST) and the Mini Nutritional Assessment (MNA) which represent the most widely used tools to screen for an altered nutritional status in cancer patients. Recently, the Global Leadership Initiative on Malnutrition (GLIM) developed an assessment tool for the diagnosis of malnutrition taking into account the presence of i) involuntary body weight loss, ii) body mass index, iii) low muscle mass, iv) low food intake and disease burden/inflammation; in particular, body weight loss, decreased body mass index (BMI), and low muscle mass are considered as phenotypic criteria, whereas reduced food intake, disease burden and inflammation are defined as etiologic criteria. To perform the diagnosis of malnutrition, GLIM consensus considered the presence of at least one phenotypic and one etiologic criterion. The above-mentioned screening tools were validated in different clinical settings and suggesting the use of one tool vs another is challenging considering, among others, different factors including the type and stage of cancer and the setting (i.e., inpatient or outpatient care). Recent data obtained among large cohorts of cancer patients indicate that personalized nutritional therapy reduced mortality risk and ameliorated quality of life and functionality among cancer patients with high nutritional risk, supporting the urgent need for implementing screening and diagnosis of malnutrition in this context.

Histomorphological and inflammatory changes of white adipose tissue in gastrointestinal cancer patients with and without cachexia

BACKGROUND

During cancer cachexia, several alterations occur in peripheral tissues, and the adipose tissue may be involved during the catabolic state. We aimed at investigating histological rearrangement and infiltration of inflammatory cells in subcutaneous adipose tissue (SAT) of patients with cancer undergoing surgery, according to the presence/absence of cachexia.

METHODS

We considered gastrointestinal cancer patients and controls with non-malignant diseases undergoing surgery. We collected SAT samples and performed histomorphological analyses [cross-sectional area (CSA) and per cent of fibrosis] and immunohistochemistry to characterize the inflammatory cells. By computed tomography (CT) scan, we calculated SAT and visceral adipose tissue (VAT).

RESULTS

We enrolled 51 participants (31 gastrointestinal cancer patients and 20 controls). In cancer patients, cachexia was present in 13/31 (42%). The CSA (μm² ) of the adipocytes from SAT was reduced in cancer patients vs. controls (3148, inter-quartile range 2574-3755 vs. 4474, inter-quartile range 3654-5183) (P < 0.001), in particular in cachectic patients vs. non-cachectic (median 2518 vs. median 3470) (P = 0.03) and in cachectic vs. controls (P < 0.001), as well as in non-cachectic vs. controls (P = 0.04). The median per cent of fibrosis was higher in cancer patients vs. controls (9 vs. 3) (P = 0.0001), in particular in cachectic vs. non-cachectic (13.35 vs. 7.13) (P = 0.03). We observed a higher number of macrophages (CD68) (P = 0.0001) and T lymphocytes (CD3) (P = 0.002) in SAT of cancer patients vs. controls, and the number of T lymphocytes was higher in cachectic vs. non-cachectic patients (P = 0.025). Anorexic cancer patients showed in SAT a higher number of macrophages and T lymphocytes with respect to controls (P < 0.0001), whereas no difference was present between anorexic and non-anorexic patients. At CT scan, cachectic patients showed lower VAT and SAT vs. non-cachectic (VAT: 97.64 ± 40.79 vs. 212.53 ± 79.24, P = 0.0002; SAT: 126.27 ± 87.92 vs. 206.27 ± 61.93, P = 0.01, respectively). Cancer patients with low CSA, high degree of fibrosis, and high number of T lymphocytes presented with lower body mass index and lower SAT and VAT at CT scan (P ≤ 0.01).

CONCLUSIONS

We found histological alterations of SAT among gastrointestinal cancer patients and in particular significant changes in CSA, fibrosis, and inflammation when cachexia was present; the changes in histomorphological parameters of the adipocytes reflected alterations in adiposity at body composition analysis.

Endocrinological and Nutritional Implications of Anorexia of Aging

Poor appetite—known as anorexia—is a common condition in aging and is associated with poor outcomes, including reduced survival and impaired quality of life. The anorexia of aging is mainly the result of several complex endocrinological, metabolic, and nutritional changes occurring with later age. The modulation of different peptides and hormones has been identified as an important determinant for the development of low appetite; in particular, an altered imbalance of plasma ghrelin, leptin, and cholecystokinin and increased inflammatory markers are implicated in its pathophysiology, and robust evidence of their involvement in anorexia of aging has been produced in the clinical setting. More recently, researchers identified that the gut microbiome composition significantly varies according to the appetite status. Other important clinical factors may worsen the symptoms of the anorexia in the elderly, in particular the potential concomitant presence of chronic catabolic comorbidities. Importantly, data indicate that anorexia is prevalent in frail older adults, negatively impacting body composition and specifically in altering muscle mass and function. For all these reasons, a prompt and early diagnosis of anorexia in the elderly is crucial to implement personalized metabolic and nutrition interventions to improve the outcomes and ameliorate quality of life.

Cancer-associated anorexia: Validity and performance overtime of different appetite tools among patients at their first cancer diagnosis

BACKGROUND & AIMS

Anorexia is a frequent symptom in cancer and we aimed to assess its prevalence among patients at their first cancer diagnosis by different appetite tools and the relationship between each tool with self-reports of food intake. We also tested whether cancer anorexia influences outcomes independently of reduced food intake or body weight loss (BWL) overtime and whether BWL was associated with complications during anticancer-therapy.

METHODS

Functional Assessment of Anorexia/Cachexia Therapy (FAACT) score, self-assessment of appetite, Anorexia Questionnaire (AQ) and Visual Analog Scale (VAS) were administered. Percent of food intake was used as a criterion measure of anorexia. We registered BWL and anticancer-therapy complications over 3-month-follow-up.

RESULTS

438 cancer patients from 7 cancer-centers worldwide were included. The prevalence of anorexia was 39.9% by FAACT score, 40.2% by VAS, 40.6% by the self-assessment of appetite and 65.4% by AQ. Low food intake (≤50%) was reported in 28% of patients. All appetite tools correlated with food intake percent (P < 0.0001). We documented a correlation between self-assessment of appetite, FAACT score, VAS and BWL overtime (P < 0.04). The self-assessment of appetite (P = 0.0152) and the FAACT score (P = 0.043) were associated with BWL independently of anticancer therapies. Among patients with BWL, the risk to develop complications was greater with respect to those who maintained a stable or gained body weight (P = 0.03).

CONCLUSIONS

In our sample of cancer patients, FAACT score and self-assessment of appetite performed well when low food intake was used as a criterion measure, and revealed an association of anorexia with BWL, which was, in turn, related to the development of anticancer-therapy complications.

A Pound of Flesh: What Cachexia Is and What It Is Not

Body weight loss, mostly due to the wasting of skeletal muscle and adipose tissue, is the hallmark of the so-called cachexia syndrome. Cachexia is associated with several acute and chronic disease states such as cancer, chronic obstructive pulmonary disease (COPD), heart and kidney failure, and acquired and autoimmune diseases and also pharmacological treatments such as chemotherapy. The clinical relevance of cachexia and its impact on patients’ quality of life has been neglected for decades. Only recently did the international community agree upon a definition of the term cachexia, and we are still awaiting the standardization of markers and tests for the diagnosis and staging of cancer-related cachexia. In this review, we discuss cachexia, considering the evolving use of the term for diagnostic purposes and the implications it has for clinical biomarkers, to provide a comprehensive overview of its biology and clinical management. Advances and tools developed so far for the in vitro testing of cachexia and drug screening will be described. We will also evaluate the nomenclature of different forms of muscle wasting and degeneration and discuss features that distinguish cachexia from other forms of muscle wasting in the context of different conditions.

Association between Growth Differentiation Factor-15 (GDF-15) Serum Levels, Anorexia and Low Muscle Mass among Cancer Patients

Simple Summary

In our study, the novel inflammatory cytokine Growth Differentiation Factor-15 (GDF-15) has been found elevated in patients with gastrointestinal and lung cancer and associated with anorexia. Patients with gastrointestinal cancer were found more anorexic (based on the FAACT score) and showed higher GDF-15 serum levels than patients with lung cancer. We also evaluated the muscularity status of the patients by CT scan. No difference was found in GDF-15 levels between cancer patients with low muscle mass vs. those with moderate/high muscularity and between patients with body weight loss vs. those with stable weight. Based on our observations, we confirm the role of GDF-15 in the pathogenesis of anorexia in cancer, although the mechanisms of action of this cytokine in cancer should be further unveiled also regarding its potential involvement in changes in muscularity.

Abstract

The pathophysiology of cancer anorexia is complex and serum biomarkers, including growth and differentiation factor(s) (GDF), may be modulated. We explored the association(s) between GDF-15 serum levels and anorexia and, secondarily, with low muscle mass and body weight loss in cancer patients. We considered gastrointestinal and lung cancer patients (CP) and healthy BMI-matched controls. The FAACT-questionnaire was administered to diagnose anorexia and we calculated the L3-SMI by CT scan to assess low muscularity, setting their cutoff values at the lowest tertile. GDF-15 serum levels were assessed by ELISA. We enrolled 59 CP and 30 controls; among CP, 25 were affected by gastrointestinal and 34 by lung cancer. Anorexia was present in 36% of CP. Gastrointestinal CP resulted more anorexic compared to lung CP (p = 0.0067). Low muscle mass was present in 33.9% of CP and L3-SMI was lower in gastrointestinal compared to lung CP (p = 0.049). The GDF-15 levels were higher in CP vs. controls (p = 0.00016), as well as in anorexic vs. non-anorexic CP (p = 0.005) and vs. controls (p < 0.0001). Gastrointestinal CP showed higher GDF-15 levels vs. lung CP (p = 0.0004). No difference was found in GDF-15 between CP with low muscle mass and those with moderate/high muscularity and between patients with body weight loss and those with stable weight. Our data support the involvement of GDF-15 in the pathogenesis of cancer anorexia. The mechanisms of action of GDF-15 in cancer should be further clarified also regarding the changes in muscularity.

Inter-tissue communication in cancer cachexia

Cachexia is a systemic condition that occurs during many neoplastic diseases, such as cancer. Cachexia in cancer is characterized by loss of body weight and muscle and by adipose tissue wasting and systemic inflammation. Cancer cachexia is often associated with anorexia and increased energy expenditure. Even though the cachectic condition severely affects skeletal muscle, a tissue that accounts for ~40% of total body weight, it represents a multi-organ syndrome that involves tissues and organs such as white adipose tissue, brown adipose tissue, bone, brain, liver, gut and heart. Indeed, evidence suggests that non-muscle tissues and organs, as well as tumour tissues, secrete soluble factors that act on skeletal muscle to promote wasting. In addition, muscle tissue also releases various factors that can interact with the metabolism of other tissues during cancer. In this Review, we examine the effect of non-muscle tissues and inter-tissue communication in cancer cachexia and discuss studies aimed at developing novel therapeutic strategies for the condition.

Cachexia Stage, Patient-Generated Subjective Global Assessment, Phase Angle, and Handgrip Strength in Patients with Gastrointestinal Cancer

The aim of this study was to correlate patients with gastrointestinal cancer, classified according to different stages of cancer cachexia (SCC) as proposed by Fearon, with nutritional assessment tools such as PG-SGA, phase angle (PA), and handgrip strength. One hundred one patients with a mean age of 61.8 ± 12.8 yr, with 58.4% being men were included. 32.6% were malnourished according to the body mass index (BMI). A severe or moderate malnutrition had been diagnosed in 63.3% when assessed using the PG-SGA, 60.4% had decreased handgrip strength, and 57.4% had lower grades of PA. Among the patients in the study, 26% did not have cachexia, 11% had precachexia, 56% cachexia, and 8% refractory cachexia. The PG-SGA, PA, and handgrip strength were associated with cachexia (P ≤ 0.001). An increased risk of death was found in patients with cachexia [RR: 9.1; confidence interval (CI) 95%: 0.1-90.2, P = 0.039], refractory cachexia (RR: 69.4, CI 95%: 4.5-1073.8, P = 0.002), and increased serum C-reactive protein (CRP) levels (P < 0.001). In conclusion, most of the patients with digestive system cancer had cachexia or refractory cachexia in the first nutritional assessment. Nutritional risk, as determined by PG-SGA, was correlated with PA and handgrip strength. High CRP levels, cachexia, and refractory cachexia were prognostic factors for cancer patients.

Cancer anorexia: hypothalamic activity and its association with inflammation and appetite-regulating peptides in lung cancer

BACKGROUND

Energy homeostasis is mediated by the hypothalamus, whose inflammation-induced functional derangements contribute to the onset of anorexia in cancer. By using functional magnetic resonance imaging (fMRI), we determined the patterns of hypothalamic activation after oral intake in anorexic (A), non-anorexic (NA) cancer patients, and in controls (C).

METHODS

Lung cancer patients were considered. Hypothalamic activation was recorded in A and NA patients and in C by fMRI, before (T0), immediately after (T1) the administration of an oral nutritional supplement, and after 15 min (T2). The grey of the hypothalamus and Blood Oxygen Level Dependent (BOLD) intensity were calculated and normalized for basal conditions. Interleukin (IL)-1, IL-6, tumour necrosis factor (TNF)-α, ghrelin, and leptin plasma levels were measured. A statistical parametric mapping was used.

RESULTS

Thirteen lung cancer patients (7 M, 6 F; 9A, 4NA) and 2 C (1 M, 1 F) were enrolled. Controls had the lowest BOLD intensity. At all-time points, anorexic patients showed lower hypothalamic activity compared with NA (P < 0.001) (T0: 585.57 ± 55.69 vs. 667.92 ± 33.18, respectively; T1: 536.50 ± 61.70 vs. 624.49 ± 55.51, respectively; T2: 556.44 ± 58.51 vs. 615.43 ± 71.50, respectively). Anorexic patients showed greater BOLD signal reduction during T0-T1 than NA (-8.5% vs. -6.80%, P < 0.001). Independently from the presence of anorexia, BOLD signals modification before and after oral challenge correlated with basal values of IL-1 and ghrelin (P < 0.001).

CONCLUSIONS

Hypothalamic activity in A cancer patients is reduced respect to NA and responds differently to oral challenges. This suggests a central control of appetite dysregulation during cancer anorexia, before, and after oral intake.

Cancer and Chemotherapy Contribute to Muscle Loss by Activating Common Signaling Pathways

Cachexia represents one of the primary complications of colorectal cancer due to its effects on depletion of muscle and fat. Evidence suggests that chemotherapeutic regimens, such as Folfiri, contribute to cachexia-related symptoms. The purpose of the present study was to investigate the cachexia signature in different conditions associated with severe muscle wasting, namely Colon-26 (C26) and Folfiri-associated cachexia. Using a quantitative LC-MS/MS approach, we identified significant changes in 386 proteins in the quadriceps muscle of Folfiri-treated mice, and 269 proteins differentially expressed in the C26 hosts (p < 0.05; -1.5 ≥ fold change ≥ +1.5). Comparative analysis isolated 240 proteins that were modulated in common, with a large majority (218) that were down-regulated in both experimental settings. Interestingly, metabolic (47.08%) and structural (21.25%) proteins were the most represented. Pathway analysis revealed mitochondrial dysfunctions in both experimental conditions, also consistent with reduced expression of mediators of mitochondrial fusion (OPA-1, mitofusin-2), fission (DRP-1) and biogenesis (Cytochrome C, PGC-1α). Alterations of oxidative phosphorylation within the TCA cycle, fatty acid metabolism, and Ca2+ signaling were also detected. Overall, the proteomic signature in the presence of both chemotherapy and cancer suggests the activation of mechanisms associated with movement disorders, necrosis, muscle cell death, muscle weakness and muscle damage. Conversely, this is consistent with the inhibition of pathways that regulate nucleotide and fatty acid metabolism, synthesis of ATP, muscle and heart function, as well as ROS scavenging. Interestingly, strong up-regulation of pro-inflammatory acute-phase proteins and a more coordinated modulation of mitochondrial and lipidic metabolisms were observed in the muscle of the C26 hosts that were different from the Folfiri-treated animals. In conclusion, our results suggest that both cancer and chemotherapy contribute to muscle loss by activating common signaling pathways. These data support the undertaking of combination strategies that aim to both counteract tumor growth and reduce chemotherapy side effects.

Use of routinely available clinical, nutritional, and functional criteria to classify cachexia in advanced cancer patients

BACKGROUND

Cachexia is a highly prevalent syndrome in cancer and chronic diseases. However, due to the heterogeneous features of cancer cachexia, its identification and classification challenge clinical practitioners.

OBJECTIVE

To determine the clinical relevance of a cancer cachexia classification system in advanced cancer patients.

DESIGN

Beginning with the four-stage classification system proposed for cachexia [non-cachexia (NCa), pre-cachexia (PCa), cachexia (Ca) and refractory cachexia (RCa)], we assigned patients to these cachexia stages according to five classification criteria available in clinical practice: 1) biochemistry (high C-reactive protein or leukocytes, or hypoalbuminemia, or anemia), 2) food intake (normal/decreased), weight loss: 3) moderate (≤5%) or 4) significant (>5%/past six months) and 5) performance status (Eastern Cooperative Oncology Group Performance Status ≥ 3). We then determined if symptom severity, body composition changes, functional levels, hospitalizations and survival rates varied significantly across cachexia stages.

RESULTS

Two-hundred and ninety-seven advanced cancer patients with primary gastrointestinal and lung tumors were included. Patients were classified into Ca (36%), PCa and RCa (21%, respectively) and NCa (15%). Significant (p < 0.05) differences were observed among cachexia stages for most of the outcome measures (symptoms, body composition, handgrip strength, emergency room visits and length of hospital stays) according to cachexia severity. Survival also differed between cachexia stages (except between PCa and Ca).

CONCLUSION

Five clinical criteria can be used to stage cancer cachexia patients and predict important clinical, nutritional and functional outcomes. The lack of statistical difference between PCa and Ca in almost all clinical outcomes examined suggests either that the PCa group includes patients already affected by early cachexia or that more precise criteria are needed to differentiate PCa from Ca patients. More studies are required to validate these findings.

Enhanced activity of hormone sensitive lipase (HSL) in mesenteric but not epididymal fat correlates with higher production of epinephrine in mesenteric adipocytes in rat model of cachectic rheumatoid arthritis

Cachectic rheumatoid arthritis, the less frequent form of the disease, is associated with loss of fat mass and often more severe course of the disease. Its experimental model represents rat adjuvant arthritis (AA) characterized by edema, lack of appetite, sharp body weight and fat loss. As individual fat depots display functional differences, here we studied lipolytic activity and sensitivity to lipolytic stimuli of nodeless epididymal fat (eWAT) and perinodal mesenteric fat (mWAT) depots at the peak of AA. We also examined changes in catecholamine and cytokine levels involved in lipolysis in plasma and/or isolated adipocytes from both WATs to identify the contribution of local, adipocyte-based processes and/or systemic events to adiposity loss in cachectic rheumatoid arthritis. AA was induced to male Lewis rats by complete Freund's adjuvant. Groups of ad libitum-fed and pair-fed controls were used to distinguish the effects of food restriction from inflammation-induced cachexia. Adipose triglyceride lipase (ATGL), hormone-sensitive lipase (HSL) and its phosphorylated form (pHSL) were analyzed by western blot. CRP and catecholamine levels in plasma or adipocyte lysates were determined using ELISA kits. Cytokine-induced neutrophil chemoattractant-1 (CINC-1/CXCL1), monocyte chemoattractant protein-1 (MCP-1/CCL2), IL-1β, IL-6, IL-10 and leptin in adipocyte lysate were analyzed by quantitative protein microarray. Plasma glycerol and FFA were measured spectrophotometrically. AA rats developed severe cachexia, with lower adiposity in mWAT compared to normal and pair-fed controls, whereas in eWAT the adiposity was similarly reduced in AA and pair-fed groups. ATGL levels in both WATs were not affected by AA or pair feeding. AA upregulated levels of HSL, pHSL and pHSL/HSL ratio in mWAT, whereas none of these parameters has changed in eWAT of AA rats or in either WATs of pair-fed rats. In AA rats plasma glycerol was elevated, whereas FFA concentration was reduced. Plasma norepinephrine and epinephrine were increased in AA compared with both groups of controls. In eWAT adipocytes, AA but not pair feeding, upregulated norepinephrine levels. In mWAT adipocytes, AA rats showed higher epinephrine levels than pair-fed controls. Leptin levels in both WATs were depleted in AA animals in accordance with body weight loss. None of the measured cytokines in eWAT and mWAT was enhanced. Our results demonstrate augmented lipolytic activity in mWAT and not eWAT during cachectic arthritis. The adipocyte-derived cytokines do not seem to contribute to activated lipolysis. We first demonstrated enhanced presence of norepinephrine in perinodal adipocytes that may contribute to the regulation of local lipolytic activity by auto/paracrine fashion and thus provide independent fuel supply to activated lymph nodes.

APPETITE PREDICTS INTAKE AND NUTRITIONAL STATUS IN PATIENTS RECEIVING PERITONEAL DIALYSIS

BACKGROUND

Sub-optimal nutrition status is common amongst patients receiving peritoneal dialysis (PD) and leads to poor clinical outcome. This population experiences multi-factorial challenges to achieving optimal nutritional status, particularly driven by inadequate intake.

OBJECTIVES

The aim of this investigation was to identify factors associated with inadequate protein intake and sub-optimal nutritional status in patients undergoing PD.

DESIGN/PARTICIPANTS

This was a cross-sectional study of 67 adult patients receiving PD (mean age 59 ± 14 years; 57% male) within a single centre. Participants were consecutively recruited and interviewed by renal dietitians, collecting: Subjective Global Assessment (SGA); quality of life (using EQ-5D); dietary intake (via dietary interview); and appetite (using Appetite and Diet Assessment Tool). Participant demographics were obtained via survey or medical charts. Main outcome measures were inadequate dietary protein intake (<1.1 g/kg adjusted body weight/day) and malnutrition (as defined by SGA rating B or C).

RESULTS

Overall, 15 (22%) patients were malnourished and 29 (43%) had inadequate protein intake. Poor appetite (anorexia) was reported in 62% (18/29) of participants with inadequate protein malnourished patients reported anorexia versus 12 (23%) of the well-nourished patients (p = 0.0001).

CONCLUSION

Anorexia was a key risk factor for inadequate protein intake and malnutrition in patients undergoing PD. These findings highlight a need to closely monitor patients with appetite disturbances.

Nonmuscle Tissues Contribution to Cancer Cachexia

Cachexia is a syndrome associated with cancer, characterized by body weight loss, muscle and adipose tissue wasting, and inflammation, being often associated with anorexia. In spite of the fact that muscle tissue represents more than 40% of body weight and seems to be the main tissue involved in the wasting that occurs during cachexia, recent developments suggest that tissues/organs such as adipose (both brown and white), brain, liver, gut, and heart are directly involved in the cachectic process and may be responsible for muscle wasting. This suggests that cachexia is indeed a multiorgan syndrome. Bearing all this in mind, the aim of the present review is to examine the impact of nonmuscle tissues in cancer cachexia.

Cancer cachexia: understanding the molecular basis

Cancer cachexia is a devastating, multifactorial and often irreversible syndrome that affects around 50-80% of cancer patients, depending on the tumour type, and that leads to substantial weight loss, primarily from loss of skeletal muscle and body fat. Since cachexia may account for up to 20% of cancer deaths, understanding the underlying molecular mechanisms is essential. The occurrence of cachexia in cancer patients is dependent on the patient response to tumour progression, including the activation of the inflammatory response and energetic inefficiency involving the mitochondria. Interestingly, crosstalk between different cell types ultimately seems to result in muscle wasting. Some of the recent progress in understanding the molecular mechanisms of cachexia may lead to new therapeutic approaches.

Immunological and hormonal effects of exercise: implications for cancer cachexia

PURPOSE OF REVIEW

There is increasing interest in the use of therapeutic exercise for cancer cachexia. Apart from the directly beneficial effects on muscle, exercise has the potential to attenuate some of the immunological and hormonal abnormalities found in cachexia. This review summarizes the findings of recent studies, which have explored such effects in patients with cancer, and discusses their relevance to patients with cancer cachexia.

RECENT FINDINGS

Our search identified 11 studies in patients with breast, colorectal, lung, and prostate cancer, predominantly with early stage disease or following primary curative treatment. Overall, exercise was associated with reduced levels of C-reactive protein (CRP), but not other markers of systemic inflammation. There was no consistent impact on levels of glucose, insulin or measures of insulin sensitivity or, in patients with prostate cancer, on levels of testosterone.

SUMMARY

There is limited scope to extrapolate these findings to patients with cancer cachexia, who are more likely to have advanced disease, higher levels of systemic inflammation, and greater degrees of metabolic dysfunction. Studies specific to this group are required to explore what, if any, changes exercise can make to levels of CRP and other immune and hormonal biomarkers, along with their potential clinical relevance.

Cancer cachexia: towards integrated therapeutic interventions

Biological treatments represent a novel approach to counteract cancer cachexia. Monoclonal antibodies targeting cytokines and molecules responsible for muscle wasting, with an anti-inflammatory effect, however, still have several limitations and need further clinical investigation. New research in this field will contribute to the better understanding of the multifactorial pathogenesis of cancer cachexia, while favoring the consolidation of multimodal preventive and therapeutic strategies encompassing nutritional and pharmacological treatments. New pharmacological therapies and conventional nutritional treatments will soon integrate in the 'parallel pathway', aimed at early recognition, prevention and treatment of the metabolic and nutritional derangements occurring in cancer. This will likely produce improvement in quality of life, tolerance to treatments and survival.

Inducible nitric oxide synthase (iNOS) in muscle wasting syndrome, sarcopenia, and cachexia

Muscle atrophy—also known as muscle wasting—is a debilitating syndrome that slowly develops with age (sarcopenia) or rapidly appears at the late stages of deadly diseases such as cancer, AIDS, and sepsis (cachexia). Despite the prevalence and the drastic detrimental effects of these two syndromes, there are currently no widely used, effective treatment options for those suffering from muscle wasting. In an attempt to identify potential therapeutic targets, the molecular mechanisms of sarcopenia and cachexia have begun to be elucidated. Growing evidence suggests that inflammatory cytokines may play an important role in the pathology of both syndromes. As one of the key cytokines involved in both sarcopenic and cachectic muscle wasting, tumor necrosis factor α (TNFα) and its downstream effectors provide an enticing target for pharmacological intervention. However, to date, no drugs targeting the TNFα signaling pathway have been successful as a remedial option for the treatment of muscle wasting. Thus, there is a need to identify new effectors in this important pathway that might prove to be more efficacious targets. Inducible nitric oxide synthase (iNOS) has recently been shown to be an important mediator of TNFα-induced cachectic muscle loss, and studies suggest that it may also play a role in sarcopenia. In addition, investigations into the mechanism of iNOS-mediated muscle loss have begun to reveal potential therapeutic strategies. In this review, we will highlight the potential for targeting the iNOS/NO pathway in the treatment of muscle loss and discuss its functional relevance in sarcopenia and cachexia.

Brain-immune interactions and the neural basis of disease-avoidant ingestive behaviour

Neuro-immune interactions are widely manifested in animal physiology. Since immunity competes for energy with other physiological functions, it is subject to a circadian trade-off between other energy-demanding processes, such as neural activity, locomotion and thermoregulation. When immunity is challenged, this trade-off is tilted to an adaptive energy protecting and reallocation strategy that is identified as 'sickness behaviour'. We review diverse disease-avoidant behaviours in the context of ingestion, indicating that several adaptive advantages have been acquired by animals (including humans) during phylogenetic evolution and by ontogenetic experiences: (i) preventing waste of energy by reducing appetite and consequently foraging/hunting (illness anorexia), (ii) avoiding unnecessary danger by promoting safe environments (preventing disease encounter by olfactory cues and illness potentiation neophobia), (iii) help fighting against pathogenic threats (hyperthermia/somnolence), and (iv) by associative learning evading specific foods or environments signalling danger (conditioned taste avoidance/aversion) and/or at the same time preparing the body to counteract by anticipatory immune responses (conditioning immunomodulation). The neurobiology behind disease-avoidant ingestive behaviours is reviewed with special emphasis on the body energy balance (intake versus expenditure) and an evolutionary psychology perspective.

Current and future pharmacologic treatment of sarcopenia

Sarcopenia is a complex multifactorial condition that can by treated with multimodal approaches. No pharmacologic agent to prevent or treat sarcopenia has been as efficacious as exercise (mainly resistance training) in combination with nutritional intervention (adequate protein and energy intake). However, performing resistance training sessions and following nutritional advice can be challenging, especially for frail, sarcopenic, elderly patients, and results remain only partial. Therefore, new pharmacologic agents may substantially reduce the functional decline in older people. This article reviews the new pharmacologic agents currently being assessed for treating sarcopenia.

Treatment strategies for sarcopenia and frailty

Sarcopenia is the key feature of frailty in older people and a major determinant of adverse health outcomes such as functional limitations and disability. Resistance training and adequate protein and energy intake are the key strategies for the management of sarcopenia. Management of weight loss and resistance training are the most relevant protective countermeasures to slow down the decline of muscle mass and muscle strength. The quality of amino acids in the diet is an important factor for stimulating protein synthesis. Vitamin D deficiency should be treated, and new pharmacologic approaches for sarcopenia are currently assessed.