Energy balance in nonsmall cell lung carcinoma patients before and after surgical resection of their tumors

Influence of body composition assessment with bioelectrical impedance vector analysis in cancer patients undergoing surgery

Background

Malnutrition is common in patients undergoing surgery for cancers and is a risk factor for postoperative outcomes. Body composition provides information for precise nutrition intervention in perioperative period for improving patients' postoperative outcomes.

Objection

The aim was to determine changes in parameters of body composition and nutritional status of cancer patients during perioperative period.

Methods

A total of 92 patients diagnosed with cancer were divided into gastrointestinal and non-gastrointestinal cancer group according to different cancer types. The patients body composition assessed by bioelectrical impedance vector analysis (BIVA) on the day before surgery, postoperative day 1 and 1 day before discharge. The changes between two groups were compared and the correlation between body composition and preoperative serum nutritional indexes was analyzed.

Results

The nutritional status of all patients become worse after surgery, and phase angle (PA) continued to decrease in the perioperative period. Fat-free mass (FFM), fat-free mass index (FFMI), skeletal muscle mass (SMM), extracellular water (ECW), total body water (TBW), hydration, and body cell mass (BCM) rise slightly and then fall in the postoperative period in patients with gastrointestinal cancer, and had a sustained increase in non-gastrointestinal patients, respectively (P<0.05). Postoperative body composition changes in patients with gastrointestinal cancer are related to preoperative albumin, pre-albumin, hemoglobin, and C-reactive protein (P<0.05), whereas postoperative body composition changes in patients with non-gastrointestinal cancer are related to age (P<0.05).

Conclusions

Significant changes in body composition both in patients with gastrointestinal cancer and non-gastrointestinal cancer during perioperative period are observed. Changes in body composition for the cancer patients who undergoing surgery are related to age and preoperative serum nutrition index.

Hypermetabolism is an independent prognostic factor of survival in metastatic non-small cell lung cancer patients

BACKGROUND & AIMS

Metastatic non-small cell lung cancer (NSCLC) is the first cause of cancer death worldwide. Increased resting energy expenditure (REE) is frequent among cancer patients and may contribute to cancer cachexia. The aim of this study was to examine the prognostic value of increased REE in metastatic NSCLC patients.

METHODS

This observational study was conducted between June 2012 and November 2017 in the outpatient unit of the oncology department of Cochin hospital, Paris. Consecutive patients with newly diagnosed stage IV NSCLC underwent measurement of REE by indirect calorimetry before treatment initiation. Uni- and multivariate analysis of overall survival (OS, Cox models) included age, sex, smoking habit, histological subtype, performance status, body mass index, weight loss, albumin and CRP levels and the ratio of measured REE to the REE predicted by the Harris Benedict formula (mREE/pREE).

RESULTS

144 patients were enrolled: mean age 64 years, 63% male, 90% non-squamous carcinoma, including 17% with ALK/EGFR alteration. In univariate analysis, tobacco consumption (p = 0.007), histo-molecular subtype (p < 10^-3), performance status (p = 0.04), weight loss (p < 10^-4), albumin (p < 10^-4), CRP (p = 0.001) and mREE/pREE ratio (>vs ≤ 120%: HR = 2.16, p < 10^-3) were significant prognostic factors of OS. Median OS were 6.1 and 17.3 months in patients with mREE/pREE ratio > and ≤120%, respectively. In multivariate analysis, histo-molecular subtype (non-squamous ALK/EGFR mutated vs squamous carcinoma: HR = 0.25, p = 0.006), weight loss (>vs ≤ 5%: HR = 1.98, p = 0.004), albumin (≥vs < 35 g/L: HR = 0.56, p = 0.02) and mREE/pREE ratio (> vs ≤120%: HR = 1.90, p = 0.004) were identified as independent prognostic factors.

CONCLUSIONS

Elevated resting energy expenditure emerges as an independent prognostic factor in metastatic NSCLC.

Estimation of perioperative invasiveness of colorectal endoscopic submucosal dissection evaluated by energy metabolism

The aim of this study was to assess the perioperative invasiveness of endoscopic submucosal dissection for colorectal cancer quantitatively by using energy metabolism. In fifty-three patients who underwent endoscopic submucosal dissection for colorectal cancer, resting energy expenditure using an indirect calorimeter, body weight and basal energy expenditure using the Harris–Benedict equation before and after endoscopic submucosal dissection. Resting energy expenditure/body weight and resting energy expenditure/basal energy expenditure were 19.7 ± 2.5 kcal/kg/day and 0.96 ± 0.12 on the day of endoscopic submucosal dissection, whereas one day after the endoscopic submucosal dissection they increased to 21.0 ± 2.9 kcal/kg/day and 1.00 ± 0.13 (p<0.001 and p<0.05, respectively). The stress factor on the postoperative day 1 was computed as 1.06. The increase was lower comparing with that experienced for surgery, suggesting that the perioperative invasiveness of colorectal endoscopic submucosal dissection is lower in comparison to that during surgery. Furthermore, in spite of technical difficulty, stress factor of colorectal endoscopic submucosal dissection was approximately equal to that of gastric endoscopic submucosal dissection. (The study of the resting energy metabolism and stress factor using an indirect calorimeter in the perioperative period of endoscopic operation: UMIN000027135)

Gender differences in the correlation between prognosis and postoperative weight loss in patients with non-small cell lung cancer

OBJECTIVES

The aim of this study was to investigate gender differences in the relationship between preoperative body mass index (BMI), postoperative body weight change and prognosis in patients with non-small cell lung cancer (NSCLC).

METHODS

Two hundred and sixty-three patients with NSCLC were enrolled in this study. Preoperative BMI was categorized based on WHO definition as follows: underweight (BMI <18.5): 21 patients (8.0%), normal (18.5 ≦ BMI <25): 179 patients (68%), overweight and obese (BMI ≧25): 63 patients (24%). Several factors such as age, sex, cancer stage, body weight change and BMI were recorded and correlated to the postoperative overall survival (OS).

RESULTS

For male patients, those in the low-BMI group had the worst prognosis (P < 0.05) whereas female patients with low BMI did not. Male patients with low BMI had statistically significant poorer prognosis compared to corresponding female patients (P < 0.05). Male patients with more than 5% body weight loss within 1 year after operation when compared to preoperative body weight had poorer prognosis than those with less than 5% body weight loss (P < 0.001). Furthermore, these male patients had statistically significant worse prognosis than the corresponding female patients (P < 0.05). In multivariable analysis, gender, more than 5% of body weight loss compared to preoperative body weight, and pathological stage were independent prognostic factors in NSCLC.

CONCLUSIONS

This study illustrates significant gender differences in the relationship between prognosis and BMI or body weight change in patients with postoperative NSCLC.

Neutral evolution of drug resistant colorectal cancer cell populations is independent of their KRAS status

Emergence of tumor resistance to an anti-cancer therapy directed against a putative target raises several questions including: (1) do mutations in the target/pathway confer resistance? (2) Are these mutations pre-existing? (3) What is the relative fitness of cells with/without the mutation? We addressed these questions in patients with metastatic colorectal cancer (mCRC). We conducted an exhaustive review of published data to establish a median doubling time for CRCs and stained a cohort of CRCs to document mitotic indices. We analyzed published data and our own data to calculate rates of growth (g) and regression (d, decay) of tumors in patients with CRC correlating these results with the detection of circulating MT-KRAS DNA. Additionally we estimated mathematically the caloric burden of such tumors using data on mitotic and apoptotic indices. We conclude outgrowth of cells harboring intrinsic or acquired MT-KRAS cannot explain resistance to anti-EGFR (epidermal growth factor receptor) antibodies. Rates of tumor growth with panitumumab are unaffected by presence/absence of MT-KRAS. While MT-KRAS cells may be resistant to anti-EGFR antibodies, WT-KRAS cells also rapidly bypass this blockade suggesting inherent resistance mechanisms are responsible and a neutral evolution model is most appropriate. Using the above clinical data on tumor doubling times and mitotic and apoptotic indices we estimated the caloric intake required to support tumor growth and suggest it may explain in part cancer-associated cachexia.

Energy metabolism during the perioperative period of gastric endoscopic submucosal dissection

The aim of this study was to investigate the change in the energy metabolism and invasiveness in the perioperative period of endoscopic submucosal dissection for early gastric cancer. Fifty-two consecutive patients were enrolled into the study between July 2013 and May 2014 and examined resting energy expenditure using an indirect calorimeter, body weight and basal energy expenditure using the Harris-Benedict equation before and after endoscopic submucosal dissection. Resting energy expenditure/body weight and resting energy expenditure/basal energy expenditure were 20.2 ± 3.0 kcal/kg/day and 0.96 ± 0.11 on the day of endoscopic submucosal dissection, whereas one day after the endoscopic submucosal dissection they were 21.7 ± 3.2 kcal/kg/day and 1.03 ± 0.14, showing significant increases (p<0.001, respectively). The stress factor on the postoperative day 1 was computed as 1.07. This increase was low in comparison to that experienced for surgery, suggesting that the degree of perioperative invasiveness in patients receiving endoscopic submucosal dissection is lower in comparison to that during surgery (The study of the resting energy metabolism and stress factor using an indirect calorimeter in the perioperative period of endoscopic operation: UMIN000027135).

Cachexia in chronic obstructive pulmonary disease: new insights and therapeutic perspective

Cachexia and muscle wasting are well recognized as common and partly reversible features of chronic obstructive pulmonary disease (COPD), adversely affecting disease progression and prognosis. This argues for integration of weight and muscle maintenance in patient care. In this review, recent insights are presented in the diagnosis of muscle wasting in COPD, the pathophysiology of muscle wasting, and putative mechanisms involved in a disturbed energy balance as cachexia driver. We discuss the therapeutic implications of these new insights for optimizing and personalizing management of COPD-induced cachexia.

Nuclear transcription factor κ B activation and protein turnover adaptations in skeletal muscle of patients with progressive stages of lung cancer cachexia

BACKGROUND

Experimental models of cancer cachexia have indicated that systemic inflammation induces muscle-protein breakdown and wasting via muscular nuclear transcription factor κB (NF-κB) activation. This process may limit the efficacy of nutritional intervention.

OBJECTIVES

We assessed muscle NF-κB activity and protein turnover signaling in progressive stages of clinical lung cancer cachexia and assessed whether circulating factors can induce muscular NF-κB activity.

DESIGN

Patients with lung cancer precachexia (n = 10) and cachexia (n = 16) were cross-sectionally compared with 22 healthy control subjects. mRNA transcripts of muscle proteolytic (ubiquitin proteasome system and autophagy lysosomal pathway) and myogenic markers and protein expression of PI3K/Akt, myostatin, and autophagy signaling were measured. A multiplex analysis showed the systemic inflammatory status, whereas plasma exposure to stable NF-κB-luciferase-reporter muscle cells revealed NF-κB inducibility.

RESULTS

Compared with healthy control subjects, cachectic patients had reduced (appendicular) muscle mass (-10%), muscle fiber atrophy (-27%), and decreased quadriceps strength (-31%). Subtle alterations in the muscle morphology were also detectable in precachectic patients, without changes in body composition. Despite increased Akt phosphorylation, downstream phosphosubstrates glycogen synthase kinase 3β, mammalian target of rapamycin, and Forkhead box protein were unaltered. The expression of autophagy effectors B cell lymphoma 2/adenovirus E1B 19-kDa protein-interacting protein 3 and microtubule-associated proteins 1A/1B light chain 3B gradually increased from precachectic to cachectic patients, without differences in E3 ubiquitin ligases. Systemic and local inflammation was evident in cachexia and intermediate in precachexia, but the plasma of both patients groups caused ex vivo muscle NF-κB activation.

CONCLUSIONS

In lung cancer, muscular NF-κB activity is induced by factors contained within the circulation. Autophagy may contribute to increased muscle proteolysis in lung cancer cachexia, whereas the absence of downstream changes in phosphosubstrates despite increased Akt phosphorylation suggests impaired anabolic signaling that may require targeted nutritional intervention.

Low perioperative serum prealbumin predicts early recurrence after curative pulmonary resection for non-small-cell lung cancer

BACKGROUND

Early recurrence after surgery for non-small-cell lung cancer (NSCLC) is often observed in spite of pathologically proven early-stage disease. The aim of this study was to identify biomarkers that might be useful in predicting postoperative early recurrence of lung cancer. In this study we evaluated the perioperative nutritional status of the patients by measuring the serum level of prealbumin and analyzed the correlation between this factor and early recurrence.

METHODS

Forty-four patients with NSCLC were enrolled in the study. Serum level of prealbumin was measured 5 days before and 7 days after surgery, respectively.

RESULTS

For the patients who developed early recurrence, the perioperative serum prealbumin level was statistically significantly lower than those of the patients who did not develop recurrence (p<0.05). Furthermore, the patients with low prealbumin level showed statistically significantly poorer outcomes compared with the patients with higher prealbumin level (p<0.001). On the other hand, there was no correlation between the pathological stage and the serum prealbumin level. Multivariate analysis revealed that low perioperative serum prealbumin level could be an independent prognostic factor of poor outcome (hazard ratio, 10.1; 95% confidence interval, 2.8-35.5; p=0.0003).

CONCLUSIONS

Low serum prealbumin level in the perioperative period is associated with a poorer prognosis in NSCLC patients and could serve as a marker for identifying patients at high risk, even at an early clinical stage.

Effect of tumor load on energy expenditure in patients with pancreatic cancer

OBJECTIVE

Increased metabolic rate may play a role in cancer cachexia, especially when caloric intake is significantly reduced. We studied the effect of tumor load on resting energy expenditure (REE) in patients with pancreatic cancer after normalizing for their daily caloric intake and body composition.

METHODS

The cross-sectional study included 45 patients with pancreatic cancer (15 postoperation) and 75 controls. Resting energy expenditure was measured by indirect calorimetry, body composition was measured by dual-energy x-ray absorptiometry, and energy intake was measured by 3-day food records.

RESULTS

There were no differences between pancreatic cancer patients who underwent surgery and those who did not in any of the anthropometric or metabolic parameters tested. Body mass index, lean body mass, body fat percentage, and energy intake were significantly lower in patients with pancreatic cancer (P < 0.0001) compared with healthy controls. Resting energy expenditure and the respiratory quotient were significantly lower in patients (P < 0.0001 and P < 0.025, respectively). There were no differences in REE between patients and controls when normalized by lean body mass. Respiratory quotients were significantly lower in patients who underwent surgery and in those who did not compared with controls.

CONCLUSIONS

Pancreatic cancer does not increase REE above the normal levels nor does tumor burden contribute to increasing REE. Decreased daily energy intake of our patients may have reduced measured REE.

[Evaluating the nutritional status of a lung cancer patient is an important element in patient management]

Nutritional status assessment during the comprehensive management of patients treated for cancer is becoming increasingly necessary. Various data are currently available which show a relationship between the nutritional status and certain morbidity-mortality parameters. In contrast, there is a paucity of data concerning lung cancer. A relationship between survival and the nutritional status has been found in the literature, exclusively in advanced stages of lung cancer. Unlike that observed in oncological digestive tract surgery, where artificial nutrition is recommended preoperatively in severely malnourished patients, no link has been evidenced between postoperative morbidity and mortality and the preoperative nutritional status in lung surgery. The scientific nutritional societies simply recommend preoperative nutritional assessment. Reflection on management of malnourished patients receiving chemotherapy is still "archaic" and recent studies and recommendations are lacking. Although largely prescribed, oral nutritional supplements have not proven efficient and patient compliance will probably have to be improved. According to "good nutrition practice" rules, the digestive tube should be used when it is functional and in theory, enteral nutrition is indicated in this situation. In addition to the lack of clinical studies, one of the obstacles to its use is cultural with the need to obtain not only patient approval but also that of the prescriber. Parenteral nutrition was discredited in earlier studies. It should probably be reevaluated in the context of new chemotherapeutic molecules and a different way of handling nutrition care. The physiological concept of omega-3 fatty acid modulation of inflammation is of interest in animal studies but the clinical modalities of use remain to be defined and determined. The role of nutrition in the management of lung cancer is still very limited but there are major expectations and many solutions are awaited in the coming years.

Body composition and time course changes in regional distribution of fat and lean tissue in unselected cancer patients on palliative care—Correlations with food intake, metabolism, exercise capacity, and hormones

BACKGROUND

Several investigations that yielded different results in terms of net changes in body composition of weight-losing cancer patients have been reported that employed a variety of methods based on fundamentally different technology. Most of those reports were cross-sectional, whereas to the authors' knowledge there is sparse information available on longitudinal follow-up measurements in relation to other independent methods for the assessment of metabolism and performance.

METHODS

For the current report, the authors evaluated time course changes in body composition (dual-energy X-ray absorptiometry) with measurements of whole body and regional distribution of fat and lean tissue in relation to food and dietary intake, host metabolism (indirect calorimetry), maximum exercise capacity (walking test), and circulating hormones in cancer patients who were receiving palliative care during 4-62 months of follow-up. The entire cohort comprised 311 patients, ages 68 years +/- 3 years who were diagnosed with solid gastrointestinal tumors (84 colorectal tumors, 74 pancreatic tumors, 73 upper gastrointestinal tumors, 51 liver-biliary tumors, 3 breast tumors, 5 melanomas, and 21 other tumor types).

RESULTS

Decreased body weight was explained by loss of body fat, preferentially from the trunk, followed by leg tissue and arm tissue, respectively. Lean tissue (fat-free mass) was lost from arm tissue, whereas trunk and leg tissue compartments increased, all concomitant with declines in serum albumin, increased systemic inflammation (C-reactive protein, erythrocyte sedimentation rate), increased serum insulin, and elevated daily caloric intake; whereas serum insulin-like growth factor 1 (IGF-1), resting energy expenditure, and maximum exercise capacity remained unchanged in the same patients. Serum albumin levels (P < 0.001), whole body fat (P < 0.02), and caloric intake (P < 0.001) predicted survival, whereas lean tissue mass did not. Daily intake of fat and carbohydrate was more important for predicting survival than protein intake. Survival also was predicted by serum IGF-1, insulin, leptin, and ghrelin levels (P < 0.02 - P < 0.001). Serum insulin, leptin, and ghrelin (total) levels predicted body fat (P < 0.001), whereas IGF-1 and thyroid hormone levels (T3, free T3) predicted lean tissue mass (P < 0.01). Systemic inflammation primarily explained variation in lean tissue and secondarily explained loss in body fat. Depletion of lean arm tissue was related most to short survival compared with the depletion of lean leg and trunk tissue.

CONCLUSIONS

The current results demonstrated that body fat was lost more rapidly than lean tissue in progressive cancer cachexia, a phenomenon that was related highly to alterations in the levels of circulating classic hormones and food intake, including both caloric amount and diet composition. The results showed importance in the planning of efficient palliative treatment for cancer patients.

Cancer-associated malnutrition

Malnutrition is a common problem among patients with cancer, affecting up to 85% of patients with certain cancers (e.g. pancreas). In severe cases, malnutrition can progress to cachexia, a specific form of malnutrition characterised by loss of lean body mass, muscle wasting, and impaired immune, physical and mental function. Cancer cachexia is also associated with poor response to therapy, increased susceptibility to treatment-related adverse events, as well as poor outcome and quality of life. Cancer cachexia is a complex, multifactorial syndrome, which is thought to result from the actions of both host- and tumour-derived factors, including cytokines involved in a systemic inflammatory response to the tumour. Early intervention with nutritional supplementation has been shown to halt malnutrition, and may improve outcome in some patients. However, increasing nutritional intake is insufficient to prevent the development of cachexia, reflecting the complex pathogenesis of this condition. Nutritional supplements containing anti-inflammatory agents, for example the polyunsaturated fatty acid (PUFA) eicosapentanoic acid (EPA), have been shown to be more beneficial to malnourished patients than nutritional supplementation alone. EPA has been shown to interfere with multiple mechanisms implicated in the pathogenesis of cancer cachexia, and in clinical studies, has been associated with reversal of cachexia and improved survival.

Longitudinal study of resting energy expenditure, body cell mass and the inflammatory response in male patients with non-small cell lung cancer

The aim of this study was to examine the inter-relationship between the inflammatory response and resting energy expenditure in patients with non-small cell lung cancer (NSCLC) before and after the onset of weight loss. Healthy subjects (n=7) and patients with NSCLC without weight loss (n=12) were studied. Resting energy expenditure adjusted for metabolically active tissue, as measured by total body potassium, was approximately 15% higher in the NSCLC group (P<0.01). Moreover, the resting energy expenditure, correlated with the magnitude of the inflammatory response (r=0.753, P<0.01). Six cancer patients subsequently lost weight and the relationship between resting energy expenditure and the inflammatory response was maintained. These results highlight the impact of the inflammatory response on the increase in the resting energy expenditure which precedes the onset of weight loss in patients with NSCLC.

Nutritional status of patients undergoing lung cancer operations

BACKGROUND

Patients referred for lung cancer operations were reported to be nutritionally depleted. This may be relevant in determining patient outcome after surgical procedures. A study was undertaken to measure a range of nutritional variables including dietary intake of patients referred to a regional cardiothoracic center for curative lung cancer operations.

METHODS

Anthropometric measurements, grip strength, fat-free mass (FFM), serum protein concentrations, lymphocyte count, creatinine-height index, subjective global assessment, and data on daily intakes of energy, protein, and vitamin C were collected prospectively. Anthropometric indices were also measured in a group of control patients with mild chronic obstructive pulmonary disease.

RESULTS

Sixty patients and 22 control patients were recruited. Weight, skin-fold thickness, and grip strength were not significantly different between patients and control patients, and both groups were similar to the general population. However, 8 patients (13.3%) had a body mass index (BMI) less than 20, and 14 patients (24.1%) had a fat-free mass index less than 15. Serum albumin and transferrin concentrations and lymphocyte count were very rarely depressed but prealbumin and retinol-binding protein levels were below normal in 11.9% and 8.3% of patients, respectively. Thirty percent of patients reported low energy intake, 13% reported a low protein intake, and 61.7% had reduced vitamin C intake.

CONCLUSIONS

Severe nutritional depletion was uncommon in patients referred for operations for lung cancer and its frequency may have been overestimated in some previous reports. A low intake of vitamin C was common in our patients but its clinical significance is unclear.

Lean body mass changes in cancer patients with weight loss

BACKGROUND AND AIMS

Metabolic measurements (e.g. resting energy expenditure) are adjusted to lean body mass to account for body composition differences. Usually lean body mass is estimated from total body water. However, this may be compromised in weight-losing cancer patients owing to alterations in the degree of hydration of the lean body mass. This study examined the relationship between two independent estimates of lean body mass in healthy subjects and cancer patients with weight loss.

METHODS AND RESULTS

Height, weight, total body water and total body potassium were measured in healthy subjects (n=9) and weight losing cancer patients (n=13). They were similar in terms of age and gender. However, the cancer group had a significantly lower percentage ideal body weight (P<0.001). The measured total body water values in both groups were similar to those predicted. In contrast, measured total body potassium values in the cancer group were significantly lower than predicted (P<0.001). There was a correlation between the ratio of measured lean body mass (water/lean bodymass (potassium) and the percentage weight loss (r=0.698, P<0.001).

CONCLUSIONS

These results suggest that total body water significantly overestimates metabolically active tissue in weight-losing cancer patients and therefore its use as the basis for metabolic requirements in this group of patients is questionable.

Beta-adrenoceptor activity and resting energy metabolism in weight losing cancer patients

This study was aimed at comparing the blocking of beta-adrenoceptor activity to changes in the resting energy metabolism of 10 cancer patients with progressive weight loss due to solid malignant tumours. Resting energy expenditure (REE) as well as whole body carbohydrate and fat oxidation were investigated and related to plasma substrate levels (glucose, glycerol, free fatty acids (FFA)) before and after 5 days of oral administration of specific beta1 receptor blocker (atenolol, 50 mg/day) and non-specific beta1,beta2-adrenoceptor (propranolol, 80 mg/day) blockade. The administration order of the drugs was random, and a 3-day washout period was used in all individuals between the provision of the first and the second drug in order to minimise the risk of carry-over effects. Resting measurements in the morning after an overnight fast were performed by indirect calorimetry. Atenolol treatment reduced REE by 77+/-14 kcal/day and propranolol by 48+/-13 kcal/day, respectively (P<0.05 versus pretreatment values). Whole body oxygen uptake and carbon dioxide production were decreased similarly by both atenolol and propranolol treatment (P<0.05). Carbohydrate oxidation was increased by atenolol and decreased by propranolol, whilst fat oxidation was decreased by atenolol and unchanged by propranolol. The decrease in REE, accounting for the decline in heart rate, was significantly more pronounced following treatment with propranolol compared with atenolol (P<0.05). Atenolol and propranolol had no effect on blood glucose, plasma glycerol and FFA. We conclude that wastage in cancer patients is in part explained by increased beta(1) and beta(2)-adrenoceptor activity, in part secondary to elevated cardiovascular activity as a result of anaemia, loss of cardiac contractile capacity and altered host metabolism.