Cardiac cachexia: a systematic overview

Elevated TNFalpha production in whole blood in patients with severe COPD: the potential link to disease severity

OBJECTIVE

The relationship between tumour necrosis factor-alpha (TNFalpha), severity of pulmonary disease and nutritional depletion in chronic obstructive pulmonary disease (COPD) remains unclear. We aimed to clarify the role of lipopolysaccharide (LPS) as a potential stimulus of cytokine production and the role of these cytokines in the alteration of body composition in patients with different degrees of COPD.

PATIENTS AND METHODS

We studied 29 weight-stable out-patients with different severites of COPD who had no evidence of recent infection or significant co-morbidity. Baseline serum TNFalpha levels and TNFalpha response to LPS in whole blood were measured in patients and 20 aged matched controls.

RESULTS

Serum TNFalpha was significantly elevated in patients versus controls (2.1 +/- 0.3 vs. 1.1 +/- 0.1 pg/ml, mean +/- SEM, P = 0.007). In patients with COPD, we found a significant correlation between serum TNFalpha levels and disease severity, assessed as FEV(1) %predicted (r = 0.49, P = 0.02). Response to lipopolysaccharide did not differ significantly between patients and controls. However, within the patient group those with more severe disease (FEV(1) < or = 30% predicted, n = 12) had an enhanced response compared to patients with mild-to-moderate disease (all P < 0.05 for LPS > 1 ng/ml). Spontaneous TNFalpha production was 5.0 times higher in patients with severe COPD compared to mild-to-moderate COPD (P = 0.02). There was no relation between body composition and serum TNFalpha or TNFalpha response to LPS.

CONCLUSION

Increasing airflow obstruction and hypercapnia are associated with an enhanced TNFalpha response in COPD.

COPD is not COPD is not allergy

Chronic obstructive pulmonary disease (COPD) is still a poorly understood disease. Its pathogenesis is excitingly complex and has systemic consequences caused not only by increased production of certain cytokines but also by neurohumoral activation, chronic bacterial infection, muscle wasting and cachexia. Asthma and COPD have many overlapping clinical features so it should not be surprising that in the pathogenesis of COPD mediators such as leukotrienes, complement activation, atopic or even autoimmune processes are possibly involved. The pathogenesis of cardiovascular system involvement in COPD is also multifaceted and includes chronic heart hypoxia, damage by smoking and pulmonary hypertension; it must also be viewed as a consequence of systemic inflammation and neurohormonal activation. COPD is among the leading causes of morbidity and mortality worldwide and therefore it should be studied intensively beyond the lung itself. Treatments directed at neurohumoral activation in COPD have not been fully addressed; this aspect of COPD should be better understood, as it may direct novel therapeutic approaches.

The burden of chronic obstructive pulmonary disease in patients hospitalized with heart failure

OBJECTIVES

Like chronic heart failure, chronic obstructive pulmonary disease (COPD) is an enormous public health problem in industrialized countries. Our aim was to determine the prevalence and clinical impact of COPD among patients hospitalized for heart failure in a community hospital serving a population of 125,000 people.

METHODS

Between 2001 and 2003 a total of 638 patients (73 +/- 10 years, 48% men, 74% NYHA class III) were identified with a discharge diagnosis of heart failure. Medical charts were reviewed and vital status was obtained from a Central Population Registry.

RESULTS

COPD was diagnosed in 106 (17%) patients whose age was similar to those without COPD (73 +/- 9 vs. 73 +/- 11 years, P = 0.35). Patients with COPD were more often males (65% vs. 45%, P < 0.001). There were no differences in arterial hypertension, atrial fibrillation, diabetes mellitus and most laboratory markers except hemoglobin (141 +/- 20 vs. 132 +/- 20 g/l, P < 0.001) and uric acid (453 +/- 136 vs. 414 +/- 139 mmol/l, P = 0.013). At discharge, patients with COPD were less likely to receive beta-blockers (12% vs. 28%, odds ratio 0.35, 95% CI0.19-0.64). During follow-up, patients with COPD had higher mortality (73% vs. 60%, P = 0.016, hazard ratio 1.48, 95% CI 1.15-1.90). Kaplan-Meier (log-rank test, P = 0.002) and Cox proportional hazard analysis, adjusted for age, sex, hemoglobin, uric acid, and treatment with beta-blockers and furosemide (hazard ratio 1.38, 95% CI1.04-1.83, P = 0.024) demonstrated the prognostic importance of COPD.

CONCLUSIONS

COPD is frequent among hospitalized patients with heart failure. Beta-blockers are largely underused, which is probably a major reason for the higher mortality observed in patients with concomitant chronic heart failure and COPD.

Nutrition in heart failure: an update

PURPOSE OF REVIEW

Chronic heart failure (CHF) is increasingly recognized as a multisystem disease with important comorbidities such as anemia, insulin resistance, autonomic dysbalance, or cardiac cachexia.

RECENT FINDINGS

Apart from these perturbations, increasing evidence points to alterations in intestinal morphology, permeability, and absorption function in patients with CHF. This review provides an overview of the sonographic, histological, and functional abnormalities of different gastrointestinal regions. This intestinal dysfunction and disturbed intestinal barrier may lead to both the chronic inflammatory state and catabolic/anabolic imbalance as seen in cardiac cachexia, as a terminal stage of CHF, which carries a particularly poor prognosis. This review highlights the current knowledge of nutritional abnormalities that may occur in CHF, including fat, carbohydrates, proteins, water, and micronutrients. The regulation of feeding is discussed, as are nutritional strategies with potentially anti-inflammatory effects in the treatment of CHF.

SUMMARY

The gut and its role for inflammation and dietary interventions in heart failure patients are a crucial target of further heart failure research.

Glutamate synthase: a fascinating pathway from L-glutamine to L-glutamate

Glutamate synthase is a multicomponent iron-sulfur flavoprotein belonging to the class of N-terminal nucleophile amidotransferases. It catalyzes the conversion of L-glutamine and 2-oxoglutarate into two molecules of L-glutamate. In recent years the X-ray structures of the ferredoxin-dependent glutamate synthase and of the a subunit of the NADPH-dependent glutamate synthase have become available. Thanks to X-ray crystallography, it is now known that the ammonia reaction intermediate is transferred via an intramolecular tunnel from the amidotransferase domain to the synthase domain over a distance of about 32A. Although ammonia channeling is a recurrent theme for N-terminal nucleophile and triad-type amidotransferases, the molecular mechanisms of ammonia transfer and its control are different for each known amidotransferase. This review focuses on the intriguing mechanism of action and self-regulation of glutamate synthase with a special focus on the structural data.