Enalapril restores depressed circulating insulin-like growth factor 1 in patients with chronic heart failure

Phloretin and Enalapril co-administration ameliorates hyperglycemia mediated exacerbation of myocardial injury in rats

Hyperglycemia exacerbates myocardial injury by amplifying oxidative stress, inflammation and apoptosis. This study explores the therapeutic potential of phloretin and enalapril co-administration in mitigating hyperglycemia-exacerbated myocardial damage. Using network pharmacology, 47 therapeutic targets and 10 hub genes, including albumin, insulin, prostaglandin endoperoxide synthase 2, matrix metallopeptidase 9, caspase3, tumor protein p53, insulin like growth factor 1, transforming growth factor beta 1, matrix metallopeptidase 2 and glycogen synthase kinase 3, were identified as critical to the drugs' synergistic action. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses highlighted key pathways, such as Interleukin-17 (IL-17), Advanced Glycation End Product-Receptor for Advanced Glycation End Products (AGE-RAGE), Mitogen activated protein kinase (MAPK), Phosphatidylinositol 3-kinase-protein kinase B (PI3K-Akt), Tumor necrosis factor (TNF) and Forkhead box O (FoxO), involved in angiogenesis, glucose metabolism, oxidative stress regulation and inflammation. Molecular docking confirmed strong affinities of phloretin and enalapril for key targets like insulin (INS), matrix metallopeptidase 9 (MMP9), prostaglandin endoperoxide synthase 2 (PTGS2) and insulin like growth factor 1 (IGF1). In-vivo studies using hyperglycemic rats with isoproterenol-induced myocardial ischemia validated the therapeutic efficacy of the combination. Co-treatment significantly enhanced antioxidant enzyme levels, reduced myocardial injury markers and improved histopathological features. These findings demonstrate the synergistic cardioprotective effects of phloretin and enalapril, offering a promising strategy for managing hyperglycemia and cardiac injury. The study provides a foundation for further preclinical and clinical evaluations to optimize the use of this combination in cardiovascular therapies.

Heart failure with Sarcopenia: A Bibliometric review from 1995 to 2022

This study aimed to dynamically track the priorities and potential research hotspots in the field of heart failure with sarcopenia. Using CiteSpace, we analyzed the literature on heart failure with sarcopenia from the Web of Science database from 1995 to 2022. The analysis encompassed 507 records, revealing an overall upward trend in annual publication volume. Europe and the United States emerged as the primary regions for publishing, particularly driven by contributions from developed countries such as the United States, Germany, and Italy. Productive institutions included the Charite Universitatsmedizin Berlin, University Medical Center Gottingen, the German Center for Cardiovascular Research (DZHK), Universita Cattolica del Sacro Cuore, and the National Institute on Aging (NIA). Noteworthy academic groups have formed around these institutions; von Haehling S, Anker Stefan D, Springer J, and Doehner W frequently collaborated. The core journals that frequently published articles in this area included Circulation, European Heart Journal, and The Journals of Gerontology Series A-Biological Sciences and Medical Sciences. Based on the keyword analysis, we identified three key research areas. First, the diagnosis and definition of sarcopenia emerged as significant themes. Second, researchers have focused on exploring the mechanisms underlying heart failure with sarcopenia, including inflammation, insulin resistance, and oxidative stress. Finally, treatment strategies, such as physical activity and nutritional support, constitute another critical research theme. Furthermore, potential research hotspots within this field include clinical randomized controlled trials, investigations into inflammatory mechanisms, cardiac rehabilitation, studies on physical activity, androgen receptor modulators, and investigations into clinical outcomes such as cognitive impairment.

The Value of IGF-1 and IGFBP-1 in Patients With Heart Failure With Reduced, Mid-range, and Preserved Ejection Fraction

BACKGROUND

Previous studies have reported inconsistent results regarding the implications of deranged insulin-like growth factor 1 (IGF-1)/insulin-like growth factor-binding protein 1 (IGFBP-1) axis in patients with heart failure (HF). This study evaluates the roles of IGF1/IGFBP-1 axis in patients with HF with reduced ejection fraction (HFrEF), mid-range ejection fraction (HFmrEF), or preserved ejection fraction (HFpEF).

METHODS

Consecutive patients with HFrEF, HFmrEF, and HFpEF who underwent comprehensive cardiac assessment were included. The primary endpoint was the composite endpoint of all-cause death and HF rehospitalization at one year.

RESULTS

A total of 151 patients with HF (HFrEF: n = 51; HFmrEF: n = 30; HFpEF: n = 70) and 50 control subjects were included. The concentrations of IGFBP-1 (p < 0.001) and IGFBP-1/IGF-1 ratio (p < 0.001) were significantly lower in patients with HF compared to controls and can readily distinguish patients with and without HF (IGFBP-1: areas under the curve (AUC): 0.725, p < 0.001; IGFBP-1/IGF-1 ratio: AUC:0.755, p < 0.001; respectively). The concentrations of IGF-1, IGFBP-1, and IGFBP-1/IGF-1 ratio were similar among HFpEF, HFmrEF, and HFrEF patients. IGFBP-1 and IGFBP-1/IGF-1 ratio positively correlated with N-terminal probrain natriuretic peptide (NT-proBNP) levels (r = 0.255, p = 0.002; r = 0.224, p = 0.007, respectively). IGF-1, IGFBP-1, and IGFBP-1/IGF-1 ratio did not predict the primary endpoint at 1 year for the whole patients with HF and HF subtypes on both univariable and multivariable Cox regression.

CONCLUSION

The concentrations of plasma IGFBP-1 and IGFBP-1/IGF-1 ratio can distinguish patients with and without HF. In HF, IGFBP-1 and IGFBP-1/IGF-1 ratio positively correlated with NT-proBNP levels.

Growth Hormone Deficiency Is Associated with Worse Cardiac Function, Physical Performance, and Outcome in Chronic Heart Failure: Insights from the T.O.S.CA. GHD Study

Background

Although mounting evidence supports the concept that growth hormone (GH) deficiency (GHD) affects cardiovascular function, no study has systematically investigated its prevalence and role in a large cohort of chronic heart failure (CHF) patients. Aim of this study is to assess the prevalence of GHD in mild-to-moderate CHF and to explore clinical and functional correlates of GHD.

Methods

One-hundred thirty CHF patients underwent GH provocative test with GHRH+arginine and accordingly categorized into GH-deficiency (GHD, n = 88, age = 61.6±1.1 years, 68% men) and GH-sufficiency (GHS, n = 42, age = 63.6±1.5 years, 81% men) cohorts. Both groups received comprehensive cardiovascular examination and underwent Doppler echocardiography, cardiopulmonary exercise testing, and biochemical and hormonal assay.

Results

GHD was detected in roughly 30% of CHF patients. Compared to GHD, GHS patients showed smaller end-diastolic and end-systolic LV volumes (-28%, p = .008 and -24%, p = .015, respectively), lower LV end-systolic wall stress (-21%, p = .03), higher RV performance (+18% in RV area change, p = .03), lower estimated systolic pulmonary artery pressure (-11%, p = .04), higher peak VO₂ (+20%, p = .001) and increased ventilatory efficiency (-12% in VE/VCO₂ slope, p = .002). After adjusting for clinical covariates (age, gender, and tertiles of LV ejection fraction, IGF-1, peak VO₂, VE/VCO₂ slope, and NT-proBNP), logistic multivariate analysis showed that peak VO₂ (β = -1.92, SE = 1.67, p = .03), VE/VCO₂ slope (β = 2.23, SE = 1.20, p = .02) and NT-proBNP (β = 2.48, SE = 1.02, p = .016), were significantly associated with GHD status. Finally, compared to GHS, GHD cohort showed higher all-cause mortality at median follow-up of 3.5 years (40% vs. 25%, p < .001, respectively), independent of age, sex, NT-proBNP, peak VO₂ and LVEF.

Conclusions

GH deficiency identifies a subgroup of CHF patients characterized by impaired functional capacity, LV remodeling and elevated NT-proBNP levels. GHD is also associated with increased all-cause mortality.

Increased IGF1 levels in relation to heart failure and cardiovascular mortality in an elderly population: impact of ACE inhibitors

OBJECTIVE

There are conflicting results regarding the association of circulating IGF1 with cardiovascular (CV) morbidity and mortality. We assessed the relationship between IGF1 levels and heart failure (HF), ischemic heart disease (IHD), and CV mortality in an elderly population taking into account the possible impact of angiotensin converting enzyme (ACE) inhibitors.

DESIGN AND METHODS

A total of 851 persons aged 66-81 years, in a rural Swedish municipality, were subjected to medical history, clinical examination, electrocardiography, echocardiography, and fasting plasma samples. They were then followed for 8 years.

RESULTS AND CONCLUSION

Patients on ACE inhibitors had higher IGF1 levels compared with those without ACE inhibitors. In patients on ACE inhibitors, higher IGF1 values were found in patients with an ejection fraction (EF) <40% compared with EF ≥40%, in patients with higher proBNP levels in quartile 4 vs 1, and in patients with IHD when compared to those without ACE inhibitors (P<0.001). In patients without ACE inhibitors, no relationship was found between IGF1 levels and HF or IHD. In multivariate regression, only ACE inhibitors, ECG changes characteristic for IHD, and gender had a significant impact on IGF1. Patients with higher IGF1 levels in quintiles 4 and 5 compared to quintiles 1 and 2 had a 50% higher risk for CV death (P=0.03). This was significant after adjustment for well-known CV risk factors and ACE inhibitors (P=0.03).

CONCLUSIONS

Our results show that treatment with ACE inhibitors in an elderly population is associated with increased IGF1 levels, especially in patients with impaired cardiac function or IHD. High IGF1 levels tend to be associated with an increased risk for CV mortality.

IGF-1 and atherothrombosis: relevance to pathophysiology and therapy

IGF-1 (insulin-like growth factor-1) plays a unique role in the cell protection of multiple systems, where its fine-tuned signal transduction helps to preserve tissues from hypoxia, ischaemia and oxidative stress, thus mediating functional homoeostatic adjustments. In contrast, its deprivation results in apoptosis and dysfunction. Many prospective epidemiological surveys have associated low IGF-1 levels with late mortality, MI (myocardial infarction), HF (heart failure) and diabetes. Interventional studies suggest that IGF-1 has anti-atherogenic actions, owing to its multifaceted impact on cardiovascular risk factors and diseases. The metabolic ability of IGF-1 in coupling vasodilation with improved function plays a key role in these actions. The endothelial-protective, anti-platelet and anti-thrombotic activities of IGF-1 exert critical effects in preventing both vascular damage and mechanisms that lead to unstable coronary plaques and syndromes. The pro-survival and anti-inflammatory short-term properties of IGF-1 appear to reduce infarct size and improve LV (left ventricular) remodelling after MI. An immune-modulatory ability, which is able to suppress 'friendly fire' and autoreactivity, is a proposed important additional mechanism explaining the anti-thrombotic and anti-remodelling activities of IGF-1. The concern of cancer risk raised by long-term therapy with IGF-1, however, deserves further study. In the present review, we discuss the large body of published evidence and review data on rhIGF-1 (recombinant human IGF-1) administration in cardiovascular disease and diabetes, with a focus on dosage and safety issues. Perhaps the time has come for the regenerative properties of IGF-1 to be assessed as a new pharmacological tool in cardiovascular medicine.

Effects of ACE-inhibition on IGF-1 and IGFBP-3 concentrations in older adults with high cardiovascular risk profile

OBJECTIVES

The present study evaluates the effects of a 6-month treatment with an ACE-inhibitor (ie, fosinopril) on serum concentrations of total IGF-1 and IGF binding protein (IGFBP)-3 in older adults at high risk for cardiovascular disease.

DESIGN

Data are from the Trial of Angiotensin Converting Enzyme Inhibition and Novel Cardiovascular Risk Factors (TRAIN) study, a double-blind, crossover, randomized, placebo-controlled trial.

SETTING

Participants were recruited from the communities of Winston Salem, NC, and Greensboro, NC.

PARTICIPANTS

Subjects > or = 55 years old with high cardiovascular disease risk profile.

INTERVENTION

The intervention consisted of 6-month administration of fosinopril vs. placebo.

MEASUREMENTS

Serum concentrations of total IGF-1 and IGFBP-3 were measured in 100 participants of the TRAIN study at baseline, 6-month and 12-month follow-up visits. Differences in total IGF-1 and IGFBP-3 concentrations were assessed using two-sided paired ttests.

RESULTS

The mean age of participants (47% women) was 66.5 (standard deviation 7.2) years. Serum concentrations of total IGF-1 were significantly higher after 6-month treatment with fosinopril compared to placebo (203.73 ng/mL vs 194.24 ng/mL; p=0.02): After ACE-inhibitor intervention, significantly higher serum IGFBP-3 concentrations compared to controls (4308.81 ng/mL vs 4086.93 ng/mL; p=0.03) were also reported.

CONCLUSIONS

A six-month treatment with fosinopril increases systemic levels of total IGF-1 and IGFBP-3 in older adults with high cardiovascular risk profile. This may represent a potential biological explanation to the beneficial effects of ACE-inhibition on stroke, ischemic heart disease and insulin resistance.

Plasma insulin-like growth factor I as predictor of progression and all cause mortality in chronic heart failure

OBJECTIVES

Insulin-like growth factor I (IGF-I) is an anabolic growth factor that seems to increase cardiac contractility. Reduced levels of IGF-I may be implicated in progression of CHF. The objective was to compare plasma IGF-I in CHF patients with healthy controls, and to examine the associations between baseline IGF-I levels, cardiac contractility and the prognosis as judged by all cause mortality and progression of CHF requiring admission to hospital.

METHODS

A prospective study comprising 194 CHF outpatients, and 169 matched controls. All patients and controls underwent echocardiographic examination at baseline. Patients were followed for a median of 30 months.

RESULTS

There was no difference in IGF-I levels between patients and controls (median and interquartile range), 78 (58-91) vs. 77 (57-94)ng/mL (P=0.92). Age-adjusted IGF-I levels were not related to left ventricular ejection fraction (LVEF) (P=0.58) or levels of N-terminal B-Type natriuretic peptide (NT-proBNP) (P=0.42). During follow-up 44 patients died and 94 were admitted to hospital due to worsening of CHF. Adjusted for cardiovascular risk factors (age, gender, NT-proBNP, lipids, diabetes mellitus, blood pressure, renal function and LVEF) IGF-I levels did not influence the overall mortality risk or the admission rate to hospital, hazard ratio (HR) (95% confidence intervals) 1.05 (0.75-1.47) (P=0.77) and 1.00 (0.80-1.26) (P=0.96), respectively per each SD increase in log IGF-I levels.

CONCLUSIONS

IGF-I levels were not reduced in patients with CHF and did not influence cardiac status at baseline or the prognosis.

Modulation of GH/IGF-1 axis: potential strategies to counteract sarcopenia in older adults

Aging is associated with progressive decline of skeletal muscle mass and function. This condition, termed sarcopenia, is associated with several adverse outcomes, including loss of autonomy and mortality. Due to the high prevalence of sarcopenia, a deeper understanding of its pathophysiology and possible remedies represents a high public health priority. Evidence suggests the existence of a relationship between declining growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels and age-related changes in body composition and physical function. Therefore, the age-dependent decline of GH and IGF-1 serum levels may promote frailty by contributing to the loss of muscle mass and strength. Preclinical studies showed that infusion of angiotensin II produced a marked reduction in body weight, accompanied by decreased serum and muscle levels of IGF-1. Conversely, overexpression of muscle-specific isoform of IGF-1 mitigates angiotensin II-induced muscle loss. Moreover, IGF-1 serum levels have been shown to increase following angiotensin converting enzyme inhibitors (ACEIs) treatment. Here we will review the most recent evidence regarding age-related changes of the GH/IGF-1 axis and its modulation by several interventions, including ACEIs which might represent a potential novel strategy to delay the onset and impede the progression of sarcopenia.

Use of ACE inhibitors is associated with elevated levels of IGFBP-3 among hypertensive older adults: results from the IlSIRENTE study

OBJECTIVE

Several studies in vitro or in rodent models have suggested a potential relationship between angiotensin-converting enzyme (ACE) inhibition and the insulin-like growth factor 1 (IGF-1) axis. However, this relationship has only rarely been investigated in humans. The aim of the present cross-sectional study was to assess the association of ACE inhibitors with free IGF-1 and IGFBP-3 in the blood of older hypertensive adults.

METHODS

Data are from the baseline evaluation of the IlSIRENTE study, which enrolled 364 subjects aged 80 or older. For the present study we selected a subpopulation of 264 hypertensive participants without congestive heart failure. Free IGF-1 and IGFBP-3 in the blood were measured by a radioimmunoassay method. Analyses of covariance were performed to evaluate the differences in free IGF-1 and IGFBP-3 levels according to the use of ACE inhibitors.

RESULTS

The mean age of participants was 85.7 years (SD: 4.9), 170 (64%) were women and 123 (47%) were using an ACE inhibitor. Following adjustment for potential confounders, the concentration of free IGF-1 was slightly, but not significantly higher among ACE inhibitor users than among non-users (0.74 vs. 0.65 ng/mL; p=0.20). In contrast, ACE inhibitor users had a significantly higher IGFBP-3 serum levels than non-users (4821 vs. 4330 ng/mL; p=0.005). In addition, the concentration of IGFBP-3 was significantly higher among ACE inhibitors users than among non-users of antihypertensive drugs (p=0.02) and users of other antihypertensive drugs (p=0.01).

CONCLUSION

Among hypertensive older adults, ACE inhibitors use is associated with higher IGFBP-3 levels.

Modulation of the growth hormone-insulin-like growth factor (GH-IGF) axis by pharmaceutical, nutraceutical and environmental xenobiotics: an emerging role for xenobiotic-metabolizing enzymes and the transcription factors regulating their expression. A review

The growth hormone-insulin-like growth factor (GH-IGF) axis has gained considerable focus over recent years. One cause of this increased interest is due to a correlation of age-related decline in plasma GH/IGF levels with age-related degenerative processes, and it has led to the prescribing of GH replacement therapy by some practitioners. On the other hand, however, research has also focused on the pro-carcinogenic effects of high GH-IGF levels, providing strong impetus for finding regimes that reduce its activity. Whereas the effects of GH/IGF activity on the action of xenobiotic-metabolizing enzyme systems is reasonably well appreciated, the effects of xenobiotic exposure on the GH-IGF axis has not received substantial review. Relevant xenobiotics are derived from pharmaceutical, nutraceutical and environmental exposure, and many of the mechanisms involved are highly complex in nature, not easily predictable from existing in vitro tests and do not always predict well from in vivo animal models. After a review of the human and animal in vivo and in vitro literature, a framework for considering the different levels of direct and indirect modulation by xenobiotics is developed herein, and areas that still require further investigation are highlighted, i.e. the actions of common endocrine disruptors such as pesticides and phytoestrogens, as well as the role of xenobiotic-metabolizing enzymes and the transcription factors regulating their expression. It is anticipated that a fuller appreciation of the existing human paradigms for GH-IGF axis modulation gained through this review may help explain some of the variation in levels of plasma IGF-1 and its binding proteins in the population, aid in the prescription of particular dietary regimens to certain individuals such as those with particular medical conditions, guide the direction of long-term drug/nutraceutical safety trials, and stimulate ideas for future research. It also serves to warn athletes that using compounds touted as performance enhancing because they promote short-term GH release could in fact be detrimental to performance in the long-run.

Relation of angiotensin-converting enzyme inhibitor treatment to insulin-like growth factor-1 serum levels in subjects >65 years of age (the InCHIANTI study)

Observational studies have shown that the use of angiotensin-converting enzyme (ACE) inhibitors is associated with the maintenance of greater muscle strength and physical performance in older subjects. However, the mechanism that underlies these beneficial effects remains poorly understood. Because ACE inhibitors block the production of angiotensin II, which is a potent inhibitor of insulin-like growth factor-1 (IGF-1) production, it was hypothesized that treatment with ACE inhibitors is associated with higher levels of IGF-1. This hypothesis was tested in 745 subjects (417 women, 328 men) enrolled in the Invecchiare in Chianti study. Of these, 160 were receiving ACE inhibitors. The association between ACE inhibitor use and serum IGF-1 was tested by linear regression models. After adjusting for multiple potential confounders, serum levels of total IGF-1 were significantly higher in participants receiving ACE inhibitors (mean +/- SD 129.0 +/- 56.1 ng/ml) compared with the rest of the study population (mean +/- SD 116.5 +/- 54.8 ng/ml) (p <0.001). Participants with short (<3 years) and long (3 to 9 years) treatment durations had higher serum IGF-1 levels than participants who were not receiving ACE inhibitor treatment, but the difference was statistically significant only for the short-duration group (p <0.05). In conclusion, in older subjects, treatment with ACE inhibitors for <3 years is associated with significantly higher levels of IGF-1. This may be 1 of the mechanisms by which ACE inhibitors might slow the decreases in muscle strength and physical function that are often observed in older subjects.

Cardiac cachexia

Chronic heart failure (CHF) remains an important and increasing public health care problem. It is a complex syndrome affecting many body systems. Body wasting (i.e., cardiac cachexia) has long been recognised as a serious complication of CHF. Cardiac cachexia is associated with poor prognosis, independently of functional disease severity, age, and measures of exercise capacity and cardiac function. Patients with cardiac cachexia suffer from a general loss of fat tissue, lean tissue, and bone tissue. Cachectic CHF patients are weaker and fatigue earlier, which is due to both reduced skeletal muscle mass and impaired muscle quality. The pathophysiologic alterations leading to cardiac cachexia remain unclear, but there is increasing evidence that metabolic, neurohormonal and immune abnormalities may play an important role. Cachectic CHF patients show raised plasma levels of epinephrine, norepinephrine, and cortisol, and they show high plasma renin activity and increased plasma aldosterone level. Several studies have also shown that cardiac cachexia is linked to raised plasma levels of tumour necrosis factor alpha and other inflammatory cytokines. The degree of body wasting is strongly correlated with neurohormonal and immune abnormalities. The available evidence suggests that cardiac cachexia is a multifactorial neuroendocrine and metabolic disorder with a poor prognosis. A complex imbalance of different body systems may cause the development of body wasting.

Growth hormone resistance in chronic heart failure and its therapeutic implications

BACKGROUND

In recent years the administration of recombinant human growth hormone (GH) has received great attention. This review compares the potential of this therapeutic intervention in heart failure with that in other diseases where wasting is commonly seen. The pathophysiologic importance of GH and insulin-like growth factor (IGF)-I in these conditions will be discussed.

METHODS AND RESULTS

Abnormalities of the GH-IGF-I axis play an important role in the development of cachexia in chronic illnesses. GH resistance is a major determinant of the wasting process, acting through several different mechanisms: increased catabolism, impaired anabolism, and enhanced apoptosis in peripheral tissues. GH therapy has been evaluated in chronic heart failure (CHF); acquired GH resistance may explain the general lack of therapeutic success in the majority of studies. The assessment of plasma levels of GH, IGF-I, and, in particular, GH binding protein may help to guide dosing of GH for CHF patients.

CONCLUSIONS

GH resistance might be overcome by use of intermittent or higher doses of GH, or alternatively by combining GH with IGF-I. Randomized studies of GH therapy in catabolic states, with targeted dosing and longer duration of treatment are required to fully assess the safety and efficacy of this treatment approach.

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

Mechanisms that lead to cachexia are still poorly understood. The neurohormonal changes that occur in severe disease states may cause an imbalance between protein synthesis and degradation at the cellular level, followed by muscle wasting. Here, we review actions of angiotensin II, TNF-alpha, corticosteroids, insulin-like growth factor-I (IGF-I), and the IGF binding proteins, factors that may each contribute to the metabolic imbalance. The complex endocrine, autocrine and intracellular interactions between these factors will be described with examples from patient, rat and cell culture studies. Moreover, some of the data supporting that each of these hormones may directly affect cellular protein degradation mechanisms will be reviewed. Knowledge on these regulatory mechanisms will facilitate the development of new pharmaceutical strategies to treat cachexia.

The syndrome of cardiac cachexia

Cachexia, i.e. body wasting, has long been recognised as a serious complication of chronic illness. The occurrence of wasting in chronic heart failure (CHF) has been known for many centuries, but it has not been investigated extensively until recently. Cardiac cachexia is a common complication of CHF which is associated with poor prognosis, independently of functional disease severity, age, measures of exercise capacity, and left ventricular ejection fraction. Patients with cardiac cachexia suffer from generalised loss of lean tissue, fat tissue, as well as bone tissue. Cachectic CHF patients are weaker and fatigue earlier. This is due to both reduced skeletal muscle mass and impaired skeletal muscle quality. Concerning the pathophysiology of cardiac cachexia, there is increasing evidence that neurohormonal and immune abnormalities may play a crucial role. Cachectic CHF patients have raised plasma levels of norepinephrine, epinephrine, and cortisol, and they show high plasma renin activity and increased plasma aldosterone levels. A number of studies have also shown that cardiac cachexia is linked to raised plasma levels of inflammatory cytokines, such as tumor necrosis factor alpha. The available evidence suggests that cardiac cachexia is a multifactorial neuroendocrine and metabolic disorder with a poor prognosis. A complex imbalance of different body systems, termed catabolic/anabolic imbalance, is likely to be responsible for the development of the wasting process. It is hoped that a better understanding of the pathophysiological mechanisms involved in cardiac cachexia will lead to novel therapeutic strategies in the (near) future.

Immune and neurohormonal pathways in chronic heart failure

Chronic heart failure is a complex disorder with interactions among the cardiovascular, immune, and neurohormonal systems. The concept that the progression of heart failure is due to neurohormonal abnormalities has received the greatest attention to date, leading to substantial therapeutic benefits. Although many current therapies are also thought to exert a variety of immunologic effects, this has been much less studied. In this review, the authors discuss a number of interactions among immune pathways and neurohormonal abnormalities relevant to heart failure. Cytokines, in particular tumor necrosis factor-alpha, have tremendous interactive opportunities within a regulatory network of energy metabolism, immune function, and neuroendocrine and hormonal function. Inflammatory cytokines are known to contribute to the progression of heart failure, and have been related to patients' prognosis. Advanced heart failure can be considered a state of chronic (low-grade) inflammation, and there are many reasons to suggest that anticytokine therapy could be successful in these patients. These novel approaches are certainly not without some risk, and many of them are very expensive, which may limit their application to certain subgroups of patients. In the future, it may not be enough to monitor cardiac function alone. Rather, the immune and neurohormonal status of patients may also need to be included in the performance of a complete assessment.

The severity of chronic heart failure due to coronary artery disease predicts the endocrine effects of short-term growth hormone administration

Treatment with human recombinant GH has yielded conflicting results in patients with heart failure. As GH sensitivity may be important for treatment effects, the present study evaluated GH secretion and sensitivity in noncachectic patients with ischemic heart failure. Twenty clinically stable, male patients with moderate heart failure (mean New York Heart Association class, 2.0 +/- 0.8; mean ejection fraction, 30.0 +/- 8.4%) due to coronary artery disease were randomly assigned single blind to a low dose (group A; n = 10) and a high dose (group B; n = 10) group, receiving either 5 microg/kg x day recombinant human GH for 4 days followed by 10 microg/kg x day GH for another 4 days or 10 and 20 microg/kg x day GH, respectively. Cardiac function was assessed by echocardiography. Serum insulin-like growth factor I (IGF-I), IGF-binding protein-3 (IGFBP-3), and 24-h urinary GH excretion as a measure of pituitary GH secretion were determined at baseline and on days 5 and 9. Baseline IGF-I and IGFBP-3 levels and GH excretion were significantly diminished compared to those in age-matched controls. There was a dose-dependent increase in IGF-I and IGFBP-3 during GH treatment. The increase in IGF-I induced by 10 microg/kg x day GH correlated positively to left ventricular ejection fraction (r = 0.59; P = 0.006) and inversely to left ventricular end-diastolic and end-systolic dimensions (r < -0.6 and P < 0.01 for both). In conclusion, GH secretion and serum levels of IGF-I and IGFBP-3 are diminished in patients with moderate ischemic heart failure. Left ventricular function determines the sensitivity of the GH/IGF-I system, measured as the IGF-I response to GH application. This finding suggests that individual dose adjustments may be an indispensable prerequisite for successful GH therapy in heart failure.