Does renin-angiotensin system inhibition have impacts on muscle mass and bone mineral density in heart failure patients?

Biological basis and treatment of frailty and sarcopenia

In an ageing society, the importance of maintaining healthy life expectancy has been emphasized. As a result of age-related decline in functional reserve, frailty is a state of increased vulnerability and susceptibility to adverse health outcomes with a serious impact on healthy life expectancy. The decline in skeletal muscle mass and function, also known as sarcopenia, is key in the development of physical frailty. Both frailty and sarcopenia are highly prevalent in patients not only with advanced age but also in patients with illnesses that exacerbate their progression like heart failure (HF), cancer, or dementia, with the prevalence of frailty and sarcopenia in HF patients reaching up to 50-75% and 19.5-47.3%, respectively, resulting in 1.5-3 times higher 1-year mortality. The biological mechanisms of frailty and sarcopenia are multifactorial, complex, and not yet fully elucidated, ranging from DNA damage, proteostasis impairment, and epigenetic changes to mitochondrial dysfunction, cellular senescence, and environmental factors, many of which are further linked to cardiac disease. Currently, there is no gold standard for the treatment of frailty and sarcopenia, however, growing evidence supports that a combination of exercise training and nutritional supplement improves skeletal muscle function and frailty, with a variety of other therapies being devised based on the underlying pathophysiology. In this review, we address the involvement of frailty and sarcopenia in cardiac disease and describe the latest insights into their biological mechanisms as well as the potential for intervention through exercise, diet, and specific therapies.

Adverse plasma branched-chain amino acid profile mirrors fatty muscle degeneration in diabetic heart failure patients

AIMS

Elevated plasma branched-chain amino acids (BCAAs) are tightly linked to incident diabetes and its complications, while lower BCAAs are associated with adverse outcomes in the elderly and heart failure (HF) patients. The interplay between body compositions and plasma BCAAs, especially under the influence of co-morbid diabetes in HF patients, is not well understood. Here, we examined the impact of diabetes on the prognostic value of plasma BCAA and its association with body compositions in HF patients.

METHODS AND RESULTS

We retrospectively examined 301 HF patients (70 ± 15 years old; 59% male), among which 36% had diabetes. Blood samples for plasma BCAA measurements were collected in a fasting state after stabilization of HF and analysed using ultraperformance liquid chromatography. A dual-energy X-ray absorptiometry scan assessed regional body compositions, and muscle wasting was defined as appendicular skeletal muscle mass index (ASMI) < 7.00 and <5.40 kg/m2 for males and females, respectively, according to the criteria of the Asian Working Group for Sarcopenia. Although analyses of covariance revealed that plasma BCAAs were significantly higher in diabetic patients, low valine (<222.1 nmol/mL) similarly predicted adverse events defined by HF hospitalization, lethal arrhythmia, or all-cause death in both diabetic and non-diabetic patients independently of age, sex, and NT-proBNP (adjusted hazard ratio [HR] 3.1, 95% confidence interval [CI] of 1.1-8.6 and adjusted HR 2.67, 95% CI 1.1-6.5, respectively; P for interaction 0.88). In multivariate linear regression analyses comprising age, sex, and regional body compositions as explanatory variables, plasma BCAAs were positively correlated with visceral adipose tissue area in non-diabetic patients (standardized β coefficients [β] = 0.44, P < 0.001). In contrast, in diabetic patients, plasma BCAAs were correlated positively with ASMI (β = 0.49, P = 0.001) and negatively with appendicular fat mass index (AFMI; β = -0.42, P = 0.004). Co-morbid diabetes was independently associated with muscle wasting (adjusted odds ratio 2.1, 95% CI 1.1-4.0) and significantly higher plasma 3-methylhistidine level, a marker of myofibrillar degradation. In diabetic patients, ASMI uniquely showed a J-shaped relationship with AFMI, and in a subgroup of HF patients with muscle wasting, diabetic patients showed 12% higher AFMI than non-diabetic patients despite comparable ASMI reductions.

CONCLUSIONS

Despite higher plasma BCAA levels in HF patients with diabetes, the prognostic value of low valine remained consistent regardless of diabetes status. However, low BCAAs were distinctly associated with fatty muscle degeneration in the extremities in diabetic patients, suggesting the importance of targeted interventions to prevent such tissue remodelling in this population.

Renin angiotensin system-induced muscle wasting: putative mechanisms and implications for clinicians

Renin angiotensin system (RAS) alters various mechanisms related to muscle wasting. The RAS system consists of classical and non-classical pathways, which mostly function differently. Classical RAS pathway, operates through angiotensin II (AngII) and angiotensin type 1 receptors, is associated with muscle wasting and sarcopenia. On the other hand, the non-classical RAS pathway, which operates through angiotensin 1-7 and Mas receptor, is protective against sarcopenia. The classical RAS pathway might induce muscle wasting by variety of mechanisms. AngII reduces body weight, via reduction in food intake, possibly by decreasing hypothalamic expression of orexin and neuropeptide Y, insulin like growth factor-1 (IGF-1) and mammalian target of rapamycin (mTOR), signaling, AngII increases skeletal muscle proteolysis by forkhead box transcription factors (FOXO), caspase activation and muscle RING-finger protein-1 transcription. Furthermore, AngII infusion in skeletal muscle reduces phospho-Bad (Ser136) expression and induces apoptosis through increased cytochrome c release and DNA fragmentation. Additionally, Renin angiotensin system activation through AT1R and AngII stimulates tumor necrosis factor-α, and interleukin-6 which induces muscle wasting, Last but not least classical RAS pathway, induce oxidative stress, disturb mitochondrial energy metabolism, and muscle satellite cells which all lead to muscle wasting and decrease muscle regeneration. On the contrary, the non-classical RAS pathway functions oppositely to mitigate these mechanisms and protects against muscle wasting. In this review, we summarize the mechanisms of RAS-induced muscle wasting and putative implications for clinical practice. We also emphasize the areas of uncertainties and suggest potential research areas.

Circulating level of β-aminoisobutyric acid (BAIBA), a novel myokine-like molecule, is inversely associated with fat mass in patients with heart failure

Results of experimental studies have shown that β-aminoisobutyric acid (BAIBA), an exercise-induced myokine-like molecule, is an endogenous negative regulator of fat mass in mice, but it remains unclear whether that is the case in humans, though an enhanced BAIBA concentration in patients receiving sodium-glucose cotransporter 2 inhibitors was found in our recent study. The objective of this study was to analyze the determinants of circulating BAIBA concentration in humans, with focus on the possible link between circulating BAIBA and body composition including fat mass. Data for 188 consecutive patients with heart failure (HF, 64 ± 13 years; 70% male) who received a dual energy X ray absorptiometry (DEXA) scan for assessment of body composition including fat mass index (FMI) and appendicular skeletal muscle mass index (ASMI) were used in this study. Plasma BAIBA concentration in a fasting state after stabilization of HF was determined using ultraperformance liquid chromatography. Plasma BAIBA was detected in 66% of the patients. In simple linear regression analyses of data from patients in whom plasma BAIBA was detected, plasma BAIBA concentration was positively correlated with uric acid and was negatively correlated with body mass index (BMI), estimated glomerular filtration rate (eGFR), FMI, and % body fat. There were no correlations between plasma BAIBA concentration and indexes of muscle mass and bone mass. The results of multiple linear regression analyses showed that FMI and % body fat in addition to BMI, but not ASMI, were independent explanatory factors for plasma BAIBA concentration. In conclusion, plasma BAIBA concentration is inversely correlated with indexes of fat mass, indicating that BAIBA may be a therapeutic target for excessive fat accumulation.

Independent Link Between Use of Mineralocorticoid Receptor Antagonists and Muscle Wasting in Heart Failure Patients Not Receiving Renin-Angiotensin System Inhibitors

BACKGROUND

The renin-angiotensin system (RAS) activation is a proposed mechanism of muscle wasting (MW i.e., reduction in muscle mass). Although we reported that RAS inhibitors (RASIs) were associated with lower prevalence of MW in heart failure (HF) patients, the relationship between mineralocorticoid receptor (MR) signaling and MW has not been analyzed.Methods and Results: We analyzed data from 320 consecutive Japanese HF patients who underwent dual-energy X-ray absorptiometry scanning for assessment of appendicular skeletal muscle mass index (ASMI). In multiple linear regression analyses, plasma renin activity (PRA) was negatively correlated with ASMI in patients not receiving RASIs, indicating an untoward role of the RAS in MW. Results of analysis of covariance in which risk factors of MW served as covariates showed that use of MR antagonists (MRAs) was associated with lower ASMI and higher PRA in the non-RASIs group. The close relationship between use of MRAs and lower ASMI or higher PRA in the non-RASIs group was confirmed in analyses in which the differences in baseline characteristics between users and non-users of MRAs were minimized by using an inverse probability of treatment weighting.

CONCLUSIONS

Increased PRA by MR inhibition without concurrent RAS inhibition, possibly contributing to upregulation of angiotensin II signaling, may be associated with reduction in muscle mass.

Independent Association Between Use of Proton Pump Inhibitors and Muscle Wasting in Patients with Heart Failure: A Single-Center, Ambispective, Observational Study

BACKGROUND

Although proton pump inhibitors (PPIs) play a pivotal role in the prevention and treatment of gastric acid-related diseases and gastrointestinal adverse events caused by antiplatelet therapies, the safety of long-term use of PPIs has been questioned.

OBJECTIVE

The aim of this study was to determine the effects of use of PPIs on muscle mass and bone mineral density in heart failure (HF) patients.

METHODS

This was a single-center, ambispective (combined retrospective and prospective), observational study. HF patients (n = 747; 72 years of age; males, 54%) who received a dual-energy x-ray absorptiometry scan were enrolled. Muscle wasting was defined as appendicular skeletal muscle mass index (ASMI) < 7.0 kg/m² in males and <5.4 kg/m² in females. Propensity scores for the use of PPIs were calculated using a multivariate logistic regression model to minimize selection bias.

RESULTS

Before propensity score matching, ASMI was significantly lower in patients receiving PPIs than in patients not receiving PPIs, resulting in a higher prevalence of muscle wasting in the PPI group. Such a relationship between use of PPIs and muscle wasting remained after propensity score matching. In multivariate Cox regression analyses, use of PPIs was independently associated with presence of muscle wasting (hazard ratio 1.68, 95% confidence interval 1.05-2.69) after adjustment for established risk factors of sarcopenia. On the other hand, there were no differences in bone mineral density between the PPI group and the no-PPI group.

CONCLUSION

Use of PPIs is associated with a high risk of muscle wasting in HF patients. Caution is warranted when long-term PPI treatment is performed in sarcopenic HF patients and HF patients with several risk factors for muscle wasting.

Impaired muscle stem cell function and abnormal myogenesis in acquired myopathies

Skeletal muscle possesses a high plasticity and a remarkable regenerative capacity that relies mainly on muscle stem cells (MuSCs). Molecular and cellular components of the MuSC niche, such as immune cells, play key roles to coordinate MuSC function and to orchestrate muscle regeneration. An abnormal infiltration of immune cells and/or imbalance of pro- and anti-inflammatory cytokines could lead to MuSC dysfunctions that could have long lasting effects on muscle function. Different genetic variants were shown to cause muscular dystrophies that intrinsically compromise MuSC function and/or disturb their microenvironment leading to impaired muscle regeneration that contributes to disease progression. Alternatively, many acquired myopathies caused by comorbidities (e.g., cardiopulmonary or kidney diseases), chronic inflammation/infection, or side effects of different drugs can also perturb MuSC function and their microenvironment. The goal of this review is to comprehensively summarize the current knowledge on acquired myopathies and their impact on MuSC function. We further describe potential therapeutic strategies to restore MuSC regenerative capacity.

Does renin-angiotensin system inhibition have impacts on muscle mass and bone mineral density in heart failure patients?

Aims

Results of experimental studies have indicated the possibility of muscle and bone mass being negatively regulated by renin‐angiotensin system (RAS) activation, but that possibility has not been analysed in patients with heart failure (HF).

Methods and results

Data for HF patients who received a dual‐energy X‐ray absorptiometry scan in our hospital were reviewed. Propensity scores for the use of RAS inhibitors (RASIs) were calculated using a multivariate logistic regression model to minimize selection bias. One hundred sixty pairs of patients were extracted. Plasma aldosterone concentration was significantly lower in the RASIs group than in the no‐RASIs group (119 [IQR 71–185] vs. 94 [IQR 60–131] pg/mL, P = 0.003), confirming RAS inhibition in the RASIs group. Skeletal muscle mass index tended to be higher in the RASIs group than in the non‐RASIs group (15.6 [IQR 14.0–17.2] vs. 15.0 [IQR 13.3–16.6] pg/mL, P = 0.065). The proportion of patients with muscle wasting, defined as appendicular skeletal muscle mass indexes of <7.00 and <5.40 kg/m² for males and females, respectively, was significantly lower in the RASIs group than in the non‐RASIs group (53% vs. 64%, P = 0.041). Multivariate logistic regression analysis showed that the no use of RASIs was associated with presence of muscle wasting independently of age, presence of diabetes, renal function, and severity of HF. Bone mineral densities and proportions of patients with osteoporosis were similar in the two groups.

Conclusions

Renin‐angiotensin system inhibition is associated with a lower prevalence of muscle wasting in HF patients independently of established risk factors.