Relationship of quadriceps muscle power and optimal shortening velocity with angiotensin-converting enzyme activity in older women

High serum angiotensin-converting enzyme 2 activity as a biomarker of frailty in nursing home residents

Angiotensin-converting enzyme (ACE) and angiotensin-converting enzyme 2 (ACE2) are two of the main components of the renin-angiotensin system (RAS). Imbalanced RAS showing lower ACE2 has been associated with increased cardiovascular risk, muscular pathologies, sarcopenia, frailty, other age-related pathologies and a poorer health status. However, its role in aging remains unclear. Thus, the aim of this work was to analyze the serum enzymatic activity of ACE and ACE2, the ACE/ACE2 ratio and its association with anthropometric parameters, blood pressure, physical function, dependence and frailty in older people living in nursing homes. This study is a secondary analysis of baseline data from two randomized clinical trials in a population of 228 older individuals living in nursing homes (Spain). Serum ACE and ACE2 enzymatic activities were measured by fluorimetry. Variables linked to cardiovascular risk, physical function, dependence and frailty were measured using validated tests, indexes and scales. Association between ACE, ACE2 serum activities, the ACE/ACE2 ratio and the rest of the quantitative variables were assessed by Pearson's correlations and by partial correlations controlled by age and sex. The association between serum ACE and ACE2 activities, the ACE/ACE2 ratio and frailty scores was analyzed by generalized linear models with and without controlling for sex and age. Differences in enzymatic activities between sexes and between frail and non-frail individuals were analyzed using Student's t-test and general linear models to control analysis by age and sex. We found that higher serum ACE2 activity was associated with a higher body mass index, worse physical function, greater dependence and increased frailty. This association is consistent with the elevation of circulating ACE2 in certain pathological conditions and in line with RAS deregulation in muscular dystrophies. Serum ACE2 activity, in combination with other molecules, could be proposed as a biomarker of poor physical function, higher dependence and frailty.

Rewinding sarcopenia: a narrative review on the renin-angiotensin system

BACKGROUND AND AIMS

The purpose of this review was two-fold. First, we aimed to provide an in-depth glance on the relationship between renin-angiotensin system (RAS) dysregulation and sarcopenia. Second, we aimed to touch upon potential treatments of sarcopenia (including RAS blockers, vitamin D, and exercise) in light of the pertinent literature.

METHODS

Currently available research regarding the effects of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers on knee extensor strength, grip strength, chair stand test, gate speed together with the effects of exercise on muscle mass, strength, physical performance, blood pressure and cognitive tests (particularly in older adults) was reviewed.

RESULTS

Although some studies have shown favorable effects of ACEIs on muscle strength and/or physical function tests, some studies have reported no/negative association in between. The favorable impact of exercise on reducing blood pressure is shown, and exercise treatment is widely recommended in the relevant literature. Different types of exercises (aerobic, resistance, dancing, music movement, water-based, golf, knitting activities or multicomponent exercises) have shown improvement in cognitive functions as well.

CONCLUSION

Classical RAS activity results in deleterious effects not only on the cardiovascular but also on the neuromusculoskeletal system. Therefore, treatments targeting inhibition of the classical RAS activity seem to be important in the management of several age-related pathologies, including sarcopenia. As such, ACEIs, vitamin D, exercise, and healthy diet can have prominent effects not only on the modulation of RAS but also on physical and cognitive functions and sarcopenia as well.

Quadriceps muscle power and optimal shortening velocity are inversely related to angiotensin converting enzyme activity in older men

Background: Methods which potentially could prevent age-related loss of muscle mass and function are still being sought. There are various attempts to use pharmacological agents to prevent loss of muscle mass, but the effectiveness of many of them still needs to be confirmed. One of the promising therapeutics are Angiotensin Converting Enzyme Inhibitors (ACEIs) and lowering of serum ACE activity. The goal of this study was to assess if taking Angiotensin Converting Enzyme Inhibitors (ACEI) and other angiotensin system blocking medications (ASBMs) can modify muscle performance in older men as well as to assess the association of serum ACE activity with muscle strength, power, muscle contraction velocity and functional performance. Methods: Seventy-nine older men took part in the study. Muscle function was assessed with hand grip strength, maximum power relative to body mass (Pmax) and optimal shortening velocity (Ʋopt) of the knee extensor muscles. Anthropometric data, ACE activity and functional performance were also measured. Results: Negative correlations between ACE activity and Pmax (rho=-0.29, p=0.04) as well as Ʋopt  (rho=-0.31, p=0.03) in a group of patients not taking ACEI and between ACE activity and Ʋopt (rho=-0.22, p=0.05) in the whole group of men were found. Positive relationship between age and ACE activity was demonstrated (rho=0.26, p=0.02). Age was the only selected variable in the multiple regression analyses to determine both Pmax and Ʋopt. Conclusions: Serum ACE activity negatively associates to muscle power and muscle contraction velocity. The issues related to the impact of taking ACEI on the maintenance of muscle function and functional performance in older man require further studies.

Quadriceps muscle power and optimal shortening velocity are inversely related to angiotensin converting enzyme activity in older men

Background: Methods which potentially could prevent age-related loss of muscle mass and function are still being sought. There are various attempts to use pharmacological agents to prevent loss of muscle mass, but the effectiveness of many of them still needs to be confirmed. One of the promising therapeutics are Angiotensin Converting Enzyme Inhibitors (ACEIs) and lowering of serum ACE activity. The goal of this study was to assess if taking Angiotensin Converting Enzyme Inhibitors (ACEI) and other angiotensin system blocking medications (ASBMs) can modify muscle performance in older men as well as to assess the association of serum ACE activity with muscle strength, power, muscle contraction velocity and functional performance. Methods: Seventy-nine older men took part in the study. Muscle function was assessed with hand grip strength, maximum power relative to body mass (Pmax) and optimal shortening velocity (Ʋopt) of the knee extensor muscles. Anthropometric data, ACE activity and functional performance were also measured. Results: Negative correlations between ACE activity and Pmax (rho=-0.29, p=0.04) as well as Ʋopt  (rho=-0.31, p=0.03) in a group of patients not taking ACEI and between ACE activity and Ʋopt (rho=-0.22, p=0.05) in the whole group of men were found. Positive relationship between age and ACE activity was demonstrated (rho=0.26, p=0.02). Age was the only selected variable in the multiple regression analyses to determine both Pmax and Ʋopt. Conclusions: Taking ACEI is not associated with a functional performance in older men of the same age and with the same anthropometric parameters. Serum ACE activity negatively associates to muscle power and muscle contraction velocity.

Angiotensin-II Drives Human Satellite Cells Toward Hypertrophy and Myofibroblast Trans-Differentiation by Two Independent Pathways

Skeletal muscle regeneration is ensured by satellite cells (SC), which upon activation undergo self-renewal and myogenesis. The correct sequence of healing events may be offset by inflammatory and/or fibrotic factors able to promote fibrosis and consequent muscle wasting. Angiotensin-II (Ang) is an effector peptide of the renin angiotensin system (RAS), of which the direct role in human SCs (hSCs) is still controversial. Based on the hypertrophic and fibrogenic effects of Ang via transient receptor potential canonical (TRPC) channels in cardiac and renal tissues, we hypothesized a similar axis in hSCs. Toward this aim, we demonstrated that hSCs respond to acute Ang stimulation, dose-dependently enhancing p-mTOR, p-AKT, p-ERK1/2 and p-P38. Additionally, sub-acute Ang conditioning increased cell size and promoted trans-differentiation into myofibroblasts. To provide a mechanistic hypothesis on TRPC channel involvement in the processes, we proved that TRPC channels mediate a basal calcium entry into hSCs that is stimulated by acute Ang and strongly amplified by sub-chronic Ang conditioning. Altogether, these findings demonstrate that Ang induces a fate shift of hSCs into myofibroblasts and provide a basis to support a benefit of RAS and TRPC channel blockade to oppose muscle fibrosis.

The Role of Genetic Profile in Functional Performance Adaptations to Exercise Training or Physical Activity: A Systematic Review of the Literature

Background: Variations in genotype may contribute to heterogeneity in functional adaptations to exercise. Methods: A systematic search of eight databases was conducted, and 9,696 citations were screened. Results: Eight citations from seven studies measuring 10 single-nucleotide polymorphisms and nine different functional performance test outcomes were included in the review. There was one observational study of physical activity and six experimental studies of aerobic or resistance training. The ACE (D) allele, ACTN3 (RR) genotype, UCP2 (GG) genotype, IL-6-174 (GG) genotype, TNF-α-308 (GG) genotype, and IL-10-1082 (GG) genotype all predicted significantly superior adaptations in at least one functional outcome in older men and women after prescribed exercise or in those with higher levels of physical activity. Conclusion: There is a small amount of evidence that older adults may have better functional outcomes after exercise/physical activity if they have specific alleles related to musculoskeletal function or inflammation. However, more robust trials are needed.