Sarcopenia – A Potential Target for Angiotensin-Converting Enzyme Inhibition?

The Relationship Between Sarcopenia And Proteinuria, What Do We Know?

Sarcopenia is one of the most common geriatric syndromes in the elderly. It is defined as a decrease in muscle mass and function, and it can lead to physical disability, falls, poor quality of life, impaired immune system, and death. It is known that, the frequency of sarcopenia increases in the kidney patient population compared to healthy individuals. Although it is known that kidney disease can lead to sarcopenia; our knowledge of whether sarcopenia causes kidney disease is limited. Prior studies have suggested that protein energy wasting may be a risk of de novo CKD. Proteinuria is an important manifestation of kidney disease and there is a relationship between sarcopenia and proteinuria in diabetes, geriatric population, kidney transplant, and nephrotic syndrome. Does proteinuria cause sarcopenia or vice versa? Are they both the results of common mechanisms? This issue is not clearly known. In this review, we examined the relationship between sarcopenia and proteinuria in the light of other studies.

The Influence of Whey Protein on Muscle Strength, Glycemic Control and Functional Tasks in Older Adults with Type 2 Diabetes Mellitus in a Resistance Exercise Program: Randomized and Triple Blind Clinical Trial

OBJECTIVES

To evaluate the effect of whey protein (WP) supplementation associated with resistance training (RT) on glycemic control, functional tasks, muscle strength, and body composition in older adults living with type 2 diabetes mellitus (T2DM). Secondly, to evaluate the safety of the protocol for renal function.

METHODS

The population comprised twenty-six older men living with T2DM (68.5 ± 11.5 years old). The participants were randomly assigned to the Protein Group (PG) and the Control Group (CG). The handgrip test and evolution of exercise loads, according to the Omni Resistance Exercise Scale, evaluated muscle strength. Functional tasks were assessed by force platform in three different protocols: Sit-to-Stand, Step/Quick Turn, and Step Up/Over. Body composition was evaluated by bioimpedance and glycemic control and renal function were assessed by biochemical analyses. Both groups performed RT for 12 weeks, twice a week, prioritizing large muscle groups. Protein supplementation was 20 g of whey protein isolate and the CG was supplemented with an isocaloric drink, containing 20 g of maltodextrin.

RESULTS

There was a significant difference in muscle strength, according to the evolution of the exercise loads, but it was not confirmed in the handgrip test. However, there was no significant difference between the groups, regarding performance in functional tasks, glycemic control, or body composition. Renal function showed no alteration.

CONCLUSION

The intake of 20 g of WP in older male adults living with T2DM did not increase the effect of RT on muscle strength, functional tasks, and glycemic control. The intervention was proven safe regarding renal function.

Frailty, sarcopenia and diabetic kidney disease: where do we stand?

The aim of this narrative non-systematic review was to investigate the potential interplay among frailty syndrome, sarcopenia and diabetic kidney disease (DKD) in type 2 diabetes mellitus (T2DM) patients. Data derived from a limited number of studies underline that DKD is a significant risk factor for frailty. On the other hand, frailty syndrome poses a higher risk for end-stage renal disease (ESRD) in subjects with DKD. In addition, frailty seems to affect the cognitive function and social life of DKD individuals, whilst as DKD deteriorates, there is a higher prevalence of sarcopenia which is a fundamental frailty factor. As a result, it is shown that a bidirectional relation is established between these entities, as diabetes mellitus (DM) affects the components of frailty and sarcopenia and vice versa. This vicious cycle is created through multiple pathophysiologic mechanisms, including the anabolic role of insulin, low-grade inflammation, cytokines and endothelial function, prompting further investigation in this area. Specific nutritional and exercise interventions are imperative to be established in order to ameliorate potential adverse outcomes, concerning these entities.

End-of-Life Care for End-stage Heart Failure Patients

Although recent heart failure (HF) guidelines highlight integrative palliative care, including end-of-life (EOL), appropriate discussing EOL issues can be challenging due to possibility of unexpected deterioration throughout HF trajectory. Open communication and discussions with multidisciplinary team are important for setting patient and family expectations and establishing mutually agreed goals of care based firmly on the patient’s ‘human dignity’ and ‘right to self-determination.’ Especially when quality-of-life outweighs expanding quantity-of-life, transition to EOL care should be considered. Advanced care planning including resuscitation, device deactivation, site for last days, and bereavement support should focus on ensuring a good death, and be reviewed regularly.

Efforts to improve end-of-life (EOL) care have generally been focused on cancer patients, but high-quality EOL care is also important for patients with other serious medical illnesses including heart failure (HF). Recent HF guidelines offer more clinical considerations for palliative care including EOL care than ever before. Because HF patients can experience rapid, unexpected clinical deterioration or sudden death throughout the disease trajectory, choosing an appropriate time to discuss issues such as advance directives or hospice can be challenging in real clinical situations. Therefore, EOL issues should be discussed early. Conversations are important for understanding patient and family expectations and developing mutually agreed goals of care. In particular, high-quality communication with patient and family through a multidisciplinary team is necessary to define patient-centered goals of care and establish treatment based on goals. Control of symptoms such as dyspnea, pain, anxiety/depression, fatigue, nausea, anorexia, and altered mental status throughout the dying process is an important issue that is often overlooked. When quality-of-life outweighs expanding quantity-of-life, the transition to EOL care should be considered. Advanced care planning including resuscitation (i.e., do-not resuscitate order), device deactivation, site for last days and bereavement support for the family should focus on ensuring a good death and be reviewed regularly. It is essential to ensure that treatment for all HF patients incorporates discussions about the overall goals of care and individual patient preferences at both the EOL and sudden changes in health status. In this review, we focus on EOL care for end-stage HF patients.

Effects of hormonal changes on sarcopenia in chronic kidney disease: where are we now and what can we do?

Sarcopenia or muscle wasting is a progressive and generalized skeletal muscle disorder involving the accelerated loss of muscle mass and function, often associated with muscle weakness (dynapenia) and frailty. Whereas primary sarcopenia is related to ageing, secondary sarcopenia happens independent of age in the context of chronic disease states such as chronic kidney disease (CKD). Sarcopenia has become a major focus of research and public policy debate due to its impact on patient's health-related quality of life, health-care expenditure, morbidity, and mortality. The development of sarcopenia in patients with CKD is multifactorial and it may occur independently of weight loss or cachexia including under obese sarcopenia. Hormonal imbalances can facilitate the development of sarcopenia in the general population and is a common finding in CKD. Hormones that may influence the development of sarcopenia are testosterone, growth hormone, insulin, thyroid hormones, and vitamin D. Although the relationship between free testosterone level that is low in uraemic patients and sarcopenia in CKD is not well-defined, functional improvement may be seen. Unlike testosterone, it is known that vitamin D is associated with muscle strength, muscle size, and physical performance in patients with CKD. Outcomes after vitamin D replacement therapy are still controversial. The half-life of growth hormone (GH) is prolonged in patients with CKD. Besides, IGF-1 levels are normal in patients with Stage 4 CKD-a minimal reduction is seen in the end-stage renal disease. Unresponsiveness or resistance of IGF-1 and changes in the GH/IGF-1 axis are the main causes of sarcopenia in CKD. Low serum T3 level is frequent in CKD, but the net effect on sarcopenia is not well-studied. CKD patients develop insulin resistance (IR) from the earliest period even before GFR decline begins. IR reduces glucose utilization as an energy source by hepatic gluconeogenesis, decreasing muscle glucose uptake, impairing intracellular glucose metabolism. This cascade results in muscle protein breakdown. IR and sarcopenia might also be a new pathway for targeting. Ghrelin, oestrogen, cortisol, and dehydroepiandrosterone may be other players in the setting of sarcopenia. In this review, we mainly examine the effects of hormonal changes on the occurrence of sarcopenia in patients with CKD via the available data.

New Therapeutic Approaches and Biomarkers for Increased Healthspan

Healthcare costs have increased in developing countries over the last few decades, mostly due to the escalation in average life expectancy and the concomitant increase in age-related disorders. To address this issue, widespread research is now being undertaken across the globe with the aim of finding a way of increasing healthy aging. A number of potential interventions have already shown promise, including lifestyle changes and the use of natural products or pharmaceuticals that may delay the onset of diseases associated with the aging process. In parallel, a number of potential biomarkers have already been identified that can be used for assessing risk of developing age-associated disorders and for monitoring response to therapeutic interventions. This review describes the most recent advances towards the goal of achieving healthier aging with fewer disabilities that may lead to enhanced quality of life and reduced healthcare costs around the world.

Effect of Antihypertensive and Statin Medication Use on Muscle Performance in Community-Dwelling Older Adults Performing Strength Training

OBJECTIVES

Antihypertensive drugs (AHTD) and statins have been shown to have effects beyond their primarily designed purpose; here we investigate their possible effect on muscle performance and strength in older adults following a physical exercise programme.

DESIGN

The Senior PRoject INtensive Training (SPRINT) study is a randomised, controlled clinical trial designed to evaluate the effects of physical exercise on the immune system and muscle performance in older adults.

PARTICIPANTS

In this secondary analysis, we included 179 independent participants (aged 65 years and above). We applied further categorisation based on medication use: AHTD (including, angiotensin-converting enzyme inhibitors [ACEI], angiotensin II receptor blockers [ARB], β-blockers, and other AHTD) and statins.

INTERVENTION

Participants were allocated randomly to one of the three exercise protocols: intensive strength training 3 times/week (3 × 10 repetitions at 80% of one-repetition maximum), strength endurance training (2 × 30 repetitions at 40% of one-repetition maximum), or control (passive stretching exercise) for 6 weeks.

MEASUREMENTS

The change in maximal hand grip strength (GS), muscle fatigue resistance (FR), Muscle Strength Index (MSI), the 6-min walk test (6MWT), and Timed Up and Go Test (TUG) were assessed before and after 6 weeks of training.

RESULTS

After 6 weeks, muscle strength (MSI and TUG) improved significantly in all training groups compared to baseline, independently of AHTD use. Moreover, AHTD had no effect on exercise improvements, with no significant differences between medication groups, except for TUG in ARB users, which exhibited a significantly lower performance. On the other hand, statin users presented a significantly longer FR time, indicating better performance compared to non-users. Finally, medication did not affect the participants' commitment to the training programme.

CONCLUSION

Our study showed that statins and ARB usage might affect participant's response to strength training. Nevertheless, 6 weeks of training significantly improved muscle strength and performance irrespective of AHTD or statin use.

Multimodal Intervention to Improve Functional Status in Hypertensive Older Adults: A Pilot Randomized Controlled Trial

This pilot randomized controlled trial (RCT) was designed to provide the preliminary data necessary to conduct a full-scale trial to compare the efficacy of differing first-line antihypertensive medications in improving functional status in older adults, when combined with exercise. The primary objectives were to assess study feasibility, safety, and protocol integrity. Dependent outcomes included gait speed, exercise capacity, body composition, and systemic cardiometabolic biomarkers. Thirty-one physically inactive older adults (70.6 ± 6.1 years) with hypertension and functional limitations were randomly assigned to (1) Perindopril (8 mg/day n = 10), (2) Losartan (100 mg/day; n = 13), or (3) Hydrochlorothiazide (HCTZ: 25 mg/day; n = 8). Participants were also assigned to a 24-week multimodal exercise intervention, separated into an aerobic and concurrent (aerobic + resistance) phase to evaluate potential mode effects. Retention was 84% (26/31), and compliance was >90% and >79% with medication and exercise, respectively. A total of 29 adverse events (Perindopril = 5; Losartan = 12; HCTZ = 11) and one unrelated serious adverse event were observed throughout the trial. Overall, this pilot RCT provided critical data and identified several challenges to ultimately designing and implementing a fully powered trial.

The Differential Effect of Excess Aldosterone on Skeletal Muscle Mass by Sex

The effects of excess aldosterone on skeletal muscle in individuals with primary aldosteronism (PA) are unknown. To examine the effects of aldosterone on skeletal muscle mass in patients with PA, by sex, 309 consecutive patients were enrolled. Skeletal muscle and fat mass of 62 patients with PA were compared with those of 247 controls with non-functioning adrenal incidentaloma (NFAI). Body composition parameters were measured using bioelectrical impedance analysis, and plasma aldosterone concentration (PAC) was measured using radioimmunoassay. The PAC in all women, but not in men, showed an inverse association with both appendicular skeletal muscle mass (ASM) (β = -0.197, P = 0.016) and height-adjusted ASM (HA-ASM) (β = -0.207, P = 0.009). HA-ASM in women (but not in men) with PA was 5.0% lower than that in women with NFAI (P = 0.036). Furthermore, women with PA had a lower HA-ASM than 1:1 age- and sex-matched controls with NFAI by 5.7% (P = 0.049) and tended to have a lower HA-ASM than 1:3 age-, sex-, and menopausal status-matched controls without adrenal incidentaloma (AI) by 7.3% (P = 0.053). The odds ratio (OR), per quartile increase in PAC, of low HA-ASM in women was 1.18 [95% confidence interval (CI), 1.01-1.39; P = 0.035]. The odds of HA-ASM in subjects with PA were 10.63-fold (95% CI: 0.83-135.50) higher, with marginal significance (P = 0.069) than in those with NFAI. Skeletal muscle mass in women with PA was lower than that in women with NFAI; suggesting that excess aldosterone has adverse effects on skeletal muscle metabolism.

Impact of drugs with anti-inflammatory effects on skeletal muscle and inflammation: A systematic literature review

BACKGROUND

Ageing-related low-grade inflammation is suggested to aggravate sarcopenia and frailty. This systematic review investigates the influence that drugs with anti-inflammatory effects (AIDs) have on inflammation and skeletal muscle.

METHODS

PubMed and Web of Science were systematically screened for articles reporting the effects of AIDs on inflammation on one hand and on muscle mass and/or performance on the other.

RESULTS

Twenty-eight articles were included. These articles were heterogeneous in terms of the subjects studied, intervention components, setting, and outcome measures. Articles on older humans with acute inflammation showed evidence that celecoxib and piroxicam could reduce inflammation and improve performance and that ibuprofen improves exercise-induced muscle hypertrophy and gains in strength. In younger humans, only the effects of AIDs combined with exercise were investigated; no significant benefits of non-selective COX-inhibitors were reported, but improved strength gains with etanercept and reduced muscle soreness with celecoxib were noted. Indomethacin increased acute exercise-induced inflammation and reduced satellite cell differentiation in exercising muscle. Most articles did not systematically report occurrences of side effects.

CONCLUSIONS

Although AIDs showed significant reduction in inflammation-induced muscle weakness in older hospitalised patients with acute inflammation, robust evidence is still lacking. When combined with exercise, AIDs presented a protective effect against age-related loss of muscle mass, thus enhancing muscle mass and performance. The mechanism regulating muscle strength and its mass seems to differ between individuals of old and young age. However, the effects seem drug-specific and dose-dependent and appear to be influenced by subjects' trainability and the clinical context. In addition, the balance between benefits and harm remains unclear.

To salt or not to salt?-That is the question in cirrhosis

Ascites is the most common complication of patients with cirrhosis, resulting from portal hypertension and vasodilatation. It is associated with an increased risk for the development of hyponatraemia and renal failure and has a high mortality rate of 20% per year. The development of ascites represents a baleful sign in the course of disease in cirrhosis. To prevent complications of cirrhosis and improve quality of life, an effective management of ascites is pivotal. Combined salt restriction and diuretic therapy is recommended as first-line therapy in numerous clinical practice guidelines. In contrast, there has been a debate on whether a strict salt-restricted diet for cirrhosis patients should be used at all since salt restriction may increase the risk for malnutrition which in turn may negatively impact on quality of life and survival. This review aims to summarize the current pros and cons regarding salt restriction in patients with cirrhosis and proposes the importance of achieving a sodium balance throughout different stages of cirrhosis.

Prediction of sarcopenia using a combination of multiple serum biomarkers

Sarcopenia is a gradual loss of skeletal muscle mass and function with aging. Given that sarcopenia has been recognized as a disease entity, effective molecular biomarkers for early diagnosis are required. We recruited 46 normal subjects and 50 patients with moderate sarcopenia aged 60 years and older. Sarcopenia was clinically identified on the basis of the appendicular skeletal muscle index by applying cutoff values derived from the Asian Working Group for Sarcopenia. The serum levels of 21 potential biomarkers were analyzed and statistically examined. Interleukin 6, secreted protein acidic and rich in cysteine, macrophage migration inhibitory factor, and insulin-like growth factor 1 levels differed significantly between the normal and sarcopenia groups. However, in each case, the area under the receiver operating characteristics curve (AUC) was <0.7. Subsequent combination of the measurements of these biomarkers into a single risk score based on logistic regression coefficients enhanced the accuracy of diagnosis, yielding an AUC value of 0.763. The best cutoff value of 1.529 had 70.0% sensitivity and 78.3% specificity (95% CI = 2.80–21.69, p < 0.0001). Combined use of the selected biomarkers provides higher diagnostic accuracy than individual biomarkers, and may be effectively utilized for early diagnosis and prognosis of sarcopenia.

Effects of Low Muscle Mass on Albuminuria and Chronic Kidney Disease in Patients With Type 2 Diabetes: The Korean Sarcopenic Obesity Study (KSOS)

Background

Previous studies have shown that chronic kidney disease (CKD) is associated with accelerated loss of skeletal muscle in patients on dialysis. However, the relationships of sarcopenia with albuminuria and early-stage CKD in patients with type 2 diabetes have not been examined.

Methods

We analyzed diabetic subgroup data from 409 patients with type 2 diabetes from the Korean Sarcopenic Obesity Study (KSOS). Sarcopenia was defined as a skeletal muscle mass index (SMI; SMI [%] = total skeletal muscle mass [kg]/weight [kg] × 100) less than 2 SD below the sex-specific mean for a younger reference group. The estimated glomerular filtration rates and urinary albumin-to-creatinine ratios were used to assess renal function and albuminuria.

Results

The prevalence of sarcopenia was significantly increased in the albuminuria group compared with the normo-albuminuria group (26.7% vs 12.6%, p = .001), as well as in CKD 3 group compared with the CKD 1-2 group (46.7% vs 15.1%, p = .005). After adjusting for age, SMI was negatively correlated with urinary albumin-to-creatinine ratios and positively correlated with aspartate aminotransferase, alanine aminotransferase, total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol levels. Multiple logistic regression analysis revealed that the odds ratio for albuminuria association was 3.02 (95% CI 1.37-6.67) in the lowest tertile of SMI compared with the highest tertile after adjusting for various confounding factors.

Conclusions

Sarcopenia is more prevalent in individuals with albuminuria than in those without albuminuria. Furthermore, increased albuminuria is independently associated with low muscle mass in patients with type 2 diabetes.

Associations between ACE-Inhibitors, Angiotensin Receptor Blockers, and Lean Body Mass in Community Dwelling Older Women

Studies suggest that ACE-inhibitors (ACE-I) and angiotensin receptor blockers (ARBs) may preserve skeletal muscle with aging. We evaluated longitudinal differences in lean body mass (LBM) among women diagnosed with hypertension and classified as ACE-I/ARB users and nonusers among Women's Health Initiative participants that received dual energy X-ray absorptiometry scans to estimate body composition (n=10,635) at baseline and at years 3 and 6 of follow-up. Of those, 2642 were treated for hypertension at baseline. Multivariate linear regression models, adjusted for relevant demographics, behaviors, and medications, assessed ACE-I/ARB use/nonuse and LBM associations at baseline, as well as change in LBM over 3 and 6 years. Although BMI did not differ by ACE-I/ARB use, LBM (%) was significantly higher in ACE-I/ARB users versus nonusers at baseline (52.2% versus 51.3%, resp., p=0.001). There was no association between ACE-I/ARB usage and change in LBM over time. Reasons for higher LBM with ACE-I/ARB use cross sectionally, but not longitundinally, are unclear and may reflect a threshold effect of these medications on LBM that is attenuated over time. Nevertheless, ACE-I/ARB use does not appear to negatively impact LBM in the long term.

Pre-sarcopenia is associated with renal hyperfiltration independent of obesity or insulin resistance: Nationwide Surveys (KNHANES 2008-2011)

Renal hyperfiltration is closely linked to cardiometabolic disorders, and it may increase the mortality risk of the general population. Despite the well-established association between cardiometabolic diseases and sarcopenia, the relationship between renal hyperfiltration and sarcopenia has not yet been assessed.This population-based, cross-sectional study used a nationally representative sample of 13,800 adults from the 2008 to 2011 Korea National Health and Nutrition Examination Survey. Renal hyperfiltration was defined as the age- and sex-specific glomerular filtration rate above the 90th percentile in subjects with normal kidney function (>60 mL/min/1.73 m). Appendicular skeletal muscle (ASM), measured by dual-energy x-ray absorptiometry, was used to assess pre-sarcopenia, which the international consensus defines as both ASM per se and ASM that was adjusted for the body mass index and the height.A total of 1402 (10.2%) participants were classified as having renal hyperfiltration. The prevalence of pre-sarcopenia ranged from 11.6% to 33.0%, by definition. Individuals with pre-sarcopenia had higher risks of renal hyperfiltration compared to those without pre-sarcopenia (10.9% vs 17.4%, P < .001; odds ratio [OR] = 1.71, 95% confidential interval [CI] = 1.48-1.99, P < .001). Multiple logistic regression analyses also demonstrated this independent association between pre-sarcopenia and renal hyperfiltration, following adjustment for confounding factors such as insulin resistance and obesity (OR = 1.84, 95% CI = 1.57-2.15, P < .001).In the general population of healthy individuals, pre-sarcopenia might be associated with renal hyperfiltration independent of obesity or insulin resistance.

Gender-Specific Associations between Low Skeletal Muscle Mass and Albuminuria in the Middle-Aged and Elderly Population

Objective This study assessed gender-specific associations between low muscle mass (LMM) and albuminuria. Methods Data from the Korea National Health and Nutrition Examination Survey 2011 were employed. The study consisted of 1,087 subjects (≥50 years old). Skeletal muscle index (SMI) was defined as the weight-adjusted appendicular skeletal muscle mass. Mild LMM and severe LMM were defined as SMI that were 1-2 and >2 standard deviations below the sex-specific mean appendicular skeletal muscle mass of young adults, respectively. Increased albuminuria was defined as albumin-to-creatinine ratio ≥30mg/g Results Men with mild and severe LMM were significantly more likely to have increased albuminuria (15.2% and 45.45%, respectively) than men with normal SMI (9.86%, P<0.0001), but not women. Severe LMM associated independently with increased albuminuria in men (OR=7.661, 95% CI=2.72-21.579) but not women. Severe LMM was an independent predictor of increased albuminuria in hypertensive males (OR=11.449, 95% CI=3.037-43.156), non-diabetic males (OR=8.782, 95% CI=3.046-25.322), and males without metabolic syndrome (MetS) (OR=8.183, 95% CI=1.539-43.156). This was not observed in males without hypertension, males with diabetes or MetS, and all female subgroups. Conclusion Severe LMM associated with increased albuminuria in men, especially those with hypertension and without diabetes or MetS.

Relationship Between Sarcopenia and Albuminuria: The 2011 Korea National Health and Nutrition Examination Survey

Studies have shown that albuminuria, obesity, and sarcopenia may share pathophysiological processes related to cardiovascular disease risk. Their direct relationships, however, have not been examined. This study investigated the association between albuminuria and sarcopenia in a representative fraction of the Korean population.Of the 10,589 people who participated in the 2011 Korea National Health and Nutrition Examination Survey, 2158 participants aged over 19 years had been tested for albumin-to-creatinine ratio and for body composition data using dual-energy x-ray absorptiometry. Albuminuria was defined as an albumin-to-creatinine ratio ≥30 mg/g. Sarcopenia was defined as a skeletal muscle index (SMI) (SMI (%) = total appendicular skeletal muscle mass [kg]/weight [kg] × 100) of less than 1 standard deviation (SD) (grade 1) or 2 SD (grade 2) below the sex-specific mean for a younger reference group.The prevalence of albuminuria was higher in those with grade 2 sarcopenia than in those with a normal SMI or grade 1 sarcopenia (33.3% versus 8.4% and 8.9%; P < 0.001). Conversely, grade 2 sarcopenia was also more prevalent in participants with albuminuria than in those with the upper tertile of normoalbuminuria. In addition, multiple logistic regression analysis showed the odds ratio for albuminuria risk in the grade 2 sarcopenia group was 2.93 (95% confidence interval [CI], 1.46-5.88), compared with normal SMI after adjusting for potential confounding factors, including the presence of obesity, diabetes, and hypertension. Moreover, individuals with albuminuria had an odds ratio of 3.39 (95% [confidence interval], 1.38-8.37) for grade 2 sarcopenia compared with those in the lowest tertile of normoalbuminuria.This is the first study to demonstrate that individuals with sarcopenia exhibited increased risk of albuminuria and vice versa.

Successful aging: Advancing the science of physical independence in older adults

The concept of 'successful aging' has long intrigued the scientific community. Despite this long-standing interest, a consensus definition has proven to be a difficult task, due to the inherent challenge involved in defining such a complex, multi-dimensional phenomenon. The lack of a clear set of defining characteristics for the construct of successful aging has made comparison of findings across studies difficult and has limited advances in aging research. A consensus on markers of successful aging is furthest developed is the domain of physical functioning. For example, walking speed appears to be an excellent surrogate marker of overall health and predicts the maintenance of physical independence, a cornerstone of successful aging. The purpose of the present article is to provide an overview and discussion of specific health conditions, behavioral factors, and biological mechanisms that mark declining mobility and physical function and promising interventions to counter these effects. With life expectancy continuing to increase in the United States and developed countries throughout the world, there is an increasing public health focus on the maintenance of physical independence among all older adults.

Multi-modal intervention to reduce cardiovascular risk among hypertensive older adults: Design of a randomized clinical trial

Persons aged over 65 years account for over 75% of healthcare expenditures and deaths attributable to cardiovascular disease (CVD). Accordingly, reducing CVD risk among older adults is an important public health priority. Functional status, determined by measures of physical performance, is an important predictor of cardiovascular outcomes in older adults and declines more rapidly in seniors with hypertension. To date, physical exercise is the primary strategy for attenuating declines in functional status. Yet despite the general benefits of training, exercise alone appears to be insufficient for preventing this decline. Thus, alternative or adjuvant strategies are needed to preserve functional status among seniors with hypertension. Prior data suggest that angiotensin converting enzyme inhibitors (ACEi) may be efficacious in enhancing exercise-derived improvements in functional status yet this hypothesis has not been tested in a randomized controlled trial. The objective of this randomized, double-masked pilot trial is to gather preliminary efficacy and safety data necessary for conducting a full-scale trial to test this hypothesis. Sedentary men and women ≥ 65 years of age with functional limitations and hypertension are being recruited into this 24 week intervention study. Participants are randomly assigned to one of three conditions: (1) ACEi plus exercise training, (2) thiazide diuretic plus exercise training, or (3) AT1 receptor antagonist plus exercise training. The primary outcome is change in walking speed and secondary outcomes consist of other indices of CV risk including exercise capacity, body composition, as well as circulating indices of metabolism, inflammation and oxidative stress.

Optimizing the benefits of exercise on physical function in older adults

As the number of older adults continues to rise worldwide, the prevention of physical disability among seniors is an increasingly important public health priority. Physical exercise is among the best known methods of preventing disability, but accumulating evidence indicates that considerable variability exists in the responsiveness of older adults to standard training regimens. Accordingly, a need exists to develop tailored interventions to optimize the beneficial effects of exercise on the physical function of older adults at risk for becoming disabled. The present review summarizes the available literature related to the use of adjuvant or alternative strategies intended to enhance the efficacy of exercise in improving the physical function of older adults. Within this work, we also discuss potential future research directions in this area.

Sarcopenia: pharmacology of today and tomorrow

Sarcopenia remains largely undiagnosed and undertreated because of the lack of a universally accepted definition, effective ways to measure it, and identification of the outcomes that should guide treatment efficacy. An ever-growing number of clinicians and researchers along with funding and regulatory agencies have gradually recognized that sarcopenia is a human condition that requires both prevention and treatment. In this article, we review sarcopenia and its common and less known pharmacological treatments, attempt to define sarcopenia in its broader context, and present some new ideas for potential future treatment for this devastating condition.

The Impacts of ACE Activity according to ACE I/D Polymorphisms on Muscular Functions of People Aged 65

OBJECTIVE

To investigate associations between angiotensin-converting enzyme (ACE) polymorphisms and muscle fatigability in 65-year-old Koreans.

METHOD

The study participants were 49 Koreans aged 65 years. ACE insertion/deletion (I/D) polymorphisms were determined by polymerase chain reaction and serum ACE activity, by spectrophotometry. Body mass index (BMI), body fat mass (BFM), and lean body mass (LBM) were determined. To evaluate muscle fatigability, dynamic Electromyography was used to measure maximum voluntary isometric contractions (MVICs) of ankle plantar flexor muscles. Patients were seated with their hips flexed at 90°, knees fully extended, and ankles at 0°. Continuous submaximal VICs (40% MVIC) were then performed, and contraction duration and EMG frequency changes during the initial 2 min were measured. A self-reported physical activity questionnaire was used to evaluate effects of ACE activity levels on muscle fatigability.

RESULTS

Among the 49 volunteers, 15 showed II genotype; 22, ID genotype; and 12, DD genotype. Serum ACE activity levels were significantly higher in DD genotype subjects than in II genotype subjects (p<0.05). Furthermore, the duration of submaximal isometric contractions was longer in II and ID genotype subjects than in DD genotype subjects (p<0.05). Dynamic EMG showed significantly lower mean frequency changes in II genotype subjects than in DD genotype subjects (p<0.05). However, LBM, BFM, and BMI were independent of ACE genotypes.

CONCLUSION

ACE II genotype subjects showed significantly higher resistant to muscle fatigue than that by DD genotype subjects. However, body composition and BMI showed no correlations with ACE I/D polymorphisms.

Ghrelin improves body weight loss and skeletal muscle catabolism associated with angiotensin II-induced cachexia in mice

Ghrelin is a gastric peptide that regulates energy homeostasis. Angiotensin II (Ang II) is known to induce body weight loss and skeletal muscle catabolism through the ubiquitin-proteasome pathway. In this study, we investigated the effects of ghrelin on body weight and muscle catabolism in mice treated with Ang II. The continuous subcutaneous administration of Ang II to mice for 6 days resulted in cardiac hypertrophy and significant decreases in body weight gain, food intake, food efficiency, lean mass, and fat mass. In the gastrocnemius muscles of Ang II-treated mice, the levels of insulin-like growth factor 1 (IGF-1) were decreased, and the levels of mRNA expression of catabolic factors were increased. Although the repeated subcutaneous injections of ghrelin (1.0mg/kg, twice daily for 5 days) did not affect cardiac hypertrophy, they resulted in significant body weight gains and improved food efficiencies and tended to increase both lean and fat mass in Ang II-treated mice. Ghrelin also ameliorated the decreased IGF-1 levels and the increased mRNA expression levels of catabolic factors in the skeletal muscle. IGF-1 mRNA levels in the skeletal muscle significantly decreased 24h after Ang II infusion, and this was reversed by two subcutaneous injections of ghrelin. In C2C12-derived myocytes, the dexamethasone-induced mRNA expression of atrogin-1 was decreased by IGF-1 but not by ghrelin. In conclusion, we demonstrated that ghrelin improved body weight loss and skeletal muscle catabolism in mice treated with Ang II, possibly through the early restoration of IGF-1 mRNA in the skeletal muscle and the amelioration of nutritional status.

Angiotensin-converting enzyme inhibitor and statin use and incident mobility limitation in community-dwelling older adults: the Health, Aging and Body Composition study

OBJECTIVES

To evaluate whether the use of angiotensin-converting enzyme (ACE) inhibitors and statins is associated with a lower risk of incident mobility limitation in older community dwelling adults.

DESIGN

Longitudinal cohort study.

SETTING

Health, Aging and Body Composition (Health ABC) study.

PARTICIPANTS

Three thousand fifty-five participants who were well functioning at baseline (no mobility limitations).

MEASUREMENTS

Summated standardized daily doses (low, medium, high) and duration of ACE inhibitor and statin use were computed. Mobility limitation (two consecutive self-reports of having any difficulty walking one-quarter of a mile or climbing 10 steps without resting) was assessed every 6 months after baseline. Multivariable Cox proportional hazards analyses were conducted, adjusting for demographics, health status, and health behaviors.

RESULTS

At baseline, 15.2% used ACE inhibitors and 12.9% used statins; use of both was greater than 25% by Year 6. Over 6.5 years of follow-up, 49.8% had developed mobility limitation. In separate multivariable models, neither ACE inhibitor (multivariate hazard ratio (HR) = 0.95, 95% confidence interval (CI) = 0.82-1.09) nor statin use (multivariate HR = 1.02, 95% CI = 0.87-1.17) was associated with lower risk of mobility limitation. Similar findings were seen in analyses examining dose-response and duration-response relationships and a sensitivity analysis restricted to those with hypertension.

CONCLUSION

ACE inhibitors and statins widely prescribed to treat hypertension and hypercholesterolemia, respectively, do not lower risk of mobility limitation, an important indicator of quality of life.

Mineralocorticoid antagonism: a novel way to treat sarcopenia and physical impairment in older people?

Dysregulation of the renin-angiotensin-aldosterone system has been associated with a number of age-related pathologies including hypertension, heart failure and chronic kidney disease. More recently, it has been suggested that alterations within the RAAS may contribute to the development of sarcopenia and subsequent decline in physical function. There is growing interest in developing interventions to prevent age-associated decline in muscle function. We postulate that inhibition of the RAAS with the mineralocorticoid antagonist spironolactone may have a role in countering the effects of physical impairment in older people by improving skeletal muscle function. Spironolactone may prevent skeletal myocyte apoptosis, improve vascular endothelial function and enhance muscle contractility by increasing muscle magnesium and sodium-potassium pumps. This article will review the literature underpinning the hypothesis that spironolactone may have a role in maintaining muscle function in older people.

[The emergent role of sarcopenia: Preliminary Report of the Observatory of Sarcopenia of the Spanish Society of Geriatrics and Gerontology]

Sarcopenia is a common and prominent geriatric syndrome, of major interest for daily clinical practice of professionals working with older people. The number of affected individuals and its relation with disability, frailty, many chronic diseases, lifestyle and adverse outcomes are extremely relevant for geriatric care. Moreover, biological changes that lead to the loss of muscle mass and strength are intrinsically related to the mechanisms of aging. It is not therefore surprising that research in this field is growing exponentially in recent years, and sarcopenia has been placed in recent years in the forefront of research in geriatric medicine and gerontology. The Spanish Society of Geriatrics and Gerontology has recently created an Observatory of Sarcopenia, which aims to promote educational and research activities in this field. The first activity of the Observatory has been to offer the Spanish speaking scientific community a review of the current status of sarcopenia, that may allow unifying concepts and fostering interest in this promising field of geriatrics.

ACE-inhibition and physical function: results from the Trial of Angiotensin-Converting Enzyme Inhibition and Novel Cardiovascular Risk Factors (TRAIN) study

OBJECTIVES

Aim of the present study was to evaluate whether an ACE inhibitor intervention is able to significantly improve physical performance and muscle strength in a sample of older persons.

DESIGN

Double-blind, cross-over, randomized, placebo-controlled trial.

SETTING

The Trial of Angiotensin-Converting Enzyme Inhibition and Novel Cardiovascular Risk Factors (TRAIN) study.

PARTICIPANTS

Participants were 257 subjects aged 55 years and older with high cardiovascular risk profile.

INTERVENTION

Six months of fosinopril use versus placebo.

MEASUREMENTS

The Short Physical Performance Battery score (rescaled to obtain a continuous variable ranging from 0 to 3 points), and the hand grip strength were measured at the baseline visit, and after 6 and 12 months of follow-up. Paired t test analyses were performed to compare results of physical function measures after ACE inhibition and placebo interventions.

RESULTS

Mean age of the sample population was 65.97 (standard deviation 7.41) years old. No statistically significant difference was found at the Short Physical Performance Battery (P=.23) and hand grip strength (P=.57) results after ACE inhibition (2.113, standard deviation [SD] 0.284; and 37.044 kg, SD 12.993 kg, respectively) compared to placebo (2.096, SD 0.298; and 36.898 kg, SD 13.178 kg, respectively). No significant effects from ACE inhibition were also found when the 3 subtests composing the Short Physical Performance Battery (ie, 4-meter walking speed, balance, and chair stand tests) were separately analyzed. Consistent negative results were obtained after analyses were restricted to participants showing the highest compliance to treatment and/or receiving the maximum fosinopril dosage.

CONCLUSION

No significant modifications in physical performance and muscle strength were reported after 6 months of fosinopril use in older persons with high cardiovascular risk profile. Given these negative findings, it is possible that the beneficial effects of ACE inhibitors on physical function might be attributable to the activation of a virtuous cycle determined by an improved cardiovascular system. Further specifically designed studies are needed to confirm our findings, and expand them to different populations and ACE inhibitors. If our findings will be confirmed, the extracardiovascular properties of ACE inhibitors in older persons might be substantially resized.

Palliative care in congestive heart failure

Symptoms and compromised quality of life prevail throughout the course of heart failure (HF) and thus should be specifically addressed with palliative measures. Palliative care for HF should be integrated into comprehensive HF care, just as evidence-based HF care should be included in end-of-life care for HF patients. The neurohormonal and catabolic derangements in HF are at the base of HF symptoms. A complex set of abnormalities can be addressed with a variety of interventions, including evidence-based HF care, specific exercise, opioids, treatment of sleep-disordered breathing, and interventions to address patient and family perceptions of control over their illness. Both potential sudden cardiac death and generally shortened length of life by HF should be acknowledged and planned for. Strategies to negotiate communication about prognosis with HF patients and their families can be integrated into care. Additional evidence is needed to direct care at the end of life, including use of HF medications, and to define management of multiple sources of distress for HF patients and their families.

Sarcopenia and functional decline: pathophysiology, prevention and therapy

Twenty years ago, the term 'sarcopenia' has been introduced to describe the ageing related loss of skeletal muscle mass. Since then, sarcopenia has been intensively studied and prevalence values have been reported in fifteen papers covering several continents and races. However, consistency regarding the outcome measures and corresponding cut-off values defining sarcopenia is lacking. Most approaches are based on estimations of muscle mass and proposed cut-off values might be too strict, thus reducing their use in daily practice. From a clinical viewpoint, the assessment of muscle performance (grip strength and endurance) can be proposed as a screening tool showing sufficient sensitivity. The pathophysiology of sarcopenia is multifactorial, and important changes at the tissue level have been identified. Close relationships with inflammatory processes have been demonstrated and there is strong evidence for the involvement of a chronic low-grade inflammatory activity. Sarcopenia is aggravated by a complex interaction of several factors among which aging, disuse, immobilization, disease and malnutrition. A comprehensive geriatric assessment should allow the clinician to estimate the relative contribution of these factors and to elaborate appropriate management. From all interventions studied, intensive resistance training seems the most efficient to counter sarcopenia, even in the very old geriatric patients. Significant ameliorations (up to >50% strength gain) can be expected after six weeks of training at a rhythm of 2-3 sessions per week. From a preventive viewpoint, all elderly patients should be advised to start such an exercise program and continue it as long as possible. To date, most pharmacological interventions to counter sarcopenia include drugs with anabolic effects. Unfortunately, their effect is questionable and no clear guidelines exist for the prescription of these products in the context of sarcopenia.

Automated drug screening with contractile muscle tissue engineered from dystrophic myoblasts

Identification of factors that improve muscle function in boys with Duchenne muscular dystrophy (DMD) could lead to an improved quality of life. To establish a functional in vitro assay for muscle strength, mdx murine myoblasts, the genetic homologue of DMD, were tissue engineered in 96-microwell plates into 3-dimensional muscle constructs with parallel arrays of striated muscle fibers. When electrically stimulated, they generated tetanic forces measured with an automated motion tracking system. Thirty-one compounds of interest as potential treatments for patients with DMD were tested at 3 to 6 concentrations. Eleven of the compounds (insulin-like growth factor-1, creatine, beta-hydroxy-beta-methylbutyrate, trichostatin A, lisinopril, and 6 from the glucocorticoid family) significantly increased tetanic force relative to placebo-treated controls. The glucocorticoids methylprednisolone, deflazacort, and prednisone increased tetanic forces at low doses (EC(50) of 6, 19, and 56 nM, respectively), indicating a direct muscle mechanism by which they may be benefitting DMD patients. The tetanic force assay also identified beneficial compound interactions (arginine plus deflazacort and prednisone plus creatine) as well as deleterious interactions (prednisone plus creatine inhibited by pentoxifylline) of combinatorial therapies taken by some DMD patients. Since mdx muscle in vivo and DMD patients respond in a similar manner to many of these compounds, the in vitro assay will be a useful tool for the rapid identification of new potential treatments for muscle weakness in DMD and other muscle disorders.

Angiotensin-converting enzyme inhibitor use and incident frailty in women aged 65 and older: prospective findings from the Women's Health Initiative Observational Study

OBJECTIVES

To examine the associations between current use, duration, and potency of angiotensin-converting enzyme (ACE) inhibitors and incident frailty in women aged 65 and older who were not frail at baseline.

DESIGN

Data were from the Women's Health Initiative Observational Study (WHI-OS), a prospective study conducted at 40 U.S. clinical centers.

PARTICIPANTS

Women aged 65 to 79 at baseline who were not frail (N=27,378).

MEASUREMENTS

Current ACE inhibitor use was ascertained through direct inspection of medicine containers at baseline. Components of frailty were self-reported low physical function or impaired walking, exhaustion, low physical activity, and unintended weight. Frailty was ascertained through self-reported and physical measurements data at baseline and 3-year clinic contacts.

RESULTS

By the 3-year follow-up, 3,950 (14.4%) women had developed frailty. Current ACE inhibitor use had no association with incident frailty (multivariate adjusted odds ratio=0.96, 95% confidence interval=0.82-1.13). Duration and potency of ACE inhibitor use were also not significantly associated with incident frailty. A similar pattern of results was observed when incident cardiovascular disease events were studied as a separate outcome or when the sample was restricted to subjects with hypertension.

CONCLUSION

Overall, incidence of frailty was similar in current ACE inhibitor users and nonusers.

Cachexia and aging: an update based on the Fourth International Cachexia Meeting

This manuscript highlights the new developments in the pathophysiology of anorexia, cachexia and sarcopenia, based on presentations given at the Fourth International Cachexia Meeting. It stresses the importance of these conditions in older persons.