Serum adipocyte fatty acid-binding protein levels are independently associated with sarcopenic obesity

Proteomic architecture of frailty across the spectrum of cardiovascular disease

While frailty is a prominent risk factor in an aging population, the underlying biology of frailty is incompletely described. Here, we integrate 979 circulating proteins across a wide range of physiologies with 12 measures of frailty in a prospective discovery cohort of 809 individuals with severe aortic stenosis (AS) undergoing transcatheter aortic valve implantation. Our aim was to characterize the proteomic architecture of frailty in a highly susceptible population and study its relation to clinical outcome and systems-wide phenotypes to define potential novel, clinically relevant frailty biology. Proteomic signatures (specifically of physical function) were related to post-intervention outcome in AS, specifying pathways of innate immunity, cell growth/senescence, fibrosis/metabolism, and a host of proteins not widely described in human aging. In published cohorts, the "frailty proteome" displayed heterogeneous trajectories across age (20-100 years, age only explaining a small fraction of variance) and were associated with cardiac and non-cardiac phenotypes and outcomes across two broad validation cohorts (N > 35,000) over ≈2-3 decades. These findings suggest the importance of precision biomarkers of underlying multi-organ health status in age-related morbidity and frailty.

A narrative review on the impact of sarcopenic obesity and its psychological consequence in quality of life

BACKGROUND AND AIM

Sarcopenia is a multifactorial metabolic-mediated complication that affects most of the geriatric population physically and mentally. In this study, we intended to study the association between sarcopenia and psychologically related symptoms. Primary objective of the study is to explore the interplay between sarcopenic obesity, psychological consequences and Quality of life in the affected population. The secondary objective is to discuss the diagnostic, treatment approaches and also the role of clinical pharmacist.

METHOD

The psychology-related complication and sarcopenia association was enumerated in this study based on previous clinical research findings.

RESULT

The clinical evidence shows a strong correlation between sarcopenia and Mental health and its health consequences and reflection on the quality of life.

CONCLUSION

Sarcopenia induced mental disturbance has been affirmed in many studies. We believe effective right pharmacological therapy and non-pharmacological therapies with respective lifestyle modification advice could be potential vital factors that can reduce further complications in geriatric populations.

Inflammation in Relation to Sarcopenia and Sarcopenic Obesity among Older Adults Living with Chronic Comorbidities: Results from the National Health and Nutrition Examination Survey 1999-2006

Loss of muscle mass and waning in muscle strength are common in older adults, and inflammation may play a key role in pathogenesis. This study aimed to examine associations of C-reactive protein (CRP) and systemic immune-inflammation index (SII) with sarcopenia and sarcopenic obesity in older adults with chronic comorbidities. Cross-sectional data from the National Health and Nutrition Examination Survey (1999–2006) were obtained for participants aged ≥60 years. Sarcopenia was defined by a lean mass and body height (males < 7.26 kg/m², females < 5.45 kg/m²). Sarcopenic obesity was defined by the concurrent presence of sarcopenia and obesity (defined by relative fat mass). Logistic regression was used to assess the associations of CRP and SII with sarcopenia and sarcopenic obesity. The dose–response relationship was examined via restricted cubic splines. Of the participants (n = 2483), 23.1% (n = 574) and 7.7% (n = 190) had sarcopenia and sarcopenic obesity, respectively. The multivariable logistic regression models suggested a positive association of SII with sarcopenia and sarcopenic obesity, but a positive statistically significant association was not consistently observed for CRP. Dose–response curves suggested similar association patterns for these biomarkers. In clinical practice, measures to prevent sarcopenia and sarcopenic obesity are needed for older vulnerable people with high systemic inflammation.

The Impact of Dysmetabolic Sarcopenia Among Insulin Sensitive Tissues: A Narrative Review

Sarcopenia is a common muscular affection among elderly individuals. More recently, it has been recognized as the skeletal muscle (SM) expression of the metabolic syndrome. The prevalence of sarcopenia is increasing along with visceral obesity, to which it is tightly associated. Nonetheless, it is a still underreported entity by clinicians, despite the worsening in disease burden and reduced patient quality of life. Recognition of sarcopenia is clinically challenging, and variability in study populations and diagnostic methods across the clinical studies makes it hard to reach a strong evidence. Impaired insulin activity in SM is responsible for the altered molecular pathways and clinical manifestations of sarcopenia, which is morphologically expressed by myosteatosis. Lipotoxicity, oxidative stress and adipose tissue-derived inflammation lead to both alterations in glucose disposal and protein synthesis in SM, with raising insulin resistance (IR) and SM atrophy. In particular, hyperleptinemia and leptin resistance interfere directly with SM activity, but also with the release of Growth Hormone from the hypohysis, leading to a lack in its anabolic effect on SM. Moreover, sarcopenia is independently associated to liver fibrosis in Non-Alcoholic Fatty Liver Disease (NAFLD), which in turn worsens SM functionality through the secretion of proinflammatory heptokines. The cross-talk between the liver and SM in the IR setting is of crucial relevance, given the high prevalence of NAFLD and the reciprocal impact of insulin-sensitive tissues on the overall disease burden. Along with the efforts of non-invasive diagnostic approaches, irisin and myostatin are two myokines currently evaluated as potential biomarkers for diagnosis and prognostication. Decreased irisin levels seem to be potentially associated to sarcopenia, whereas increased myostatin has shown to negatively impact on sarcopenia in pre-clinical studies. Gene variants in irisin have been explored with regard to the impact on the liver disease phenotype, with conflicting results. The gut-muscle axis has gain relevance with the evidence that insulin resistance-derived gut dysbiosis is responsible for increased endotoxemia and reduction in short-chain free fatty acids, directly affecting and predisposing to sarcopenia. Based on the current evidence, more efforts are needed to increase awareness and improve the management of sarcopenic patients.

Adiponectin and Sarcopenia: A Systematic Review With Meta-Analysis

BACKGROUND

Sarcopenia is a progressive loss of skeletal muscle mass whose pathophysiology has been proposed to possibly involve mechanisms of altered inflammatory status and endocrine function. Adiponectin has been shown to modulate inflammatory status and muscle metabolism. However, the possible association between adiponectin levels and sarcopenia is poorly understood. In order to fill this gap, in the present manuscript we aimed to summarize the current evidence with a systematic review and a meta-analysis of studies reporting serum adiponectin levels in patients with sarcopenia compared to non-sarcopenic controls.

METHODS

An electronic search through Medline/PubMed, Cochrane Library, and Science Direct was performed till March 1, 2020. From the included papers, meta-analysis of cross-sectional studies comparing serum levels of adiponectin between patients with sarcopenia and controls was performed.

RESULTS

Out of 1,370 initial studies, seven studies were meta-analyzed. Sarcopenic participants had significantly higher levels of adiponectin Hedges' g with 95% confidence interval (CI): 1.20 (0.19-2.22), p = 0.02 than controls. Subgroup analysis, performed in Asian population and focused on identification of the condition based on AWGS criteria, reported higher adiponectin levels in sarcopenic population (2.1 (0.17-4.03), p = 0.03 and I2 = 98.98%. Meta-regression analysis revealed female gender to significantly influence the results as demonstrated by beta = 0.14 (95% CI (0.010-0.280), p = 0.040).

CONCLUSIONS

Our meta-analysis found evidence that sarcopenia is associated with higher adiponectin levels. However, caution is warranted on the interpretation of these findings, and future longitudinal research is required to disentangle and better understand the topic.

Proteomic profiling of fatty acid binding proteins in muscular dystrophy

Introduction: Duchenne muscular dystrophy is a neuromuscular disorder, which is caused by abnormalities in the DMD gene that encodes the membrane cytoskeletal protein dystrophin. Besides progressive skeletal muscle wasting, dystrophinopathy also affects non-skeletal muscle tissues, including cells in the cardio-respiratory system, the central nervous system, the liver and the kidney.Areas covered: This review summarizes the proteomic characterization of a key class of lipid chaperones, the large family of fatty acid binding proteins, and their potential role in muscular dystrophy. Recent proteomic surveys using animal models and patient specimens are reviewed. Pathobiochemical changes in specific proteoforms of fatty acid binding protein in the multi-system pathology of dystrophinopathy are discussed.Expert opinion: The mass spectrometric identification of distinct changes in fatty acid binding proteins in muscle, heart, liver, kidney and serum demonstrates that considerable alterations occur in key steps of metabolite transport and fat metabolism in muscular dystrophy. These new findings might be helpful to further develop a comprehensive biomarker signature of metabolic changes in X-linked muscular dystrophy, which should improve (i) our understanding of complex pathobiochemical changes due to dystrophin deficiency, (ii) the identification of novel therapeutic targets, and (iii) the design of differential diagnostic, prognostic and therapy-monitoring approaches.

Cardiometabolic disease in the older person: prediction and prevention for the generalist physician

Ageing is associated with chronic inflammation and oxidative stress that increase the risk of cardiovascular disease. Frailty and sarcopenia, which are associated with increased visceral obesity and muscle mass loss, are now emerging as new potential risk factors for cardiovascular disease. Increased muscle visceral fat leads to increased secretion of harmful proinflammatory adipokines and reduced muscle mass leads to reduced secretion of the protective myokines creating an abnormal cardiometabolic state increasing the risk of cardiovascular disease. This review: (1) explore traditional and newly emerging cardiometabolic risk factors in older people; (2) investigate methods of prediction and prevention of cardiovascular disease in those with diabetes; and (3) concludes that the development of a subspeciality of Cardiometabolic Medicine should be considered.

Sarcopenia and fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is the most common liver disease which may progress to non-alcoholic steatohepatitis. The prevalence of sarcopenia, which is the loss of muscle mass and strength, is increasing in the aging society. Recent studies reported the relationship between NAFLD and sarcopenia. The skeletal muscle is the primary organ for glucose disposal. Loss of muscle mass can cause insulin resistance, which is an important risk factor for NAFLD. Moreover, obesity, chronic low-grade inflammation, vitamin D deficiency, physical inactivity, hepatokines, and myokines might be involved in the pathophysiologic mechanism of sarcopenia and NAFLD. Although most of the previous studies have demonstrated the positive correlation between sarcopenia and NAFLD, the difference in diagnostic methods of sarcopenia and NAFLD leads to difficulties in interpretation and application. This review discusses the concept and diagnosis of sarcopenia and NAFLD, common pathophysiology, and clinical studies linking sarcopenia to NAFLD. The presentation of the association between sarcopenia and NAFLD may provide an opportunity to prevent the deterioration of fatty liver disease.

Mechanisms Underlying Metabolic Syndrome-Related Sarcopenia and Possible Therapeutic Measures

Although there are several reviews that report the interrelationship between sarcopenia and obesity and insulin resistance, the relation between sarcopenia and the other signs that compose the metabolic syndrome (MetS) has not been extensively revised. Here, we review the mechanisms underlying MetS-related sarcopenia and discuss the possible therapeutic measures proposed. A vicious cycle between the loss of muscle and the accumulation of intramuscular fat might be associated with MetS via a complex interplay of factors including nutritional intake, physical activity, body fat, oxidative stress, proinflammatory cytokines, insulin resistance, hormonal changes, and mitochondrial dysfunction. The enormous differences in lipid storage capacities between the two genders and elevated amounts of endogenous fat having lipotoxic effects that lead to the loss of muscle mass are discussed. The important repercussions of MetS-related sarcopenia on other illnesses that lead to increased disability, morbidity, and mortality are also addressed. Additional research is needed to better understand the pathophysiology of MetS-related sarcopenia and its consequences. Although there is currently no consensus on the treatment, lifestyle changes including diet and power exercise seem to be the best options.

Decreased serum fatty acid binding protein 4 concentrations are associated with sarcopenia in chronic hemodialysis patients

BACKGROUND

Fatty acid binding protein 4 (FABP4) is found to play a role in skeletal muscle homeostasis. Since the dysregulation of FABP4 and sarcopenia are both highly prevalent in patients on chronic hemodialysis (HD), the correlation between them remains unknown. We aimed to examine this relationship in a cross-sectional study.

METHODS

A total of 120 chronic HD patients were recruited, and whose skeletal muscle mass, handgrip strength, and gait speed were assessed and blood samples were obtained. We grouped these participants into sarcopenia (n = 20) and non-sarcopenia groups according to European Working Group on Sarcopenia in Older People criteria.

RESULTS

The sarcopenia group exhibited lower weight (P < 0.001), height (P = 0.019), waist circumference (P < 0.001), body mass index (P < 0.001), body fat mass (P = 0.004), and lower serum triglycerides (P = 0.009), creatinine (P < 0.001), phosphorus (P = 0.013), intact parathyroid hormone (P = 0.012), and FABP4 concentrations (P = 0.005), and higher malnutrition-inflammation scores (MIS) (P = 0.031), urea reduction rates (P < 0.001), and fractional clearance index for urea (Kt/V) values (P < 0.001). Serum FABP4 concentrations (odds ratio (OR): 0.98, 95% confidence interval (CI): 0.96-0.99, P = 0.043), body fat mass (OR: 0.86, 95% CI: 0.77-0.97, P = 0.013), MIS (OR: 6.90, 95% CI: 1.31-36.36, P = 0.023), and Kt/V (each increase of 0.1, OR: 2.15, 95% CI: 1.29-3.57, P = 0.003) were independent predictors of sarcopenia in chronic HD patients.

CONCLUSIONS

We delineated the association between serum FABP4 concentrations and sarcopenia in chronic HD patients.

Sarcopenia and sarcopenic obesity in comparison: prevalence, metabolic profile, and key differences. A cross-sectional study in Italian hospitalized elderly

BACKGROUND

The aim of this study is to identify the prevalence, assess the metabolic profile, and key differences (versus healthy) in a cohort of subjects with sarcopenia (S) and in sarcopenic obesity (SO) hospitalized elderly.

METHODS

A standardized comprehensive geriatric assessment was performed. We enrolled 639 elderly subjects (196 men, 443 women) with a mean age of 80.90 ± 7.77 years. Analysis of variance and a multinomial logistic regression analysis adjusting for covariates were used to assess the differences between groups.

RESULTS

The prevalence of (S) was 12.42% in women and 23.47% in men. (SO) was 8.13% in women and 22.45% in men. Data showed that either groups had a functional impairment (Barthel index < 50 points). (S) had the mean value of erythrocyte sedimentation rate (ESR) (>15 mm/h), CPR (>0.50 mg/dl) homocysteine (>12 micromol/l), and hemoglobin (<12 g/dl). Ferritin level over the range (>145 mcg/dl) was detected in either cohort (due to inflammation). (SO) had glycemia (>110 mg/dl). Key differences in (S) cohort (versus healthy) were a reduction in functional impairment (p < 0.001), an increase in white blood cell (p < 0.01), a decrease in iron level (p < 0.05), in electrolytes balance (Na: p < 0.01 and Cl: p < 0.01), and tyroid function (TSH: p < 0.001). In addition, (S) had higher state of inflammation (erythrocyte sedimentation rate: p < 0.05 and C-reactive protein: p < 0.01), and an increase of risk of fractures (FRAX: OR 1.07; p < 0.001), risk of malnutrition (mini nutritional assessment: p < 0.001), and risk of edema (extra cellular water: p < 0.001). In (SO) cohort, an increase in white blood cell (p < 0.001) and erythrocyte sedimentation rate (p < 0.05) was observed.

CONCLUSIONS

(S) subjects appears more vulnerable than (SO). Sarcopenia is closely linked to an increase in the risk of hip-femur fractures, inflammation, edema, and malnutrition. The (SO) subjects seem to benefit from the "obesity paradox."

Association between ratio indexes of body composition phenotypes and metabolic risk in Italian adults

The ratio between fat mass (FM) and fat-free mass (FFM) has been used to discriminate individual differences in body composition and improve prediction of metabolic risk. Here, we evaluated whether the use of a visceral adipose tissue-to-fat-free mass index (VAT:FFMI) ratio was a better predictor of metabolic risk than a fat mass index to fat-free mass index (FMI:FFMI) ratio. This is a cross-sectional study including 3441 adult participants (age range 18-81; men/women: 977/2464). FM and FFM were measured by bioelectrical impedance analysis and VAT by ultrasonography. A continuous metabolic risk Z score and harmonised international criteria were used to define cumulative metabolic risk and metabolic syndrome (MetS), respectively. Multivariate logistic and linear regression models were used to test associations between body composition indexes and metabolic risk. In unadjusted models, VAT:FFMI was a better predictor of MetS (OR 8.03, 95%CI 6.69-9.65) compared to FMI:FFMI (OR 2.91, 95%CI 2.45-3.46). However, the strength of association of VAT:FFMI and FMI:FFMI became comparable when models were adjusted for age, gender, clinical and sociodemographic factors (OR 4.06, 95%CI 3.31-4.97; OR 4.25, 95%CI 3.42-5.27, respectively). A similar pattern was observed for the association of the two indexes with the metabolic risk Z score (VAT:FFMI: unadjusted b = 0.69 ± 0.03, adjusted b = 0.36 ± 0.03; FMI:FFMI: unadjusted b = 0.28 ± 0.028, adjusted b = 0.38 ± 0.02). Our results suggest that there is no real advantage in using either VAT:FFMI or FMI:FFMI ratios as a predictor of metabolic risk in adults. However, these results warrant confirmation in longitudinal studies.

Inflammation and sarcopenia: A systematic review and meta-analysis

Inflammatory cytokines have been shown to prompt muscle wasting, ultimately stimulating protein catabolism and suppressing muscle synthesis. However, the possible association between inflammatory parameters and sarcopenia is poorly understood. We therefore aimed to summarize the current evidence about this topic with a meta-analysis of studies reporting serum inflammatory parameters in patients with sarcopenia vs. people without sarcopenia (controls). An electronic PubMed and Scopus search through to 09/01/2016 and meta-analysis of cross-sectional studies comparing serum levels of inflammatory cytokines between patients with sarcopenia and controls was made, calculating random-effects standardized mean differences (SMDs) ±95% confidence intervals (CIs) as the effect size. Out of 1370 initial hits, 17 studies with a total of 11249 participants (3072 with sarcopenia and 8177 without) were meta-analyzed. Sarcopenic participants had significantly higher levels of CRP (SMD=0.51; 95%CI 0.26, 0.77; p<0.0001; I²=96%) than controls. Conversely, serum IL6 levels were not significantly different (SMD=0.35; 95%CI: -0.19, 0.89; p=0.21; I²=97%) in people with sarcopenia versus controls. Sarcopenic people did not have higher levels of TNF-α than controls (SMD=0.28; 95%CI -0.26, 0.83; p=0.31; I²=97%). In conclusion, sarcopenia seems to be associated with elevated serum CRP levels; future longitudinal studies are needed to clarify this relationship.

Serum Fatty Acid Binding Protein 4 Concentrations Are Positively and Independently Associated with Blood Pressure and Abdominal Fat among Parameters in Health Check-Ups in Ordinary Middle-Aged Japanese Males

We wished to examine potential associations among blood concentrations of fatty acid-binding protein (FABP) 4 and parameters in health check-ups such as abdominal fat area (AFA) and blood pressure (BP) in middle-aged Japanese males. We conducted a cross-sectional study of males who participated in health check-ups in Japan. We excluded participants diagnosed with metabolic diseases by the time of their check-up. A total of 305 subjects (30-64 [mean±standard deviation, 47.3±8.5] y) were recruited. Areas of total-abdominal, visceral and subcutaneous fat were measured using computed tomography. We compared the association of serum concentrations of FABP4 with various clinical parameters by Pearson product-moment correlation coefficient (PPMCC) analyses, and by step-wise multivariate linear regression analyses (MLRA). PPMCC analyses showed that blood concentrations of FABP4 were positively associated with: body mass index; areas of fat (total abdominal, visceral, subcutaneous); systolic BP; diastolic BP; total cholesterol; low-density lipoprotein-cholesterol; triacylglycerol; activities of γ-glutamyl transpeptidase, aspartate aminotransferase and alanine aminotransferase; white blood cell count; and levels of creatinine. Step-wise MLRA showed that AFAs (visceral and subcutaneous) and diastolic BP were positively and independently associated with serum concentrations of FABP4 among the parameters tested. These data suggest that serum concentrations of FABP4 are independently and positively associated with BP and AFA among parameters measured in health check-ups in middle-aged Japanese males.

The implications of sarcopenia and sarcopenic obesity on cardiometabolic disease

The important changes in body composition associated with aging are a decline in skeletal muscle mass and an increase in body fat. Body fat distribution also changes with age; subcutaneous fat decreases and visceral abdominal fat increase, which contributes to numerous cardiometabolic diseases (CMDs) such as type 2 diabetes, dyslipidemia, and cardiovascular disease (CVD). Sarcopenia often accompanied by an increase in body fat and vice versa, a scenario termed sarcopenic obesity (SO), which might lead to the cumulative risk of both sarcopenia and obesity. However, there is still no consensus regarding the definition and consequences of SO. The lack of a unified definition for SO might contribute to inconsistent findings about the association of SO with CMD. Complex etiologies are associated with development of SO. A vicious cycle between the loss of muscle and the accumulation of ectopic fat might be associated with CMD via an intricate interplay of factors including proinflammatory cytokines, oxidative stress, mitochondrial dysfunction, insulin resistance, dietary energy, physical activity, mitochondrial dysfunction, and other factors that have yet to be identified. Moreover, recent epidemiological studies suggest that SO is related to CVD and mortality. This review focuses on the current literature with regard to the association between sarcopenia, dynapenia, and obesity, as well as their implications for CMD. The ultimate goal of this Prospects is to encourage conduct of well-designed future studies that elucidate the relationship among sarcopenia, SO, and CMD.

The Link between Dietary Protein Intake, Skeletal Muscle Function and Health in Older Adults

Skeletal muscle mass and function are progressively lost with age, a condition referred to as sarcopenia. By the age of 60, many older adults begin to be affected by muscle loss. There is a link between decreased muscle mass and strength and adverse health outcomes such as obesity, diabetes and cardiovascular disease. Data suggest that increasing dietary protein intake at meals may counterbalance muscle loss in older individuals due to the increased availability of amino acids, which stimulate muscle protein synthesis by activating the mammalian target of rapamycin (mTORC1). Increased muscle protein synthesis can lead to increased muscle mass, strength and function over time. This review aims to address the current recommended dietary allowance (RDA) for protein and whether or not this value meets the needs for older adults based upon current scientific evidence. The current RDA for protein is 0.8 g/kg body weight/day. However, literature suggests that consuming protein in amounts greater than the RDA can improve muscle mass, strength and function in older adults.

Association of low muscle mass and combined low muscle mass and visceral obesity with low cardiorespiratory fitness

Objective

Previous studies have shown that low cardiorespiratory fitness (CRF), visceral obesity and low muscle mass may share pathophysiological mechanisms, such as insulin resistance and chronic inflammation. In this study, we investigated whether low CRF is associated with low muscle mass, visceral obesity, and visceral obesity combined with low muscle mass.

Research Design and Methods

The associations between CRF and low muscle mass and combined low muscle mass and visceral obesity were examined in 298 apparently healthy adults aged 20–70 years. Low muscle mass was defined using a skeletal muscle mass index (SMI) that was calculated using dual energy X-ray absorptiometry. Visceral obesity was defined as a visceral fat area (VFA) exceeding 100 cm² in women and 130 cm² in men. We classified the participants into 4 low muscle mass/visceral obesity groups according to SMI and VFA. CRF was measured using a cycle ergometer test.

Results

CRF level correlated positively with SMI and negatively with VFA. Individuals with low muscle mass had lower CRF values than those without low muscle mass. After adjustment for age, sex, lifestyle factors, and markers for insulin resistance and inflammation, participants in the lowest quartile of CRF had an odds ratio (OR) for low muscle mass of 4.98 compared with those in the highest quartile (95% confidence interval (CI) = 1.19–12.99; P for trend = 0.001) and an OR for combined low muscle mass and visceral obesity of 31.46 (95% CI = 4.31–229.68; P for trend = 0.001).

Conclusions

Individuals with lower CRF exhibited increased risk of low muscle mass and combined low muscle mass and visceral obesity. These results suggest that low CRF may be a potential indicator for low muscle mass and combined low muscle mass and visceral obesity in Korean adults.