Sarcopenic Obesity: Epidemiologic Evidence, Pathophysiology, and Therapeutic Perspectives

Sarcopenic Obesity in Children and Adolescents: A Systematic Review

Sarcopenic obesity (SO) is defined as co-occurrence of increased fat mass and sarcopenia and may predict adverse health outcomes in the pediatric population. However, the prevalence of SO and its association with adverse health outcomes have not been well defined in children and adolescents. We systematically reviewed data on the SO definition, prevalence, and adverse outcomes in the pediatric population. A total of 18 articles retrieved from PubMed or Web of Science databases were included. Overall, there was a wide heterogeneity in the methods and thresholds used to define SO. The prevalence of SO ranged from 5.66% to 69.7% in girls, with a range between 7.2% and 81.3% in boys. Of the 8 studies that evaluated outcomes related to SO, all showed a significant association of SO with cardiometabolic outcomes, non-alcoholic fatty liver disease (NAFLD) severity, inflammation, and mental health. In conclusion, this review found that SO is highly prevalent in children and adolescents and is associated with various adverse health outcomes. Findings of this review highlight the need for the development of a consensus regarding definition, standardized evaluation methods, and age and gender thresholds for SO for different ethnicities in the pediatric population. Further studies are needed to understand the relationship between obesity and sarcopenia and SO impact on adverse health outcomes in children and adolescents.

Could gut mycobiome play a role in NAFLD pathogenesis? Insights and therapeutic perspectives

The entire spectrum of nonalcoholic fatty liver disease (NAFLD) ranging from fatty liver to cirrhosis has been considered as the result of specific metabolic pathways and mediators, gut barrier function alterations and inflammatory responses. Previous studies have associated intestinal microbiota with NAFLD pathogenesis, focusing mostly on bacteria. In a recent study by Demir et al. in the Journal of Hepatology, researchers characterized the fecal mycobiome of patients with NAFLD and controls. NAFLD severity was linked to a specific fecal mycobiome signature, particularly in patients without obesity, highlighting previously undescribed aspects of the non obese phenotype of NAFLD. There has recently been a growing interest in the pathophysiology and progression of non obese NAFLD, as its actual incidence seems to be higher than previously described. Moreover, the authors demonstrated that in subjects with NAFLD and advanced fibrosis, there was an augmented systemic immune response to Candida albicans. Amphotericin B, which has been widely regarded as an antifungal with a good safety profile, low rate of resistance and high efficacy, has already been shown to prevent liver injury and steatosis in mice. Similarly in this study when germ-free mice colonized with feces from patients with NASH were fed with a Western diet, treatment with amphotericin B protected against steatohepatitis and liver fibrosis. In conclusion, this study has provided novel insights into the fecal mycobiome composition in advanced NAFLD especially in the non obese population while suggesting a role for antifungal therapy in the management of NAFLD.

Sarcopenic Obesity: An Emerging Public Health Problem

Population aging and the obesity epidemic are important global public health problems that pose an unprecedented threat to the physical and mental health of the elderly and health systems worldwide. Sarcopenic obesity (SO) is a new category of obesity and a high-risk geriatric syndrome in the elderly. SO is associated with many adverse health consequences such as frailty, falls, disability, and increased morbidity and mortality. The core mechanism of SO is the vicious circle between myocytes and adipocytes. In order to implement effective prevention and treatment strategies and reduce adverse clinical outcomes, it is essential to further our understanding of SO in the elderly. Herein, we reviewed the definition, diagnosis, epidemiology, pathogenesis, and treatment of SO in older adults.

Circulating Chemerin and Its Kinetics May Be a Useful Diagnostic and Prognostic Biomarker in Critically Ill Patients with Sepsis: A Prospective Study

Chemerin, a novel adipokine, is a potent chemoattractant molecule with antimicrobial properties, implicated in immune responses. Our aim was to investigate circulating chemerin and its kinetics, early in sepsis in critically ill patients and its association with severity and prognosis. Serum chemerin was determined in a cohort of 102 critically ill patients with sepsis during the first 48 h from sepsis onset and one week later, and in 102 age- and gender-matched healthy controls. Patients were followed for 28 days and their outcomes were recorded. Circulating chemerin was significantly higher in septic patients at onset compared to controls (342.3 ± 108.1 vs. 200.8 ± 40.1 μg/L, p < 0.001). Chemerin decreased significantly from sepsis onset to one week later (342.3 ± 108.1 vs. 308.2 ± 108.5 μg/L, p < 0.001), but remained higher than in controls. Chemerin was higher in patients presenting with septic shock than those with sepsis (sepsis onset: 403.2 ± 89.9 vs. 299.7 ± 99.5 μg/L, p < 0.001; one week after: 374.9 ± 95.3 vs. 261.6 ± 91.9 μg/L, p < 0.001), and in nonsurvivors than survivors (sepsis onset: 427.2 ± 96.7 vs. 306.9 ± 92.1 μg/L, p < 0.001; one week after: 414.1 ± 94.5 vs. 264.2 ± 79.9 μg/L, p < 0.001). Moreover, patients with septic shock and nonsurvivors, presented a significantly lower absolute and relative decrease in chemerin one week after sepsis onset compared to baseline (p < 0.001). Based on ROC curve analyses, the diagnostic performance of chemerin (AUC 0.78, 95% CI 0.69–0.87) was similar to C-reactive protein (CRP) (AUC 0.78, 95% CI 0.68–0.87) in discriminating sepsis severity. However, increased chemerin at sepsis onset and one week later was an independent predictor of 28-day mortality (sepsis onset: HR 3.58, 95% CI 1.48–8.65, p = 0.005; one week after: HR 10.01, 95% CI 4.32–23.20, p < 0.001). Finally, serum chemerin exhibited significant correlations with the severity scores, white blood cells, lactate, CRP and procalcitonin, as well as with biomarkers of glucose homeostasis, but not with cytokines and soluble urokinase-type plasminogen activator receptor (suPAR). Circulating chemerin is increased early in sepsis and its kinetics may have diagnostic and prognostic value in critically ill patients. Further studies are needed to shed light on the role of chemerin in sepsis.

SARS-CoV-2 adipose tissue infection and hyperglycemia: A further step towards the understanding of severe COVID-19

Numerous studies have highlighted the prognostic significance of hyperglycemia in the outcomes of SARS-CoV-2 infection. A number of mechanisms have been proposed as potential drivers of this association, which were, however, up until recently based rather on speculation than on investigational evidence. It has been recently come to light that the development of insulin resistance in the frame of COVID-19 is likely the driving force behind the development of overt hyperglycemia. This results through the infectious insult of the adipose tissue, and is observed in conjunction with aberrant adipokine secretion by host adipocytes, such as decreased adiponectin, as well as a switch towards an antiviral immune secretory profile. These data could have a considerable relevance not only for the management of hyperglycemia in the course of the infection but also for the overall understanding of the pathogenesis of severe COVID-19.

Definition and Diagnostic Criteria for Sarcopenic Obesity: ESPEN and EASO Consensus Statement

INTRODUCTION

Loss of skeletal muscle mass and function (sarcopenia) is common in individuals with obesity due to metabolic changes associated with a sedentary lifestyle, adipose tissue derangements, comorbidities (acute and chronic diseases) and during the ageing process. Co-existence of excess adiposity and low muscle mass/function is referred to as sarcopenic obesity (SO), a condition increasingly recognized for its clinical and functional features that negatively influence important patient-centred outcomes. Effective prevention and treatment strategies for SO are urgently needed, but efforts are hampered by the lack of a universally established SO definition and diagnostic criteria. Resulting inconsistencies in the literature also negatively affect the ability to define prevalence as well as clinical relevance of SO for negative health outcomes.

AIMS AND METHODS

The European Society for Clinical Nutrition and Metabolism (ESPEN) and the European Association for the Study of Obesity (EASO) launched an initiative to reach expert consensus on a definition and diagnostic criteria for SO. The jointly appointed international expert panel proposes that SO is defined as the co-existence of excess adiposity and low muscle mass/function. The diagnosis of SO should be considered in at-risk individuals who screen positive for a co-occurring elevated body mass index or waist circumference, and markers of low skeletal muscle mass and function (risk factors, clinical symptoms, or validated questionnaires). Diagnostic procedures should initially include assessment of skeletal muscle function, followed by assessment of body composition where presence of excess adiposity and low skeletal muscle mass or related body compartments confirm the diagnosis of SO. Individuals with SO should be further stratified into stage I in the absence of clinical complications or stage II if cases are associated with complications linked to altered body composition or skeletal muscle dysfunction.

CONCLUSIONS

ESPEN and EASO, as well as the expert international panel, advocate that the proposed SO definition and diagnostic criteria be implemented into routine clinical practice. The panel also encourages prospective studies in addition to secondary analysis of existing data sets, to study the predictive value, treatment efficacy and clinical impact of this SO definition.

Are sociodemographic and anthropometric variables effective in screening probable and confirmed sarcopenia in community-dwelling older adults? A cross-sectional study

BACKGROUND

Screening for probable and confirmed sarcopenia using sociodemographic and anthropometric indicators can be a practical, cheap, and effective strategy to identify and treat older people susceptible to this condition.

OBJECTIVES

To identify cutoff points for sociodemographic and anthropometric variables in screening probable and confirmed sarcopenia in community-dwelling older adults.

DESIGN AND SETTING

This was a cross-sectional study of community-dwelling older adults in Araranguá, Santa Catarina, Brazil.

METHODS

Sociodemographic (age, education) and anthropometric (weight, height, body mass index [BMI], waist circumference [WC], and dominant calf circumference [DCC]) factors were considered as predictors. The outcomes were probable sarcopenia (reduction in muscle strength assessed by time ≥ 15 s in the five-time sit-to-stand test) and confirmed sarcopenia (reduction in strength and muscle mass). Receiver operating characteristic curve analysis was used to analyze the ability to track sociodemographic and anthropometric variables for sarcopenia.

RESULTS

In 308 older adults, WC > 91 cm in women and age > 69 years in men were useful in screening for probable sarcopenia. The variables age, weight, BMI, WC, and DCC can be used to screen for sarcopenia in older women and men.

CONCLUSION

Sociodemographic and anthropometric variables are simple and accessible tools for sarcopenia screening in older adults.

The Association of Sarcopenia and Visceral Obesity with Lean Nonalcoholic Fatty Liver Disease in Chinese Patients with Type 2 Diabetes Mellitus

BACKGROUND

Few studies have specifically observed the relationship of sarcopenia, visceral obesity, or their joint effects with lean NAFLD in patients with diabetes. We aimed to investigate the associations of lean NAFLD with sarcopenia, visceral obesity, and sarcopenic visceral obesity (SV) in Chinese patients with type 2 diabetes mellitus (T2DM).

METHODS

Altogether, 1,112 T2DM patients with BMI <25 kg/m² were enrolled, and 33.18% of them were diagnosed with lean NAFLD by abdominal ultrasonography. Body composition markers were measured by bioelectrical impedance (BIA). Skeletal muscle mass index (SMI) was calculated as appendicular skeletal muscle mass (ASM) divided by weight, and sarcopenia was defined as SMI < 1 standard deviation (SD) below the sex-specific average for a young reference population. Visceral obesity was defined as visceral fat area (VFA) ≥ 100 cm². Participants were categorized into one of the four body composition groups: nonsarcopenia/nonvisceral obesity (NN), nonsarcopenia/visceral obesity (NV), sarcopenia/nonvisceral obesity (SN), and SV.

RESULTS

Compared to those in the NN group, patients in the NV and SN groups had a higher risk of lean NAFLD after full adjustments (NV: OR = 1.74; 95% CI: 1.09, 2.78; SN: OR =2.07; 95% CI: 1.23, 3.46). Of note, patients in the SV group had the highest odds of lean NAFLD (OR = 3.29; 95% CI: 2.10, 5.17). There were no significant interaction effects between sarcopenia and metabolic risk factors on prevalent lean NAFLD.

CONCLUSIONS

The current study demonstrated that SV was more closely associated with higher prevalent lean NAFLD than sarcopenia or visceral obesity alone in Chinese patients with T2DM. Besides, the harmful effect of sarcopenia on lean NAFLD was not influenced by visceral obesity or other metabolic risk factors. We hypothesize that increasing skeletal muscle mass more than just reducing visceral fat might be more optimal for the prevention and management of lean NAFLD, which needs further investigation in future studies.

Association of Sarcopenia and A Body Shape Index With Overall and Cause-Specific Mortality

AIM

This observational study aimed to examine the association between the A Body Shape Index (ABSI) and/or sarcopenia and total, cardiovascular, and cancer mortality.

METHODS

The associations of sarcopenia and ABSI with all-cause, cardiovascular, and cancer mortality were assessed in 4,488 participants from the 1999-2004 National Health and Nutrition Examination Survey (NHANES) who were followed up until December 31, 2015. Models were analyzed separately for men and women and adjusted for age, race, and other confounding factors. ABSI was assessed as a continuous measurement by quartile for men and women. Population attributable fractions (PAFs) were calculated to assess mortality caused by sarcopenia and/or ABSI in the study population.

RESULTS

When ABSI was assessed as a continuous variable, the ABSI quartile showed a linear trend for total (p = 0.0001), cardiovascular (p = 0.04), and cancer (p = 0.02) mortality in men and for total (p = 0.06) and cardiovascular (p = 0.06) mortality in women. The hazard ratios (HRs) of the fourth ABSI quartile were 1.51 [95% confidence interval (CI): 1.20-1.89] in men and 1.23 (95% CI: 0.93-1.64) in women, compared with those in the first quartile. When ABSI was assessed by quartile, the appendicular skeletal mass index (ASMI) was lower in the groups with high ABSI. When high ABSI was combined with sarcopenia, the HRs of all-cause mortality were 2.05 (95% CI: 1.60-2.62) in men and 1.51 (95% CI: 1.19-1.92) in women. In the subpopulation (sarcopenia group or higher ABSI), the PAFs of mortality due to sarcopenia were 26.16% (95% CI: 12.68-37.56) in men and 21.89% (95% CI: 5.64-35.35) in women, and the PAF of mortality due to higher ABSI was 23.70% (95% CI: 12.11-33.77) in men.

CONCLUSION

The ABSI value was significantly associated with all-cause and cardiovascular mortality, and the co-existence of higher ABSI values and sarcopenia can contribute to a more significant death risk in comparison with high ABSI values or sarcopenia. Moreover, the ABSI values in combination with the ASMI can be used to preliminarily evaluate the content and distribution of fat and muscle and to predict the risk of death in obese and sarcopenic populations.

Body composition assessment and sarcopenia in patients with biliary tract cancer: A systematic review and meta-analysis

BACKGROUND

Sarcopenia, as assessed by body composition, can affect morbidity and survival in several gastrointestinal cancer. However, the impact of sarcopenia, referring to both quantity and quality of skeletal muscle, in biliary tract cancer (BTC) is debatable. We aimed to investigate the impact of sarcopenia on morbidity and mortality in patients with BTC.

METHODS

Electronic databases and trial registries were searched through July 2021 to perform random-effects meta-analyses. Study selection, data abstraction and quality assessment were independently performed using the Grading of Recommendations, Assessment, Development, and Evaluation approach.

RESULTS

Twenty-nine studies (4443 patients) were included; 28 used computed tomography and one used dual-energy X-ray absorptiometry to assess body composition. Eighteen studies reported the impact of pre-operative sarcopenia on postoperative outcomes; namely, sarcopenia increased postoperative complications (risk ratio = 1.23, 95% confidence interval [CI] = 1.07 to 1.41; I² = 2%), and decreased recurrence-free survival (hazard ratio [HR] = 2.20, 95% CI = 1.75 to 2.75; I² = 0%) in multivariable analyses. Low muscle quantity (HR = 2.26, 95% CI = 1.75 to 2.92; I² = 66%) and quality (HR = 1.75, 95% CI = 1.33 to 2.29; I² = 50%) decreased overall survival in multivariable analyses. The certainty of the evidence was low because of heterogeneity and imprecision.

CONCLUSIONS

In sarcopenia, low muscle quantity and quality by body composition conferred an independent risk of morbidity and mortality in patients with BTC. Further studies are needed to confirm these findings and mitigate risk.

Understanding the enigmatic association between mycosis fungoides and psoriasis: Report of two cases and review of the literature

Psoriatic patients present an increased risk for developing lymphoma, particularly cutaneous T-cell lymphoma (CTCL). To what degree psoriasis itself through chronic immune stimulation, or the immunosuppressive medications used for its treatment or comorbidities (obesity, diabetes mellitus, etc), or lifestyle (smoking, alcohol, diet, etc) may play a role in the onset of MF is not yet clear. Psoriasis and Mycosis Fungoides (MF), the most common variant of CTCL, represent two distinct entities sharing common pathogenetic mechanisms and a wide spectrum of common clinical features associated with the abnormal activation of T-cells. The aim of this study is to explore the relationship between MF and psoriasis by presenting two cases with clinical and histopathologic features of both psoriasis and MF with a particular emphasis on the time of presentation of both disorders, the use of previous immunosuppressive drugs as well as the therapeutic management of patients. Biopsy of the cutaneous lesions before the introduction of biologics should be incorporated in clinical practice. Biopsy of the cutaneous lesion should also be performed in the case of appearance of psoriasiform lesions during biologic treatment for autoimmune disorders because this may represent an indolent form of MF. Psoriatic patients with poor or no-response to treatment should be examined thoroughly for MF using immunochemistry and, if necessary, molecular biology techniques. In concomitant MF and psoriasis, combination treatment may be beneficial for both entities. Finally, a large multicentric registry of MF patients who were treated for benign dermatoses (i.e. eczema, psoriasis) with classic immunosuppressive drugs and/or biologics is needed to collect data and further clarify the enigmatic relationship between psoriasis, MF and immunosuppressive treatment.

The Critical Role of Oxidative Stress in Sarcopenic Obesity

Sarcopenic obesity (SO) is a combination of obesity and sarcopenia that primarily develops in older people. Patients with SO have high fat mass, low muscle mass, low muscle strength, and low physical function. SO relates to metabolic syndrome and an increased risk of morbimortality. The prevalence of SO varies because of lacking consensus criteria regarding its definition and the methodological difficulty in diagnosing sarcopenia and obesity. SO includes systemic alterations such as insulin resistance, increased proinflammatory cytokines, age-associated hormonal changes, and decreased physical activity at pathophysiological levels. Interestingly, these alterations are influenced by oxidative stress, which is a critical factor in altering muscle function and the generation of metabolic dysfunctions. Thus, oxidative stress in SO alters muscle mass, the signaling pathways that control it, satellite cell functions, and mitochondrial and endoplasmic reticulum activities. Considering this background, our objectives in this review are to describe SO as a highly prevalent condition and look at the role of oxidative stress in SO pathophysiology.

Trimetazidine and exercise provide comparable improvements to high fat diet-induced muscle dysfunction through enhancement of mitochondrial quality control

Obesity induces skeletal muscle dysfunction. The pathogenesis of which appears to substantially involve mitochondrial dysfunction, arising from impaired quality control. Exercise is a major therapeutic strategy against muscle dysfunction. Trimetazidine, a partial inhibitor of lipid oxidation, has been proposed as a metabolic modulator for several cardiovascular pathologies. However, the effects of Trimetazidine on regulating skeletal muscle function are largely unknown. Our present study used cell culture and obese mice models to test a novel hypothesis that Trimetazidine could improve muscle atrophy with similar results to exercise. In C2C12 cells, high palmitic acid-induced atrophy and mitochondrial dysfunction, which could be reversed by the treatment of Trimetazidine. In our animal models, with high-fat diet-induced obesity associated with skeletal muscle atrophy, Trimetazidine prevented muscle dysfunction, corrected metabolic abnormalities, and improved mitochondrial quality control and mitochondrial functions similarly to exercise. Thus, our study suggests that Trimetazidine successfully mimics exercise to enhance mitochondrial quality control leading to improved high-fat diet-induced muscle dysfunction.

Skeletal muscle myostatin gene expression and sarcopenia in overweight and obese middle‐aged and older adults

Background

Myostatin (MSTN) is a key negative regulator of muscle mass in humans and animals, having direct and indirect influences on molecular regulators of atrophy and hypertrophy, thus potentially impacting fitness and physical function. We have shown that myostatin is elevated in conditions of chronic disability (e.g. paretic limb of stroke). Our hypothesis is that myostatin would be elevated in older adults with sarcopenia. The purpose of this study was to examine the role of skeletal muscle myostatin in sarcopenia.

Methods

Sixty-four overweight to obese aged 45–81 years underwent a maximal aerobic capacity (VO₂max) test, dual-energy X-ray absorptiometry (DXA) scan to determine appendicular lean tissue (ALM), and vastus lateralis muscle biopsy to determine myostatin mRNA expression by quantitative real time PCR (Q-RT-PCR). Rates of sarcopenia were determined using (ALM/BMI), and sarcopenia was defined as <0.789 in men and <0.512 in women. Subjects had low fitness (VO₂max: 22.7 ± 0.7 mL/kg/min) and on average 40.9 ± 1% body fat.

Results

The prevalence of sarcopenia in this cohort was 16%. BMI, % body fat, and fat mass were higher in adults with sarcopenia than those without sarcopenia (all P < 0.001). Myostatin mRNA expression was lower in those without sarcopenia than those with sarcopenia (P < 0.05) and higher in men than women (P < 0.001). Myostatin expression was associated with BMI (r = 0.36, P < 0.01) and mid-thigh intramuscular fat (r = 0.29, P < 0.05).

Conclusion

Given that myostatin is important in muscle atrophy, fat accumulation, and sarcopenia, further work could address its implication in other aging cohorts of disability and chronic disease.

Understanding the Co-Epidemic of Obesity and COVID-19: Current Evidence, Comparison with Previous Epidemics, Mechanisms, and Preventive and Therapeutic Perspectives

PURPOSE OF REVIEW

A growing body of evidence suggests that obesity and increased visceral adiposity are strongly and independently linked to adverse outcomes and death due to COVID-19. This review summarizes current epidemiologic data, highlights pathogenetic mechanisms on the association between excess body weight and COVID-19, compares data from previous pandemics, discusses why COVID-19 challenges the "obesity paradox," and presents implications in prevention and treatment as well as future perspectives.

RECENT FINDINGS

Data from meta-analyses based on recent observational studies have indicated that obesity increases the risks of infection from SARS-CoV-2, severe infection and hospitalization, admission to the ICU and need of invasive mechanical ventilation (IMV), and the risk of mortality, particularly in severe obesity. The risks of IMV and mortality associated with obesity are accentuated in younger individuals (age ≤ 50 years old). The meta-inflammation in obesity intersects with and exacerbates underlying pathogenetic mechanisms in COVID-19 through the following mechanisms and factors: (i) impaired innate and adaptive immune responses; (ii) chronic inflammation and oxidative stress; (iii) endothelial dysfunction, hypercoagulability, and aberrant activation of the complement; (iv) overactivation of the renin-angiotensin-aldosterone system; (v) overexpression of the angiotensin-converting enzyme 2 receptor in the adipose tissue; (vi) associated cardiometabolic comorbidities; (vii) vitamin D deficiency; (viii) gut dysbiosis; and (ix) mechanical and psychological issues. Mechanistic and large epidemiologic studies using big data sources with omics data exploring genetic determinants of risk and disease severity as well as large randomized controlled trials (RCTs) are necessary to shed light on the pathways connecting chronic subclinical inflammation/meta-inflammation with adverse COVID-19 outcomes and establish the ideal preventive and therapeutic approaches for patients with obesity.

Sarcopenic obesity is associated with macroalbuminuria in patients with type 2 diabetes: a cross-sectional study

Sarcopenia is associated with the risk of albuminuria in patients with type 2 diabetes mellitus (T2DM), and obesity is a risk factor for proteinuria. However, the association between sarcopenic obesity and diabetic nephropathy, including albuminuria, in patients with T2DM has not been reported. The study included 206 men and 163 women with T2DM who participated in the KAMOGAWA-DM cohort, which investigating the natural history of diabetes since 2014. Sarcopenia was defined as having both low skeletal muscle mass index (SMI, kg/m²) (<7.0 kg/m² for men and <5.7 kg/m² for women) and low handgrip strength (<28 kg for men and <18 kg for women). Obesity was diagnosed by the percentage of body fat (>30% for men and >35% for women). The patient was said to have sarcopenic obesity if he/she had both sarcopenia and obesity. Urinary albumin excretion of patients with sarcopenic obesity was higher than that of patients without sarcopenic obesity (median [interquartile range]: 342.0 [41.8-467.5] vs. 21.0 [9.0-75.4] mg/g Cr, p = 0.016). Additionally, sarcopenic obesity was associated with the presence of macroalbuminuria, compared with non-sarcopenic obesity (adjusted odds ratio 6.92 [95% confidence interval:1.63-29.4], p = 0.009). Adjusted odds ratios of sarcopenic obesity, sarcopenia only, and obesity only for the presence of macroalbuminuria were 6.52 (1.47-28.8, p = 0.014), 1.29 (0.45-3.71, p = 0.638), and 0.78 (0.38-1.58, p = 0.482), respectively, compared with neither sarcopenia nor obesity. This study indicated that sarcopenic obesity is associated with albuminuria, especially macroalbuminuria, in Japanese patients with T2DM.

The Relevance of Diet, Physical Activity, Exercise, and Persuasive Technology in the Prevention and Treatment of Sarcopenic Obesity in Older Adults

The aging population faces two conditions that threaten healthy aging: high fat mass (obesity) and low muscle mass and function (sarcopenia). The combination of both-referred to as sarcopenic obesity-synergistically increases the risk of adverse health outcomes. The two conditions often co-occur because they reinforce each other and share common etiologies, including poor nutrition and inactivity. All aging people are at risk of gaining weight and losing muscle mass and could benefit from improvements in physical activity, exercise and dietary intake. one specific window of opportunity is during the transient time of retirement, as older adults already need to restructure their daily activities. It is key to change lifestyle behavior in a sustainable manner, providing scientifically proven, personalized, and acceptable principles that can be integrated in daily life. Health technologies (e.g., applications) can provide promising tools to deliver personalized and appealing lifestyle interventions to a large group of people while keeping health care costs low. Several studies show that health technologies have a strong positive effect on physical activity, exercise and dietary intake. Specifically, health technology is increasingly applied to older people, although strong evidence for long term effects in changing lifestyle behavior is generally lacking. Concluding, technology could play an important role in the highly warranted prevention of sarcopenic obesity in older adults. Although health technology seems to be a promising tool to stimulate changes in physical activity, exercise and dietary intake, studies on long lasting effects and specifically targeted on older people around the time of retirement are warranted.

Associations of sarcopenic obesity versus sarcopenia alone with functionality

BACKGROUND & AIMS

There have been several attempts to come up with a global operational definition of sarcopenia (S), and consequently, a definition of S has been established, to some extent. That said, the definition of sarcopenic obesity (SO), which is defined as the presence of obesity + sarcopenia, remains obscure, hindering evaluations of the prevalence and relevance of SO. It has yet to be elucidated whether SO is associated with worse functionality when compared to S alone (S without obesity). In the present study, we compare SO and S alone in terms of their associations with functional measures through the application of alternative definitions of SO. As a secondary output, we document the prevalence of SO based on alternative definitions.

METHODS

This retrospective cross-sectional study included community-dwelling adults over 60 years of age who presented as outpatients to a university hospital between 2012 and 2020. All were evaluated for body composition (bioimpedance analysis), handgrip strength (Jamar hand dynamometer) and functional health status [activities of daily living (ADL), instrumental activities of daily living (IADL)]. The fat percentile method was used to define the obesity component of SO. Low muscle mass (LMM) was defined using two different adjustment methods of skeletal muscle mass (LMM adjusted by height² or LMM adjusted by BMI). S was defined based on the EWGSOP2 definition, as probable S (low muscle strength) or confirmed S (low muscle strength + LMM). Accordingly, three alternative definitions of SO were applied based on three alternative definitions of S, i.e., "obesity + sarcopenia (probable)", "obesity + sarcopenia (confirmed, LMM adjusted by height²)" and "obesity + sarcopenia (confirmed, LMM adjusted by BMI)". The associations of SO and S alone with functional measures were examined with univariate analyses and adjusted multivariate analyses.

RESULTS

Included in the study were 1468 older adults (median age 75; 68.8% female). The prevalence of SO was very low (0.2%) based on the SO definition "obesity + sarcopenia (confirmed, LMM adjusted by height²), but it was present at a considerable and comparable rate based on SO definition "obesity + sarcopenia (probable)" and SO definition "obesity + sarcopenia (confirmed, LMM adjusted by BMI)" (4.1%, 4.0%; respectively). As SO by "obesity + sarcopenia (confirmed, LMM adjusted by height²)" had an ignorable prevalence, this definition of SO was excluded from further analyses. Multivariate analyses revealed that, when compared to the Non-S Non-Obese group, S alone definitions had odds ratio (OR) of 5.4 and 3.4 while SO definitions had an OR of 3.2 and 2.7 for impaired ADL, and an OR of 7.9 and 6.4, while SO definitions had an OR of 3.0 and 2.7 for impaired IADL. SO was thus found to be associated with a lower prevalence of impaired functional measures than that of S alone.

CONCLUSIONS

Our results suggest that the SO definition confirmed, LMM adjusted by height² has an ignorable prevalence in populations in which underweight or malnutrition is uncommon. Among sarcopenic older individuals, obesity may have a protective effect against the limitations of some functional measures, providing evidence of the possible protective effect of obesity in sarcopenic individuals.

Prediabetes screening: Questionable benefits in the golden years

Irrespective of the definition and diagnostic criteria used, the term prediabetes denotes a state of dysmetabolism with a high risk of progression to diabetes mellitus. Although diabetes-related complications may already be evident among individuals with prediabetes, interventions at this stage primarily aim to hinder the development of overt hyperglycemia rather than to prevent complications. Current recommendations for prediabetes testing are common across all adult age categories. Recent evidence arising from the prospective investigation of the natural course of prediabetes among elderly individuals pose questions regarding the benefits of meticulous prediabetes screening in this age group. In view of this and due to the lack of sufficient data to concretely support a positive impact of further preventive strategies among older individuals, screening recommendations should be reevaluated to target selected elderly individuals who are most likely to benefit in terms of quality of life and prognosis. Further therapeutic measures should be tailored to the inherent features of this frail age group, in order to exert a meaningful effect on overall health status.

FGF19 protects skeletal muscle against obesity-induced muscle atrophy, metabolic derangement and abnormal irisin levels via the AMPK/SIRT-1/PGC-α pathway

Obesity is associated with biological dysfunction in skeletal muscle. As a condition of obesity accompanied by muscle mass loss and physical dysfunction, sarcopenic obesity (SO) has become a novel public health problem. Human fibroblast growth factor 19 (FGF19) plays a therapeutic role in metabolic diseases. However, the protective effects of FGF19 on skeletal muscle in obesity and SO are still not completely understood. Our results showed that FGF19 administration improved muscle loss and grip strength in young and aged mice fed a high‐fat diet (HFD). Increases in muscle atrophy markers (FOXO‐3, Atrogin‐1, MuRF‐1) were abrogated by FGF19 in palmitic acid (PA)‐treated C2C12 myotubes and in the skeletal muscle of HFD‐fed mice. FGF19 not only reduced HFD‐induced body weight gain, excessive lipid accumulation and hyperlipidaemia but also promoted energy expenditure (PGC‐1α, UCP‐1, PPAR‐γ) in brown adipose tissue (BAT). FGF19 treatment restored PA‐ and HFD‐induced hyperglycaemia, impaired glucose tolerance and insulin resistance (IRS‐1, GLUT‐4) and mitigated the PA‐ and HFD‐induced decrease in FNDC‐5/irisin expression. However, these beneficial effects of FGF19 on skeletal muscle were abolished by inhibiting AMPK, SIRT‐1 and PGC‐1α expression. Taken together, this study suggests that FGF19 protects skeletal muscle against obesity‐induced muscle atrophy, metabolic derangement and abnormal irisin secretion partially through the AMPK/SIRT‐1/PGC‐α signalling pathway, which might be a potential therapeutic target for obesity and SO.

The Association Between Sarcopenic Obesity and Hypertension, Diabetes, and Abnormal Lipid Metabolism in Chinese Adults

OBJECTIVE

Sarcopenic obesity is associated with several negative health outcomes. However, there are only a few studies on the relationship between SO and metabolic diseases such as diabetes, hypertension, and abnormal lipid metabolism in Chinese adults. The aim of this work was to evaluate the association between SO and hypertension, diabetes, and abnormal lipid metabolism in Chinese adults, and explore the prediction of SO using relevant anthropometric indicators.

MATERIALS AND METHODS

All participants underwent a questionnaire interview for the collection of demographic data. Thereafter, they underwent physical examination for the measurement of anthropometric variables, which was performed using bioelectrical impedance analysis. Biochemical measurements were determined according to standard laboratory procedures used for the evaluation of blood parameters.

RESULTS

We included 14,926 patients aged 35-74 years old. The mean age of the participants was 56.75 ± 9.76 years old, and 39.80% of them were male. The mean body mass index (BMI) was 24.94 ± 3.40 kg/m², and the overall prevalence of SO was 65.1%. The results showed that shorter people; people with faster heart rate; heavier weight; lower waist circumference (WC), BMI, triglyceride level, total cholesterol, and low-density lipoprotein cholesterol levels; and higher high-density lipoprotein cholesterol level are at risk for SO.

CONCLUSION

The prevalence of SO is high (65.1%) in Chinese adults aged 35-74 years old. The occurrence of SO is related to hypertension, diabetes, and abnormal lipid metabolism. BMI, WC, and waist-hip ratio may be predictive indicators of SO. The incidence of SO may be reduced by timely intervention and health education for persons at risk of the condition.

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.

Prevalence and risk factors of primary sarcopenia in community-dwelling outpatient elderly: a cross-sectional study

No previous study has investigated the prevalence and risk factors for primary sarcopenia in outpatient setting. This study aims to evaluate the prevalence and factors associated with primary sarcopenia in outpatient elderly. Additionally, we compared the severity of sarcopenia based on the 2014 and 2019 Asian Working Group for Sarcopenia (AWGS) criteria. This cross-sectional study was performed in 330 subjects aged over 60 years in an outpatient setting. The muscle strength, muscle performance and muscle mass were assessed using the handheld dynamometer, 6-m gait speed, and bioelectrical impedance analysis, respectively. The prevalence of sarcopenia was 10% as per the 2014 and 2019 AWGS criteria. The development of sarcopenia was positively correlated with the age with an odds ratio (OR) of 6.87 [95% confidence interval (CI) 1.63–28.88] in the middle-old group (70–79 years), and 13.71 (95%CI 3.66–51.41; p = 0.009) in the very old group (≥ 80 years). Prefrailty and low physical activity were significantly associated with sarcopenia with an OR of 4.75 (95%CI 1.90—11.89) in prefrailty, 15.35 (95%CI 1.69–139.47) in the middle activity group, and 17.99 (95%CI 1.95–165.73) in the lowest activity group. In conclusion, primary sarcopenia was found in one-tenth of outpatient elderly. Age, prefrailty, and low activity were independent factors associated with sarcopenia.

Deciphering the Association Between Psoriasis and Obesity: Current Evidence and Treatment Considerations

PURPOSE OF REVIEW

Obesity and psoriasis represent chronic inflammatory states that are interconnected in a vicious cycle, sharing also a degree of synergy. In this review, we aim to decipher the various lines of evidence supporting the bidirectional association between psoriasis and obesity highlighting their pathophysiologic connections as well as we attempt to strategize a therapeutic holistic approach for obese psoriatic patients.

RECENT FINDINGS

Recent meta-analyses have shown that (1) genetically higher BMI increased the odds of psoriasis occurrence; (2) obesity is associated with higher incidence and prevalence of psoriasis as well as psoriasis severity; (3) obesity is associated with lower efficacy to anti-TNF agents and may predict biologic treatment discontinuation; and (4) weight loss through diet and physical exercise may improve pre-existing psoriasis and prevent from de novo psoriasis. Methotrexate, acitretin, and cyclosporine could worsen hypertension, liver steatosis, and dyslipidemia. Since infliximab and ustekinumab are weight adjusted, they may be ideal drugs to treat obese psoriatic patients. IL-17 inhibitors are very effective independently from body weight; however, they tend to present better clearance rates in normal weight patients. There is a paucity on weight data regarding the efficacious IL-23 inhibitors. Apremilast may induce weight loss as an adverse effect presenting also some beneficial metabolic actions. Finally, simvastatin and some antidiabetic drugs could decrease psoriasis severity. More mechanistic, observational studies and well-conducted RCTs are necessary to decipher the enigmatic link between psoriasis and obesity, and to provide evidence-based specific guidelines for the screening and management of obese psoriatic patients.

Is There an Obesity Paradox in Critical Illness? Epidemiologic and Metabolic Considerations

PURPOSE OF REVIEW

Obesity represents a global epidemic with serious implications in public health due to its increasing prevalence and its known association with a high morbidity and mortality burden. However, a growing number of data support a survival benefit of obesity in critical illness. This review summarizes current evidence regarding the obesity paradox in critical illness, discusses methodological issues and metabolic implications, and presents potential pathophysiologic mechanisms.

RECENT FINDINGS

Data from meta-analyses and recent studies corroborate the obesity-related survival benefit in critically ill patients as well as in selected populations such as patients with sepsis and acute respiratory distress syndrome, but not trauma. However, this finding warrants a cautious interpretation due to certain methodological limitations of these studies, such as the retrospective design, possible selection bias, the use of BMI as an obesity index, and inadequate adjustment for confounding variables. Main pathophysiologic mechanisms related to obesity that could explain this phenomenon include higher energy reserves, inflammatory preconditioning, anti-inflammatory immune profile, endotoxin neutralization, adrenal steroid synthesis, renin-angiotensin system activation, cardioprotective metabolic effects, and prevention of muscle wasting. The survival benefit of obesity in critical illness is supported from large meta-analyses and recent studies. Due to important methodological limitations, more prospective studies are needed to further elucidate this finding, while future research should focus on the pathophysiologic role of adipose tissue in critical illness.

A Call to Action: Now Is the Time to Screen Elderly and Treat Osteosarcopenia, a Position Paper of the Italian College of Academic Nutritionists MED/49 (ICAN-49)

Aging is a risk factor for the development of multiple chronic diseases, including cardiovascular disease, cancer and dementia. Life expectancy has increased in certain countries but this phenomenon is associated with a reduction of years of healthy life. Aging is associated with a number of physical and functional changes, especially sarcopenia. Sarcopenia is a clinical condition associated with a decrease in skeletal muscle and muscle strength, however, sarcopenia is a reversible condition. On the basis of the current scientific literature, sarcopenia could more appropriately capture an individual's vulnerability to negative health-related outcomes since it represents an early form of the chronic diseases. Recognition of this clinical condition can improve the management of older individuals in many different clinical settings. Despite the limitations of the indirect methods used to study body composition, the Italian College of the Academic Nutritionists ME/49 recommends that health authorities and health professionals around the world should make a greater effort to diagnose sarcopenia earlier and to manage it more effectively. In line with the development of cancer screening, the use of two diagnostic tools for sarcopenia (BIA and DXA) should be implemented.

Competing interplay between systemic and periodontal inflammation: obesity overrides the impact of oral periphery

Objectives

We aimed at investigating whether the interaction between the local inflammation, periodontitis, and obesity is independently associated with systemic inflammation.

Methods

From the population-based Study of Health in Pomerania, 3366 participants, without (2366) and with (1000) obesity, were studied for the association of periodontitis, measured as probing depth (PD) and plaque together with body mass index (BMI) on C-reactive protein (CRP). Quantile regression was used to evaluate the association between periodontal, anthropometric, and inflammatory variables (outcomes).

Results

The overall prevalence of obesity in this adult population was 31.4% in men and 28.1% in women. Both PD and plaque were positively associated with CRP, revealing an increasing impact across the CRP concentration distribution. Adjusting the regression of CRP or fibrinogen on PD for waist circumference attenuated but did not abolish the PD coefficients. Dental plaque was similarly associated with these interrelations. Association between PD and a dental plaque was different among participants with low-, medium-, or high-risk CRP concentrations.

Conclusion

Local and systemic sources of inflammation contribute to blood levels of inflammatory markers. The respective contributions depend on the relative rate in each of the inflammation-inducing risks and are dominated by adiposity.

Clinical relevance

Keeping systemic inflammation low in order to prevent age-related disease sequelae.

Electronic supplementary material

The online version of this article (10.1007/s00784-020-03514-y) contains supplementary material, which is available to authorized users.

Prevalence and significance of sarcopenia in multiple myeloma patients undergoing autologous hematopoietic cell transplantation

Sarcopenia, defined as loss of muscle mass, can occur with aging. We conducted a single-center retrospective analysis to evaluate the impact of muscle quality in multiple myeloma (MM), a hematologic cancer of older adults, undergoing autologous hematopoietic cell transplantation (autoHCT). Healthy muscle was quantified by measuring the percent of high-density muscle within the L3 psoas muscle using a novel computed tomography method in 142 eligible patients. Early post-transplant complications were assessed in the first 100 days after transplant. Sarcopenia, defined as ≤80% high-density muscle, was found in 72 (51%) patients. Sarcopenic obesity, defined as sarcopenia and a BMI≥30, was found in 32 (23%) patients. One or more early complications occurred in 22 (16%) patients. Cardiovascular events accounted for 36% of all complications. Patients with sarcopenia had more cardiac complications (12.5%) than patients without (2.9%, p=0.03). Multivariate analysis revealed increased BMI at transplant, but not sarcopenia, was associated with worse OS (hazard ratio: 1.11, 95% confidence interval: 1.02–1.22, p=0.02). Our analysis suggests that sarcopenia is prevalent in MM and associated with increased early post-transplant cardiovascular complications in MM. Obesity, regardless of sarcopenia, is associated with worse survival in MM. Our study generates hypothesis-generating data to risk-stratify patients being considered for autoHCT.

Comparison of visceral fat area measured by CT and bioelectrical impedance analysis in Chinese patients with gastric cancer: a cross-sectional study

OBJECTIVES

Bioelectrical impedance analysis (BIA) is a simple and inexpensive method to estimate body composition. However, the accuracy of BIA is unknown. We aimed to assess the accuracy of BIA in estimating visceral fat area (VFA) in patients with gastric cancer.

STUDY DESIGN

This was a cross-sectional study comparing the accuracy of BIA in estimating VFA with the gold standard method measured by CT. VFA was measured in enrolled patients both by CT and BIA. VFA by CT at umbilical level ≥100 cm² was considered as visceral obesity. Reliability between the two methods was assessed by intraclass correlation coefficient (ICC) and consistency was assessed by Bland-Altman method (95% limits of agreement). The area under the receiver operating characteristic curve (AUROC) was used to assess the performance of BIA in diagnosing visceral obesity.

SETTING

The study was conducted in China.

PARTICIPANTS

From 1 January 2017 to 1 December 2018, a total of 157 patients diagnosed with gastric cancer were enrolled.

RESULTS

Overall, VFA by CT and BIA in patients was 84.39±46.43 cm² and 71.94±22.44 cm², respectively. VFA estimated by BIA was positively correlated with VFA measured by CT using Pearson's test (r=0.650, p<0.001). Overall, ICC for the two methods was 0.675. The mean bias between the two measurements was 12.45±36.13 cm². The 95% limits of agreement ranged from -58.36 cm² to 83.26 cm². The cut-off value for diagnosing visceral obesity by BIA was 81 cm² (AUROC: 0.822, p<0.001, 95% CI 0.758 to 0.887).

CONCLUSIONS

VFA measured by BIA showed satisfactory reliability with that measured by CT. However, the absolute values of the two methods were not interchangeable. The cut-off value for VFA by BIA in diagnosing visceral obesity was 81 cm² for patients with gastric cancer in the Chinese population.

Sarcopenic obesity: Myokines as potential diagnostic biomarkers and therapeutic targets?

Sarcopenic obesity (SO) is a condition characterized by the occurrence of both sarcopenia and obesity and imposes a heavy burden on the health of the elderly. Controversies and challenges regarding the definition, diagnosis and treatment of SO still remain because of its complex pathogenesis and limitations. Over the past few decades, numerous studies have revealed that myokines secreted from skeletal muscle play significant roles in the regulation of muscle mass and function as well as metabolic homeostasis. Abnormalities in myokines may trigger and promote the pathogenesis underlying age-related and metabolic diseases, including obesity, sarcopenia, type 2 diabetes (T2D), and SO. This review mainly focuses on the role of myokines as potential biomarkers for the early diagnosis and therapeutic targets in SO.

Diabetes and Sarcopenic Obesity: Pathogenesis, Diagnosis, and Treatments

Sarcopenic obesity and diabetes are two increasing health problems worldwide, which both share many common risk factors, such as aging, and general obesity. The pathogenesis of sarcopenic obesity includes aging, physical inactivity, malnutrition, low-grade inflammation, insulin resistance, and hormonal changes. Nevertheless, there are two major reasons to cause diabetes: impaired insulin secretion and impaired insulin action. Furthermore, the individual diagnosis of obesity and sarcopenia should be combined to adequately define sarcopenic obesity. Also, the diagnosis of diabetes includes fasting plasma glucose test (FPG), 2-h oral glucose tolerance test (OGTT), glycated hemoglobin (A1C), and random plasma glucose coupled with symptoms. Healthy diet and physical activity are beneficial to both sarcopenic obesity and diabetes, but there are only recommended drugs for diabetes. This review consolidates and discusses the latest research in pathogenesis, diagnosis, and treatments of diabetes and sarcopenic obesity.

Skeletal Muscle Mass by Bioelectrical Impedance Analysis and Calf Circumference for Sarcopenia Diagnosis

Skeletal muscle mass (SMM) plays an important role in health and physical performance. Its estimation is critical for the early detection of sarcopenia, a disease with high prevalence and high health costs. While multiple methods exist for estimating this body component, anthropometry and bioelectrical impedance analysis (BIA) are the most widely available in low- to middle-income countries. This study aimed to determine the correlation between muscle mass, estimated by anthropometry through measurement of calf circumference (CC) and skeletal mass index (SMI) by BIA. This was a cross-sectional and observational study that included 213 functional adults over 65 years of age living in the community. Measurements of height, weight, CC, and SMM estimated by BIA were made after the informed consent was signed. 124 women mean age 69.6 ± 3.1 years and 86 men mean age 69.5 ± 2.9 years had the complete data and were included in the analysis. A significant positive moderate correlation among CC and SMI measured by BIA was found (Pearson r= 0.57 and 0.60 for women and men respectively (p=0.0001)). A moderate significant correlation was found between the estimation of SMM by CC and by BIA. This suggests that CC could be used as a marker of sarcopenia for older adults in settings in lower-middle-income countries where no other methods of diagnosing muscle mass are available. Although the CC is not the unique parameter to the diagnosis of sarcopenia, it could be a useful procedure in the clinic to identify patients at risk of sarcopenia.