Sarcopenia, sarcopenic obesity and mortality in older adults: results from the National Health and Nutrition Examination Survey III. Eur J Clin Nutr. 2014;68:1001-1007. [PMID: 24961545 DOI: 10.1038/ejcn.2014.117]

Weight Management in Older Adults

As the number of older adults increases rapidly, the national epidemic of obesity is also affecting our aging population. This is particularly concerning given the numerous health risks and increased costs associated with this condition. Weight management is extremely important for older adults given the risks associated with abdominal adiposity, which is a typical fat redistribution during aging, and the prevalence of comorbid conditions in this age group. However, approaches to weight loss must be considered critically given the dangers of sarcopenia (a condition that occurs when muscle mass and quality are lost), the increased risk of hip fracture with weight loss, and the association between reduced mortality and increased BMI in older adults. This overview highlights the challenges and implications of measuring adiposity in older adults and the dangers and benefits of weight loss in this population and provides an overview of the new Medicare Obesity Benefit. In addition, we provide a summary of outcomes from successful weight loss interventions for older adults and discuss implications for advancing clinical practice.

Sarcopenic obesity and complex interventions with nutrition and exercise in community-dwelling older persons--a narrative review

One of the many threats to independent life is the age-related loss of muscle mass and muscle function commonly referred to as sarcopenia. Another important health risk in old age leading to functional decline is obesity. Obesity prevalence in older persons is increasing, and like sarcopenia, severe obesity has been consistently associated with several negative health outcomes, disabilities, falls, and mobility limitations. Both sarcopenia and obesity pose a health risk for older persons per se, but in combination, they synergistically increase the risk for negative health outcomes and an earlier onset of disability. This combination of sarcopenia and obesity is commonly referred to as sarcopenic obesity. The present narrative review reports the current knowledge on the effects of complex interventions containing nutrition and exercise interventions in community-dwelling older persons with sarcopenic obesity. To date, several complex interventions with different outcomes have been conducted and have shown promise in counteracting either sarcopenia or obesity, but only a few studies have addressed the complex syndrome of sarcopenic obesity. Strong evidence exists on exercise interventions in sarcopenia, especially on strength training, and for obese older persons, strength exercise in combination with a dietary weight loss intervention demonstrated positive effects on muscle function and body fat. The differences in study protocols and target populations make it impossible at the moment to extract data for a meta-analysis or give state-of-the-art recommendations based on reliable evidence. A conclusion that can be drawn from this narrative review is that more exercise programs containing strength and aerobic exercise in combination with dietary interventions including a supervised weight loss program and/or protein supplements should be conducted in order to investigate possible positive effects on sarcopenic obesity.

Sarcopenia--The search for emerging biomarkers

Sarcopenia, an age-related decline in skeletal muscle mass and function, dramatically affects the life quality of elder people. In view of increasing life expectancy, sarcopenia renders a heavy burden on the health care system. However, although there is a consensus that sarcopenia is a multifactorial syndrome, its etiology, underlying mechanisms, and even definition remain poorly delineated, thus, preventing development of a precise treatment strategy. The main aim of our review is to critically analyze potential sarcopenia biomarkers in light of the molecular mechanisms of their involvement in sarcopenia pathogenesis. Normal muscle mass and function maintenance are proposed to be dependent on the dynamic balance between the positive regulators of muscle growth such as bone morphogenetic proteins (BMPs), brain-derived neurotrophic factor (BDNF), follistatin (FST) and irisin, and negative regulators including TGFβ, myostatin, activins A and B, and growth and differentiation factor-15 (GDF-15). We hypothesize that the shift in this balance to muscle growth inhibitors, along with increased expression of the C- terminal agrin fragment (CAF) associated with age-dependent neuromuscular junction (NMJ) dysfunction, as well as skeletal muscle-specific troponin T (sTnT), a key component of contractile machinery, is a main mechanism underlying sarcopenia pathogenesis. Thus, this review proposes and emphasizes that these molecules are the emerging sarcopenia biomarkers.

Sarcopenic obesity and risk of new onset depressive symptoms in older adults: English Longitudinal Study of Ageing

Background:

We examined the role of sarcopenic obesity as a risk factor for new-onset depressive symptoms over 6-year follow-up in a large sample of older adults.

Methods:

The sample comprised 3862 community dwelling participants (1779 men, 2083 women; mean age 64.6±8.3 years) without depressive symptoms at baseline, recruited from the English Longitudinal Study of Ageing. At baseline and 4-year follow-up, handgrip strength (kg) of the dominant hand was assessed using a hand-held dynamometer, as a measure of sarcopenia. The outcome was new onset depressive symptoms at 6-year follow-up, defined as a score of ⩾4 on the 8-item Centre of Epidemiological Studies Depression scale. Sarcopenic obesity was defined as obese individuals (body mass index ⩾30 kg m⁻²) in the lowest tertile of sex-specific grip strength (<35.3 kg men; <19.6 kg women).

Results:

Using a multivariable logistic regression model, the risk of depressive symptoms was greatest in obese adults in the lowest tertile of handgrip strength (odds ratio (OR), 1.79, 95% confidence interval (CI), 1.10, 2.89) compared with non-obese individuals with high handgrip strength. Participants who were obese at baseline and had a decrease of more than 1 s.d. in grip strength over 4-year follow-up were at greatest risk of depressive symptoms (OR=1.97, 95% CI, 1.22, 3.17) compared with non-obese with stable grip strength.

Conclusions:

A reduction in grip strength was associated with higher risk of depressive symptoms in obese participants only, suggesting that sarcopenic obesity is a risk factor for depressive symptoms.

Sarcopenia: Current Concepts and Imaging Implications

OBJECTIVE

The purpose of this article is to review the nomenclature, clinical impact, and diagnostic techniques characterizing sarcopenia.

CONCLUSION

Sarcopenia-defined as significant loss of muscle-is associated with cachexia and frailty. Specific diagnostic criteria for sarcopenia continue to evolve, but imaging can play a role in the detection and quantification of muscle depletion. Emerging evidence indicates that sarcopenia is a relevant predictor of quality and quantity of life, particularly in patients who are elderly, have cancer, or undergo surgery.

Prevention and optimal management of sarcopenia: a review of combined exercise and nutrition interventions to improve muscle outcomes in older people

The growing recognition of sarcopenia, the age-related loss of skeletal muscle mass and function, has highlighted the need to understand more about its etiology. Declines in muscle mass and strength are expected aspects of aging, but there is significant variability between individuals in rates of loss. Although some of these differences can be explained by fixed factors, such as sex, much of the remaining variation is unexplained. This has led to increasing interest in the influence of adult lifestyle, particularly in the effects of modifiable factors such as physical activity and diet, and in identifying intervention opportunities both to prevent and manage sarcopenia. A number of trials have examined the separate effects of increased exercise or dietary supplementation on muscle mass and physical performance of older adults, but less is known about the extent to which benefits of exercise training could be enhanced when these interventions are combined. In a comprehensive review of the literature, we consider 17 studies of older adults (≥65 years) in which combined nutrition and exercise interventions were used to increase muscle strength and/or mass, and achieve improvements in physical performance. The studies were diverse in terms of the participants included (nutritional status, degree of physical frailty), supplementation strategies (differences in nutrients, doses), exercise training (type, frequency), as well as design (duration, setting). The main message is that enhanced benefits of exercise training, when combined with dietary supplementation, have been shown in some trials – indicating potential for future interventions, but that existing evidence is inconsistent. Further studies are needed, particularly of exercise training combined with dietary strategies that increase intakes of a range of nutrients, as well as bioactive non-nutrients, to provide the evidence on which public health and clinical recommendations can be based.

The effect of sarcopenic obesity on cardiovascular disease and all-cause mortality in older people

Obesity is a major public health problem with increasing prevalence worldwide. It is well recognized as a risk factor for cardiovascular morbidity and mortality in adult populations. Obesity prevalence is also increasing with age, and this may be particularly important in an ageing population. Ageing is associated with an increase in visceral fat and a progressive loss of muscle mass. Sarcopenia has been defined as the age-associated loss of skeletal muscle mass and has been associated with metabolic impairment, cardiovascular disease (CVD) risk factors, physical disability and mortality. Sarcopenia is often associated with obesity. Sarcopenic obesity is a new category of obesity in older adults who have high adiposity coupled with low muscle mass. Thus sarcopenia with obesity may synergistically increase their effect on metabolic disorders, CVD and mortality. This review focuses on the effects of sarcopenic obesity on the risk of cardiovascular disease and mortality in older adults.

Muscle loss and obesity: the health implications of sarcopenia and sarcopenic obesity

This paper reviews the health implications of obesity, sarcopenia and sarcopenic obesity on CVD and mortality in older adults and discusses the obesity paradox seen in patients with CVD. Obesity is a major public health problem with increasing prevalence worldwide. It is an established risk factor for cardiovascular morbidity and mortality in adult populations. However, there is controversy surrounding the effects of obesity as measured by BMI in older people, and overweight and obesity (BMI ⩾ 25 kg/m2) are apparently associated with increased survival in those with CVD (obesity paradox). Ageing is associated with an increase in visceral fat and a progressive loss of muscle mass which have opposing effects on mortality. Thus BMI is not a good indicator of obesity in older adults. Sarcopenia, the age-associated loss of skeletal muscle mass, is a major concern in ageing populations and has been associated with metabolic impairment, CVD risk factors, physical disability and mortality. Sarcopenia often coexists with obesity. Sarcopenic obesity is a new category of obesity in older adults who have high adiposity coupled with low muscle mass. To fully understand the effect of obesity on mortality in the elderly it is important to take muscle mass into account. The evidence suggests that sarcopenia with obesity may be associated with higher levels of metabolic disorders and an increased risk of mortality than obesity or sarcopenia alone. Efforts to promote healthy ageing should focus on both preventing obesity and maintaining or increasing muscle mass.

The role of computed tomography in evaluating body composition and the influence of reduced muscle mass on clinical outcome in abdominal malignancy: a systematic review

It is estimated that there were 3.45 million new cases and 1.75 million deaths from cancer in Europe in 2012. Colorectal cancer was one of the most common cancers, accounting for 13% of new cases and 12.2% of all deaths. Conditions causing reduced muscle mass, such as sarcopenia, can increase the morbidity and mortality of people with cancer. Computed tomography (CT) scans can provide accurate, high-quality information on body composition, including muscle mass. To date, there has been no systematic review on the role of CT scans in identifying sarcopenia in abdominal cancer. This review aimed to examine the role of CT scans in determining the influence of reduced muscle mass on clinical outcome in abdominal cancer. A systematic review of English-language articles published in 2000 or later was conducted. Articles included cohort, randomised controlled trials and validation studies. Participants were people diagnosed with abdominal cancer who had undergone a CT scan. Data extraction and critical appraisal were undertaken. Ten cohort studies met the inclusion criteria. Seven studies demonstrated that low muscle mass was significantly associated with poor clinical outcome, with six specifically demonstrating reduced survival rates. Eight studies demonstrated that a greater number of patients (27.3-66.7%) were identified as sarcopenic using CT scans compared with numbers identified as malnourished using body mass index. CT scans can identify reduced muscle mass and predict negative cancer outcomes in people with abdominal malignancies, where traditional methods of assessment are less effective.

Stress and inflammatory biomarkers and symptoms are associated with bioimpedance measures

BACKGROUND

This large cross-sectional, multi-centre study evaluated the association of body composition measurements by a novel dual frequency bioimpedance device (BIA-ACC) with chronic stress/inflammation biomarkers and the presence of medically unexplained symptoms (MUS).

MATERIALS AND METHODS

Participants were adult Caucasians of both sexes and included 10,416 lean subjects with no MUS (Group A), 58,710 lean subjects with MUS (Group B) and 30,445 overweight/obese subjects with no MUS and excessive fat mass (FM) (Group C).

RESULTS

Total body extracellular water (ECW) was higher, while intracellular water (ICW) was lower in Group B than both other groups (P < 0.01). Group A had significantly lower FM and higher skeletal mass (SK) and phase angle (PA) than Group B and lower circulating high sensitivity (hs) CRP levels than both other groups. hsCRP was higher in Group C than Group A though (P < 0.01). Salivary cortisol in Group B was lower in the morning and higher in the evening than both other groups (P < 0.001), indicating circadian rhythm obliteration or reversal in this group. ECW correlated positively with serum hsCRP and 8 p.m. salivary cortisol, but negatively with 8 a.m. salivary cortisol, while PA correlated positively with 8 a.m. and negatively with 8 p.m. salivary cortisol and serum hsCRP. Both 8 a.m. and 8 p.m. salivary cortisol and serum hsCRP were associated with the presence of MUS and BIA-ACC measurements, including ECW, ICW, FM, SK and PA.

CONCLUSIONS

MUS is an index of chronic stress and inflammation and BIA-ACC may provide a useful, bloodless and rapid tool in the clinical setting, distinguishing patients with chronic stress/inflammation from healthy subjects and monitoring their response to treatment.

Impact of L-citrulline supplementation and whole-body vibration training on arterial stiffness and leg muscle function in obese postmenopausal women with high blood pressure

Aging is associated with increased arterial stiffness (pulse wave velocity, PWV) and muscle strength/mass loss. Exercise training alone is not always effective to improve PWV and lean mass (LM) in older women. To investigate the independent and combined effects of whole-body vibration training (WBVT) and L-citrulline supplementation on PWV and muscle function in women, forty-one postmenopausal women aged 58 ± 3 years and body mass index (34 ± 2 kg/m(2)) were randomly assigned to the following groups: WBVT, L-citrulline, and WBVT + L-citrulline for 8 weeks. WBVT consisted of four leg exercises three times weekly. Aortic (cfPWV) and leg (faPWV) PWV, leg LM index, leg strength, and body fat percentage (BF%) were measured before and after the interventions. WBVT + L-citrulline decreased cfPWV (-0.91 ± 0.21 m/s, P < 0.01) compared to both groups. All interventions decreased faPWV (P < 0.05) similarly. Leg LM index increased (2.7 ± 0.5%, P < 0.001) after WBVT + L-citrulline compared with L-citrulline. Both WBVT interventions increased leg strength (~37%, P < 0.001) compared to L-citrulline while decreased BF% (~2.0%, P < 0.01). Reductions in cfPWV were correlated with increases in leg LM index (r = -0.63, P < 0.05). Our findings suggest that leg muscle strength and arterial stiffness can be improved after WBVT, but its combination with L-citrulline supplementation enhanced benefits on aortic stiffness and leg LM. Therefore, WBVT + L-citrulline could be an intervention for improving arterial stiffness and leg muscle function in obese postmenopausal women with prehypertension or hypertension, thereby reducing their cardiovascular and disability risk.

Body mass index and other anthropometric parameters in patients with diffuse large B-cell lymphoma: physiopathological significance and predictive value in the immunochemotherapy era

Diffuse large B-cell lymphoma (DLBCL) is the most common form of aggressive non-Hodgkin lymphoma, accounting for 30-40% of newly diagnosed cases. Obesity is a well-defined risk factor for DLBCL. However, the impact of body mass index (BMI) on DLBCL prognosis is controversial. Recent studies suggest that skeletal muscle wasting (sarcopenia) or loss of fat mass can be detected by computed tomography (CT) images and is useful for predicting the clinical outcome in several types of cancer including DLBCL. Several hypotheses have been proposed to explain the differences in DLBCL outcome according to BMI or weight that include tolerance to treatment, inflammatory background and chemotherapy or rituximab metabolism. In this review, we summarize the available literature, addressing the impact and physiopathological relevance of simple anthropometric tools including BMI and tissue distribution measurements. We also discuss their relationship with other nutritional parameters and their potential role in the management of patients with DLBCL.

CVD-predictive performances of "a body shape index" versus simple anthropometric measures: Tehran lipid and glucose study

PURPOSE

To examine whether a body shape index (ABSI) calculated by using waist circumference (WC) adjusted for height and weight could improve the predictive performances for cardiovascular disease (CVD) of the Framingham's general CVD algorithm and to compare its predictive performances with other anthropometric measures.

METHODS

We analyzed data on a 10-year population-based follow-up of 8,248 (4,471 women) individuals aged ≥30 years, free of CVD at baseline. CVD risk was estimated for a 1 SD increment in ABSI, body mass index (BMI), waist-to-hip ratio (WHpR) and waist-to-height ratio (WHtR), by incorporating them, one at a time, into multivariate accelerated failure time models.

RESULTS

ABSI was associated with multivariate-adjusted increased risk of incident CVD among both men (1.26, 95% CI 1.09-1.46) and women (1.17, 1.03-1.32). Among men, for a one-SD increment, ABSI conferred a greater increase in the hazard of CVD [1.26 (1.09-1.46)] than did BMI [1.06 (0.94-1.20)], WC [1.15(1.03-1.28)], WHpR [1.02 (1.01-1.03)] and WHtR [1.16 (1.02-1.31)], and the corresponding figures among women were 1.17 (1.03-1.32), 1.02 (0.90-1.16), 1.11 (0.98-1.27), 1.03 (1.01-1.05) and 1.14 (0.99-1.03), respectively. ABSI as well as other anthropometric measures failed to add to the predictive ability of the Framingham general CVD algorithm either.

CONCLUSIONS

Although ABSI could not improve the predictability of the Framingham algorithm, it provides more information than other traditional anthropometric measures in settings where information on traditional CVD risk factors are not available, and it can be used as a practical criterion to predict adiposity-related health risks in clinical assessments.

Gamma-glutamyl transferase is associated with sarcopenia and sarcopenic obesity in community-dwelling older adults: results from the Fifth Korea National Health and Nutrition Examination Survey, 2010-2011

Although elevated serum gamma-glutamyl transferase activity (GGT) has been linked with metabolic risk factors for sarcopenia, including non-alcoholic fatty liver disease, adiposity, and insulin resistance, whether GGT independently associated with sarcopenia and sarcopenic obesity has not yet been investigated. We analyzed cross-sectional data of 3,193 community-dwelling adults (42.2% men, age 63.4 ± 8.7) aged ≥50 years from the Fifth Korean National Health and Nutrition Examination Survey, 2010-2011. Sarcopenia was defined as a calculated value of the appendicular skeletal muscle mass divided by body weight (ASM/Wt, %) <1 standard deviation below the sex-specific mean for healthy young adults. Sarcopenic obesity was defined as sarcopenia combined with a waist circumference ≥90 cm for men and ≥85 cm for women. The prevalence of sarcopenia and sarcopenic obesity increased stepwise from the lowest to highest GGT quintiles (sarcopenia, 20.2-39.7%; sarcopenic obesity, 7.5-27.3%; P for trend, <0.001). Serum GGT activity was associated negatively with ASM and positively with waist circumference. In multivariate logistic regression analyses, participants in the highest GGT quintile had a 2.3-fold increased risk of sarcopenia and 3.4-fold risk of sarcopenic obesity versus those in the lowest quintile, whereas each single-unit increase in natural log-GGT associated independently with a 35% increased risk of sarcopenia and 62% increased risk of sarcopenic obesity after adjusting for age, sex, body mass index, and other confounders. Elevated serum GGT activity was independently associated with sarcopenia and sarcopenic obesity in community-dwelling older adults.

Prevalence, incidence, and clinical impact of sarcopenia: facts, numbers, and epidemiology-update 2014

Sarcopenia is now defined as a decline in walking speed or grip strength associated with low muscle mass. Sarcopenia leads to loss of mobility and function, falls, and mortality. Sarcopenia is a major cause of frailty, but either condition can occur without the other being present. Sarcopenia is present in about 5 to 10 % of persons over 65 years of age. It has multiple causes including disease, decreased caloric intake, poor blood flow to muscle, mitochondrial dysfunction, a decline in anabolic hormones, and an increase in proinflammatory cytokines. Basic therapy includes resistance exercise and protein and vitamin D supplementation. There is now a simple screening test available for sarcopenia-SARC-F. All persons 60 years and older should be screened for sarcopenia and treated when appropriate.

Sarcopenic obesity: molecular clues to a better understanding of its pathogenesis?

An age-dependent decline in skeletal muscle mass, strength, and endurance during the aging process is a physiological development, but several factors may exacerbate this process, leading to the threatening state of sarcopenia, frailty, and eventually higher mortality rates. Obesity appears to be such a promoting factor and has been linked in several studies to sarcopenia. The reason for this causal association remains poorly understood. Notwithstanding the fact that a higher body mass might simply lead to diminished physical activity and therefore contribute to a decline in skeletal muscle, several molecular mechanisms have been hypothesized. There could be an obesity derived intracellular lipotoxicity (i.e., elevated intramuscular levels of lipids and their derivatives), which induces apoptosis by means of an elevated oxidative stress. Paracrine mechanisms and inflammatory cytokines, such as CRP and IL-6 could be confounders of the actual underlying pathological mechanism. Due to a cross-talk of the hypothalamo-pituitary axis with nutritional status, obese subjects are more in a catabolic state of metabolism, with a higher susceptibility to muscle wasting under energy restriction. Obesity induces insulin resistance in the skeletal muscle, which consequently leads to perturbed metabolism, and misrouted signaling in the muscle cells. In obesity, muscle progenitor cells could differentiate to an adipocyte-like phenotype as a result of paracrine signals from (adipo)cytokines leading to a reduced muscular renewal capacity. The present review outlines current knowledge concerning possible pathways, which might be involved in the molecular pathogenesis of sarcopenic obesity.