A Vicious Cycle of Osteosarcopenia in Inflammatory Bowel Diseases—Aetiology,Clinical Implications and Therapeutic Perspectives

Sarcopenia is a disorder characterized by a loss of muscle mass which leads to the reduction of muscle strength and a decrease in the quality and quantity of muscle. It was previously thought that sarcopenia was specific to ageing. However, sarcopenia may affect patients suffering from chronic diseases throughout their entire lives. A decreased mass of muscle and bone is common among patients with inflammatory bowel disease (IBD). Since sarcopenia and osteoporosis are closely linked, they should be diagnosed as mutual consequences of IBD. Additionally, multidirectional treatment of sarcopenia and osteoporosis including nutrition, physical activity, and pharmacotherapy should include both disorders, referred to as osteosarcopenia.     

Amount and type of protein influences bone health

Many factors influence bone mass. Protein has been identified as being both detrimental and beneficial to bone health, depending on a variety of factors, including the level of protein in the diet, the protein source, calcium intake, weight loss, and the acid/base balance of the diet. This review aims to briefly describe these factors and their relation to bone health. Loss of bone mass (osteopenia) and loss of muscle mass (sarcopenia) that occur with age are closely related. Factors that affect muscle anabolism, including protein intake, also affect bone mass. Changes in bone mass, muscle mass, and strength track together over the life span. Bone health is a multifactorial musculoskeletal issue. Calcium and protein intake interact constructively to affect bone health. Intakes of both calcium and protein must be adequate to fully realize the benefit of each nutrient on bone. Optimal protein intake for bone health is likely higher than current recommended intakes, particularly in the elderly. Concerns about dietary protein increasing urinary calcium appear to be offset by increases in absorption. Likewise, concerns about the impact of protein on acid production appear to be minor compared with the alkalinizing effects of fruits and vegetables. Perhaps more concern should be focused on increasing fruit and vegetable intake rather than reducing protein sources. The issue for public health professionals is whether recommended protein intakes should be increased, given the prevalence of osteoporosis and sarcopenia.     

Exercise and Nutrition Impact on Osteoporosis and Sarcopenia—The Incidence of Osteosarcopenia: A Narrative Review

Osteoporosis and sarcopenia are diseases which affect the myoskeletal system and often occur in older adults. They are characterized by low bone density and loss of muscle mass and strength, factors which reduce the quality of life and mobility. Recently, apart from pharmaceutical interventions, many studies have focused on non-pharmaceutical approaches for the prevention of osteoporosis and sarcopenia with exercise and nutrition to being the most important and well studied of those. The purpose of the current narrative review is to describe the role of exercise and nutrition on prevention of osteoporosis and sarcopenia in older adults and to define the incidence of osteosarcopenia. Most of the publications which were included in this review show that resistance and endurance exercises prevent the development of osteoporosis and sarcopenia. Furthermore, protein and vitamin D intake, as well as a healthy diet, present a protective role against the development of the above bone diseases. However, current scientific data are not sufficient for reaching solid conclusions. Although the roles of exercise and nutrition on osteoporosis and sarcopenia seem to have been largely evaluated in literature over the recent years, most of the studies which have been conducted present high heterogeneity and small sample sizes. Therefore, they cannot reach final conclusions. In addition, osteosarcopenia seems to be caused by the effects of osteoporosis and sarcopenia on elderly. Larger meta-analyses and randomized controlled trials are needed designed based on strict inclusion criteria, in order to describe the exact role of exercise and nutrition on osteoporosis and sarcopenia.     

Signaux anaboliques et optimisation du métabolisme musculaire

Control of muscle mass and function is dependent on biochemical processes for synthesis and protein degradation. Dynamic imbalance of these pathways necessarily causes a gain or loss of muscle. These pathways are also regulated by nutrients, hormones or exercise. Thus, it is of interest to understand their effects and their involvement in physiological and pathological conditions such as aging or chronic diseases. Daily metabolic changes induced by food intake can help fight against muscle loss. New strategies to limit sarcopenia are precisely based on the nutritional characteristics of dietary protein, including feeding pattern and the timing of protein ingestion. Essential amino acids are also interesting to reach these objectives. Finally, multimodal therapeutic approaches to limit muscle loss may combine adequate protein intake, physical exercise, hormonal therapy or selective drugs.     

Abstracts of Articles on Lipid Metabolism

Human aging is associated with an increased incidence of several chronic diseases including coronary artery disease, non insulin-dependent diabetes mellitus and osteoporosis. Concurrent with the increased prevalence of these diseases in the elderly are well-documented changes in body composition that include an increased fat mass and a progressive decline in skeletal muscle mass and bone mineral density. Together these factors result in age-related decreases in muscle strength and aerobic capacity which contribute to decreases in functional independence. Progressive resistance (strength) training interventions have been proposed as countermeasures to some of these degenerative processes. Recently, several studies have reported on the effects of high intensity resistance training on muscle function and size in both healthy middle-aged men and women (50-75 years) and older frail men and women (80-100 years). In total, the majority of these studies have shown substantial increases (> 100%) in the one repetition maximum muscle strength of the muscle's being exercised in response to 8 to 12 weeks of strength training (3 to 4 times per week at 70 to 90% of the 1 repetition maximum). In addition, a subset of these reports has also reported significant increases in muscle size either by computed tomography (CT) analysis of muscle cross-sectional area (9 to 17%) or by biopsy examination of muscle fiber size changes (20 to 30%). There is now compelling evidence that progressive resistance training in the elderly can positively influence whole body energy expenditure, muscle growth, and function. In addition, strength training interventions may be a powerful tool in the prevention of age-associated sarcopenia (loss of muscle mass).     

Research hypotheses on muscle wasting, aging, loss of function and disability

Advancing age is accompanied by modifications in body composition such as increase in fat and decrease in bone and muscle mass. Loss of muscle mass or sarcopenia is characterized by a decrease in the total number of muscle fibers, a reduced cross-sectional area of the thigh, and decreased muscle density associated with increased intramuscular fat. Loss of skeletal muscle mass may be a common pathway by which multiple diseases contribute to the risk of disability. Decreases in muscle mass are associated with an increased risk of morbidity, mortality and disability in old age, but the mechanisms by which this occurs are not fully understood. Inflammatory cytokines interfere with muscle contraction and are linked with sarcopenia. Recent evidence showing that decline in left ventricular function is accompanied by sarcopenia and an increase in cytokines might help to understand the role of cytokines in muscle loss in aging and disease. The Health and Body Changes (Health ABC) study, a large population-based cohort study sponsored by the National Institute on Aging, will prospectively address the issues related to sarcopenia and incident disability. Defining modifiable risk factors of sarcopenia is the first step towards the identification of interventions for preventing or reversing disability in older persons.     

Frequency and Characteristics of Overestimated Renal Function in Japanese Patients with Chronic Liver Disease and Its Relation to Sarcopenia

Renal dysfunction and sarcopenia are important prognostic factors in patients with chronic liver disease (CLD). Muscle atrophy can cause the overestimation of renal function based on serum creatinine. However, the frequency of overestimated renal function in Japanese patients with CLD and its relationship with sarcopenia are unclear. In present study, we evaluated the frequency of overestimated renal function, defined as a >20% higher eGFR using creatinine than using cystatin C, in 307 patients with CLD as well as its relationship with indicators of sarcopenia. In total, 24.8% of patients had overestimated renal function. In a multivariate regression analysis, liver cirrhosis (p = 0.004) and psoas muscle mass index (p = 0.049) were significantly associated with overestimated renal function. Loss of skeletal muscle mass was significantly more frequent in both male and female patients with overestimated renal function than without. In males, the loss of muscle strength and rate of sarcopenia, defined as loss of muscle mass and strength, were significantly higher in patients with than without overestimated renal function. The high frequency of overestimated renal function in Japanese patients suggests that indicators of renal function should be carefully considered; furthermore, monitoring and interventions for both renal function and sarcopenia are needed in patients with CLD.     

Optimal Protein Intake in Pre-Dialysis Chronic Kidney Disease Patients with Sarcopenia: An Overview

Multi-factors, such as anorexia, activation of renin-angiotensin system, inflammation, and metabolic acidosis, contribute to malnutrition in chronic kidney disease (CKD) patients. Most of these factors, contributing to the progression of malnutrition, worsen as CKD progresses. Protein restriction, used as a treatment for CKD, can reduce the risk of CKD progression, but may worsen the sarcopenia, a syndrome characterized by a progressive and systemic loss of muscle mass and strength. The concomitant rate of sarcopenia is higher in CKD patients than in the general population. Sarcopenia is also associated with mortality risk in CKD patients. Thus, it is important to determine whether protein restriction should be continued or loosened in CKD patients with sarcopenia. We may prioritize protein restriction in CKD patients with a high risk of end-stage kidney disease (ESKD), classified to stage G4 to G5, but may loosen protein restriction in ESKD-low risk CKD stage G3 patients with proteinuria <0.5 g/day, and rate of eGFR decline <3.0 mL/min/1.73 m²/year. However, the effect of increasing protein intake alone without exercise therapy may be limited in CKD patients with sarcopenia. The combination of exercise therapy and increased protein intake is effective in improving muscle mass and strength in CKD patients with sarcopenia. In the case of loosening protein restriction, it is safe to avoid protein intake of more than 1.5 g/kgBW/day. In CKD patients with high risk in ESKD, 0.8 g/kgBW/day may be a critical point of protein intake.     

Extra Virgin Olive Oil (EVOO), a Mediterranean Diet Component,in the Management of Muscle Mass and Function Preservation

Aging results in a progressive decline in skeletal muscle mass, strength and function, a condition known as sarcopenia. This pathological condition is due to multifactorial processes including physical inactivity, inflammation, oxidative stress, hormonal changes, and nutritional intake. Physical therapy remains the standard approach to treat sarcopenia, although some interventions based on dietary supplementation are in clinical development. In this context, thanks to its known anti-inflammatory and antioxidative properties, there is great interest in using extra virgin olive oil (EVOO) supplementation to promote muscle mass and health in sarcopenic patients. To date, the molecular mechanisms responsible for the pathological changes associated with sarcopenia remain undefined; however, a complete understanding of the signaling pathways that regulate skeletal muscle protein synthesis and their behavior during sarcopenia appears vital for defining how EVOO might attenuate muscle wasting during aging. This review highlights the main molecular players that control skeletal muscle mass, with particular regard to sarcopenia, and discusses, based on the more recent findings, the potential of EVOO in delaying/preventing loss of muscle mass and function, with the aim of stimulating further research to assess dietary supplementation with EVOO as an approach to prevent or delay sarcopenia in aging individuals.     

Role of dietary protein in the sarcopenia of aging

Sarcopenia is a complex, multifactorial process facilitated by a combination of factors including the adoption of a more sedentary lifestyle and a less than optimal diet. Increasing evidence points to a blunted anabolic response after a mixed nutrient meal as a likely explanation for chronic age-related muscle loss. There is currently insufficient longer-term research with defined health outcomes to specify an optimal value for protein ingestion in elderly individuals. However, there is general agreement that moderately increasing daily protein intake beyond 0.8 g x kg(-1) x d(-1) may enhance muscle protein anabolism and provide a means of reducing the progressive loss of muscle mass with age. The beneficial effects of resistance exercise in aging populations are unequivocal. However, research has not identified a synergistic effect of protein supplementation and resistance exercise in aging populations. There is little evidence that links high protein intakes to increased risk for impaired kidney function in healthy individuals. However, renal function decreases with age, and high protein intake is contraindicated in individuals with renal disease. Assessment of renal function is recommended for older individuals before they adopt a higher-protein diet.     

Uremic Sarcopenia and Its Possible Nutritional Approach

Uremic sarcopenia is a frequent condition present in chronic kidney disease (CKD) patients and is characterized by reduced muscle mass, muscle strength and physical performance. Uremic sarcopenia is related to an increased risk of hospitalization and all-causes mortality. This pathological condition is caused not only by advanced age but also by others factors typical of CKD patients such as metabolic acidosis, hemodialysis therapy, low-grade inflammatory status and inadequate protein-energy intake. Currently, treatments available to ameliorate uremic sarcopenia include nutritional therapy (oral nutritional supplement, inter/intradialytic parenteral nutrition, enteral nutrition, high protein and fiber diet and percutaneous endoscopic gastrectomy) and a personalized program of physical activity. The aim of this review is to analyze the possible benefits induced by nutritional therapy alone or in combination with a personalized program of physical activity, on onset and/or progression of uremic sarcopenia.     

Optimal protein intake in the elderly

The recommended dietary allowance (RDA) for protein, as promulgated by the Food and Nutrition Board of the United States National Academy of Science, is 0.8 g protein/kg body weight/day for adults, regardless of age. This value represents the minimum amount of protein required to avoid progressive loss of lean body mass in most individuals. There is an evidence that the RDA for elderly may be greater than 0.8 g/kg/day. Evidence indicates that protein intake greater than the RDA can improve muscle mass, strength and function in elderly. In addition, other factors, including immune status, wound healing, blood pressure and bone health may be improved by increasing protein intake above the RDA. Furthermore, the RDA does not address the recommended intake of protein in the context of a balanced diet. Concerns about potential detrimental effects of increased protein intake on bone health, renal function, neurological function and cardiovascular function are generally unfounded. In fact, many of these factors are improved in elderly ingesting elevated quantities of protein. It appears that an intake of 1.5 g protein/kg/day, or about 15-20% of total caloric intake, is a reasonable target for elderly individuals wishing to optimize protein intake in terms of health and function.     

Sarcopenia: an undiagnosed condition in older adults. Current consensus definition: prevalence, etiology, and consequences. International working group on sarcopenia

Sarcopenia, the age-associated loss of skeletal muscle mass and function, has considerable societal consequences for the development of frailty, disability, and health care planning. A group of geriatricians and scientists from academia and industry met in Rome, Italy, on November 18, 2009, to arrive at a consensus definition of sarcopenia. The current consensus definition was approved unanimously by the meeting participants and is as follows: Sarcopenia is defined as the age-associated loss of skeletal muscle mass and function. The causes of sarcopenia are multifactorial and can include disuse, altered endocrine function, chronic diseases, inflammation, insulin resistance, and nutritional deficiencies. Although cachexia may be a component of sarcopenia, the 2 conditions are not the same. The diagnosis of sarcopenia should be considered in all older patients who present with observed declines in physical function, strength, or overall health. Sarcopenia should specifically be considered in patients who are bedridden, cannot independently rise from a chair, or who have a measured gait speed less that 1 m/s(-1). Patients who meet these criteria should further undergo body composition assessment using dual energy x-ray absorptiometry with sarcopenia being defined using currently validated definitions. A diagnosis of sarcopenia is consistent with a gait speed of less than 1 m·s(-1) and an objectively measured low muscle mass (eg, appendicular mass relative to ht(2) that is ≤ 7.23 kg/m(2) in men and ≤ 5.67 kg/m(2) in women). Sarcopenia is a highly prevalent condition in older persons that leads to disability, hospitalization, and death.     

Metabolic Syndrome and Sarcopenia

Skeletal muscle is a major organ of insulin-induced glucose metabolism. In addition, loss of muscle mass is closely linked to insulin resistance (IR) and metabolic syndrome (Met-S). Skeletal muscle loss and accumulation of intramuscular fat are associated with a variety of pathologies through a combination of factors, including oxidative stress, inflammatory cytokines, mitochondrial dysfunction, IR, and inactivity. Sarcopenia, defined by a loss of muscle mass and a decline in muscle quality and muscle function, is common in the elderly and is also often seen in patients with acute or chronic muscle-wasting diseases. The relationship between Met-S and sarcopenia has been attracting a great deal of attention these days. Persistent inflammation, fat deposition, and IR are thought to play a complex role in the association between Met-S and sarcopenia. Met-S and sarcopenia adversely affect QOL and contribute to increased frailty, weakness, dependence, and morbidity and mortality. Patients with Met-S and sarcopenia at the same time have a higher risk of several adverse health events than those with either Met-S or sarcopenia. Met-S can also be associated with sarcopenic obesity. In this review, the relationship between Met-S and sarcopenia will be outlined from the viewpoints of molecular mechanism and clinical impact.     

Sarcopenia: a major modifiable cause of frailty in the elderly

Sarcopenia is the loss of muscle mass and strength that occurs with aging. It is a consequence of normal aging, and does not require a disease to occur, although muscle loss can be accelerated by chronic illness. Sarcopenia is a major cause of disability and frailty in the elderly. There are many candidate mechanisms leading to sarcopenia, including age-related declines in alpha-motor neurons, growth hormone production, sex steroid levels, and physical activity. In addition, fat gain, increased production of catabolic cytokines, and inadequate intake of dietary energy and protein are also potentially important causes of sarcopenia. The relative contribution of each of these factors is not yet clear. Sarcopenia can be reversed with high-intensity progressive resistance exercise, which can probably also slow its development. A major challenge in preventing an epidemic of sarcopenia-induced frailty in the future is developing public health interventions that deliver an anabolic stimulus to the muscle of elderly adults on a mass scale.     

Evolution of sarcopenia research

The term "saropenia" was coined by Irwin Rosenberg in 1989 to refer to age-related loss of skeletal muscle mass. The purpose of this current opinion is to provide an evolutionary overview of sarcopenia research since 1989. This includes the creation of an operational definition of sarcopenia; consideration of the impacts of sarcopenia on physical function, chronic disease, and mortality risk; the distinction between the process of sarcopenia and the process of age-related loss of muscle strength, a phenomenon that has recently been termed dynapenia; a comparison of the independent effects of sarcopenia and dynapenia on physical function, chronic disease, and mortality risk; and consideration of the combined influence of sarcopenia and dynapenia with obesity (i.e., sarcopenic-obesity and dynapenic-obesity) on physical function, chronic disease, and mortality risk.     

Effects of sodium chloride on bone health

This paper discusses the physiology of sodium effects on calcium metabolism and possible implications of increased salt intake on bone remodelling and bone mass. Osteoporosis is an increasing public health problem affecting more than 200 million of women around the world. The major complications of osteoporosis are fractures, which are frequently associated with high morbidity and mortality. A number of clinical, epidemiological and experimental studies aim at identifying lifestyle factors that may improve bone mass and prevent bone loss. Different nutrients are proposed to play a role in bone development during growth and in the maintenance of bone mass thereafter. However, the importance of sodium intake for bone health has not been elucidated. It is well known that high dietary sodium intake decreases renal calcium reabsorption, which in turn leads to a greater urinary calcium excretion. This effect has been demonstrated in studies in humans of all ages as well as in experimental animals. It is not clear to what extent sodium-induced calcium loss is compensated for by increased intestinal calcium absorption. It is suspected that, if not fully compensated, sustained hypercalciuria due to increased sodium intake may diminish bone mass. Postmenopausal women showed that increased dietary salt may indeed augment bone resorption. Sodium effects on bone mass in various studies are inconsistent and there is still no evidence that increased salt intake is a risk factor in the aetiology of osteoporosis A randomized longitudinal study of different sodium intake in two groups of subject could clarify the role of sodium in bone mass.     

Osteosarcopenia,an Asymmetrical Overlap of Two Connected Syndromes: Data from the OsteoSys Study

Osteoporosis and sarcopenia are two chronic conditions, which widely affect older people and share common risk factors. We investigated the prevalence of low bone mineral density (BMD) and sarcopenia, including the overlap of both conditions (osteosarcopenia) in 572 older hospitalized patients (mean age 75.1 ± 10.8 years, 78% women) with known or suspected osteoporosis in this prospective observational multicenter study. Sarcopenia was assessed according to the revised definition of the European Working Group on Sarcopenia in Older People (EWGSOP2). Low BMD was defined according to the World Health Organization (WHO) recommendations as a T-score < −1.0. Osteosarcopenia was diagnosed when both low BMD and sarcopenia were present. Low BMD was prevalent in 76% and the prevalence of sarcopenia was 9%, with 90% of the sarcopenic patients showing the overlap of osteosarcopenia (8% of the entire population). Conversely, only few patients with low BMD demonstrated sarcopenia (11%). Osteosarcopenic patients were older and frailer and had lower BMI, fat, and muscle mass, handgrip strength, and T-score compared to nonosteosarcopenic patients. We conclude that osteosarcopenia is extremely common in sarcopenic subjects. Considering the increased risk of falls in patients with sarcopenia, they should always be evaluated for osteoporosis.     

骨质疏松症的膳食危险因素研究进展

膳食因素是影响骨质疏松症的一个方便的人为可控因素。通过合理膳食 ,不但有利于生命前期最佳骨峰值的获得 ,而且有利于生命后期骨丢失的减少 ,这对预防骨质疏松症有重要意义。本文就影响骨质疏松症的膳食危险因素包括低钙摄入、低蛋白或高蛋白摄入、低维生素摄入、吸烟、过量饮酒、摄入过多的咖啡、碳酸饮料、食盐等进行了综述