Sophie Allepaerts

Does nutrition play a role in the prevention and management of sarcopenia

There is a growing body of evidence that links nutrition to muscle mass, strength and function in older adults, suggesting that it has an important role to play both in the prevention and management of sarcopenia. This review summarises the discussions of a working group [ESCEO working group meeting 8th September 2016] that met to review current evidence and to consider its implications for preventive and treatment strategies. The review points to the importance of healthier dietary patterns that are adequate in quality in older age, to ensure sufficient intakes of protein, vitamin D, antioxidant nutrients and long-chain polyunsaturated fatty acids. In particular, there is substantial evidence to support the roles of dietary protein and physical activity as key anabolic stimuli for muscle protein synthesis. However, much of the evidence is observational and from high-income countries. Further high-quality trials, particularly from more diverse populations, are needed to enable an understanding of dose and duration effects of individual nutrients on function, to elucidate mechanistic links, and to define optimal profiles and patterns of nutrient intake for older adults.

Pitfalls in the measurement of muscle mass: a need for a reference standard

All proposed definitions of sarcopenia include the measurement of muscle mass, but the techniques and threshold values used vary. Indeed, the literature does not establish consensus on the best technique for measuring lean body mass. Thus, the objective measurement of sarcopenia is hampered by limitations intrinsic to assessment tools. The aim of this study was to review the methods to assess muscle mass and to reach consensus on the development of a reference standard.

Energy and nutrient content of food served and consumed by nursing home residents

ObjectiveThe aim of this study was to compare energy and protein content of the served food with the actual intake from the food consumed by nursing home residents. This study also aimed to compare food intake and dietary allowances.DesignThis is a cross sectional study.SettingThis study was performed in nursing homes.ParticipantsResidents of these 2 nursing homes were eligible for the study if they agreed to participate and if they meet the selection criteria (to be older than 65 years and have a regular texture diet).MeasurementNutrient content of the served food and real food consumption was calculated for all meals during a 5-day period by precise weighting method. Difference between consumed and served dietary content was evaluated by the Chi² test.ResultsSeventy-four Belgian nursing home residents (75% of women, 85.8 ± 7.04 years on average) were included in this study. These subjects had a mean body mass index of 24.9 ± 4.83 kg/m². The mean energy content of the served food was 1783.3 ± 125.7 kcal per day. However, residents did not eat the whole of the meals and the actual energy content of the consumed food was significantly less (1552.4 ± 342.1 kcal per day; p<.001). The average protein content of the food served was equal to 0.96 ± 0.20 g/kg/day and the average consumption of protein by the residents was 0.88 ± 0.25 g/kg/day. The difference between protein served and consumed was also significant (p=.04). Moreover, people considered as well nourished, eating significantly more energy than the others (p=.04).ConclusionMeals served in nursing homes are not entirely consumed by their residents. As expected, the energy consumed are lower in subjects considered as malnourished or at risk of malnutrition.

Assessment of the energy expenditure of Belgian nursing home residents using indirect calorimetry

OBJECTIVESnThe aim of this study was to assess the energy expenditure of Belgian nursing home residents using indirect calorimetry and compare the energy expenditure with energy intake.nnnMETHODSnIndirect calorimetry was performed in nursing home residents to estimate their basal metabolism. The basal metabolism was multiplied by a physical activity level coefficient and energy expenditure that was related to thermogenesis (i.e., 10% of the total amount of energy ingested over 24 h) was added. In this way, we obtained the total energy expenditure of each nursing home resident. The nutritional intake of each resident was calculated using the precise food-weighing method over a 3-d period. The difference between energy expenditure and consumption was calculated for each patient and the mean of the difference in the population was calculated. These quantitative variables were compared by means of analysis of variance.nnnRESULTSnA total of 25 subjects were included in this study (88.1 ± 5.8 y; 84% women). The estimated mean basal metabolism was 1087.2 ± 163.2 kcal. The physical activity level was 1.29 ± 0.1 on average and the energy expenditure due to thermogenesis was 163.1 ± 28.9 kcal. Thus, the mean daily energy expenditure was 1575.2 ± 210.6 kcal, which was within the range of the actual calculated energy intake of the residents (1631.5 ± 289.3 kcal; Pu202f=u202f0.33).nnnCONCLUSIONSnThe estimated energy intake of Belgian nursing home residents seems appropriate for their energy expenditure.

The Authors reply: “Dual energy X-ray absorptiometry: gold standard for muscle mass?” by Scafoglieri et al.: Correspondence

We appreciate your interest in our recent publication and your valuable comments. We completely agree that there is still ambiguity in the literature on the definition and use of parameters characterizing body composition. From this perspective, DXA actually is a progress as the definition of lean and fat (according to DXA terminology) and based on differences of X-ray mass absorption coefficients. With a two energy X-ray system, two materials that differ in atomic number can be uniquely identified using a so-called base material composition. Specific calibration equations of identification of dedicated anatomical entities consisting of either one of thematerials is not required. As shown by Pietrobelli et al. 4 in terms of the so-called R-value that quantifies differences in the mass absorption coefficient for a given material at different X-ray energies fatty acids and triglycerides the ingredients of can well be separated from non-lipid body composition materials. From this perspective, lean and fat mass as measured by DXA are clearly defined, but do not necessarily agree with anatomical entities such as the amount of adipose tissue. As fat is a term used in many different contexts, perhaps a different name should have been given to what is now known as DXA fat mass. We agree that DXA lean body mass is smaller than FFM. FFM is the mass of the body excluding the chemical fat. So essential lipids are also excluded. Lean body mass, interpreted the ‘DXA way’, is the soft lean tissue of the body, excluding the bone minerals and the chemical fat. However, lean body mass from a historical point of view, does include the bone, and very closely resembles FFM (but is not perfectly the same). What we would like to stress is that the concept of lean body mass (of FFM for that matter) is not very useful for muscle research. You would like to focus on the bone-free and fat-free mass of the arms and legs, as this measure most closely resembles the actual skeletal muscle tissue. Apparently, a standardization of terminology in the field of body composition is required. We agree with comments that lean mass and muscle mass are two different measurements but this was clearly outlined as a weakness of DXA in Table 1. However, as the commentators showed themselves, the correlation was high (r = 0.94), and lean was almost the sum of muscle, skin, and viscera. In the appendicular skeleton, there is no viscera, thus only the difference in the lean composition, i.e. the variation of relative amounts of water, protein, and glycogen remains. With regard to estimations of fat-free mass and (appendicular) lean mass using bioelectrical impedance (BIA), we appreciate the confirmation that large prediction errors at the individual level may occur which hampers the use of BIA in clinical practice. We also showed that on a group level, discrepancies might occur between lean mass predicted by BIA and lean mass measured by DXA. We agree these discrepancies should not be interpreted as BIA not being valid to assess lean mass. We merely provided these examples to highlight the fact that estimates of lean mass from BIA clearly differ from those from DXA, thereby influencing the interpretation of findings (e.g. the prevalence of sarcopenia and the comparison of data obtained with different methods). Given the high degree of DXA standardization, excellent precision, the high correlation of DXA lean mass with muscle mass and muscle volume, currently DXA seems to be the best reference technique, in particular for appendicular muscle measurements. This does not imply that DXA will be the gold standard for the diagnosis of sarcopenia, which requires a functional component in addition to appendicular muscle mass assessments. It also calls for further efforts to develop anthropometric standards representing the wide range of body compositions encountered in the clinical routine in order to validate the accuracy of methods, such as DXA and BIA. At this stage, the scientific evidence derived from the published literature seems to support the conclusions of the original article.