A novel oral nutritional supplement improves gait speed and mitochondrial functioning compared to standard care in older adults with (or at risk of) undernutrition: results from a randomized controlled trial

Impact of an oral nutritional supplement on the body composition of older adults with or at risk of malnutrition in an institutionalised setting: A randomised controlled trial

BACKGROUND

Malnutrition often manifests as a body weight (BW) reduction and unhealthy alteration in body composition. The present study aimed to assess the efficacy of an oral nutritional supplement (ONS) in improving BW and body composition among older adults with malnutrition.

METHODS

An open-label randomised controlled, parallel-group study was conducted among older adults (age ≥ 60 years) with/at risk of malnutrition (mini nutrition assessment-short form score ≤ 11). In total, 50 participants were randomly assigned to the intervention (IG) and control (CG) groups (1:1 ratio). The IG received the ONS (57 g/day; 247 kcal/serving, 12 g protein) before bedtime for 12 weeks. CG received 200 mL of water. Anthropometric measurements, body composition analysis, and dietary and physical activity assessments were performed at the beginning and end of the study.

RESULTS

Forty-two participants (IG: 20, CG: 22) completed the study. The mean ± SD ages of the IG and CG were 75.4 ± 6.1 and 74.8 ± 5.2 years, respectively (p = 0.73). The IG had a significant increase in BW (+1.68 ± 1.16 vs. -0.46 ± 0.95 kg; p < 0.001), lean mass (+1.23 ± 0.93 vs. -0.45 ± 0.90 kg; p < 0.001) and fat mass (+0.54 ± 0.82 vs. -0.06 ± 0.82 kg; p = 0.02) compared to the CG. One-quarter of the IG (n = 5) achieved a weight gain > 5% of BW, whereas none in the CG did (p = 0.01). No significant changes were observed in bone mineral content in either group.

CONCLUSIONS

For malnourished older adults, supplementing with an ONS, along with regular food intake, significantly increased BW, lean mass and fat mass compared to control following the regular diet without supplementation.

Dietary protein and amino acid intakes for mitigating sarcopenia in humans

Adult humans generally experience a 0.5-1%/year loss in whole-body skeletal muscle mass and a reduction of muscle strength by 1.5-5%/year beginning at the age of 50 years. This results in sarcopenia (aging-related progressive losses of skeletal muscle mass and strength) that affects 10-16% of adults aged ≥ 60 years worldwide. Concentrations of some amino acids (AAs) such as branched-chain AAs, arginine, glutamine, glycine, and serine are reduced in the plasma of older than young adults likely due to insufficient protein intake, reduced protein digestibility, and increased AA catabolism by the portal-drained viscera. Acute, short-term, or long-term administration of some of these AAs or a mixture of proteinogenic AAs can enhance blood flow to skeletal muscle, activate the mechanistic target of rapamycin cell signaling pathway for the initiation of muscle protein synthesis, and modulate the metabolic activity of the muscle. In addition, some AA metabolites such as taurine, β-alanine, carnosine, and creatine have similar physiological effects on improving muscle mass and function in older adults. Long-term adequate intakes of protein and the AA metabolites can aid in mitigating sarcopenia in elderly adults. Appropriate combinations of animal- and plant-sourced foods are most desirable to maintain proper dietary AA balance.

Effect of multicomponent intervention on malnutrition in older adults: A multicenter randomized clinical trial

BACKGROUND & AIMS

Malnutrition is a significant geriatric syndrome (GS) prevalent in older adults and seriously affects patient prognosis and quality of life. We assessed the impact of the multicomponent intervention of health education, dietary advice, and exercise with oral nutritional supplementation (ONS) on nutritional status, body composition, physical functions, and quality of life.

METHODS

This multicenter randomized clinical trial (RCT) was performed from April 2021 to April 2022. The intervention lasted for 12 weeks, and 99 older adults with malnutrition or at risk of malnutrition were enrolled in six nursing homes. All participants were randomly assigned to the control (health education plus standard diet plus exercise) or research (health education plus standard diet plus exercise plus ONS) group. The research group consumed ONS (244 kcal, 9.8g protein, and 9.6g fat per time) twice a day between meals. The primary outcomes were changes in the nutritional status and body composition from baseline to 12 weeks. The secondary outcomes were changes in physical function, quality of life and nutritional associated other blood markers.

RESULTS

For primary outcomes, after 12 weeks, body weight increased similarly in both treatment arms (time × treatment effect, P > 0.05). There were no between-group differences in body mass index (BMI) or mini nutritional assessment tool-short form (MNA-SF) scores (time × treatment effects, P > 0.05). The MNA-SF score from 11.0 (10.5, 12.0) to 13.0 (11.0, 13.0) in the research group and from 11.0 (10.0, 12.0) to 12.0 (11.0, 13.0) in the control group (both P < 0.05). There were no between-group differences in the skeletal muscle mass index (SMI), fat-free mass index (FFMI), appendicular skeletal muscle mass (ASMM), fat mass (FAT), or leg muscle mass (LMM) (time × treatment effects, P > 0.05). Both groups showed similar and highly significant increases in SMI, FFMI, and LMM after (P < 0.05). The research group showed an increase in fat-free mass (FFM) and ASMM and a decrease in the percent of body fat (PBF) and waist circumference (WC) (P < 0.05). For secondary outcomes, There were no between-group differences in grip strength, short physical performance battery (SPPB), 6-min walking distance (6MWD), activities of daily living (ADL), instrumental activities of daily living (IADL), frailty status (FRAIL), mini-mental state examination (MMSE), Tinetti, geriatric depression scale-15 (GDS-15), or 12-item short form survey (SF-12) (time × treatment effects, P > 0.05). Although there was no significant difference, the 6MWD changed differentially between the two treatment arms during the study period in favor of the research group. Although not significant, SF-12 scores improved after 12 weeks in both groups. No between-group differences were observed in prealbumin (PRE), c-reactive protein (CRP), vitamin D (VIT-D), insulin-like growth factor 1 (IGF-1), alanine transaminase (ALT), aspartate aminotransferase (AST), serum creatinine (Scr), interleukin-6 (IL-6), interleukin-10 (IL-10), tumor necrosis factor-α (TNF-α), insulin, and adiponectin levels (time × treatment effects, P > 0.05). Insulin and adiponectin levels were significantly higher in the control group (P < 0.05).

CONCLUSION

The twelve-week multicomponent intervention improved the nutritional status of older people in China at risk of malnutrition. ONS may enhance the effects of exercise on muscle mass. This clinical trial was registered (https://www.

CLINICALTRIALS

gov). The trial number is ChiCTR2000040343.

The Role of Nutrition in the Treatment of Sarcopenia in Old Patients: From Restoration of Mitochondrial Activity to Improvement of Muscle Performance, a Systematic Review

Sarcopenia is an age-related disease characterized by loss of muscle strength, mass and performance. Malnutrition contributes to sarcopenia pathogenesis. The aim of this systematic review is to analyze existing evidence on the efficacy of nutritional supplementation on muscle and mitochondrial health among sarcopenic or malnourished older adults. We included randomized controlled trials (RCTs) assessing the effect of branched-chain amino acid (BCAA), vitamin D and/or omega-3 polyunsaturated fatty acid (PUFA) on muscle mass, strength and performance and/or on mitochondrial activity and redox state in older sarcopenic and/or malnourished adults. The literature search was on MEDLINE, Embase and Cochrane Central, restricted to articles published in the last 10 years (2012-2022). Twelve RCTs with a total of 1337 subjects were included. BCAA with vitamin D significantly ameliorates appendicular muscle mass (4 RCTs), hand grip strength (4 RCTs), gait speed (3 RCTs), short physical performance battery (3 RCTs) or chair stand test (3 RCTs) among six out of nine RCTs. BCAA alone (2 RCTs) or PUFA (1 RCT) were not effective in improving muscle health. Mitochondrial function was significantly improved by the administration of BCAA alone (1 RCT) or in association with vitamin D (1 RCT). In conclusion, BCAA in association with vitamin D may be useful in the treatment of sarcopenia and boost mitochondrial bioenergetic and redox activity. PROSPERO CRD42022332288.

Caloric Restriction Combined with Immobilization as Translational Model for Sarcopenia Expressing Key-Pathways of Human Pathology

The prevalence of sarcopenia is increasing while it is often challenging, expensive and time-consuming to test the effectiveness of interventions against sarcopenia. Translational mouse models that adequately mimic underlying physiological pathways could accelerate research but are scarce. Here, we investigated the translational value of three potential mouse models for sarcopenia, namely partial immobilized (to mimic sedentary lifestyle), caloric restricted (CR; to mimic malnutrition) and a combination (immobilized & CR) model. C57BL/6J mice were calorically restricted (-40%) and/or one hindleg was immobilized for two weeks to induce loss of muscle mass and function. Muscle parameters were compared to those of young control (4 months) and old reference mice (21 months). Transcriptome analysis of quadriceps muscle was performed to identify underlying pathways and were compared with those being expressed in aged human vastus lateralis muscle-biopsies using a meta-analysis of five different human studies. Caloric restriction induced overall loss of lean body mass (-15%, p<0.001), whereas immobilization decreased muscle strength (-28%, p<0.001) and muscle mass of hindleg muscles specifically (on average -25%, p<0.001). The proportion of slow myofibers increased with aging in mice (+5%, p<0.05), and this was not recapitulated by the CR and/or immobilization models. The diameter of fast myofibers decreased with aging (-7%, p<0.05), and this was mimicked by all models. Transcriptome analysis revealed that the combination of CR and immobilization recapitulated more pathways characteristic for human muscle-aging (73%) than naturally aged (21 months old) mice (45%). In conclusion, the combination model exhibits loss of both muscle mass (due to CR) and function (due to immobilization) and has a remarkable similarity with pathways underlying human sarcopenia. These findings underline that external factors such as sedentary behavior and malnutrition are key elements of a translational mouse model and favor the combination model as a rapid model for testing the treatments against sarcopenia.

The Effects of Protein and Supplements on Sarcopenia in Human Clinical Studies: How Older Adults Should Consume Protein and Supplements

Sarcopenia is a condition in which muscle mass, strength, and performance decrease with age. It is associated with chronic diseases such as diabetes, cardiovascular disease, and hypertension, and contributes to an increase in mortality. Because managing sarcopenia is critical for maintaining good health and quality of life for the elderly, the condition has sparked concern among many researchers. To counteract sarcopenia, intake of protein is an important factor, while a lack of either protein or vitamin D is a major cause of sarcopenia. In addition, essential amino acids, leucine, β-hydroxy β-methylbutyrate (HMB), creatine, and citrulline are used as supplements for muscle health and are suggested as alternatives for controlling sarcopenia. There are many studies on such proteins and supplements, but it is necessary to actually organize the types, amounts, and methods by which proteins and supplements should be consumed to inhibit sarcopenia. In this study, the efficacy of proteins and supplements for controlling sarcopenia according to human clinical studies is summarized to provide suggestions about how the elderly may consume proteins, amino acids, and other supplements.

Protein intake and bone mineral density: Cross-sectional relationship and longitudinal effects in older adults

BACKGROUND

There are several mechanisms via which increased protein intake might maintain or improve bone mineral density (BMD), but current evidence for an association or effect is inconclusive. The objectives of this study were to investigate the association between dietary protein intake (total, plant and animal) with BMD (spine and total body) and the effects of protein supplementation on BMD.

METHODS

Individual data from four trials that included either (pre-)frail, undernourished or healthy older adults (aged ≥65 years) were combined. Dietary intake was assessed with food records (2, 3 or 7 days) and BMD with dual-energy X-ray absorptiometry (DXA). Associations and effects were assessed by adjusted linear mixed models.

RESULTS

A total of 1570 participants [57% women, median (inter-quartile range): age 71 (68-75) years] for which at least total protein intake and total body BMD were known were included in cross-sectional analyses. In fully adjusted models, total protein intake was associated with higher total body and spine BMD [beta (95% confidence interval): 0.0011 (0.0006-0.0015) and 0.0015 (0.0007-0.0023) g/cm² , respectively]. Animal protein intake was associated with higher total body and spine BMD as well [0.0011 (0.0007-0.0016) and 0.0017 (0.0010-0.0024) g/cm² , respectively]. Plant protein intake was associated with a lower total body and spine BMD [-0.0010 (-0.0020 to -0.0001) and -0.0019 (-0.0034 to -0.0004) g/cm² , respectively]. Associations were similar between sexes. Participants with a high ratio of animal to plant protein intake had higher BMD. In participants with an adequate calcium intake and sufficient serum 25(OH)D concentrations, the association between total protein intake with total body and spine BMD became stronger. Likewise, the association between animal protein intake with total body BMD was stronger. In the longitudinal analyses, 340 participants [58% women, median (inter-quartile range): age 75 (70-81) years] were included. Interventions of 12 or 24 weeks with protein supplementation or protein supplementation combined with resistance exercise did not lead to significant improvements in BMD.

CONCLUSIONS

An association between total and animal protein intake with higher BMD was found. In contrast, plant protein intake was associated with lower BMD. Research is warranted to further investigate the added value of dietary protein alongside calcium and vitamin D for BMD improvement, especially in osteopenic or osteoporotic individuals. Moreover, more research on the impact of a plant-based diet on bone health is needed.

The Association between Malnutrition and Physical Performance in Older Adults: A Systematic Review and Meta-Analysis of Observational Studies

In recent years the focus of healthcare and nutritional science in older adults has shifted from mortality towards physical performance and quality of life. The aim of this review was to summarize observational studies on physical performance in malnourished (MN) or at risk of malnutrition (RMN) older adults compared with well-nourished (WN) older adults. Eligible studies had to report on nutritional status and objectively measured physical performance in older adults (≥60 y). MN or RMN groups had to be compared with a WN group, measured with a validated nutrition screener. Ovid Medline and Web of Science were searched until 13 November, 2020. Study quality was scored using a modified Newcastle-Ottawa Scale (NOS). Results were analyzed by meta-analysis when possible, or narratively reviewed otherwise. Forty-five studies (16,911 participants in total) were included from studies in outpatient clinics (n = 6), nursing homes (n = 3), community-dwelling older adults (n = 20), hospitalized patients (n = 15), or a combination (n = 1). Studies used 11 different screeners of malnutrition, and 8 types of physical performance measures. Meta-analysis showed that compared with MN, WN groups had better hand grip strength (mean difference [MD] = 4.92 kg; 95% CI: 3.43, 6.41; P < 0.001; n = 23), faster gait speed (MD = 0.16 m/s; 95% CI: 0.05, 0.27; P = 0.0033; n = 7), performed faster on timed-up-and-go (MD = -5.94 s; 95% CI: -8.98, -2.89; P < 0.001; n = 8), and scored 1.2 more short physical performance battery points (95% CI: 1.32, 2.73; P < 0.001; n = 6). Results were less pronounced when compared with RMN. Narratively, all studies showed an association for knee extension strength, 6-min walking test, and multicomponent tests, except for the chair stand test. Study limitations include no studies scoring "good" on NOS, lack of confounder adjustment, and high heterogeneity. Overall, evidence from cross-sectional studies indicate an association between malnutrition and worse physical performance in older adults. This study is registered in PROSPERO as CRD42020192893.

Estimation of the proportion of treatment effect explained by a high-dimensional surrogate

Clinical studies examining the effectiveness of a treatment with respect to some primary outcome often require long-term follow-up of patients and/or costly or burdensome measurements of the primary outcome of interest. Identifying a surrogate marker for the primary outcome of interest may allow one to evaluate a treatment effect with less follow-up time, less cost, or less burden. While much clinical and statistical work has focused on identifying and validating surrogate markers, available approaches tend to focus on settings in which only a single surrogate marker is of interest. Limited work has been done to accommodate the high-dimensional surrogate marker setting where the number of potential surrogates is greater than the sample size. In this article, we develop methods to estimate the proportion of treatment effect explained by high-dimensional surrogates. We study the asymptotic properties of our proposed estimator, propose inference procedures, and examine finite sample performance via a simulation study. We illustrate our proposed methods using data from a randomized study comparing a novel whey-based oral nutrition supplement with a standard supplement with respect to change in body fat percentage over 12 weeks, where the surrogate markers of interest are gene expression probesets.