β-hydroxy-β-methylbutyrate supplementation in older persons - an update

Role of muscle-targeted nutritional therapy: new data

PURPOSE OF REVIEW

To provide an updated overview of recent efficacy data on the use of muscle-targeted nutritional therapy, which should consider the optimization of protein and essential amino acids intakes, possibly in combination with supplementation with vitamin D (correction of deficiency/insufficiency status) and v-3 fatty acids.

RECENT FINDINGS

Intervention studies conducted in the last years in different healthcare settings and heterogeneous patient populations support the use of muscle-targeted oral nutritional supplementation to improve muscle mass, function and physical performance in patients with sarcopenia. Higher efficacy is likely to be achieved in combination with individually tailored resistance exercise training programs and when nutritional therapy and the provision of specific nutrients result in an adequate protein-calorie balance. However, not only a reactive but also a pro-active application of this therapy could be proposed as evidence exists on the maintenance of or improvement in the same outcome variables in patients at risk of losing skeletal muscle mass.

SUMMARY

Based on available efficacy data, both a reactive and pro-active use of muscle-targeted nutritional therapy are promising and should be proposed. However, future research should be directed toward the management of patient populations characterized by substantial muscle wasting, as these have been frequently excluded from previous trials, perhaps to avoid confounding.

β-Hydroxy-β-methylbutyrate (HMB) supplementation and functional outcomes in multi-trauma patients: a study protocol for a pilot randomised clinical trial (BOOST trial)

Background

There are no therapies proven to diminish the muscle wasting that occurs in patients after major trauma who are admitted to the intensive care unit (ICU). β-Hydroxy-β-methylbutyrate (HMB) is a nutrition intervention that may attenuate muscle loss and, thereby, improve recovery. The primary aim of this study is to determine the feasibility of a blinded randomised clinical trial of HMB supplementation to patients after major trauma who are admitted to the ICU. Secondary aims are to establish estimates for the impact of HMB when compared to placebo on muscle mass and nutrition-related patient outcomes.

Methods

This prospective, single-centre, blinded, randomised, placebo-controlled, parallel-group, feasibility trial with allocation concealment will recruit 50 participants over 18 months. After informed consent, participants will be randomised [1:1] to receive either the intervention (three grams of HMB dissolved in either 150 ml of orange juice for those allowed oral intake or 150 ml of water for those being enterally fed) or placebo (150 ml of orange juice for those allowed oral intake or 150 ml of water for those being enterally fed). The intervention will be commenced in ICU, continued after ICU discharge and ceased at hospital discharge or day 28 post randomisation, whichever occurs first. The primary outcome is the feasibility of administering the intervention. Secondary outcomes include change in muscle thickness using ultrasound and other nutritional and patient-centred outcomes.

Discussion

This study aims to determine the feasibility of administering HMB to critically ill multi-trauma patients throughout ICU admission until hospital discharge. Results will inform design of a larger randomised clinical trial.

Trial registration

The protocol is registered with Australian New Zealand Clinical Trials Registry (ANZCTR) ANZCTR: 12620001305910. UTN: U1111-1259-5534.

In-vivo production of branched-chain amino acids, branched-chain keto acids, and β-hydroxy β-methylbutyric acid

PURPOSE OF REVIEW

The branched-chain amino acids (BCAA), branched-chain keto acids (BCKA), and β-hydroxy β-methylbutyric acid (HMB) have regained interest as food ingredients in health and disease. To support nutritional strategies, it is critical to gain insight into the whole body and transorgan kinetics of these components. We, therefore, reviewed the most recent literature in this field on in vivo analysis of BCAA, BCKA, and HMB kinetics in health and disease.

RECENT FINDINGS

With a new comprehensive metabolic flux analysis BCAA, BCKA, and HMB whole body production, interconversion and disposal rates can be measured simultaneously. Recent studies have provided us with a better understanding of whole-body and transorgan kinetics under postabsorptive, postprandial, hibernating, and lactating conditions. In human pathophysiological conditions like COPD, obesity, and diabetes, the added value of BCAA kinetic measurements over the commonly used concentration measurements only, is discussed.

SUMMARY

This article highlights the importance of implementing BCAA, BCKA, and HMB kinetic studies to further advance the field by gaining more mechanistic insights and providing direction to the development of new targeted (nutritional) strategies.

Sarcopenia: Etiology, Nutritional Approaches, and miRNAs

Sarcopenia, an age-related decline in skeletal muscle mass and function, dramatically affects the quality of life. Although there is a consensus that sarcopenia is a multifactorial syndrome, the etiology and underlying mechanisms are not yet delineated. Moreover, research about nutritional interventions to prevent the development of sarcopenia is mainly focused on the amount and quality of protein intake. The impact of several nutrition strategies that consider timing of food intake, anti-inflammatory nutrients, metabolic control, and the role of mitochondrial function on the progression of sarcopenia is not fully understood. This narrative review summarizes the metabolic background of this phenomenon and proposes an integral nutritional approach (including dietary supplements such as creatine monohydrate) to target potential molecular pathways that may affect reduce or ameliorate the adverse effects of sarcopenia. Lastly, miRNAs, in particular those produced by skeletal muscle (MyomiR), might represent a valid tool to evaluate sarcopenia progression as a potential rapid and early biomarker for diagnosis and characterization.