Strategies to Prevent Sarcopenia in the Aging Process: Role of Protein Intake and Exercise.

Sarcopenia is one of the main issues associated with the process of aging. Characterized by muscle mass loss, it is triggered by several conditions, including sedentary habits and negative net protein balance. According to World Health Organization, it is expected a 38% increase in older individuals by 2025. Therefore, it is noteworthy to establish recommendations to prevent sarcopenia and several events and comorbidities associated with this health issue condition. In this review, we discuss the role of these factors, prevention strategies, and recommendations, with a focus on protein intake and exercise.

Crosstalk Between Skeletal Muscle and Immune System: Which Roles Do IL-6 and Glutamine Play?

The skeletal muscle was always seen from biomechanical and biochemical views. It is well-established that an active muscle brings many benefits for different body organs and tissues, including the immune system. Since the 1970s, many studies have shown the importance of regular exercise and physical activity in increasing the body's ability to fight opportunist infections, as well as a strategy to fight established diseases. This interaction was mainly attributed to the glutamine, a non-essential amino acid produced by the active skeletal muscle and primarily consumed by rapidly dividing cells, including lymphocytes and monocytes/macrophages, as their main source of energy. Therefore, these cells' function would be significantly improved by the presence of a bigger glutamine pool, facilitating phagocytosis, antigen-presentation, proliferative capacity, cytokine synthesis and release, among other functions. Despite its importance, glutamine is not the only molecule to connect these two tissues. The presence of cytokines is crucial for a proper immune system function. Many of them have well-established pro-inflammatory properties, while others are known for their anti-inflammatory role. Interleukin-6 (IL-6), however, has been in the center of many scientific discussions since it can act as pro- and anti-inflammatory cytokine depending on the tissue that releases it. Skeletal muscle is an essential source of IL-6 with anti-inflammatory properties, regulating the function of the immune cells after tissue injury and the healing process. Therefore, this review aims to discuss further the role of these four components (glutamine, and interleukin-6, and its interface with monocytes/macrophages, and lymphocytes) on the communication between the skeletal muscle and the immune system.

Does long-term creatine supplementation impair kidney function in resistance-trained individuals consuming a high-protein diet?

BACKGROUND: The aim of this study was to determine the effects of creatine supplementation on kidney function in resistance-trained individuals ingesting a high-protein diet. METHODS: A randomized, double-blind, placebo-controlled trial was performed. The participants were randomly allocated to receive either creatine (20 g/d for 5 d followed by 5 g/d throughout the trial) or placebo for 12 weeks. All of the participants were engaged in resistance training and consumed a high-protein diet (i.e., ≥ 1.2 g/Kg/d). Subjects were assessed at baseline (Pre) and after 12 weeks (Post). Glomerular filtration rate was measured by 51Cr-EDTA clearance. Additionally, blood samples and a 24-h urine collection were obtained for other kidney function assessments. RESULTS: No significant differences were observed for 51Cr-EDTA clearance throughout the trial (Creatine: Pre 101.42 ± 13.11, Post 108.78 ± 14.41 mL/min/1.73m2; Placebo: Pre 103.29 ± 17.64, Post 106.68 ± 16.05 mL/min/1.73m2; group x time interaction: F = 0.21, p = 0.64). Creatinine clearance, serum and urinary urea, electrolytes, proteinuria, and albuminuria remained virtually unchanged. CONCLUSIONS: A 12-week creatine supplementation protocol did not affect kidney function in resistance-trained healthy individuals consuming a high-protein diet; thus reinforcing the safety of this dietary supplement. TRIAL REGISTRATION: ClinicalTrials.gov NCT01817673.

Creatine supplementation does not augment muscle carnosine content in type 2 diabetic patients.

We examined whether creatine supplementation affects muscle carnosine content in type 2 diabetic patients. Subjects were randomly assigned to receive either creatine (5 g·day(-1)) or placebo in a double-blind fashion. At baseline and after 12 weeks, carnosine content was evaluated in gastrocnemius and soleus muscles by using a 1H-MRS technique. No changes were found in gastrocnemius (p = 0.81) and soleus (p = 0.85). We concluded that creatine supplementation does not augment muscle carnosine content in type 2 diabetic patients.

Avaliação qualitativa e quantitativa do consumo alimentar de mulheres fisicamente ativas / Qualitative and quantitative evaluation of nourishing consumption of physically active women / Evaluación cualitativa y cuantitativa del consumo alimentario de mujeres físicamente activas

O presente estudo teve como objetivo avaliar quanti e qualitativamente o consumo alimentar de mulheres fisicamente ativas, com a finalidadede investigar o seu padrão alimentar e tecer recomendações de consumo alimentar com base na Pirâmide Alimentar Brasileira. Para tanto, foram selecionadas em 3 academias de médio e grande porte, 83 fichas de anamnese alimentar e registro de 24 horas, para a análise das variáveis antropométricas:peso, estatura, índice de massa corporal, além do gasto e do consumo energético total, assim como o consumo alimentar qualitativo em 8 diferentes grupos alimentares segundo a Pirâmide Alimentar Brasileira. Constatou-se baixo consumo energético total, frente ao gasto em atividades físicas diárias,acompanhado de baixíssima ingestão dos grupos dos pães e cereais, hortaliças, frutas e lácteos; e baixo consumo dos grupos das leguminosas e açúcares. Globalmente, nossos resultados apontaram uma alimentação abaixo das recomendações, nos âmbitos quanti e qualitativo dessas mulheres fisicamente ativas. Dessa forma, em futuros desdobramentos, um instrumento de obtenção mais fidedigno e representativo do consumo habitual deve ser empregado,para confirmar as hipóteses levantadas neste estudo exploratório. Como recomendação nutricional para esse grupo, seria desejável aumentar o consumo energético proveniente do grupo dos pães e cereais, leite e das FLV (frutas, legumes e verduras), cujo padrão é condizente, segundo diversas diretrizes nacionais e internacionais, com a adequação nutricional para a qualidade de vida e manutenção de um padrão de vida ativo fisicamente.

This study aimed to evaluate quantitatively and qualitatively the nourishing consumption of physically active women in order to investigatetheir nourishing style and to weave recommendations of nourishing consumption base on the Brazilian Nourishing Pyramid. For that, we selected, in 3 reputed fitness centers 83 cards of nourishing anamnesis and registry of 24 hours for analysis of the anthropometric variables: weight, height, index of corporal mass, besides the cost and total power consumption, as well as the qualitative nourishing consumption in 8 different nourishing groups according to the Brazilian Nourishing Pyramid. We observed total power consumption inferior to the cost in daily physical activities, accompanied by lowest ingestion by the groups of breads and milky cereals, vegetables, fruits and milk by products; and low consumption of the groups of leguminous and sugars. In globalterms, our results have indicated feeding underthe recommendations both in quantitative and qualitative terms of those physically active women; thus, in future deployments, a more reliable and representative instrumentfor habitual consumption must be used in order to confirm the assumptions formulated in this exploratory study. As nutritional recommendation for that group, it would be desirable to increase power coming from the consumption of thegroup of breads and cereals, milk, and FLV (fruits, leguminous and vegetables), whose register is agreed, according to diverse national and international directives, with nutritional adjustment for quality of life and maintenance of a physically active life style.

Este estudio ha tenido como objetivo evaluar cuanti y cualitativamente el consumo alimentario de mujeres físicamente activas con la finalidadde investigar su padrón alimentario y tejer recomendaciones de consumo alimentario con base en la Pirámide Alimentaria Brasileña. Para eso, han sido seleccionadas, en 3 academias de medio y grande porte, 83 fichas de anamnesis alimentaria y registro de 24 horas para análisis de las variables antropométricas: peso, talla, índice de masa corporal, además del gasto y del consumo energético total, así como el consumo alimentario cualitativo en 8 diferentes grupos alimentarios según la Pirámide Alimentaria Brasileña. Constatóse bajo consumo energético total delante del gasto en actividades físicas diarias, acompañado de bajísima ingestión de los grupos de los panes y cereales, hortalizas, frutas y lácteos; y bajo consumo de los grupos de las leguminosas y azúcares. En términos globales, nuestros resultados han indicado alimentación debajo de las recomendaciones en los ámbitos cuanti y cualitativo de esas mujeres físicamente activas; de esa manera, en futuros desdoblamientos, debe ser empleado un instrumento de obtención más confiable y representativadel consumo habitual a fin de confirmar los supuestos formulados en este estudio exploratorio. Como recomendación nutricional para ese grupo, sería deseable aumentar el consumo energético proveniente del grupo de los panes y cereales, leche, y de las FLV (frutas, legumbres y verduras), cuyo padrón es acorde, según diversas directrices nacionales e internacionales, con adecuación nutricional para calidad de vida y mantenimiento de un padrón de vidafísicamente activo.

Creatine supplementation does not impair kidney function in type 2 diabetic patients: a randomized, double-blind, placebo-controlled, clinical trial.

Creatine supplementation may have a therapeutic role in diabetes, but it is uncertain whether this supplement is safe for kidney function. The aim of this study was to investigate the effects of creatine supplementation on kidney function in type 2 diabetic patients. A randomized, double-blind, placebo-controlled trial was performed. The patients were randomly allocated to receive either creatine or placebo for 12 weeks. All the patients underwent exercise training throughout the trial. Subjects were assessed at baseline and after the intervention. Blood samples and 24-h urine samples were obtained for kidney function assessments. Additionally, (51)Cr-EDTA clearance was performed. To ensure the compliance with creatine intake, we also assessed muscle phosphorylcreatine content. The creatine group presented higher muscle phosphorylcreatine content when compared to placebo group (CR Pre 44 ± 10, Post 70 ± 18 mmol/kg/wt; PL Pre 52 ± 13, Post 46 ± 13 mmol/kg/wt; p = 0.03; estimated difference between means 23.6; 95% confidence interval 1.42-45.8). No significant differences were observed for (51)Cr-EDTA clearance (CR Pre 90.4 ± 16.9, Post 96.1 ± 15.0 mL/min/1.73 m(2); PL Pre 97.9 ± 21.6, Post 96.4 ± 26.8 mL/min/1.73 m(2); p = 0.58; estimated difference between means -0.3; 95% confidence interval -24.9 to 24.2). Creatinine clearance, serum and urinary urea, electrolytes, proteinuria, and albuminuria were unchanged. CR supplementation does not affect kidney function in type 2 diabetic patients, opening a window of opportunities to explore its promising therapeutic role in this population. ClinicalTrials.gov registration number: NCT00992043.