ABSTRACT Recently the possibility of a causal link between fibromyalgia (FM) and micronutrient deficiency, a type of malnutrition known as “hidden hunger”, has been suggested. However, the results are controversial, which raises questions and debates on the actual influence of “hidden hunger” on the development of FM. In this review, we present and discuss scientific evidence related to micronutrient deficiencies and FM, highlighting key micronutrients involved. We searched PubMed and Science Direct databases for all observational studies published between 2000 to March 2017. We selected fourteen observational studies, eight studies aimed at linking vitamin D deficiency to the presence of FM and six studies focused on the association of mineral deficiency with FM. The association between vitamin D deficiency and increased pain sensitivity in FM is suggested, although such insufficiency is also associated with other chronic musculoskeletal disorders. It appears that mineral deficiency (e.g., iron, magnesium, manganese, zinc and calcium) plays an important role in the onset of FM and its main symptoms.

RESUMEN Recientemente há sido discutida la posibilidad de una relación causal entre la fibromialgia (FM) y la deficiencia de micronutrientes, un tipo de deficiencia nutricional conocida como “hambre oculta”. Sin embargo, los estudios son pocos y los resultados controversiales, lo que genera debates sobre la influencia real del “hambre oculta” en el proceso de la enfermedad en las personas con fibromialgia. En está revisión se presentan y discuten evidencias científicas relacionadas con la deficiencia de micronutrientes y FM, destacando los principales micronutrientes relacionados. El levantamiento de información fue realizado en los bases de datos de PubMed y Science Direct en estudios observacionales publicados entre los años 2000 y 2017. Fueron seleccionados 14 estudios, ocho dirigidos a la asociación de la deficiencia de vitamina D y la presencia de FM y seis enfocados en la asociación de la deficiencia de minerales con FM. Se sugiere una relación entre la deficiencia de vitamina D y el aumento de la sensibilidad al dolor en la FM. Aunque esa insuficiencia también está asociada a otras enfermedades muscoesqueléticas crónicas. Además, parece que la deficiencia mineral (p.ej.o., hierro, magnesio, zinc y calcio) también desempeña un papel importante en el inicio de la FM y sus principales síntomas.

Introduction: The effects of dietary glycemic load (GL) on cardiometabolic risk factors in physically active subjects are not completely known. Objective: This cross-sectional study assessed the association of habitual dietary GL with cardiometabolic risk factors in physically active Brazilian middle-aged men. Methods: One-hundred seventy-six subjects (Age: 50.6 ± 5.0 years, BMI: 25.5 ± 3.6 kg/m²) were evaluated. Anthropometry, lifestyle features, insulin resistance, oxidative stress biomarkers (8-iso-prostaglandin F2α; 8-iso-PGF2α and 8-hydroxydeoxyguanosine; 8-OHdG) and lipid profile were assessed. Dietary intake was estimated through a quantitative food frequency questionnaire. Results: The dietary GL was positively associated with free fatty acid concentrations (β = 0.311, r² = 0.13, P-value = 0.034) and triglycerides/HDL cholesterol ratio (β = 0.598, r² = 0.19, P-value = 0.028) regardless of confounding factors (central obesity, red meat consumption, age and energy intake). The oxidative stress biomarker, 8-OHdG, was associated with habitual dietary GL (β = 0.432, r² = 0.11, P-value = 0.004), regardless of previous confounding factors plus excessive alcohol consumption, iron intake and current smoking status. Conclusions: The dietary GL was positively associated with lipid profile (free fatty acid concentrations and triglycerides/HDL cholesterol ratio) and oxidative stress biomarker (8-OHdG). These results indicate potential harmfulness of diet with higher GL to cardiometabolic risk factors in middle-aged men, even in physically active individuals.

Introducción: Los efectos de la carga glucémica (CG) de la dieta sobre los factores de riesgo cardiometabólico en sujetos físicamente activos no están establecidos por completo. Objetivo: Este estudio transversal evaluó la asociación entre la CG de la dieta habitual y los factores de riesgo cardiometabólico en hombres brasileños de mediana edad físicamente activos. Métodos: Ciento setenta y seis sujetos (índice de masa corporal: 25,5 ± 3,6 kg/m²; edad: 50,6 ± 5,0 años) fueron evaluados. Antropometría, características del estilo de vida, la resistencia a la insulina, biomarcadores del estrés oxidativo (8-iso-prostaglandina F2α, 8-iso-PGF2α y 8 hidroxideoxiguanosina, 8-OHdG) y el perfil lipídico fueron evaluados. La ingesta dietética se estimó por medio de un cuestionario cuantitativo de frecuencia de consumo. Resultados: La CG de la dieta se asoció positivamente con las concentraciones de ácidos grasos libres (β = 0,311, r² = 0,13, P = 0,034) y la razón triglicéridos/colesterol HDL (β = 0,598, r² = 0,19, P = 0,028), independientemente de los factores de confusión (obesidad central, consumo de carne roja, edad e ingesta calórica). El biomarcador del estrés oxidativo, 8-OHdG, también se asoció con CG de la dieta habitual (β = 0,432, r² = 0,11, P = 0,004), independientemente de los factores de confusión anteriores más el consumo excesivo de alcohol, la ingesta de hierro y tabaquismo actual. Conclusiones: La CG de la dieta se asoció positivamente con el perfil lipídico (concentraciones de ácidos grasos libres y razón triglicéridos/HDL colesterol) y el biomarcador de estrés oxidativo 8-OHdG. Estos resultados indican el potencial de nocividad de una dieta con mayor CG respecto a los factores de riesgo cardiometabólico en hombres de mediana edad, incluso en aquellos físicamente activos.

INTRODUÇÃO: A creatina é um dos suplementos mais usados por atletas para incrementar a síntese protéica e aumentar a massa e força muscular. OBJETIVO: Investigou-se os efeitos da suplementação de creatina associada a um programa de treinamento de potência (saltos verticais) sobre a performance e a composição da massa corporal magra de ratos Wistar. MÉTODOS: Ratos Wistar adultos foram distribuídos em quatro grupos: SSC (sedentário sem creatina); SC (sedentário com creatina); ESC (exercício sem creatina) e EC (exercício com creatina). Os animais receberam água e ração ad libitum. Os grupos SC e EC ingeriam dose de creatina diariamente, adotando o procedimento de carga (0,430g/kg p.c. por 7 dias) e manutenção (0,070g/kg p.c. por 6 semanas). Os grupos EC e ESC foram submetidos a um regime progressivo de saltos verticais (5x10 saltos com 1 min de intervalo) em tanque com água, 5 dias/semana, durante 7 semanas. A performance foi avaliada pelo tempo de execução das 5 séries de 10 saltos verticais e a composição da massa corporal magra (músculos e ossos) foi avaliada pelas porções: água, proteína e gordura. RESULTADOS: A performance não foi afetada pela ingestão de creatina (p > 0,05). Os animais suplementados tiveram o percentual de proteína elevado e o de gordura reduzido (p < 0,05), independente do treinamento. Os animais exercitados exibiram maior percentual de proteína, e menor de gordura, além de menor ganho de peso corporal, comparados com os sedentários, independente da suplementação (p < 0,05). Não houve diferença para o percentual de água e consumo alimentar (p > 0,05). CONCLUSÃO: A suplementação de creatina não afetou a performance dos animais, mas alterou a massa corporal magra. A suplementação de creatina e o programa de treinamento de potência, de forma independente, elevaram o percentual de proteína dos músculos e ossos e reduziram o percentual de gordura, sem alterar o percentual de água.

INTRODUCTION: Creatine is one of the supplements most used by athletes in order to increase protein synthesis and consequently muscle mass and strength. OBJECTIVE: This study investigated the effects of creatine intake on the performance and lean body mass of Wistar rats. METHODS: Male Wistar rats were allocated into one of the four groups: sedentary without creatine (S); Sedentary with creatine (SC); exercise without creatine (E); and exercise with creatine (EC) and received water and chow ad libitum. Those animals in SC and EC groups ingested creatine daily (0.430 g/kg body weight for 7 days and 0.070 g/kg body weight for the following 6 weeks). Animals from E and EC groups underwent a progressive vertical jump regimen (5 x 10 jumps with 1 min. resting interval) in a tank filled with water at 30 ± 1ºC, 5 days/wk for 7 weeks. Performance was assessed by taking the time to perform 5 x 10 vertical jumps. The contents of water, fat and protein of the rat's muscles and bones were measured. RESULTS: The performance was not affected by creatine intake (P > 0.05). Animals supplemented with creatine had an increased percentage of protein and a reduced percentage of fat (P < 0.05), regardless the exercise training. Exercised animals exhibited a higher percentage of protein and a lower percentage of fat and gained less body weight when compared to sedentary animals (P < 0.05), regardless the creatine supplementation. There was no difference between groups for water content and food intake (P > 0.05). CONCLUSION: Creatine supplementation did not affect performance of the animals. Nevertheless, it altered the lean body mass. Creatine supplementation as well as the power training program, independently, raised the protein percentage of the muscles and bones and reduced the fat percentage, with no alteration in the water percentage.