Flávia Moraes Silva

Fiber intake and glycemic control in patients with type 2 diabetes mellitus: a systematic review with meta-analysis of randomized controlled trials

This systematic review with meta-analysis of randomized controlled trials (RCT) aimed to analyze the effect of fiber intake on glycemic control in patients with type 2 diabetes. Databases were searched up to November 2012 using the following medical subject headings: diabetes, fiber, and randomized controlled trial. Absolute changes in glycated hemoglobin and fasting plasma glucose were reported as differences between baseline and end-of-study measures. Pooled estimates were obtained using random-effects models. Of the 22,046 articles initially identified, 11 (13 comparisons; range of duration, 8-24 weeks) fulfilled the inclusion criteria, providing data from 605 patients. High-fiber diets, including diets with foods rich in fiber (up to 42.5 g/day; four studies) or supplements containing soluble fiber (up to 15.0 g/day; nine studies), reduced absolute values of glycated hemoglobin by 0.55% (95% CI -0.96 to -0.13) and fasting plasma glucose by 9.97 mg/dL (95% CI -18.16 to -1.78). In conclusion, increased fiber intake improved glycemic control, indicating it should be considered as an adjunctive tool in the treatment of patients with type 2 diabetes.

Improvement of the metabolic syndrome profile by soluble fibre - guar gum - in patients with type 2 diabetes: a randomised clinical trial.

A diet rich in fibre seems to protect against the metabolic syndrome (MetS), but there is scarce information about the role of fibre intake in patients with the MetS and diabetes. The aim of the present study was to evaluate the effects of soluble fibre from partially hydrolysed guar gum (PHGG) on the MetS and cardiovascular risk factors in patients with type 2 diabetes. In the present randomised controlled clinical trial, forty-four patients with type 2 diabetes (males 38·6 %, age 62 (SD 9) years, diabetes duration 14·2 (SD 9·6) years) and the MetS underwent clinical, laboratory and dietary evaluations at baseline, 4 and 6 weeks. All patients followed their usual diet and the intervention group (n 23) received an additional 10 g/d of PHGG. In the intervention group, waist circumference (WC), glycated Hb (HbA1c), 24 h urinary albumin excretion (UAE) and serum trans-fatty acids (FA) were reduced in comparison with baseline after 4 and 6 weeks: WC 103·5 (SD 9·5) to 102·1 (SD 10) to 102·3 (SD 9·7) cm; HbA1c 6·88 (SD 0·99) to 6·64 (SD 0·94) to 6·57 (SD 0·84) %; 24 h UAE 6·8 (interquartile range 3·0-17·5) to 4·5 (interquartile range 3·0-10·5) to 6·2 (interquartile range 3·0-9·5) mg; trans-FA 71 (interquartile range 46-137) to 67 (interquartile range 48-98) to 57 (interquartile range 30-110) mg/l (P< 0·05 for all). The only change in the control group was weight reduction: 77·0 (SD 13·5) to 76·2 (SD 13·3) to 76·1 (SD 13·4) kg (P= 0·005). Other MetS components (blood pressure, TAG, HDL-cholesterol, fasting plasma glucose), total and LDL-cholesterol, C-reactive protein and endothelin-1 did not change in either group. In patients with type 2 diabetes and the MetS, the addition of PHGG to the usual diet improved cardiovascular and metabolic profiles by reducing WC, HbA1c, UAE and trans-FA.

High Dietary Glycemic Index and Low Fiber Content Are Associated with Metabolic Syndrome in Patients with Type 2 Diabetes

Objective: To investigate possible associations of dietary glycemic index (GI) and fiber content with metabolic syndrome (MetS) in patients with type 2 diabetes. Methods: In this cross-sectional study, 175 outpatients with type 2 diabetes (aged 61.1 ± 9.7 years; HbA1c 7.3% ± 1.4%; diabetes duration of 11 years [range, 5–17]) had food intake assessed by 3-day weighed-diet records. Dietary GI (according to FAO/WHO) and fiber content were categorized as high or low based on median values. MetS was defined according to the 2009 Joint Interim Statement. Results: Patients with MetS (n = 109) had higher 24-hour GI (60.0% ± 6.3% vs 57.5% ± 6.4%), higher breakfast GI (59.8% ± 8.0% vs 55.0% ± 9.9%), and lower fiber intake at 24 hours (17.0 ± 6.6 g vs 21.2 ± 8.0 g), breakfast (1.9 [1.2–3.2] vs 3.1 [1.8–4.9] g), lunch (6.2 [3.9–8.0] vs 7.5 [4.7–9.4] g), and dinner (3.3 [2.1–5.2] vs 4.9 [3.1–6.4] g; p < 0.05 for all comparisons) than patients without MetS. In multivariate analyses, high GI (∼60%) of 24 hours (odds ratio [OR], 2.12; 95% confidence interval [CI], 1.10–4.11; p = 0.025), breakfast (OR, 2.20; 95% CI, 1.15–4.21; p = 0.017), and lunch (OR, 2.46; 95% CI, 1.28–4.74; p = 0.007) was associated with MetS. Breakfast (OR, 2.14; 95% CI, 1.04–4.41; p = 0.039) and dinner (OR, 2.27; 95% CI, 1.15–4.49; p = 0.019) with low fiber content were also associated with MetS. When high GI and low fiber intake were combined into the same variable, associations with MetS were maintained. Conclusions: Increased dietary GI and reduced fiber content were positively associated with MetS, mainly due to breakfast intake, in patients with type 2 diabetes.

Antioxidant micronutrients and cardiovascular risk in patients with diabetes: a systematic review.

Background Inverse associations between micronutrient intake and cardiovascular outcomes have been previously shown, but did not focus on diabetic patients. Objective To systematically review the role of micronutrients in the development/presence of cardiovascular outcomes in patients with diabetes. Methods We searched Medline, Embase, and Scopus (January/1949-March/2012) for observational studies that evaluated micronutrients and cardiovascular outcomes in patients with diabetes, and then selected and extracted the data (two independent reviewers). Results From the 15 658 studies identified, five were included, comprising three case-control and two cohorts, with a follow-up of 7-15 years. A meta-analysis was not performed due to the different antioxidant micronutrients (types and measurement methods) and outcomes evaluated. The micronutrients assessed were vitamin C intake in diet and/ or supplementation, chromium and selenium in toenail samples, and α-tocopherol and zinc in serum levels. Intake of > 300 mg of vitamin C through supplementation was associated with increased risk of cardiovascular disease, coronary artery disease (CAD), and stroke (RR 1.69-2.37). High levels of α-tocopherol in serum were associated with 30% lower CAD risk in another study (HR 0.71; 95%CI 0.53-0.94). Among minerals (zinc, selenium, and chromium), an inverse association between zinc and CAD was observed; levels lower than 14.1 μmol/L were associated with an increased risk for CAD (RR 1.70; 95%CI 1.21-2.38). Conclusion The information available on this issue is scarce. Further prospective studies are needed to elucidate the role of these nutrients in the cardiovascular risk of patients with diabetes.

A High–Glycemic Index, Low-Fiber Breakfast Affects the Postprandial Plasma Glucose, Insulin, and Ghrelin Responses of Patients with Type 2 Diabetes in a Randomized Clinical Trial

BACKGROUND Meals with a low glycemic index (GI) and rich in fiber could be beneficial with regard to postprandial metabolic profile and satiety. OBJECTIVE The aim of this study was to investigate the effect of 4 breakfasts with a different GI and amount of fiber on postprandial plasma glucose, insulin, and appetite in patients with type 2 diabetes. METHODS This randomized 4-intervention crossover trial included 14 patients [7 men; ages 65.8 ± 5.2 y; glycated hemoglobin: 6.6 ± 0.9%; BMI (in kg/m(2)): 27.2 ± 3.1]. Dietary interventions were as follows: breakfasts with a high GI (60.4 ± 0.1%) and high fiber (6.0 ± 0.3 g) (HGI-HF), a high GI (60.9 ± 1.7%) and low fiber (2.5 ± 0.4 g) (HGI-LF), a low GI (37.7 ± 0.1%) and high fiber (6.2 ± 0.3 g) (LGI-HF), and a low GI (39.8 ± 1.3%) and low fiber (2.0 ± 0.1 g) (LGI-LF). Plasma glucose, insulin, and total ghrelin were evaluated postprandially (0-180 min). A visual analog scale was used to assess appetite. Data were analyzed by generalized estimating equations and post hoc least significant difference (LSD) tests. Data are reported as means ± SDs. RESULTS The area under the curve (AUC) [mean (95% CI); P for LSD tests] for plasma glucose (mmol/L × min) was higher after patients consumed the HGI-LF breakfast [9.62 (8.39, 10.84)] than after the LGI-HF breakfast [8.95 (7.71, 10.18)] (P ≤ 0.05). Insulin AUC (μIU/mL × min) after patients consumed the HGI-LF meal [65.72 (38.24, 93.19)] was higher than after the HGI-HF meal [57.24 (32.44, 82.04)] (P ≤ 0.05). The other observed difference was higher insulin AUC after the consumption of the LGI-LF breakfast [61.54 (36.61, 86.48)] compared with the AUC after the LGI-HF breakfast [54.16 (31.43, 76.88)] (P ≤ 0.05). Plasma ghrelin decreased in comparison with baseline only after patients consumed the LGI-HF and LGI-LF breakfasts (P ≤ 0.05). Subjective satiety did not differ between breakfasts. CONCLUSIONS Plasma glucose, insulin, and ghrelin responses were least favorable when patients with type 2 diabetes consumed a breakfast with a high GI and low fiber, which suggests that reducing the GI or increasing the fiber content or both of breakfasts may be a useful strategy to improve the postprandial metabolic profile of these patients. This trial was registered at clinicaltrials.gov as NCT01410292.

Qualidade da dieta de indivíduos expostos e não expostos a um programa de reeducação alimentar

OBJETIVO: O presente estudo teve como objetivo comparar a qualidade da dieta de individuos expostos e nao expostos a um programa de reeducacao alimentar. METODOS: Foi realizado estudo transversal, envolvendo 100 individuos, com idade media de 40,7, DP=12,4 anos e indice de massa corporal medio de 27,4, DP=4,7kg/m². Foram avaliados dois grupos: um grupo com 54 individuos expostos a um programa de reeducacao alimentar por 18 meses (grupo E) e um grupo composto por 46 individuos sem orientacao nutricional previa nos ultimos 6 meses (grupo-controle). Ambos os grupos foram submetidos a avaliacao antropometrica (peso, estatura, indice de massa corporal e circunferencia da cintura) e do consumo alimentar (dois recordatorios alimentares de 24 horas). A analise dietetica foi realizada no software Avanutri®, e a qualidade da dieta foi estimada pelo Indice de Alimentacao Saudavel adaptado para a populacao brasileira. RESULTADOS: A pontuacao no Indice de Alimentacao Saudavel, adaptado para a populacao brasileira, foi maior no grupo E do que no grupo-controle (M=97,0, DP= 6,2 vs M=84,2, DP=15,2; p<0,001). Em relacao as categorias de classificacao desse indice, os grupos diferiram quanto ao percentual de individuos com dieta de boa qualidade (29,6% dos individuos do grupo E vs 17,4% dos individuos do grupo-controle) e de ma qualidade (0% no grupo E vs 10,9% no grupo-controle). Os individuos expostos ao programa de reeducacao alimentar apre-sentaram maior pontuacao para vegetais, frutas, laticinios, colesterol e variedade, assim como menor pontuacao para oleos e acucares, em comparacao ao grupo-controle. CONCLUSAO: Individuos expostos ao programa de reeducacao alimentar apresentaram dieta com melhor qualidade do que individuos sem acompanhamento nutricional previo. Tais achados reforcam a importância da educacao nutricional na promocao da alimentacao saudavel.

Revisão sistemática de dietas de emagrecimento: papel dos componentes dietéticos

O excesso de peso corporal e o sexto mais importante fator de risco para doencas cronicas nao transmissiveis. Inumeras publicacoes foram produzidas nos ultimos anos para avaliar a melhor alternativa para perda de peso. O objetivo desta revisao sistematica foi analisar criticamente o papel dos componentes dieteticos (macronutrientes e/ou alimentos) nas dietas de emagrecimento para individuos adultos descritas recentemente na literatura. Foram selecionados ensaios clinicos randomizados com pelo menos um ano de acompanhamento publicados no MedLine (lingua portuguesa, inglesa e espanhola) de 2004 a 2009. Dos 23 estudos com diferentes tipos de dietas, 13 apresentaram taxa de abandono > 25% em pelo menos uma das dietas. Em conclusao, nos estudos em que a perda ponderal foi > 5% do peso inicial, essa perda foi associada a restricao de energia proveniente da dieta. Alem disso, o seguimento de dieta com restricao de carboidratos ou mediterrânea poderia representar uma alternativa a restricao energetica, devendo esses dados ainda ser confirmados.

Lunch energy density and the metabolic syndrome in patients with type 2 diabetes mellitus.

The aim of the present study was to investigate the possible associations between dietary energy density (ED) and the metabolic syndrome (MetS) in patients with type 2 diabetes. In the present case-control study, the dietary ED of 125 patients with type 2 diabetes (seventy-eight with (cases) the MetS and forty-seven without (controls) the MetS; mean age 62·0 (SD 9·4) years, mean diabetes duration 12·5 (SD 8·4) years and mean glycated Hb 7·2 (SD 1·3) %) was assessed by weighed diet records. The MetS was defined according to the 2009 Joint Interim Statement and ED by the amount of energy (kJ) in a given weight of food. Data are expressed as means (standard deviations) or medians (interquartile ranges). Patients with the MetS reported lower intakes of total energy and fibre, and a higher total food amount than the controls; the total ED did not differ, but the cases had a higher ED at lunch (mean 6·3 (SD 1·3) v. 5·9 (SD 0·8) kJ/g; P= 0·017). In this meal, patients with the MetS had lower intakes of beans (median 0·7 (interquartile range 0·4-1·1) v. 1·1 (interquartile range 0·6-1·6) g/kg; P= 0·020), vegetables (median 1·2 (interquartile range 0·6-1·7) v. 1·4 (interquartile range 1·0-2·0) g/kg; P= 0·046) and total meat (median 1·3 (interquartile range 1·0-1·6) v. 1·4 (interquartile range 1·2-1·8) g/kg; P= 0·034) than patients without the MetS. The associations between lunch ED (kJ/g) and food groups (g/kg) were confirmed for vegetables (r - 0·584; P< 0·001), fruits (r - 0·233; P= 0·070), beans (r - 0·189; P= 0·037) and oils (r 0·323; P< 0·001). In a multivariate logistic regression model, a high lunch ED was associated with the MetS (OR 6·89, 95 % CI 1·35, 35·15; P =0·020) after adjusting for confounders. In conclusion, a high ED at lunch increased the odds of the presence of the MetS in patients with type 2 diabetes. Beans and vegetables may be the major contributors to this association and their consumption might be considered to decrease ED.

Glycemic index and glycemic load in the prevention and treatment of type 2 diabetes mellitus

The tight glycemic control can prevent and/or delay the development of chronic complications of diabetes mellitus (DM). Dietary carbohydrates are the main determinant of postprandial blood glucose and glycemic index (GI) and glycemic load are used to predict blood glucose response to foods. The aim of this paper was to critically review the role of low GI diets in type 2 diabetes mellitus (T2DM) prevention and metabolic control. The risk for development of T2DM with high GI diets ranged from 1.21 to 1.59.The reduction from 12-32 units in the GI of diets decreased 0.39-0.50% in HbA1c values. However, the effects of these diets on lipid profile and body weight in patients with T2DM remain controversial. In conclusion, the current evidence indicates that the inclusion of GI in the dietary planning for patients with T2DM contributes to the improvement of glycemic control.

Associação entre o índice glicêmico e a carga glicêmica da dieta de frequentadores de clínicas estéticas privadas de Porto Alegre - RS e indicadoresde adiposidade corporal

Objective: To evaluate the possible association between dietary glycemic index (GI) and glycemic load (GL) and anthropometric indicators of adiposity in clients of private esthetics clinics of Porto Alegre, Rio Grande do Sul state, Brazil. Methods:Observational, cross-section study in which all participants underwent anthropometric (measurement of weight, height, BMI, and waist circumference) and dietary (24-hour recall) assessments. The dietary GI and GL were calculated as proposed by the Food and Agriculture Organization ? FAO, considering the values of the International Table of GlycemicIndex (2008). Dietary analysis was performed using DietWin® software and statistical analysis using SPPS 16.0 Package®. Results: One hundred nineteen clients of three private cosmetic clinics of Porto Alegre were Included in the current study. The following data were collected from the study subjects: 39.12 ± 13.55 years old, BMI equals to 26.21 ± 5.10kg/m², and waist circumference equal to 80.5 ± 11.3 cm for women and 99.7 ± 13.7 cm for men. The daily GL was equal to 89.9 ± 38.7 grams and the GI was equal to 54.4 ± 7.5%. The daily GL differed between participants categorized byBMI, considering the cutoff of the World Health Organization (WHO): higher GL was observed among overweight and obese participants in comparison to participants with underweight and normal weight (89.9 ± 38.7 g vs 89.9 ± 38.7 grams, p = 0.02). The GL explained approximately 26% of the variability in waist circumference values (p <0.001). Conclusion: Clients of private cosmetic clinics of Porto Alegre included in the current study presented overweight in a high proportion; it could be related to a high dietary GL. This aspect should be considered in the nutrition counseling ofthis group of patients regarding carbohydrate intake(AU) Objetivo: Avaliar a possivel associacao entre o indice glicemico (IG) e a carga glicemica (CG) da dieta de frequentadores de clinicas esteticas privadas de Porto Alegre/RS e indicadores antropometricos de adiposidade corporal. Metodos: Estudo observacional transversal em que os participantes foram submetidos a avaliacao antropometrica [peso, estatura, indice de massa corporal (IMC) e circunferencia da cintura (CC)] e do consumo alimentar (recordatorio de 24 horas). O IG e a CG das dietas foram calculados conforme padrao proposto pela FAO, a partir dos valores de IG da Tabela internacional (2008). A analise dietetica dos dados foi realizada no software DietWin® e as analises estatisticas no Pacote SPPS 16.0®. Resultados: Foram avaliados 119 frequentadores de tres clinicas esteticas privadas de Porto Alegre com idade media de 39,12 ± 13,55 anos, IMC de 26,21 ± 5,10Kg/m² e CC de 80,5 ± 11,3cm (para mulheres) e de 99,7 ± 13,7cm (para homens). A CG diaria foi igual a 89,9 ± 38,7g e o IG igual a 54,4 ± 7,5%. A CG diaria diferiu entre os grupos quando categorizados pelo IMC, considerando-se os pontos de corte da Organizacao Mundial de Saude (OMS): maior CG diaria entre os participantes com sobrepeso e obesidade em comparacao aqueles com baixo peso e eutrofia (89,9 ± 38,7g vs. 89,9 ± 38,7g, P=0,02). A CG da dieta explicou cerca de 26% da variabilidade nos valores de CC dos participantes (P<0.001). Conclusao: Elevada prevalencia de excesso de peso corporal foi observada na amostra de frequentadoresde clinicas esteticas privadas avaliada, o que foi relacionado ao consumo de dieta com elevada CG. A orientacao nutricional desse grupo especifico de individuos deve ponderar para esse aspecto quando da escolha de alimentos-fonte de carboidrato. (AU)