Paula Guedes Cocate

Metabolic responses to high glycemic index and low glycemic index meals: a controlled crossover clinical trial

BackgroundThe consumption of low glycemic index (LGI) foods before exercise results in slower and more stable glycemic increases. Besides maintaining an adequate supply of energy during exercise, this response may favor an increase in fat oxidation in the postprandial period before the exercise compared to high glycemic index (HGI) foods. The majority of the studies that evaluated the effect of foods differing in glycemic index on substrate oxidation during the postprandial period before the exercise are acute studies in which a single meal is consumed right before the exercise. The purpose of this study was to investigate the effect of consuming two daily HGI or LGI meals for five consecutive days on substrate oxidation before the exercise and in the concentrations of glucose, insulin and free fatty acids before and during a high intensity exercise.MethodsFifteen male cyclists, aged 24.4 ± 3.8 years, with body mass index of 21.9 ± 1.4 kg.m-2 and a VO2 max of 70.0 ± 5.3 mL.kg-1.min-1, participated in this crossover study. All test meals were consumed in the laboratory. On days 1 and 5, substrate oxidation (30 minutes before and 90 minutes after breakfast (HGI or LGI)) and diet-induced thermogenesis (90 minutes postprandial) were assessed before the exercise. The levels of glucose, insulin, and free fatty acids were determined during 2 h after breakfast on these same days. Ninety minutes after breakfast, subjects completed a 30 min cycloergometric exercise at 85 to 95% of their maximum heart rate, during which lactate concentrations were assessed.ResultsThe consumption of HGI meals resulted in higher areas under the glycemic and insulinemic curves in the postprandial period. However, glycemia did not differ by study treatment during exercise. There were no differences in free fatty acids in the postprandial period or in lactate levels during exercise. LGI meals resulted in lower fat oxidation and higher carbohydrate oxidation than the HGI meal in the postprandial period.ConclusionsThe results do not support a differential glycemia according to glycemic index during exercise. The ingestion of LGI foods did not lead to higher fat oxidation relative to the ingestion of HGI foods.Trial registrationACTRN: ACTRN12609000522213

Red but not white meat consumption is associated with metabolic syndrome, insulin resistance and lipid peroxidation in Brazilian middle-aged men

Background The influence of diet on metabolic syndrome and oxidative stress are not completely known. Design This cross-sectional study assessed the association of red meat and white meat consumption with metabolic syndrome, insulin resistance and lipid peroxidation in Brazilian middle-aged men. Methods A total of 296 subjects (age: 50.5 ± 5.0 years, body mass index: 25.8 ± 3.5 kg/m2) were evaluated. Anthropometry, lifestyle features, blood biochemical parameters, diagnosis of metabolic syndrome, homeostatic model assessment for insulin resistance, a lipid peroxidation marker (oxidized low-density lipoprotein) and triglycerides:high-density lipoprotein cholesterol ratio were assessed. Dietary intake was estimated by a food frequency questionnaire. Results The subjects included in the highest tertile red meat (≥81.5 g/d) and saturated fatty acid from red meat consumption (≥4.3 g/d) had higher occurrence of central obesity (nearly 60%, p < 0.01), hypertriglyceridaemia (nearly 43%, p < 0.01) and metabolic syndrome (35%, p < 0.01). They also had higher values of homeostatic model assessment for insulin resistance, oxidized low-density lipoprotein, and triglycerides:high-density lipoprotein cholesterol ratio, regardless of interfering factors. There were no associations of highest white meat tertile (≥39.4 g/d) and saturated fatty acid from white meat (≥1.0 g/d) consumption with the assessed parameters (p > 0.05). Conclusions Red meat consumption was cross-sectionally associated with the occurrence of central obesity, hypertriglyceridaemia, and metabolic syndrome as well as with higher homeostatic model assessment for insulin resistance, oxidized low-density lipoprotein concentrations and triglycerides:high-density lipoprotein cholesterol ratio. The content of saturated fatty acid from red meat consumption may be a factor that contributed to this relationship, while white meat consumption was not associated with metabolic syndrome and the assessed biomarkers.

Benefits and relationship of steps walked per day to cardiometabolic risk factor in Brazilian middle-aged men

OBJECTIVES We evaluated the benefits and relationship of the number of steps per day to the cardiometabolic risk factors: adiposity indicators; insulin resistance; and metabolic syndrome (MetS) in apparently healthy Brazilian middle-aged men. DESIGN Cross-sectional. METHODS Apparently healthy men (age: 50 ± 5 years; n=299) were studied. The number of steps per day was measured by pedometer. The adiposity indicators (waist circumference, total body fat, android and gynoid body fat), serum insulin, glucose and triglycerides, triglycerides/high-density lipoprotein cholesterol (HDL-c) ratio, homeostasis model assessment of insulin resistance (HOMA-IR) and MetS were assessed. Subjects were placed in groups to reflect different levels of steps per day (average of 7 consecutive days): Group 1<10,000 and Group 2 ≥ 10,000. Relationships among variables were measured by multiple linear regressions and the Spearman correlation coefficient as appropriate (p<0.05). RESULTS The cardiometabolic risk factors were lower (p<0.05) in Group 2 than in Group 1. The number of steps per day was a negative predictive factor for total body fat, android and gynoid body fat and HOMA-IR independent of age, working position, android fat, overweight/obesity prevalence, and triglycerides/HDL-c ratio. Moreover, there was a negative correlation between the number of steps and total body fat, android and gynoid body fat, HOMA-IR and MetS. CONCLUSIONS Brazilian middle-aged men performing more than 10,000 steps per day have better cardiometabolic conditions than those walking fewer than 10,000 steps. The number of steps per day is inversely related to the indicators of total and regional adiposity, insulin resistance and MetS.

Consumption of branched-chain amino acids is inversely associated with central obesity and cardiometabolic features in a population of Brazilian middle-aged men: Potential role of leucine intake

ObjectiveTo assess the potential associations of branched-chain amino acids (BCAA) consumption with central obesity (CObesity) and cardiometabolic risk factors in a population of Brazilian middle-aged men. Special attention was given to leucine intake.DesignCross-sectional study.SettingUniversidade Federal de Viçosa, Viçosa, Brazil.ParticipantsTwo-hundred ninety-six middle-aged men (Age: 50.5 ± 5.0 years; Body mass index: 25.8 ± 3.5 kg/m2).MeasurementsAnthropometry, lifestyle features, blood biochemical parameters were assessed and dietary intake was estimated by a food frequency questionnaire. Participants were classified by the occurrence of CObesity, hypertriglyceridemia (HTG), hypertriglyceridemic waist phenotype (HWP) and metabolic syndrome (MetS).ResultsSubjects in the BCAA highest tertile (≥0.17 g/kg/d) presented lower occurrence of CObesity (36.0% vs 72.4%, P<0.01, z=−5.10), HTG (17.0% vs 30.6% P<0.032, z=−2.32), HWP (23.0% vs 46.9%, P<0.01, z=−3.57) and MetS (19.0% vs 34.7%, P<0.01, z=−2.57). They also exhibited lower values for Castelli index (total cholesterol:HDL-c) and triglycerides: HDL-c ratio than those in the first tertile, regardless of interfering factors (i.e. habitual physical activity, work position, smoking habit, and energy intake). Interestingly, leucine consumption showed similar associations with cardiometabolic risk factors, as compared to BCAA consumption (P<0.05).ConclusionBCAA consumption was cross-sectionally and negatively associated with relevant cardiometabolic risk factors in a population of Brazilian middle-aged men. The content of leucine in BCAA consumption may have contributed to such relationship.

Accuracy of plasma interleukin-18 and adiponectin concentrations in predicting metabolic syndrome and cardiometabolic disease risk in middle-age Brazilian men.

The aims of this cross-sectional study were to explore the ability of serum interleukin 18 (IL-18) and adiponectin to identify metabolic syndrome (MetS), and to verify their association with an index of central lipid overaccumulation (lipid accumulation product (LAP)) and cardiometabolic risk factors in a population of middle-aged Brazilian men. A group of 218 apparently healthy middle-aged Brazilian men (age, 50.3 ± 4.97 years) underwent anthropometric, clinical, sociodemographic, and standard serum biochemical assessments. LAP was calculated and the study participants were categorized into 3 groups according to serum IL-18 and adiponectin cut-points tertiles to verify the association of these biomarkers with cardiometabolic risk factors. The MetS group had more less active (p = 0.03) and obese (p < 0.01) individuals who exhibited higher IL-18 (p < 0.01) and lower adiponectin (p < 0.01) than did those in the group with no MetS. After adjustments (age, smoking, alcohol consumption, physical activity level, and total body fat), serum IL-18 ≥ 336.4 pg/mL was an independent factor for MetS occurrence and it was directly associated with LAP (≥51.28), central obesity, hypertriglyceridemia, and hypertension (p < 0.05), but not with high-density lipoprotein cholesterol (HDL-C). Serum adiponectin ≥ 7.02 μg/mL was negatively associated with MetS occurrence, LAP, hypertriglyceridemia, and low HDL-C (p < 0.05), but not with central obesity and hypertension. In conclusion, both IL-18 and adiponectin demonstrated the ability to identify MetS in this population, with IL-18 being more accurate. The association of these biomamarkers with LAP and cardiometabolic risk factors highlights its relevance as a diagnostic tool.

Usual dietary glycemic load is associated with cardiometabolic risk factors in physically active Brazilian middle-aged men

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 triglyce rides/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.

Levels of adiponectin and exercise: associations with insulin sensitivity

El objetivo de esta revision fue presentar y discutir la influencia del ejercicio sobre las concentraciones sericas de adiponectina y su asociacion con sensibilidad a la insulina. Los estudios realizados en los ultimos 10 anos muestran que el ejercicio agudo de alta intensidad causa una reduccion en las concentraciones sanguineas de adiponectina, sin cambiar las concentraciones de insulina. Sin embargo, el ejercicio agudo de intensidad moderada no altera las concentraciones sanguineas de adiponectina, aunque proporciona sensibilidad a la insulina. Ejercicio cronico, a su vez, aumenta los niveles sanguineos de adiponectina mejora la sensibilidad a la insulina, sino que altera la composicion corporal en sujetos obesos. En individuos normales, sin embargo, los niveles de adiponectina no se ven afectados, a pesar de los beneficios del ejercicio cronica de la composicion corporal y la sensibilidad a la insulina.

Taxa metabólica de repouso de ciclistas estimada por equações e obtida por calorimetria indireta

The resting metabolic rate (RMR) can be determined by indirect calorimetry (IC). However, the clinical estimation of this parameter has been done using mathematical equations, which were developed in studies involving non-athletes. Although some authors have indicated that such equations do not estimate correctly the RMR, they have been constantly used to estimate such parameter and to prescribe diets, including for athletes. The objective of this study was to compare the RMR determined by IC with the ones estimated using the equations proposed by Harris & Benedict (HB), Schofield, FAO/WHO/UNU and Henry & Rees (HR), in 15 male cyclists, aged 24.4±3.68 years, body mass index of 21.97±1.46 kg/m2 and VO2max of 70.00±5.32 mL(kg.min)-1. Students t test (when data presented normal distribution) and Mann-Whitney (when data did not present normal distribution) were used to compare the RMR determined by IC and the ones estimated by the equations. Probability values below 0.05 were considered statistically significant. Pearson bivariate correlation coefficients were calculated to evaluate the relationship between RMR and fat free mass (FFM). It was verified that the RMR was significantly underestimated in 23.5%, 16.7%, 16.8% and 16.9%, respectively by the equations proposed by HR, FAO/WHO/UNU, Schofield and HB in comparison to RMR obtained by IC. RMR values were significantly correlated with FFM (r=0.551, p=0.03). These results confirm that the equations evaluated in this study are not appropriate to estimate the RMR of athletes. Such results can be explained by the fact that athletes have more FFM and possibly a greater β- adrenergic receptors response to the sympathetic nervous system, which in turn leads to RMR higher than in sedentary people. Therefore, we created an equation considering the FFM and age variables to better estimate athletes´ RMR. However, this equation should be validated in a study involving a greater number of cyclists before it can be clinically used.

Los niveles de adiponectina y el ejercicio: asociaciones con sensibilidad a la insulina

El objetivo de esta revision fue presentar y discutir la influencia del ejercicio sobre las concentraciones sericas de adiponectina y su asociacion con sensibilidad a la insulina. Los estudios realizados en los ultimos 10 anos muestran que el ejercicio agudo de alta intensidad causa una reduccion en las concentraciones sanguineas de adiponectina, sin cambiar las concentraciones de insulina. Sin embargo, el ejercicio agudo de intensidad moderada no altera las concentraciones sanguineas de adiponectina, aunque proporciona sensibilidad a la insulina. Ejercicio cronico, a su vez, aumenta los niveles sanguineos de adiponectina mejora la sensibilidad a la insulina, sino que altera la composicion corporal en sujetos obesos. En individuos normales, sin embargo, los niveles de adiponectina no se ven afectados, a pesar de los beneficios del ejercicio cronica de la composicion corporal y la sensibilidad a la insulina.

Concentrações sanguíneas de adiponectina e exercício físico: associações com a sensibilidade insulínica

El objetivo de esta revision fue presentar y discutir la influencia del ejercicio sobre las concentraciones sericas de adiponectina y su asociacion con sensibilidad a la insulina. Los estudios realizados en los ultimos 10 anos muestran que el ejercicio agudo de alta intensidad causa una reduccion en las concentraciones sanguineas de adiponectina, sin cambiar las concentraciones de insulina. Sin embargo, el ejercicio agudo de intensidad moderada no altera las concentraciones sanguineas de adiponectina, aunque proporciona sensibilidad a la insulina. Ejercicio cronico, a su vez, aumenta los niveles sanguineos de adiponectina mejora la sensibilidad a la insulina, sino que altera la composicion corporal en sujetos obesos. En individuos normales, sin embargo, los niveles de adiponectina no se ven afectados, a pesar de los beneficios del ejercicio cronica de la composicion corporal y la sensibilidad a la insulina.