Gender-specific relationships between plasma oxidized low-density lipoprotein cholesterol, total antioxidant capacity, and central adiposity indicators.

BACKGROUND: Oxidative stress has a pivotal role in the onset of obesity-related chronic diseases. This study assessed potential gender differences in the associations of adiposity (total vs. central) with oxidative stress markers in healthy young adults. METHODS: This cross-sectional study enrolled 272 subjects (97 males, 175 females; 22 ± 3 years, body mass index 22.0 ± 2.8 kg/m(2)). Body composition, cardiometabolic and lifestyle features, oxidized low-density lipoprotein cholesterol (ox-LDL) concentrations, plasma total antioxidant capacity (TAC), and glutathione peroxidase (GPx) activity in erythrocytes were determined by validated procedures. RESULTS: Compared to women, men had statistically higher concentrations of ox-LDL (61.7 vs. 53.5 U/l, p = 0.022). In analyses with the whole sample, those individuals included in the highest tertile of central adiposity indicators (waist circumference, WC, or waist-to-hip ratio, WHR) presented higher ox-LDL and lower TAC values (p < 0.01), while no statistical differences were found across tertiles of total body fat. WHR values were more strongly associated with ox-LDL and TAC concentrations, compared to other adiposity indicators, with higher slopes for women. Sex differences in ox-LDL concentrations were abolished (p > 0.05) after individual pairing of men and women for WC (53.8 vs. 61.6 U/l, p = 0.225) or WHR (56.1 vs. 56.3 U/l, p = 0.471). No differences were found in GPx values concerning gender or adiposity indicators. CONCLUSIONS: Plasma ox-LDL and TAC values were more strongly influenced by central adiposity indicators (WHR and WC) in women than in men, suggesting that the change of the gynoid to android pattern phenotype among young women could lead to a steeper unfavourable redox status compared to men.

Contribution of gender and body fat distribution to inflammatory marker concentrations in apparently healthy young adults.

OBJECTIVE: This cross-sectional study assessed the potential contribution of gender, body fat distribution, and their interactions to some inflammatory marker concentrations [C-reactive protein (CRP), complement factor 3 (C3), and ceruloplasmin (Cp)] in young adults. METHODS: Measurements included body composition, lifestyle features, blood biochemical and selected inflammatory markers on 317 healthy subjects [122 males/195 females; 22 ± 3 years; 22.1 ± 2.8 kg/m(2) (mean ± SD)]. RESULTS: Women had significantly higher CRP and Cp concentrations than men. No gender difference was noted in C3 concentrations. In a multivariate model of the whole sample, body fat (BF), waist circumference (WC) and the sex × WC interaction term presented the highest R (2) for variance of CRP (11%), C3 (2%), and Cp (12%), respectively. In regression models separated by sex, BF was the adiposity indicator that explained the variability of CRP in men (13%) and women (7%). WC was the only variable significantly associated with C3 concentrations in women (3%). BF presented the highest partial R (2) for Cp in men (8%) and WC in women (16%). CONCLUSION: Our findings indicate a relevant interaction between gender and body fat distribution on the variance of CRP, C3, and Cp concentrations in apparently healthy young adults.

Vitamin C and fibre consumption from fruits and vegetables improves oxidative stress markers in healthy young adults.

The aim of the present cross-sectional study was to assess the potential relationships between fruit and vegetable (FV) consumption and some oxidative stress markers in young adults, with particular emphasis on fibre and vitamin C intake. The study enrolled 246 healthy subjects (eighty-eight men and 158 women), with a mean age of 22 (sd 3) years and a mean BMI of 21·9 (sd 2·8) kg/m2. Dietary intake, anthropometry, blood pressure, lifestyle features and blood biochemical data were assessed with validated procedures. Those subjects in the highest tertile (T) of FV consumption ( ≥ 705 g/d) had statistically lower oxidised LDL (ox-LDL) concentrations as well as higher plasma total antioxidant capacity (TAC) and glutathione peroxidase (GPx) activity (P for trend <0·05), after adjusting for sex, age, energy intake, physical activity, smoking, BMI, vitamin supplement use and other confounding factors. Moreover, plasma ox-LDL concentrations showed a decreasing trend and TAC an increasing trend across tertiles of fibre (T3: ≥14 g/d) and vitamin C (T3: ≥150 mg/d) from FV intake, while GPx activity was positively associated with vitamin C intake (P for trend < 0·05). In conclusion, greater FV consumption was independently associated with reduced ox-LDL as well as increased TAC and GPx activity in healthy young adults, with dietary fibre and vitamin C from FV clearly being implicated in this beneficial relationship.

Dietary total antioxidant capacity is inversely related to central adiposity as well as to metabolic and oxidative stress markers in healthy young adults.

BACKGROUND: Dietary total antioxidant capacity (TAC) has been assumed as a useful tool to assess the relationship between the cumulative antioxidant food capacity and several chronic disorders. The aim of this cross-sectional study was to investigate the potential relationships of dietary TAC with adiposity, metabolic and oxidative stress markers in healthy young adults. METHODS: This study enrolled 266 healthy subjects (105 men/ 161 women; 22 ± 3 years-old; 22.0 ± 2.7 kg/m2). Dietary intake, anthropometry, blood pressure, lifestyle features, and biochemical data were assessed with validated procedures. RESULTS: In linear regression analyses, dietary TAC values were inversely associated with glycemia, total cholesterol:HDL-c ratio, triglycerides and oxidized-LDL concentrations, and positively associated with HDL-c concentrations, independently of gender, age, smoking status, physical activity, vitamin use supplement, waist circumference, energy intake, fatty acid intake. In addition, plasma TAC was negatively correlated with ox-LDL concentrations (r= -0.20, P = 0.003), independently of the assessed confounding variables. Finally, dietary TAC values were inversely related to waist circumference values (r= -0.17, P = 0.005) as well as to lower mild central obesity occurrence (waist circumference ≥ 80/ 94 cm for women/ men, respectively). CONCLUSION: Dietary TAC values are inversely associated with glucose and lipid biomarkers as well as with central adiposity measurements in healthy young adults, indicating dietary TAC as a useful tool to assess the health benefits of cumulative antioxidant capacity from food intake. In addition, the independent and inverse relationships of ox-LDL concentrations with dietary and plasma TAC respectively suggest a putative role of antioxidant rich-diet in the link between redox state and atherogenesis at early stage.

Relationship of oxidized low density lipoprotein with lipid profile and oxidative stress markers in healthy young adults: a translational study.

BACKGROUND: Despite oxidized low density lipoprotein (ox-LDL) plays important roles in the pro-inflammatory and atherosclerotic processes, the relationships with metabolic and oxidative stress biomarkers have been only scarcely investigated in young adult people. Thus, the aim of this study was to assess plasma ox-LDL concentrations and the potential association with oxidative stress markers as well as with anthropometric and metabolic features in healthy young adults. METHODS: This study enrolled 160 healthy subjects (92 women/68 men; 23±4 y; 22.0±2.9 kg/m2). Anthropometry, body composition, blood pressure, lifestyle features, biochemical data, and oxidative stress markers were assessed with validated tools. Selenium, copper, and zinc nail concentrations were measured by atomic absorption spectrophotometry. RESULTS: Total cholesterol (TC), LDL-c and uric acid concentrations, TC-to-HDL-c ratio, and glutathione peroxidase (GPx) activity were positive predictors of ox-LDL concentrations, while nail selenium level (NSL) was a negative predictor, independently of gender, age, smoking status, physical activity. Those individuals included in the highest tertile of GPx activity (≥611 nmol/[mL/min]) and of NSL (≥430 ng/g of nail) had higher and lower ox-LDL concentrations, respectively, independently of the same covariates plus truncal fat or body mass index, and total cholesterol or LDL-c concentrations. CONCLUSIONS: Ox-LDL concentrations were significantly associated with lipid biomarkers, GPx activity, uric acid concentration, and NSL, independently of different assayed covariates, in young healthy adults. These findings jointly suggest the early and complex relationship between lipid profile and redox status balance.

[Effect of diet macronutrients profile on leptin concentration]. / Efeito do perfil de macronutrientes da dieta na leptinemia.

The aim of this study was to investigate the effect of ingesting high-sucrose (HSD) and high-lipid diets (HLD) on the concentrations of plasma glucose and leptin in lean and overweight women. Twenty healthy women were selected: 13 lean (G1) and 7 overweight (G2). The test diets HSD (23% sucrose) and HLD (45% lipid) were calculated for intake under non-restrictive conditions during 14 days. Anthropometry, body composition, plasma glucose and leptin determinations were carried out. The fasting and postprandial plasma leptin values were higher in G2 (p< 0.05), correlating positively with the anthropometry and body composition data (p< 0.05), and special positive correlation with hip circumference. Glucose and leptin concentrations did not differ between diets. Circulating glucose 30 (p< 0.01) and 60 (p< 0.05) minutes after ingestion of HSD were positively correlated with postprandial leptin concentration. The results confirm the positive association between plasma leptin concentration and body fat, specifically the subcutaneous fat tissue, and suggest that more studies are necessary to identify the modulating role of energy intake and macronutrients profile on leptin concentration.

Efeito do perfil de macronutrientes da dieta na leptinemia / Effect of diet macronutrients profile on leptin concentration / Effect of diet macronutrients profile on leptin concentration

O presente estudo teve como objetivo investigar o efeito da ingestão de dietas ricas em sacarose (DRS) e em lipídio (DRL) nas concentrações de glicose e leptina plasmáticas. Foram selecionadas 20 mulheres hígidas, 13 com peso normal (G1) e 7 com sobrepeso (G2). As dietas testes DRS (23,0 por cento de sacarose) e DRL (45,0 por cento de lipídio) foram calculadas para consumo em condições de vida livre, por 14 dias. Foram realizadas determinações de antropometria, de composição corporal, de glicose e leptina plasmáticas. Os valores de leptina plasmática de jejum e pós-prandiais foram maiores em G2 (p< 0,05) e correlacionaram-se positivamente com os dados antropométricos e de composição corporal (p< 0,05), destacando-se sua correlação positiva com a circunferência do quadril. As concentrações de glicose e leptina de jejum e pós-prandiais não diferiram entre as dietas. A glicemia nos tempos de 30 (p< 0,01) e 60 (p< 0,05) minutos após a ingestão de DRS correlacionou-se positivamente com a leptinemia pós-prandial. Os resultados confirmam a relação positiva entre a leptinemia e a gordura corporal, especificamente com o tecido adiposo subcutâneo e indicam que mais estudos são necessários para identificar o papel modulador da ingestão energética e do perfil de macronutrientes na leptinemia.

The aim of this study was to investigate the effect of ingesting high-sucrose (HSD) and high-lipid diets (HLD) on the concentrations of plasma glucose and leptin in lean and overweight women. Twenty healthy women were selected: 13 lean (G1) and 7 overweight (G2). The test diets HSD (23 percent sucrose) and HLD (45 percent lipid) were calculated for intake under non-restrictive conditions during 14 days. Anthropometry, body composition, plasma glucose and leptin determinations were carried out. The fasting and postprandial plasma leptin values were higher in G2 (p< 0.05), correlating positively with the anthropometry and body composition data (p< 0.05), and special positive correlation with hip circumference. Glucose and leptin concentrations did not differ between diets. Circulating glucose 30 (p< 0.01) and 60 (p< 0.05) minutes after ingestion of HSD were positively correlated with postprandial leptin concentration. The results confirm the positive association between plasma leptin concentration and body fat, specifically the subcutaneous fat tissue, and suggest that more studies are necessaries to identify the modulating role of energy intake and macronutrients profile on leptin concentration.