Roberta Hack Mendes

Moderate hyperhomocysteinemia provokes dysfunction of cardiovascular autonomic system and liver oxidative stress in rats

Hyperhomocysteinemia (HHcy) is associated with cardiovascular disease, atherosclerosis and reactive oxygen species generation. Thus, our aim was to investigate whether there was an association between HHcy, blood pressure, autonomic control and liver oxidative stress. Male Wistar rats were divided into 2 groups and treated for 8weeks: one group (control, CO) received tap water, while the other group (methionine, ME) was given a 100mg/kg of methionine in water by gavage. Two catheters were implanted into the femoral artery and vein to record arterial pressure (AP) and heart rate (HR) and drug administration. Signals were recorded by a data acquisition system. Baroreflex sensitivity was evaluated by HR responses to AP changes induced by vasoactive drugs. HR variability and AP variability were performed by spectral analysis in time and frequency domains to evaluate the contribution of the sympathetic and parasympathetic modulation. Lipid peroxidation and antioxidant enzyme activities were evaluated by measuring superoxide dismutase, catalase and glutathione peroxidase in liver homogenates. The ME group presented a significant increase in systolic arterial pressure (118±9 vs 135±6mmHg), diastolic arterial pressure (81±6 vs. 92±4) and mean arterial pressure (95±7 vs. 106±6). In addition, pulse interval variability presented a significant decrease (41%), while the low frequency component of AP was significantly increased (delta P=6.24mmHg(2)) in the ME group. We also found a positive association between lipid peroxidation and cardiac sympathetic modulation, sympathetic and vagal modulation ratio and systolic pressure variability. Collectively, these findings showed that HHcy induced dysfunction of cardiovascular autonomic system and liver oxidative stress.

Blood Pressure Variation Throughout Pregnancy According to Early Gestational BMI: A Brazilian Cohort

Background The maternal cardiovascular system undergoes progressive adaptations throughout pregnancy, causing blood pressure fluctuations. However, no consensus has been established on its normal variation in uncomplicated pregnancies. Objective To describe the variation in systolic blood pressure (SBP) and diastolic blood pressure (DBP) levels during pregnancy according to early pregnancy body mass index (BMI). Methods SBP and DBP were measured during the first, second and third trimesters and at 30-45 days postpartum in a prospective cohort of 189 women aged 20-40 years. BMI (kg/m2) was measured up to the 13th gestational week and classified as normal-weight (<25.0) or excessive weight (≥25.0). Longitudinal linear mixed-effects models were used for statistical analysis. Results A decrease in SBP and DBP was observed from the first to the second trimester (βSBP=-0.394; 95%CI: -0.600- -0.188 and βDBP=-0.617; 95%CI: -0.780- -0.454), as was an increase in SBP and DBP up to 30-45 postpartum days (βSBP=0.010; 95%CI: 0.006-0.014 and βDBP=0.015; 95%CI: 0.012-0.018). Women with excessive weight at early pregnancy showed higher mean SBP in all gestational trimesters, and higher mean DBP in the first and third trimesters. Excessive early pregnancy BMI was positively associated with prospective changes in SBP (βSBP=7.055; 95%CI: 4.499-9.610) and in DBP (βDBP=3.201; 95%CI: 1.136-5.266). Conclusion SBP and DBP decreased from the first to the second trimester and then increased up to the postpartum period. Women with excessive early pregnancy BMI had higher SBP and DBP than their normal-weight counterparts throughout pregnancy, but not in the postpartum period.

Nutritional status, lipid profile and HOMA-IR in post-liver transplant patients

INTRODUCTION A high prevalence of overweight, obesity, diabetes and dyslipidemia has been reported following liver transplantation (LT). Although these conditions are known to induce an increased risk for cardiovascular events, which are among the major causes of death in post-LT patients, much debate remains in the literature regarding the applicability of different nutritional assessments methods to this population. OBJECTIVE To assess the nutritional status, lipid profile, homeostatic model assessment of insulin resistance (HOMA-IR) and dietary intake adequacy in the post-LT period. METHODS Cross-sectional study of patients after a maximum of 2 years post-LT, involving the assessment of body mass index (BMI), percent weight loss, arm (AC) and arm muscle circumference (AMC), triceps skinfold (TSF), neck (NC) and waist (WC) circumference, lipid profile, HOMA-IR and percent adequacy of dietary intake. RESULTS In the group of 36 patients, 61.1% were male, mean age 53.2 years (± 10.6). Severe weight loss was noted in 66.7% of patients. Most individuals were eutrophic according to BMI, AC and AMC, while TSF showed malnutrition, NC demonstrated overweight and WC showed metabolic risk. Dyslipidemia was diagnosed in 87.5% of patients, and insulin resistance in 57% of the patients. Most patients had adequate dietary intake, although the time since transplant was positively correlated with AC (r = 0.353; p = 0.035) and negatively correlated with vitamin A intake (r = - 0.382; p = 0.022), with the caloric adequacy (r = -0.338; p = 0.044) and vitamin A adequacy (r = -0.382; p = 0.021). CONCLUSION Although anthropometry provided somewhat variable nutritional diagnoses, when combined with biochemical tests, findings showed the prevalence of cardiovascular risk. As such, patients should be provided with transdisciplinary assistance, and strategies should be developed so as to reduce the risk factors recorded in this population.

High cholesterol dietary intake during pregnancy is associated with large for gestational age in a sample of low-income women of Rio de Janeiro, Brazil.

The association between the quality of maternal dietary fat intake during pregnancy and the infants birthweight (BW) remains controversial. Our goal was to investigate the association between maternal dietary fat intake during pregnancy and the rate of large for gestational age (LGA) newborns. This study employed a cross-sectional analysis of 297 pairs of mothers/children attending a public maternity at Rio de Janeiro, Brazil. BW for gestational age according to the Intergrowth 21st was defined as follows: adequate for gestational age (AGA ≤ 90th percentile) and LGA (>90th percentile). The statistical analysis was a Poisson regression with robust estimations of the standard errors. Maternal dietary fat intake variables comprised lipids (% total energy); saturated (mg/1000 kcal), monounsaturated (mg/1000 kcal) and polyunsaturated (mg/1000 kcal) fats; and cholesterol (mg/1000 kcal), all of which were obtained with a Food Frequency Questionnaire. The mean BW was 3338 g (SD = 446.9), and the rate of LGA newborns was 13.1%. The mean maternal total energy intake was 2880 kcal (SD = 1074), cholesterol was 154.3 mg/1000 kcal (SD = 68.1) and monounsaturated fat was 6.9 mg/1000 kcal (SD = 2). Mothers of LGA newborns reported higher cholesterol dietary intake (195.8 vs. 148 mg/1000 kcal; P < 0.001), pre-pregnancy body mass index (25.1 vs. 23.5 kg/m2 ; P = 0.026) when compared with mothers of AGA newborns. Women with cholesterol intake within the fourth quartile were 2.48 (95% confidence interval: 1.31-4.66) times more likely to have an LGA infant compared with those in the 1-3 quartiles. Dietary intake of cholesterol during pregnancy influences LGA even after adjusting for other confounders.

Hepatic, renal and inflammatory biomarkers are positively associated with blood pressure changes in healthy pregnant women: a prospective cohort.

AbstractThis article evaluates the association of hepatic, renal, and inflammatory biomarkers with changes in systolic (SBP) and diastolic (DBP) blood pressure (BP) during healthy pregnancies.A prospective cohort study with 225 healthy pregnant women was conducted in Rio de Janeiro, Brazil. SBP and DBP were evaluated throughout pregnancy (5th–13th, 20th–26th, and 30th–36th gestational weeks) and were the outcomes. The following biomarkers were measured at the first trimester and analyzed according to tertiles of the sample distribution and were considered the main independent predictors: alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), uric acid (UA), creatinine (Cr), and C-reactive protein (CRP) concentrations. The statistical analysis included 3 stages of modeling with the longitudinal linear mixed-effects procedures: Model 1 was adjusted for gestational age and quadratic gestational age; Model 2 included interactions between the biomarkers and gestational age; and Model 3 was adjusted for self-reported skin color, education, parity, early-pregnancy body mass index (BMI) (under/normal <25; overweight/obese ≥25 kg/m2), smoking habit, and leisure-time physical activity. Additional models were performed for CRP and UA with the inclusion of interaction terms between the biomarkers and BMI.Women classified in the third tertile of the ALP (≥61.1 U/L; &bgr;SBP = 3.474; 95% confidence interval [CI]: 0.955–5.992; &bgr;DBP = 3.291; 95% CI: 1.098–5.485), ALT (≥14.3 U/L; &bgr;SBP = 2.232; 95% CI: 0.221–4.242; &bgr;DBP = 2.355; 95% CI: 0.721–3.989), and Cr values (≥48.6 &mgr;mol/L; &bgr;DBP = 1.927; 95% CI: 0.347–3.508) presented higher BP levels during pregnancy compared to those in the first and second tertiles. Women in the highest tertile of the ALP concentration distribution presented a lower rate of change in SBP and DBP during pregnancy (interaction term with gestational age &bgr;SBP = −0.004; 95% CI: −0.007 to −0.001; P = 0.02; &bgr;DBP = −0.003; 95% CI: −0.006 to −0.001; P = 0.01). Higher UA concentrations were associated with higher SBP levels only in overweight/obese women (&bgr; = 3.878; 95% CI: 0.687–7.068), whereas higher CRP concentrations (≥2.6 mg/L) were associated with higher DBP in under/normal weight women (&bgr; =2.252; 95% CI: 0.267–4.236).ALP, ALT, and Cr concentrations were positively associated with BP levels, whereas ALP was associated with a lower rate of change in BP. The associations of UA and CRP with BP differ according to the early-pregnancy BMI.

Effects of isolated vitamin B6 supplementation on oxidative stress and heart function parameters in experimental hyperhomocysteinemia

Introduction : The purpose of this study was to investigate the effects of isolated vitamin B 6 (VB 6 ) supplementation on experimental hyperhomocysteinemia (Hhe) induced by homocysteine thiolactone (HcyT). Methods: Fifteen male Wistar rats were divided into three groups according to their treatment. Animals received water and food ad libitum and an intragastric probe was used to administer water for 60 days (groups: CB 6, HcyT, and HB 6 ). On the 30th day of treatment, two groups were supplemented with VB 6 in the drinking water (groups: CB 6 and HB 6 ). After 60 days of treatment, homocysteine (Hcy), cysteine, and hydrogen peroxide concentration, nuclear factor (erythroid-derived 2)-like 2 (NRF2) and glutathione S-transferase (GST) immunocontent, and superoxide dismutase (SOD), catalase (CAT), and GST activities were measured. Results: The HcyT group showed an increase in Hcy concentration (62%) in relation to the CB 6 group. Additionally, GST immunocontent was enhanced (51%) in the HB 6 group compared to the HcyT group. Also, SOD activity was lower (17%) in the HB 6 group compared to the CB 6 group, and CAT activity was higher in the HcyT group (53%) compared to the CB 6 group. Ejection fraction (EF) was improved in the HB 6 group compared to the HcyT group. E/A ratio was enhanced in the HB 6 group compared to the CB 6 group. Correlations were found between CAT activity with myocardial performance index (MPI) (r = 0.71; P = 0.06) and E/A ratio (r = 0.6; P = 0.01), and between EF and GST activity (r = 0.62; P = 0.02). Conclusions: These findings indicate that isolated VB 6 supplementation may lead to the reduction of Hcy concentration and promotes additional benefits to oxidative stress and heart function parameters. Keywords: Homocysteine; oxidative stress; vitamin B 6.

Leptin concentrations and SCD-1 indices in classical homocystinuria: Evidence for the role of sulfur amino acids in the regulation of lipid metabolism

BACKGROUND We describe body composition, lipid metabolism and Stearoyl-CoA desaturase-1 (SCD-1) indices in patients with classical homocystinuria (HCU). METHODS Eleven treated HCU patients and 16 healthy controls were included. Body composition and bone mineral density were assessed by dual X-ray absorptiometry. Sulfur amino acids (SAA) and their derivatives (total homocysteine, cysteine, methionine, S-adenosylmethionine, S-adenosylhomocysteine, and glutathione), lipids (free fatty acids, acylcarnitines, triglycerides and lipoproteins), glucose, insulin, leptin, adiponectin, and isoprostanes were measured in plasma. Insulin resistance was evaluated by HOMA-IR. To estimate liver SCD-1 activity, SCD-16 [16:1(n-7)/16:0] and SCD-18 [18:1(n-9)/18:0] desaturation indices were determined. RESULTS In HCU patients, SCD-16 index was significantly reduced (p=0.03). A trend of an association of SCD-16 index with cysteine was observed (r=0.624, p=0.054). HCU patients displayed lower lean mass (p<0.05), with no differences in fat mass percentage. Leptin and low-density lipoprotein concentrations were lower in HCU patients (p<0.05). Femur bone mineral density Z-scores were correlated with plasma cysteine (r=0.829; p=0.04) and total homocysteine (r=-0.829; p=0.04) in HCU patients. CONCLUSIONS We report alterations in leptin and SCD-1 in HCU patients. These results agree with previous findings from epidemiologic and animal studies, and support a role for SAA on lipid homeostasis.