Background: Obesity is a chronic disease associated to an inflammatory process resulting in oxidative stress that leads to morpho-functional microvascular damage that could be improved by some dietary interventions. In this study, the intake of Brazil nuts (Bertholletia excelsa), composed of bioactive substances like selenium, α- e γ- tocopherol, folate and polyunsaturated fatty acids, have been investigated on antioxidant capacity, lipid and metabolic profiles and nutritive skin microcirculation in obese adolescents. Methods: Obese female adolescents (n = 17), 15.4 ± 2.0 years and BMI of 35.6 ± 3.3 kg/m², were randomized 1:1 in two groups with the diet supplemented either with Brazil nuts [BNG, n = 08, 15-25 g/day (equivalent to 3 to 5 units/day)] or placebo [PG (lactose), n = 09, one capsule/day] and followed for 16 weeks. Anthropometry, metabolic-lipid profiles, oxidative stress and morphological (capillary diameters) and functional [functional capillary density, red blood cell velocity (RBCV) at baseline and peak (RBCV_max) and time (TRBCV_max) to reach it during post-occlusive reactive hyperemia, after 1 min arterial occlusion] microvascular variables were assessed by nailfold videocapillaroscopy at baseline (T0) and after intervention (T1). Results: T0 characteristics were similar between groups. At T1, BNG (intra-group variation) had increased selenium levels (p = 0.02), RBCV (p = 0.03) and RBCV_max (p = 0.03) and reduced total (TC) (p = 0.02) and LDL-cholesterol (p = 0.02). Compared to PG, Brazil nuts intake reduced TC (p = 0.003), triglycerides (p = 0.05) and LDL-ox (p = 0.02) and increased RBCV (p = 0.03). Conclusion: Brazil nuts intake improved the lipid profile and microvascular function in obese adolescents, possibly due to its high level of unsaturated fatty acids and bioactive substances. Trial Registration: Clinical Trials.gov NCT00937599

Microcirculation influences peripheral vascular resistance and therefore contributes to arterial blood pressure. The aim of this study was to investigate the correlation between serum markers of inflammation and microcirculatory parameters observed by nailfold videocapillaroscopy (NVC) in patients with resistant (RH, 58 [50–63] years, n = 25) or mild-to-moderate hypertension (MMH, 56 [47–64] years, n = 25) compared to normotensive patients (control group (CG), 33 [27–52] years, n = 25). C-reactive protein (CRP), endothelin, adiponectin, I-CAM and V-CAM levels were obtained by laboratory analysis. Functional capillary density (FCD; the number of capillaries with flowing red blood cells by unit tissue area), capillary diameters, maximum red blood cell velocity (RBCV_max) during the reactive hyperemia response/RBCV_baseline after 1 min of arterial occlusion at the finger base and time to reach RBCV_max were determined by NVC. A sub-analysis was also conducted on hypertensive patients not taking statins, with controlled/uncontrolled blood pressure. The RH group showed lower RBCV and RBCV_max values and longer TRBCV_max compared to MMH and CG patients, with worse values in those with uncontrolled blood pressure. FCD and diameters showed no significant differences among the three groups, with higher CRP values in the RH and MMH groups. An increase in endothelin was observed only in patients not taking statins in both hypertensive groups. Patients with severe hypertension and uncontrolled blood pressure levels presented more pronounced microvascular dysfunction, as well as higher serum values for CRP and endothelin (without statin treatment), suggesting that the use of statins decreases endothelin release.

Background: We aimed to evaluate the multivariate association between functional microvascular variables and clinical-laboratorial-anthropometrical measurements.Methods: Data from 189 female subjects (34.0±15.5 years, 30.5±7.1 kg/m²), who were non-smokers, non-regular drug users, without a history of diabetes and/or hypertension, were analyzed by principal component analysis (PCA). PCA is a classical multivariate exploratory tool because it highlights common variation between variables allowing inferences about possible biological meaning of associations between them, without pre-establishing cause-effect relationships. In total, 15 variables were used for PCA: body mass index (BMI), waist circumference, systolic and diastolic blood pressure (BP), fasting plasma glucose, levels of total cholesterol, high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), triglycerides (TG), insulin, C-reactive protein (CRP), and functional microvascular variables measured by nailfold videocapillaroscopy. Nailfold videocapillaroscopy was used for direct visualization of nutritive capillaries, assessing functional capillary density, red blood cell velocity (RBCV) at rest and peak after 1 min of arterial occlusion (RBCV_max), and the time taken to reach RBCV_max(TRBCV_max).Results: A total of 35% of subjects had metabolic syndrome, 77% were overweight/obese, and 9.5% had impaired fasting glucose. PCA was able to recognize that functional microvascular variables and clinical-laboratorial-anthropometrical measurements had a similar variation. The first five principal components explained most of the intrinsic variation of the data. For example, principal component 1 was associated with BMI, waist circumference, systolic BP, diastolic BP, insulin, TG, CRP, and TRBCV_maxvarying in the same way. Principal component 1 also showed a strong association among HDL-c, RBCV, and RBCV_max, but in the opposite way. Principal component 3 was associated only with microvascular variables in the same way (functional capillary density, RBCV and RBCV_max). Fasting plasma glucose appeared to be related to principal component 4 and did not show any association with microvascular reactivity.Conclusions: In non-diabetic female subjects, a multivariate scenario of associations between classic clinical variables strictly related to obesity and metabolic syndrome suggests a significant relationship between these diseases and microvascular reactivity.