No abstract

Platelet volume indices (PVI) are associated with hematological and non-hematological diseases, notably cardiovascular and cerebrovascular diseases. The establishment of PVI reference intervals (RIs) are essential to evaluate whether these indices are useful in clinical practice. Healthy-associated RIs have not yet been established for the Brazilian population. Here, we determined RIs of PVI for a health adult population, participants of the Brazilian Longitudinal Study of Adult Health ELSA-Brasil. A total of 580 individuals out of an initial sample of 3115 subjects constituted the healthy reference sample. To be part of the study, individuals had to fulfill the following criteria: blood count within 2 hours of collection, no use of continuous medication, self-rated health as good or very good, no reported diagnosis of diabetes and/or arterial hypertension, not smoking, lack of metabolic syndrome, body mass index (BMI) <30 kg/m(2), and platelet, hemoglobin, and creatinine beyond reference values. The RIs are mean platelet volume (MPV): 8.9-11.8 fL, platelet distribution width (PDW): 9.6-15.3 fL, platelet large cell ratio (P-LCR): 15.6-39.5%. These parameters were not significantly affected by age, gender, smoking, obesity, and alcohol abuse. However, significant differences were found among self-rated race/color groups. Standardization of measurement procedures and the establishment of healthy-associated PVI RIs are essential to be able to support clinical decision-making from laboratorial test results. This study at the baseline of the ELSA Brasil reported herein may contribute to future efforts aiming to evaluate whether PVI values are associated with clinical conditions in the Brazilian population.

Antarctic climate is challenging, since the cold, wind and sensory monotony are stressful stimuli to individuals. Moreover, camp activities and heavy clothes may contribute to increase physiological strain. Thus, we aimed to characterise the physiological demand of a 24-day period in the Antarctic field and then to evaluate the effect of this expedition on the aerobic fitness in individuals with heterogeneous initial aerobic fitness (as determined by estimating maximum oxygen consumption – V̊O2MAX). Before and after the 24-day period in Antarctica, 7 researchers and 2 mountaineers were subjected to incremental tests to estimate their V̊O2MAX. Field effort was characterised by measuring heart rate (HR). During the field trips, their HR remained 33.4% of the recording time between 50–60% HRMAX, 22.3% between 60–70% HRMAX, and only 1.4% between 80 and 90% HRMAX. The changes in estimated V̊O2MAX during the expedition depended on the pre-expedition aerobic fitness. The post-expedition V̊O2MAX increased by 5.9% and decreased by 14.3%in individuals with lower (researchers) and higher (mountaineers) initial V̊O2MAX, respectively. We concluded that physical effort in the Antarctic field is characterised as predominantly of low- to moderate-intensity. This effort represented an effective training load for individuals with lower initial V̊O2MAX, but not for those with higher V̊O2MAX.

BackgroundHigh-sensitivity C reactive protein (hsCRP) has been proposed as a marker of incident cardiovascular disease and vascular mortality, and may also be a marker of non-vascular mortality. However, most evidence comes from either North American or European cohorts. The present proposal aims to investigate the association of hsCRP with the risk of all-cause mortality in a multiethnic Brazilian population.MethodsBaseline data (2008–2010) of a cohort of 14 238 subjects participating in the Brazilian Longitudinal Study of Adult Health were used. hsCRP was assayed with immunochemistry. The association of baseline covariates with all-cause mortality was calculated by Cox regression for univariate model and adjusted for different confounders after a mean follow-up of 8.0±1.1 years. The final model was adjusted for age, sex, self-rated race/ethnicity, schooling, health behaviours and prevalent chronic disease.ResultsThe risk of death increased steadily by quartiles of hsCRP, from 1.45 (95% CI 1.05 to 2.01) in quartile 2 to 1.95 (95% CI 1.42 to 2.69) in quartile 4, compared with quartile 1. Furthermore, the persistence of a significant graded association after the exclusion of deaths in the first year of follow-up suggests that these results are unlikely to be due to reverse causality. Finally, the HR was unaffected by the exclusion of participants who had self-reported medical history of diabetes, cancer and chronic obstructive pulmonary disease.ConclusionsOur study shows that hsCRP level is associated with mortality in a highly admixed population, independent of a large set of lifestyle and clinical variables.

Increased PVI was independently correlated with higher CVD risk based on the FRS, diabetes, and systolic hypertension. Prospective follow up of this cohort is warranted to confirm that PVI is associated with the development of CVD.