Impact of an active lifestyle on heart rate variability and oxidative stress markers in offspring of hypertensives.

Familial history of hypertension is associated with autonomic dysfunction and increase in blood pressure (BP). However, an active lifestyle has been found to improve a number of health outcomes and reduce all-cause mortality. The aim of the present study was to investigate the effects of an active lifestyle on hemodynamics, heart rate variability (HRV) and oxidative stress markers in offspring of hypertensive parents. One hundred twenty-seven subjects were assigned into four groups: sedentary offspring of normotensives (S-ON) or hypertensives (S-OH); and physically active offspring of normotensives (A-ON) or hypertensives (A-OH). Diastolic BP and heart rate were reduced in the physically active groups when compared to S-OH group. A-ON and A-OH groups presented increased values of RR total variance when compared to the sedentary ones (A-ON: 4,912 ± 538 vs. S-ON: 2,354 ± 159; A-OH: 3,112 ± 236 vs. S-OH: 2,232 ± 241 ms2). Cardiac sympato-vagal balance (LF/HF), systemic hydrogen peroxide and superoxide anion were markedly increased in S-OH group when compared to all other studied groups. Additionally, important correlations were observed between LF/HF with diastolic BP (r = 0.30) and hydrogen peroxide (r = 0.41). Thus, our findings seem to confirm an early autonomic dysfunction in offspring of hypertensive parents, which was associated with a systemic increase in reactive oxygen species and blood pressure. However, our most important finding lies in the attenuation of such disorders in offspring of physically active hypertensives, thus emphasizing the importance of a physically active lifestyle in the prevention of early disorders that may be associated with onset of hypertension.

Prevalence and associated factors for asthma in Brazilian and Japanese schoolchildren living in the city of São Paulo, Brazil.

OBJECTIVES: Ethnic background interferes on the prevalence of asthma among schoolchildren (4 to 9 years old, SC) born and living in São Paulo, Brazil. METHODS: International Study of Asthma and Allergy in Childhood (ISAAC)'s written standard and complementary questionnaires were applied to SC (similar socioeconomic status) living in the city of São Paulo: no-Japanese Brazilian (NJB, N = 306) and Japanese Brazilian (third generation, born in Brazil, from Japanese families with no miscegenation, JB, N = 258). RESULTS: The prevalence of current asthma was significantly higher among NJB in comparison to JB (22.2% vs 14.7%, respectively). To have rhinitis and to exercise less than once/week were risk factors for both groups of children. CONCLUSION: Although both groups were apparently exposed to the same environment, other cultural differences do not allow us to conclude about the ethnic component having greater influence than the environment in the development of asthma in these individuals.

Variable positive end-expiratory pressure can maintain oxygenation in experimental acute respiratory distress syndrome induced by oleic acid in dogs.

The use of positive end-expiratory pressure (PEEP) or lung recruitment maneuvers (RM) to improve oxygenation in acute respiratory distress syndrome (ARDS) is used but it may reduce cardiac output (CO). Intermittent PEEP may avoid these complications. Our objective was to determine if variable PEEP compared with constant PEEP is capable of maintaining arterial oxygenation and minimizing hemodynamic alterations with or without RM. Eighteen dogs with ARDS induced by oleic acid were randomized into three equal groups: group 1, low variable PEEP; group 2, high variable PEEP, and group 3, RM + high variable PEEP. All groups were submitted to constant PEEP, followed by variable PEEP (PEEP was increased from 5 to 10 cmH(2)O in group 1, and from 5 to 18 cmH(2)O in the other two groups). PaO(2) was higher in group 3 (356.2 +/- 65.4 mmHg) than in group 1 (92.7 +/- 29.7 mmHg) and group 2 (228.5 +/- 72.4 mmHg), P < 0.05. PaO(2) was maintained during variable PEEP except in group 2 (318.5 +/- 82.9 at constant PEEP to 228.5 +/- 72.4 at variable PEEP). There was a reduction in CO in group 3 after RM (3.9 +/- 1.1 before to 2.7 +/- 0.5 L*min(-1)*(m(2))(-1) after; P < 0.05), but there was not any difference between constant and variable PEEP periods (2.7 +/- 0.5 and 2.4 +/- 0.7 L*min(-1)*(m(2))(-1); P > 0.05. Variable PEEP is able to maintain PaO(2) when performed in combination with RM in dogs with ARDS. After RM, CO was reduced and there was no relevant difference between the variable and constant PEEP periods.

Variable positive end-expiratory pressure can maintain oxygenation in experimental acute respiratory distress syndrome induced by oleic acid in dogs

The use of positive end-expiratory pressure (PEEP) or lung recruitment maneuvers (RM) to improve oxygenation in acute respiratory distress syndrome (ARDS) is used but it may reduce cardiac output (CO). Intermittent PEEP may avoid these complications. Our objective was to determine if variable PEEP compared with constant PEEP is capable of maintaining arterial oxygenation and minimizing hemodynamic alterations with or without RM. Eighteen dogs with ARDS induced by oleic acid were randomized into three equal groups: group 1, low variable PEEP; group 2, high variable PEEP, and group 3, RM + high variable PEEP. All groups were submitted to constant PEEP, followed by variable PEEP (PEEP was increased from 5 to 10 cmH2O in group 1, and from 5 to 18 cmH2O in the other two groups). PaO2 was higher in group 3 (356.2 ± 65.4 mmHg) than in group 1 (92.7 ± 29.7 mmHg) and group 2 (228.5 ± 72.4 mmHg), P < 0.05. PaO2 was maintained during variable PEEP except in group 2 (318.5 ± 82.9 at constant PEEP to 228.5 ± 72.4 at variable PEEP). There was a reduction in CO in group 3 after RM (3.9 ± 1.1 before to 2.7 ± 0.5 L·min-1·(m2)-1 after; P < 0.05), but there was not any difference between constant and variable PEEP periods (2.7 ± 0.5 and 2.4 ± 0.7 L·min-1·(m2)-1; P > 0.05. Variable PEEP is able to maintain PaO2 when performed in combination with RM in dogs with ARDS. After RM, CO was reduced and there was no relevant difference between the variable and constant PEEP periods.