RESUMO

OBJECTIVE: To investigate the cardiovascular effects produced by transthoracic application of low-intensity pulsed ultrasound therapy (LIPUST). METHODS: Three-month-old male Wistar rats (± 300 g, N=16) were randomly allocated in two groups, namely SHAM (control group, faked procedures) and UST (animals treated with LIPUST). These animals, under anesthesia, were instrumented (femoral artery and vein catheterization) for hemodynamic recordings (mean blood pressure [MBP], heart rate [HR]) and blood biochemical profile (lipids, creatine kinase-myocardial band [CK-MB]). Then, LIPUST (spatial average-temporal average [ISATA] 1-MHz, power 0.1 to 1.2 W/cm2, pulsed 2:8 ms, cycle at 30%, for three minutes) was applied to animals from the UST group, externally to their thorax. SHAM animals were equally manipulated, but without application of ultrasound energy. After the hemodynamic and biochemical measurements, animals were sacrificed, and their hearts were mounted in a Langendorff apparatus for coronary reactivity evaluation. Standard histology techniques were employed to analyze the hearts. RESULTS: LIPUST application caused statistically significant reductions in MBP (92±4 vs. 106±1 mmHg) and HR (345±14 vs. 380±17 rpm) when compared with SHAM procedures. UST rats exhibited higher CK-MB levels (318±55 vs. 198±26 U/dL) and lower plasma triglycerides levels (38±7 vs. 70±10 mg/dL) than SHAM animals. Coronary reactivity was not significantly changed by LIPUST. Cardiac histopathology showed an increase in capillary permeability in treated animals when compared with SHAM animals. CONCLUSION: Noninvasive LIPUST induces significant metabolic and hemodynamic changes, including intensity-dependent bradycardia and hypotension, indicating a possible therapeutic effect for cardiac events.

Assuntos

RESUMO

Abstract Objective: To investigate the cardiovascular effects produced by transthoracic application of low-intensity pulsed ultrasound therapy (LIPUST). Methods: Three-month-old male Wistar rats (± 300 g, N=16) were randomly allocated in two groups, namely SHAM (control group, faked procedures) and UST (animals treated with LIPUST). These animals, under anesthesia, were instrumented (femoral artery and vein catheterization) for hemodynamic recordings (mean blood pressure [MBP], heart rate [HR]) and blood biochemical profile (lipids, creatine kinase-myocardial band [CK-MB]). Then, LIPUST (spatial average-temporal average [ISATA] 1-MHz, power 0.1 to 1.2 W/cm2, pulsed 2:8 ms, cycle at 30%, for three minutes) was applied to animals from the UST group, externally to their thorax. SHAM animals were equally manipulated, but without application of ultrasound energy. After the hemodynamic and biochemical measurements, animals were sacrificed, and their hearts were mounted in a Langendorff apparatus for coronary reactivity evaluation. Standard histology techniques were employed to analyze the hearts. Results: LIPUST application caused statistically significant reductions in MBP (92±4 vs. 106±1 mmHg) and HR (345±14 vs. 380±17 rpm) when compared with SHAM procedures. UST rats exhibited higher CK-MB levels (318±55 vs. 198±26 U/dL) and lower plasma triglycerides levels (38±7 vs. 70±10 mg/dL) than SHAM animals. Coronary reactivity was not significantly changed by LIPUST. Cardiac histopathology showed an increase in capillary permeability in treated animals when compared with SHAM animals. Conclusion: Noninvasive LIPUST induces significant metabolic and hemodynamic changes, including intensity-dependent bradycardia and hypotension, indicating a possible therapeutic effect for cardiac events.

Assuntos

RESUMO

BACKGROUND AND OBJECTIVES: Diabetic retinopathy is the main microvascular complication in diabetes mellitus and needs to be diagnosed early to prevent severe sight-threatening retinopathy. The purpose of this study was to quantify the retinal microvasculature pattern and analyze the influence of blood glucose level and the duration of diabetes mellitus on the retinal microvasculature. METHODS: Two groups were analyzed: patients with diabetes (N=26) and patients without diabetes, ie, controls (N=26). A quantitative semiautomated method analyzed retinal microvasculature. The diameters of arterioles and venules were measured. The total numbers of arterioles and venules were counted. The ratio of arteriole diameter to venule diameter was calculated. The retinal microvasculature pattern was related to clinical and biochemical parameters. RESULTS: Patients with diabetes exhibited larger venule diameters in the upper temporal quadrant of the retina compared to the lower temporal quadrant (124.85±38.03 µm vs 102.92±15.69 µm; P<0.01). Patients with diabetes for 5 or more years had larger venule diameters in the upper temporal quadrant than patients without diabetes (141.62±44.44 vs 112.58±32.11 µm; P<0.05). The degree of venodilation in the upper temporal quadrant was positively correlated with blood glucose level and the estimated duration of diabetes mellitus. INTERPRETATION AND CONCLUSION: The employed quantitative method demonstrated that patients with diabetes exhibited venule dilation in the upper temporal quadrant, and the duration of diabetes mellitus was positively correlated with blood glucose level. Therefore, the early assessment of retinal microvascular changes is possible prior to the onset of diabetic retinopathy.

RESUMO

Com o objetivo de comparar as respostas cardiorrespiratórias no limiar anaeróbico ventilatório (LAV) em relação ao gênero, faixa etária e dados publicados na literatura, foram avaliados 289 adolescentes, de ambos os sexos, entre 10 e 14 anos. Foi realizado um teste cardiopulmonar, utilizando o protocolo de rampa em esteira ergométrica. O LAV foi identificado pelos métodos do V-slope e/ou do equivalente ventilatório de oxigênio. Os resultados mostraram que o consumo de oxigênio (VO2 LAV) absoluto foi maior nos meninos aos 13 e 14 anos; o VO2 LAV relativo ao peso corporal foi diferente entre os gêneros apenas aos 14 anos, sendo maior nos meninos. Conclui-se que há perda da aptidão física aeróbica dos adolescentes, de ambos os sexos, a partir dos 12 anos, com valores inferiores comparados à literatura.

In order to compare the cardiorespiratory responses in ventilatory anaerobic threshold (VAT) in relation to gender, age and published data, were evaluated 289 adolescents of both sexes, between 10 and 14 years, who underwent a cardiopulmonary test using a ramp protocol on treadmill. The VAT was identified by the methods of the V-slope and/or ventilatory equivalent of oxygen. The results showed that oxygen consumption (VO2 VAT) absolute was higher in boys at 13 and 14 years. The VO2 VAT relative to body weight was different only between genders aged 14 years old, and being higher in boys than girls. We conclude that there is loss of aerobic fitness in adolescents of both sexes from the age of 12. The VO2 VAT was lower when compared with the literature.

A fin de comparar las respuestas cardiorrespiratorias en el umbral anaeróbico ventilatorio (UAV) en relación con el género, la edad y los datos publicados, se evaluaron 289 adolescentes de ambos sexos, entre 10 y 14 años. Se realizó una prueba de esfuerzo cardiopulmonar utilizando un protocolo de rampa en la cinta. El UAV fue identificado por los métodos de la V-slope y/o equivalentes ventilatorio de oxígeno. Los resultados mostraron que el consumo de oxígeno (VO2 UAV) absoluta fue mayor en los varones de 13 y 14 años, la VO2 UAV relativo al peso corporal fue diferente entre los sexos sólo 14 años, siendo mayor en los varones. En conclusión de que hay una pérdida de la aptitud aeróbica de los adolescentes de ambos sexos de 12 años de edad, con valores más bajos en comparación con la literatura.

RESUMO

OBJECTIVE: To evaluate the occurrence of metabolic syndrome (MS) and independent associated risk factors in adolescents in the city of Vitória, Brazil. METHODS: We assessed 380 adolescents aged 10 to 14 years attending public schools. Body mass index and blood pressure at rest were measured. Fasting plasma concentrations of total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides and glucose were also obtained. RESULTS: The prevalence of overweight was 9.6% for boys and 7.4% for girls, while obesity was found in 6.2 and 4.9%, respectively. Triglyceride concentrations were borderline or high in 6.8 and 3.4% of the boys and in 11.8 and 5.9% of the girls. HDL-cholesterol was below recommended levels in 8.5% of the boys and in 9.9% of the girls. Blood pressure at rest was borderline for 5.1% of the boys and 7.9% of the girls, while 3.4% of both boys and girls were hypertensive. Fasting glycemia was high in 0.6% of the boys and in 0.5% of the girls. In the group studied, 2.8% of the boys and 2.5% of the girls had two risk factors associated with MS. Prevalence of MS was 1.1% for boys and 1.5% for girls, and overall prevalence was 1.3%. CONCLUSIONS: MS and associated cardiovascular risk factors are serious clinical conditions in this age group. A significant number of adolescents showed borderline results, which may increase the prevalence of MS or independent risk factors in the short term. More investments should be made in primary prevention, considering that early diagnosis is an issue of fundamental importance.

Assuntos

RESUMO

OBJETIVO: Avaliar a ocorrência de síndrome metabólica (SM) e fatores de risco associados em adolescentes de Vitória (ES). MÉTODOS: Foram avaliados 380 adolescentes de 10 a 14 anos de idade estudantes de escolas públicas. Foram mensurados: índice de massa corporal, pressão arterial em repouso, dosagens séricas em jejum das concentrações de colesterol total, LDL-colesterol, HDL-colesterol, triglicerídeos e glicose. RESULTADOS: Identificou-se prevalência de sobrepeso em 9,6 por cento dos meninos e em 7,4 por cento das meninas, enquanto que obesidade foi observada em 6,2 e 4,9 por cento, respectivamente. As concentrações de triglicerídeos foram limítrofes ou altas em 6,8 e 3,4 por cento dos meninos e em 11,8 e 5,9 por cento das meninas. A concentração de HDL-colesterol estava abaixo dos níveis padronizados em 8,5 por cento dos meninos e em 9,9 por cento das meninas. A pressão arterial em repouso foi limítrofe para 5,1 por cento dos meninos e 7,9 por cento das meninas, enquanto que 3,4 por cento tanto dos meninos quanto das meninas foram considerados hipertensos. Glicemia de jejum foi alta em 0,6 por cento dos meninos e em 0,5 por cento das meninas. No grupo estudado, 2,8 por cento dos meninos e 2,5 por cento das meninas apresentaram dois fatores de risco associados a SM. A prevalência de SM foi de 1,1 por cento para meninos e 1,5 por cento para meninas e a total foi de 1,3 por cento. CONCLUSÕES: Fatores de risco cardiovasculares associados a SM são condições clínicas importantes nessa faixa etária. Um número significativo de adolescentes apresentou resultados limítrofes, os quais podem aumentar a prevalência de SM ou de fatores de risco independentes em curto prazo. Mais investimentos devem ser feitos na prevenção primária, considerando que o diagnóstico precoce é uma questão de fundamental importância.

OBJECTIVE: To evaluate the occurrence of metabolic syndrome (MS) and independent associated risk factors in adolescents in the city of Vitória, Brazil. METHODS: We assessed 380 adolescents aged 10 to 14 years attending public schools. Body mass index and blood pressure at rest were measured. Fasting plasma concentrations of total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides and glucose were also obtained. RESULTS: The prevalence of overweight was 9.6 percent for boys and 7.4 percent for girls, while obesity was found in 6.2 and 4.9 percent, respectively. Triglyceride concentrations were borderline or high in 6.8 and 3.4 percent of the boys and in 11.8 and 5.9 percent of the girls. HDL-cholesterol was below recommended levels in 8.5 percent of the boys and in 9.9 percent of the girls. Blood pressure at rest was borderline for 5.1 percent of the boys and 7.9 percent of the girls, while 3.4 percent of both boys and girls were hypertensive. Fasting glycemia was high in 0.6 percent of the boys and in 0.5 percent of the girls. In the group studied, 2.8 percent of the boys and 2.5 percent of the girls had two risk factors associated with MS. Prevalence of MS was 1.1 percent for boys and 1.5 percent for girls, and overall prevalence was 1.3 percent. CONCLUSIONS: MS and associated cardiovascular risk factors are serious clinical conditions in this age group. A significant number of adolescents showed borderline results, which may increase the prevalence of MS or independent risk factors in the short term. More investments should be made in primary prevention, considering that early diagnosis is an issue of fundamental importance.

Assuntos

RESUMO

BACKGROUND: The acute blood pressure response to physical exertion has been used as an indicator of the risk of developing hypertension. The factors associated with this response need to be clarified for timely intervention in preventing hypertensive disease. OBJECTIVE: To describe the response of cardiovascular variables to acute physical exertion in overweight adolescents using cardiopulmonary exercise testing. METHODS: The sample consisted of 104 adolescents (56 boys and 48 girls), divided into two groups: the obese/overweight group (OOG) and the eutrophic group (EG). The following variables were measured: anthropometric (weight, height, and BMI), body composition (skin fold thickness), as well as hemodynamic variables such as systolic arterial pressure (SAP), diastolic arterial pressure (DAP), and heart rate (HR), at rest and at maximal physical exertion during the cardiopulmonary test. RESULTS: In the male group, the greatest values of systolic arterial pressure at rest were recorded in the OOG as compared to the EG (113 +/- 13 vs 106 +/- 8 mmHg; p = 0.009), pre-exertion SAP (120 +/- 14 vs 109 +/- 10 mmHg; p = 0.003), and SAP during maximal exertion conditions (156 +/- 20 vs 146 +/- 14 mmHg; p = 0.03). In the female group, only pre-exertion SAP was higher in the overweight group as compared to the eutrophic girls (114 +/- 11 vs 106 +/- 10 mmHg; p = 0.009). CONCLUSION: The response of arterial blood pressure during physical exercise was most exacerbated in obese adolescents as compared to eutrophic teens, suggesting greater reactivity to physical exertion.

Assuntos

RESUMO

FUNDAMENTO: A resposta aguda da pressão arterial ao esforço tem sido utilizada como indicador de risco para o desenvolvimento de hipertensão arterial. Os fatores associados com essa resposta precisam ser esclarecidos a fim de se intervir na prevenção da doença hipertensiva. OBJETIVO: Descrever o comportamento das variáveis cardiovasculares ao esforço agudo em adolescentes com excesso de peso, por meio de teste cardiopulmonar. MÉTODOS: A amostra foi constituída de 104 adolescentes (56 meninos e 48 meninas), divididos nos grupos de sobrepeso/obesos (GSO) e eutróficos (GE). Foram aferidas variáveis antropométricas (peso, estatura e IMC), de composição corporal (dobra cutânea) e variáveis hemodinâmicas de pressão arterial sistólica (PAS) e diastólica (PAD) e freqüência cardíaca (FC), no repouso e no esforço máximo do teste cardiopulmonar. RESULTADOS: No grupo masculino, identificaram-se maiores valores de pressão arterial sistólica de repouso para o GSO, quando comparados com o GE (113 ± 13 vs 106 ± 8 mmHg; p = 0,009), a PAS pré-exercício (120 ± 14 vs 109 ± 10 mmHg; p = 0,003) e de PAS na carga máxima de trabalho (156 ± 20 vs 146 ± 14 mmHg; p = 0,03). No grupo feminino, apenas a PAS pré-exercício foi superior no grupo de sobrepeso, quando isso foi comparado com as eutróficas (114 ± 11 vs 106 ± 10 mmHg; p = 0,009). CONCLUSÃO: A resposta pressórica durante o exercício foi mais exacerbada em adolescentes obesos quando comparada com àquela obtida em eutróficos, o que indica maior reatividade ao estresse físico.

BACKGROUND: The acute blood pressure response to physical exertion has been used as an indicator of the risk of developing hypertension. The factors associated with this response need to be clarified for timely intervention in preventing hypertensive disease. OBJECTIVE: To describe the response of cardiovascular variables to acute physical exertion in overweight adolescents using cardiopulmonary exercise testing. METHODS: The sample consisted of 104 adolescents (56 boys and 48 girls), divided into two groups: the obese/overweight group (OOG) and the eutrophic group (EG). The following variables were measured: anthropometric (weight, height, and BMI), body composition (skin fold thickness), as well as hemodynamic variables such as systolic arterial pressure (SAP), diastolic arterial pressure (DAP), and heart rate (HR), at rest and at maximal physical exertion during the cardiopulmonary test. RESULTS: In the male group, the greatest values of systolic arterial pressure at rest were recorded in the OOG as compared to the EG (113 ± 13 vs 106 ± 8 mmHg; p = 0.009), pre-exertion SAP (120 ± 14 vs 109 ± 10 mmHg; p = 0.003), and SAP during maximal exertion conditions (156 ± 20 vs 146 ± 14 mmHg; p = 0.03). In the female group, only pre-exertion SAP was higher in the overweight group as compared to the eutrophic girls (114 ± 11 vs 106 ± 10 mmHg; p = 0.009). CONCLUSION: The response of arterial blood pressure during physical exercise was most exacerbated in obese adolescents as compared to eutrophic teens, suggesting greater reactivity to physical exertion.

Assuntos