Breaks no tempo em comportamento sedentário e marcadores cardiometabólicos em adolescentes / Breaks in sedentary time and cardiometabolic markers in adolescents

Resumo Fundamento: Interrupções no tempo despendido em comportamento sedentário (breaks) têm sido associadas a melhores níveis de indicadores cardiometabólicos na população adulta. No entanto, em adolescentes, os achados sobre essa associação ainda são conflitantes. Objetivos: Analisar a associação do número de breaks por dia em comportamento sedentário com marcadores cardiometabólicos e avaliar se ela é moderada pelo estado nutricional e o tempo excessivo em comportamento sedentário em adolescentes. Métodos: Estudo transversal com 537 adolescentes (52,3% do sexo feminino), de 10 a 14 anos de idade, de escolas públicas de João Pessoa (PB). O número diário de breaks em comportamento sedentário (>100 counts/minutos) foi mensurado por meio de acelerômetros (Actigraph GT3X+). Os marcadores cardiometabólicos analisados foram: pressão arterial sistólica e diastólica (mmHg), glicose de jejum, colesterol total, triglicerídeos, HDL-c, LDL-c (todos em mg/dL) e índice de massa corporal (IMC) (kg/m2). Utilizou-se a regressão linear para analisar a associação do número de breaks com marcadores cardiometabólicos e avaliar se ela é moderada pelo estado nutricional e o tempo excessivo em comportamento sedentário. O nível de significância de p<0,05 foi adotado para todas as análises. Resultados: O número de breaks por dia se associou negativamente ao IMC (ß = −0,069; IC95%: −0,102; −0,035), mas não aos demais marcadores cardiometabólicos, e essa associação não foi moderada pelo estado nutricional dos adolescentes (p=0,221) e nem pelo tempo excessivo em comportamento sedentário (p=0,176). Conclusão: A inclusão de breaks no tempo em comportamento sedentário parece contribuir para valores mais baixos do IMC em adolescentes.

Abstract Background: The interruption of the time spent in sedentary behavior (breaks) has been associated with better levels of cardiometabolic indicators in the adult population, but in adolescents, further investigations are still needed to confirm these findings. Objectives: To analyze the association of the number of breaks per day in sedentary behaviors with cardiometabolic markers and whether it was moderated by nutritional status and excessive time on sedentary behavior in adolescents. Methods: This is a cross-sectional study of 537 adolescents (52.3% girls), aged between 10 and 14 years, enrolled in public schools in the city of João Pessoa, Paraíba state, Brazil. The number of daily breaks (>100 counts/minutes) in sedentary time was measured by Actigraph GT3X+ accelerometers. The following cardiometabolic markers were analyzed: systolic and diastolic blood pressure (mmHg), fasting blood glucose levels, total cholesterol, triglycerides, HDL-c, LDL-c (all in mg/dL) and body mass index (BMI) (kg/m2). Linear regression was used to analyze the association between the number of breaks and cardiometabolic markers and whether this association was moderated by nutritional status and excessive time in sedentary behavior. The significance level of p<0.05 was adopted for all analyses. Results: The number of daily breaks was negatively associated with BMI (boys - ß = −0.083; 95%CI: −0.132; −0.034 and girls - ß = −0.115; 95%CI: −0.169; −0.061), but not with the remaining cardiometabolic markers. The number of breaks per day was negatively associated with BMI (ß = −0.069; 95% CI: −0.102; −0.035), but not with the other cardiometabolic markers and this association was not moderated by the adolescents' nutritional status (p=0.221), or by excessive time in sedentary behavior (p=0.176). Conclusions: Including breaks in sedentary time seems to contribute to lower BMI values in adolescents.

Sensibilidade e especificidade de pontos de corte para frequência cardíaca em repouso de 6. 794 adolescentes Brasileiros: Um estudo transversal / Sensitivity and specificity of cutoff points of resting heart rate from 6, 794 brazilian adolescents: A cross-sectional study

Resumo Fundamento A frequência cardíaca em repouso (FCR) pode ser uma ferramenta útil de triagem para o risco cardiovascular. Porém, os pontos de corte para FCR nunca foram descritos em populações jovens. Objetivo Estabelecer os pontos de corte para FCR em adolescentes brasileiros e analisar se há associação entre pontos de corte e fatores de risco cardiovascular. Métodos A amostra foi composta por 6.794 adolescentes (de 10 a 19 anos). A pressão arterial e a FCR foram avaliadas por dispositivo oscilométrico. Também foram avaliados o índice de massa corporal e a circunferência da cintura. Foi adotada a curva ROC para analisar a sensibilidade e especificidade, e as associações de FCR elevada com os fatores de risco cardiovascular foram analisadas por regressão logística binária. Foi considerado estatisticamente significante um valor de p < 0,05 para todas as análises. Resultados Os valores médios da FCR eram mais altos entre os participantes de 10 a 14 anos do naqueles de 15 a 19 anos, em meninos (p < 0,001) e meninas (< 0,001). Os pontos de corte de FCR propostos para detecção de fatores de risco cardiovascular foram significativos para meninos de 10 a 14 (> 92 bpm) e de 15 a 19 anos (> 82 bpm) e para meninas de 15 a 19 anos (> 82 bpm) (p < 0,05 para todos), enquanto nenhum ponto de corte foi identificado para as meninas de 10 a 14 anos (p > 0,05). Os pontos de corte propostos para a FCR foram associados com obesidade abdominal, sobrepeso e pressão arterial elevada em meninos e meninas. Os pontos de corte da FCR foram associados ao conjunto de fatores de risco cardiovascular em adolescentes de 15 a 19 anos. Conclusões Os pontes de corte propostos para a FCR foram associados com os fatores de risco cardiovascular em adolescentes.

Abstract Background Resting heart rate (RHR) may be a useful screening tool for cardiovascular risk. However, RHR cutoff points, an interesting clinical approach, have never been described in young populations. Objective To establish RHR cutoff points in Brazilian adolescents and to analyze whether cutoff points are associated with cardiovascular risk factors. Methods The sample was composed of 6,794 adolescents (10 to 19 years old). Blood pressure and RHR were assessed by oscillometric device. Body mass index and waist circumference were also assessed. Receiver operating characteristic curve was adopted to analyze the sensitivity and specificity, and associations of high RHR with cardiovascular risk factors were analyzed by binary logistic regression. A p value < 0.05 was considered statistically significant for all the analyses. Results Mean RHR values were higher among participants ages 10 to 14 years than 15 to 19 years, for boys (p < 0.001) and girls (< 0.001). The proposed RHR cutoff points for cardiovascular risk factors detection were significant for boys ages 10 to 14 (> 92 bpm) and 15 to 19 years (> 82 bpm), as well as for girls ages 15 to 19 years (> 82 bpm) (p < 0.05 for all), whereas no cutoff point was identified for girls ages 10 to 14 years (p > 0.05). Proposed RHR cutoff points were associated with abdominal obesity, overweight, and high blood pressure in boys in girls. RHR cutoff points were associated with the cluster of cardiovascular risk factors in adolescents ages 15 to 19 years. Conclusion The proposed RHR cutoff points were associated with cardiovascular risk factors in adolescents.

Associação entre Ácido Úrico Sérico e Pré-Hipertensão e Hipertensão entre Adultos Chineses / Association between Serum Uric Acid and Pre-hypertension and Hypertension among Chinese Adults

Resumo Fundamento O ácido úrico , produto final do metabolismo dos nucleotídeos das purinas, participa dos processos de doenças metabólicas e cardiovasculares. Evidências experimentais sugerem que o ácido úrico é um mediador importante na resposta fisiológica ao aumento da pressão arterial. Objetivo Avaliar a associação entre os níveis séricos de AU e pré-hipertensão e hipertensão em uma população chinesa. Métodos Conduziu-se um estudo transversal entre março e setembro de 2017, e 1.138 participantes com idades entre 35 e 75 anos foram incluídos neste estudo, onde 223 normotensos, 316 pré-hipertensos e 599 hipertensos foram selecionados para avaliar a associação entre níveis séricos de AU e hipertensão. Considerou-se um valor de p<0,05 estatisticamente significativo. Resultados Os níveis séricos de AU foram significativamente maiores no grupo pré-hipertensão e hipertensão em comparação com o grupo controle em toda a população (p<0,05 para todos). A análise quantitativa das características indicou níveis séricos de AU (2,92±0,81, 3,06±0,85, 3,22±0,98 mg/d) linearmente aumentados em mulheres normotensas, pré-hipertensas e hipertensas, com um valor de p de 0,008. Os níveis séricos de AU nos quartis correlacionaram-se positivamente com a PAD (p<0,05), principalmente em mulheres. Após o ajuste para idade, sexo, índice de massa corporal (IMC), glicose (GLI), colesterol total (CT), triglicerídeos (TG), colesterol HDL (lipoproteína de alta densidade), as razões de chances ( odds ratios — ORs) e intervalos de confiança (IC) de 95% da pré-hipertensão, dos níveis séricos de AU mais baixos (referentes) aos mais altos foram 1,718 (1,028-2,872), 1,018 (0,627-1,654) e 1,738 (1,003-3,010). Além disso, o segundo quartil dos níveis séricos de AU esteve significativamente associado à hipertensão, com uma OR (IC 95%) de 2,036 (1,256-3,298). Conclusões O presente estudo sugere que níveis séricos mais elevados de AU estão positivamente associados à pré-hipertensão e hipertensão entre adultos chineses.

Abstract Background Uric acid (UA), the end product of purine nucleotide metabolism, participates in the processes of metabolic and cardiovascular diseases. Experimental evidence suggests it is an important mediator in the physiological response to blood pressure increase. Objective To evaluate the association between serum UA levels and pre-hypertension and hypertension in a Chinese population. Methods A cross-sectional study was conducted from March to September 2017, and 1,138 participants aged 35 to 75 were enrolled in this study, where 223 normotensive, 316 pre-hypertensive, and 599 hypertensive subjects were selected to evaluate the association between serum UA levels and hypertension. A p-value <0.05 was considered statistically significant. Results Serum UA levels were significantly higher in the pre-hypertension and hypertension group compared to the control group in the entire population (p<0.05 for all). Quantitative trait analysis indicated that serum UA levels were (2.92±0.81, 3.06±0.85, 3.22±0.98 mg/d) linearly increased in normotensive, pre-hypertensive and hypertensive females, with a p value of 0.008. Serum UA levels in the quartiles were positively correlated with DBP (p<0.05), particularly in females. After adjusting for age, gender, body mass index (BMI), glucose (GLU), total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-c), the odds ratios (ORs) and 95% confidence intervals (CIs) of pre-hypertension from the lowest (referent) to the highest levels of serum UA were 1.718 (1.028-2.872), 1.018 (0.627-1.654) and 1.738 (1.003-3.010). Additionally, the second quartile of serum UA levels were significantly associated with hypertension, with an OR (95% CI) of 2.036 (1.256-3.298). Conclusions This study suggests that higher serum UA levels are positively associated with pre-hypertension and hypertension among Chinese adults.

Carboxyhemoglobin Levels during High and Minimal Flow Anesthesia / 대한마취과학회지

BACKGROUND: Minimal flow anesthesia preserves the moisture content of CO2 absorbents and seems to be a factor inhibiting carbon monoxide generation. In order to assess the safety of minimal flow anesthesia, we studied carboxyhemoglobin (COHb) level in minimal flow anesthesia. METHODS: Forty women, ASA physical status I or II, undergoing total abdominal hysterectomy were randomly allocated to one of two groups with N2O-enflurane anesthesia. Anesthesia was maintained with O2 2 l/min and N2O 2 l/min (group 1) or O2 0.3 l/min and N2O 0.2 l/min (group 2). The arterial COHb levels were measured immediately after induction (T1), 45 min after induction (T2), 75 min after induction (T3), and after recovery from anesthesia (T4). RESULTS: Although there was no statistically significant change in both groups, the COHb level at T3 and T4 increased more than that at T1 in group 1, and that at T3 and T4 decreased more than that at T1 in group 2. There was a significant difference in the COHb level at T4 between group 1 (0.93 0.31%) and 2 (0.68 0.36%) (P <0.05). CONCLUSIONS: These results show that minimal flow anesthesia does not increase the COHb level and may be performed safely.

Activated Coagulation Time (ACT) Differences between Arterial and Venous Blood Samples in Patients with Open Heart Surgery / 대한마취과학회지

BACKGROUND: Activated coagulation time (ACT) is commonly used to guide heparin and protamine dosing during cardiovascular surgery. There are many factors that influence the ACT such as time of test, hemodilution, temperature, aprotinin and etc. We considered the other factor that influence the ACT, the route of blood sample. METHODS: This study included 40 patients who were scheduled for cardiac surgery. Whole blood was sampled through arterial and central venous line at 10 minutes after surgical incision and heparin administration. The ACT was measured with Hemochron 801 blood coagulation timer with 12 mg of celite surface activator. RESULTS: At 10 minutes after surgical incision and heparin administration, arterial blood and venous blood ACTs were 127 20, 537 214 seconds and 118 18, 496 145 seconds respectively (p<0.05). CONCLUSIONS: We conclude that the venous blood ACT is more less than arterial blood ACT during cardiovascular surgery.