Salim Kanaan

Body mass index for predicting hyperglycemia and serum lipid changes in Brazilian adolescents

OBJETIVO: Determinar os melhores pontos de corte do indice de massa corporal (IMC) para identificar alteracoes no perfil lipemico e glicemico em adolescentes. METODOS: Foram avaliados 577 adolescentes de 12 a 19 anos (210 meninos e 367 meninas) em uma amostra probabilistica de estudantes de escolas estaduais da cidade de Niteroi (RJ), em 2003. Foi utilizada a curva Receiver Operating Characteristic para identificar o melhor ponto de corte, ajustado para idade, para predizer valores elevados de colesterol total serico (>150mg/dL), LDL-C (>100mg/dL), triglicerides (>100mg/dL), glicose plasmatica (>100mg/dL) e baixos valores de HDL-C ( 50%) foram: colesterol total elevado e HDL-C baixa. O IMC foi capaz de predizer valores elevados de triglicerides nos meninos, LDL-C nas meninas e colesterol total e presenca de tres ou mais alteracoes metabolicas em ambos os sexos (area sob a curva - 0,59 a 0,67), embora com baixa sensibilidade (57% a 66%) e especificidade (58% a 66%). Os melhores pontos de corte na amostra estudada (20,3 kg/m² a 21,0 kg/m²) foram inferiores aos propostos pelas outras referencias. CONCLUSOES: Embora valores de IMC menores do que os das referencias internacionais tenham sido preditores de algumas alteracoes metabolicas em adolescentes brasileiros, o IMC nao foi um bom indice para identificar estas anormalidades na amostra estudada.OBJECTIVE To determine the best cut-offs of body mass index for identifying alterations of blood lipids and glucose in adolescents. METHODS A probabilistic sample including 577 adolescent students aged 12-19 years in 2003 (210 males and 367 females) from state public schools in the city of Niterói, Southeastern Brazil, was studied. The Receiver Operating Characteristic curve was used to identify the best age-adjusted BMI cut-off for predicting high levels of serum total cholesterol (> or =150 mg/dL), LDL-C (> or =100 mg/dL), serum triglycerides (> or =100 mg/dL), plasma glucose (> 100 mg/dL) and low levels of HDL-C (< 45 mg/dL). Four references were used to calculate sensitivity and specificity of BMI cut-offs: one Brazilian, one international and two American. RESULTS The most prevalent metabolic alterations (>50%) were: high total cholesterol and low HDL-C. BMI predicted high levels of triglycerides in males, high LDL-C in females, and high total cholesterol and the occurrence of three or more metabolic alterations in both males and females (areas under the curve range: 0.59 to 0.67), with low sensitivity (57%-66%) and low specificity (58%-66%). The best BMI cut-offs for this sample (20.3 kg/m(2) to 21.0 kg/m(2)) were lower than those proposed in the references studied. CONCLUSIONS Although BMI values lower than the International cut-offs were better predictor of some metabolic abnormalities in Brazilian adolescents, overall BMI is not a good predictor of these abnormalities in this population.

Estudo do perfil lipídico em crianças e jovens do ambulatório pediátrico do Hospital Universitário Antônio Pedro associado ao risco de dislipidemias

Atherosclerotic plaques form early in childhood and progress slowly until adult life, when clinical manifestations show. The goal of this study was to analyze the concentrations in plasma of total cholesterol, LDL-cholesterol (LDL-C), triglycerides (TG) and HDL-cholesterol (HDL-C) in a group of children of both sexes and up to 19 years of age, who are attending at the University Hospital Antonio Pedro (HUAP). Patient admission sheets between December 2004 and January 2006 were analyzed for dyslipidemic risk factors, and correlated with the respective lipid plasma concentrations, determined at the Laboratory of Clinical Chemistry (HUAP). The plasma levels of total cholesterol, LDL-C, TG and HDL-C in female patients were higher than in male patients, suggesting the influence of sexual maturation as described in the literature. The mean concentrations of total cholesterol, LDL-C, TG and HDL-C were elevated in the investigated group, mainly in patients presenting with other pathologies, such as nephrotic syndromes, diabetes mellitus and systemic lupus erythematosus. Our results suggest that, in Brazil, the reference value interval of lipoprotein levels should be investigated more thoroughly in this age group, as well as in children who are considered healthy.

Óxido nítrico: inibição das plaquetas e participação na formação do trombo

In this article we make a review above the way that nitric oxide (NO) influence platelets over the past 25 years. The role of NO in biology has evolved from being recognized as an environmental pollutant to an endogenously produced substance involved in intracellular and intercellular communication and signal transduction. NO is a multifunctional molecule that plays a role in the regulation of hemostasis. It is responsible for platelets inhibition in all levels of its action, from adhesion to aggregation, preventing in this manner, thrombus formation. Several clinical disorders have been reported in which endogenous NO production insufficiency and, as a consequence, the absence of platelets action inhibition, seems to contribute to thrombotic events.

Avaliação do glicogênio hepático correlacionado com glicose sérica em ratas castradas sob tratamento com tibolona

INTRODUCAO: O glicogenio representa a forma de armazenamento de acucares na celula animal, sendo estocada naturalmente no hepatocito. Em sua dinâmica metabolica ocorre participacao de receptores, hormonios e enzimas que mantem e equilibram os niveis sericos desse componente. OBJETIVO: O presente estudo investigou a influencia da tibolona no metabolismo glicidico hepatico por meio de avaliacao da presenca do glicogenio hepatico e niveis sericos de glicose. MATERIAL E METODOS: Utilizamos ao todo 14 ratas Wistar, em menopausa cirurgica comprovada citologicamente, tratadas diariamente com tibolona (n = 9) ou com placebo (n = 5) durante 20 semanas. Efetuou-se avaliacao dos pesos do animal e do figado e dos niveis de glicose serica. O estudo morfologico foi realizado em cortes histologicos de tecido hepatico, corados com hematoxilina e eosina (HE) e com acido periodico de Schiff (PAS), com e sem amilase salivar. Para avaliacao do glicogenio no figado, utilizou-se grade de estudo morfologico (GEM), que delineia as regioes metabolicas e circulatorias do lobulo hepatico. RESULTADOS: O peso dos animais foi menor no Grupo Tibolona, com glicose serica em niveis mais baixos; ja o peso relativo do figado foi significativamente maior (p < 0,001). No Grupo Controle o glicogenio apresentou distribuicao heterogenea em tres diferentes padroes e o Grupo Tibolona mostrou glicogenio uniforme em toda a estrutura lobular. CONCLUSAO: A tibolona, administrada em alta dose e por tempo prolongado, determina perda de peso por deficiencia alimentar, que leva a alteracoes nas funcoes hepaticas, podendo influir na glicogenolise e na gliconeogenese, com modificacoes do glicogenio hepatico e da glicose circulante.

Índice de massa corporal para predizer hiperglicemia e alterações lipídicas em adolescentes brasileiros

OBJETIVO: Determinar os melhores pontos de corte do indice de massa corporal (IMC) para identificar alteracoes no perfil lipemico e glicemico em adolescentes. METODOS: Foram avaliados 577 adolescentes de 12 a 19 anos (210 meninos e 367 meninas) em uma amostra probabilistica de estudantes de escolas estaduais da cidade de Niteroi (RJ), em 2003. Foi utilizada a curva Receiver Operating Characteristic para identificar o melhor ponto de corte, ajustado para idade, para predizer valores elevados de colesterol total serico (>150mg/dL), LDL-C (>100mg/dL), triglicerides (>100mg/dL), glicose plasmatica (>100mg/dL) e baixos valores de HDL-C ( 50%) foram: colesterol total elevado e HDL-C baixa. O IMC foi capaz de predizer valores elevados de triglicerides nos meninos, LDL-C nas meninas e colesterol total e presenca de tres ou mais alteracoes metabolicas em ambos os sexos (area sob a curva - 0,59 a 0,67), embora com baixa sensibilidade (57% a 66%) e especificidade (58% a 66%). Os melhores pontos de corte na amostra estudada (20,3 kg/m² a 21,0 kg/m²) foram inferiores aos propostos pelas outras referencias. CONCLUSOES: Embora valores de IMC menores do que os das referencias internacionais tenham sido preditores de algumas alteracoes metabolicas em adolescentes brasileiros, o IMC nao foi um bom indice para identificar estas anormalidades na amostra estudada.OBJECTIVE To determine the best cut-offs of body mass index for identifying alterations of blood lipids and glucose in adolescents. METHODS A probabilistic sample including 577 adolescent students aged 12-19 years in 2003 (210 males and 367 females) from state public schools in the city of Niterói, Southeastern Brazil, was studied. The Receiver Operating Characteristic curve was used to identify the best age-adjusted BMI cut-off for predicting high levels of serum total cholesterol (> or =150 mg/dL), LDL-C (> or =100 mg/dL), serum triglycerides (> or =100 mg/dL), plasma glucose (> 100 mg/dL) and low levels of HDL-C (< 45 mg/dL). Four references were used to calculate sensitivity and specificity of BMI cut-offs: one Brazilian, one international and two American. RESULTS The most prevalent metabolic alterations (>50%) were: high total cholesterol and low HDL-C. BMI predicted high levels of triglycerides in males, high LDL-C in females, and high total cholesterol and the occurrence of three or more metabolic alterations in both males and females (areas under the curve range: 0.59 to 0.67), with low sensitivity (57%-66%) and low specificity (58%-66%). The best BMI cut-offs for this sample (20.3 kg/m(2) to 21.0 kg/m(2)) were lower than those proposed in the references studied. CONCLUSIONS Although BMI values lower than the International cut-offs were better predictor of some metabolic abnormalities in Brazilian adolescents, overall BMI is not a good predictor of these abnormalities in this population.

Effects of Heart Rate Reduction With Either Pyridostigmine or Ivabradine in Patients With Heart Failure: A Randomized, Double-Blind Study

Background: Heart rate (HR) reduction with ivabradine has been proved to reduce hospitalization and death from heart failure (HF). We sought to investigate whether pyridostigmine would effectively reduce HR in patients with chronic HF as compared with ivabradine. Methods: Twenty-one patients with HF who were in sinus rhythm with a resting HR over 70 bpm, despite optimal medical treatment, were included in a randomized, double-blind study comparing pyridostigmine versus ivabradine. The initial dose of ivabradine was 5 mg twice daily to reach a target HR between 50 and 60 bpm and could be titrated to a maximum of 7.5 mg twice daily. Pyridostigmine was used in a fixed dose of 30 mg 3 times daily. Results: The baseline HR for ivabradine and pyridostigmine groups was 89.1 (13.5) and 80.1 (7.2) bpm, respectively (P = .083). After 6 months of treatment, HR was significantly reduced to 64.8 (8.3) bpm in the ivabradine group (P = .0014) and 63.6 (5.9) bpm in the pyridostigmine group (P = .0001). The N-terminal pro-B-type natriuretic peptide was reduced in the ivabradine group (median: 1308.4 [interquartile range: 731-1896] vs 755.8 [134.5-1014] pg/mL; P = .027) and in the pyridostigmine group (132.8 [89.9-829] vs 100.7 [38-360] pg/mL; P = .002). Inflammatory markers interleukin-1, interleukin-6, and tumor necrosis factor were reduced in both groups. Exercise capacity was improved in both groups, with increments in volume of oxygen utilization ( V ˙ O2; ivabradine: 13.1 vs 15.6, P = .048; pyridostigmine: 13.3 vs 16.7, P = .032). Heart rate recovery in the first minute postexercise was improved with pyridostigmine (11.8 [3.9] vs 18 [6.5]; P = .046), but not with ivabradine (13.3 [6.9] vs 14.1 [8.2]; P = .70). No differences in either group were observed in the myocardial scintigraphy with 123-iodine-metaiodobenzylguanidine. Conclusion: Both drugs significantly reduced HR, with improvements in exercise capacity and in neurohormonal and inflammatory profiles.

Increased Cytokeratin 19 Fragment Levels Are Positively Correlated with Adenosine Deaminase Activity in Malignant Pleural Effusions from Adenocarcinomas

Adenosine deaminase (ADA) and cytokeratin 19 (CK19) are known pleural biomarkers. Although ADA in humans functions mainly in the immune system, it also appears to be associated with the differentiation of epithelial cells. Keratin filaments are important structural stabilizers of epithelial cells and potent biomarkers in epithelial differentiation. This study aimed to investigate the simultaneous presence of the ADA enzyme and CK19 fragments to assess epithelial differentiation in malignant and benign pleural fluids. Diagnosis of the cause of pleural effusion syndrome was confirmed by means of standard examinations and appropriate surgical procedures. An ADA assay, in which ADA irreversibly catalyzes the conversion of adenosine into inosine, was performed using a commercial kit. The CK19 assay was performed using a CYFRA 21-1 kit, developed to detect quantitative soluble fragments of CK19 using an electrochemiluminescence immunoassay. One hundred nineteen pleural fluid samples were collected from untreated individuals with pleural effusion syndrome due to several causes. ADA levels only correlated with CK19 fragments in adenocarcinomas, with high significance and good correlation (rho = 0.5145, P = 0.0036). However, further studies are required to understand this strong association on epithelial differentiation in metastatic pleural fluids from adenocarcinomas.

Clinical and laboratory diagnosis of Zika fever: an update

Zika fever can be defined as an acute febrile viral illness, mainly transmitted by the mosquito of the genus Aedes. It makes a differential diagnosis from diseases caused by other flaviviruses, such as chikungunya and dengue fever. Many people with Zika virus (ZIKV) infection will not have symptoms or will only have mild clinical symptoms. The clinical conditions are nonspecific and characterized by low-grade fever, pruritic erythematous maculopapular rash, non-purulent conjunctival hyperemia without pruritus, arthralgia, myalgia, and headache. It is a benign, self-limiting and short-duration condition. Complications such as Guillain-Barré syndrome (GBS), spontaneous abortion and fetal malformations, mainly microcephaly and retinal lesions, may occur. The laboratory investigation is more important in cases suspected of ZIKV infection that have evolved with neurological complications, in pregnant women, abortion or congenital malformations, and is a key part for diagnostic definition. Real-time polymerase chain reaction (RT-PCR) can detect the virus in blood samples about four to seven days after the onset of symptoms. In urine, it is possible to identify viral ribonucleic acid (RNA) up to 15 days after clinical onset, even if viremia has ceased, and it is an alternative for late diagnosis. Serological tests may also be performed, while there may be cross-reactivity with other flaviviruses. Immunoglobulin class M (IgM) can be screened between the 2 and 12 week after clinical presentation. The immunoglobulin class G (IgG) can be identified after the 15 day, and is present even in the convalescence and cure phase. Non-specific laboratory abnormalities, in general, do not present significant alterations. Patients with GBS must have cerebrospinal fluid (CSF) collection for analysis.

Role of advanced glycation end products related to the onset of diabetic kidney disease complications

Advanced glycation end products are known to play an important role in the diabetes complications, such as diabetic nephropathy. Most known pathways of diabetic complications involve oxidative stress, that have pivotal role in cell dysfunction onset and progression of angiopathies. This review will explore how AGEs cause endothelial dysfunction in diabetes and what current biochemical mechanisms have been proposed as an explanation for the development of diabetic nephropathy. Keywords: Type 2 diabetes mellitus; advanced glycation end products; endothelial dysfunction; hyperglycemia; oxidative stress; vascular complication; diabetic nephropathy

Is the creatine kinase isoenzyme MB level a marker of myocardial ischemia in ventilated premature infants

INTRODUCTION: It is not clear whether the levels of troponin I (TI) and creatine kinase isoenzyme MB (CK-MB) are changed in premature infants (PI) without evidence of myocardial ischemia (MI). OBJECTIVES: To investigate whether TI and CK-MB change their levels in newborns without MI while on mechanical ventilation (MV). METHODS: We conducted a prospective cohort study in which 165 PI were divided into control group ([CG]; n = 68), mechanical ventilated group ([VG]; n = 21) and a surfactant therapy group ([SG]; n = 76), and had their TI, creatine kinase (CK) and CK-MB levels were determined. After the division, within the first four hours after the introduction of the mechanical ventilation (MV) and one hour after the withdrawal of it, we performed a new measurement of TI, CK and CK-MB to all PI from VG and VS. We used the chi-square test to evaluate the association among qualitative variables and the Kruskall-Wallis test to compare the serum levels of TI, and CK-MB among the groups, before, during and after MV using the statistical package SPSS 16.0 software. RESULTS: TI, CK, and CK-MB serum values before the groups were divided were considered normal. The TI concentration among the groups before and after MV (p > 0.05) did not changed; however, the CK-MB levels were higher in VG when compared to the CG (p = 0.009). CONCLUSION: The increase of CK-MB serum levels in VG and SG seems to indicate an increased work of thoracic skeletal muscle and do not represent a MI signal, which invalidate its use as a marker.