Associação entre polimorfismo Gln27Glu do receptor beta2-adrenérgico e hipertensão arterial sistêmica em obesos mórbidos

Abstract

RESUMOHá alguns relatos na literatura sugerindo associação entre polimorfismos do receptor b 2 -adrenérgico com obesidade e outros com hipertensão arterial. O objetivo do nosso estudo foi estudar a freqüência de um polimorfismo do receptor b 2 adrenérgico (Gln27Glu) em pacientes obesos (BMI 48 ± 8,2kg/m 2 ) e relacioná-lo com hipertensão arterial, e níveis de triglicérides, colesterol, insulina e glicose no sangue. Encontramos associação deste polimorfismo em obesos com hipertensão arterial. The sympathetic nervous system activation stimulates energy mobilization and utilization in the adipose tissue that is a favored target for high-energy substrate storage, mobilization and utilization. Adrenergic responsiveness may be altered in obesity and could be an important factor in the pathogenesis and maintenance of obesity state. In the hypertensive state there is physiological and biochemical evidence that b-adrenergic responsiveness is diminished in the face of increased sympathetic tone. Recently, several different polymorphic forms of the human b 2 AR have been identified in general population, including N-terminal substitutions of glutamine (Gln) for glutamic acid (Glu) at position 27. The aim of this study was to investigate the potential interaction between the b 2 AR (Gln27Glu) polymorphism and obesity accumulation and hypertension in morbidly obese subjects. The Ita I genotypes of b 2 AR were established using RFLP methods in 135 individuals with BMI 48 ± 8.02kg/m 2 . The frequency of Gln/Glu was 31.9% and in the homozygous Glu/Glu was 12.6%. No association was found between BMI, weight gain during the past years and the Ita I genotypes and neither was associated with levels of triglycerides, cholesterol, insulin and glucose. Positive association was found between blood pressure (systolic and diastolic) and presence of polymorphism. The results indicate at the first time that presence of polymorphism 27Glu may provide a mechanism for enhanced vascular reactivity and identify a candidate gene for hypertension in this obesity group. Na última década, a comunidade científica tem procurado estabelecer o papel da genética na etiologia da obesidade humana e de outras doenças complexas que têm componentes ambientais, comportamentais e genéticos. Estuda-se em que extensão os genes herdados têm influência no

Obstáculos diagnósticos e desafios terapêuticos no paciente obeso

“…O mecanismo exato de desenvolvimento da hipertensão arterial em pacientes obesos provavelmente envolve uma interação entre fatores genéticos, hormonais, renais e hemodinâmicos (97). A hiperinsulinemia, característica da obesidade, pode contribuir ativando o sistema nervoso simpático (com aumento do nível basal de noradrenalina e aumento da resposta da mesma a variações posturais e exercício isométrico) e levando à retenção de sódio.…”

ADRB2 Gln27Glu polymorphism influenced changes in leptin but not body composition or metabolic and other inflammatory parameters after twelve weeks of combined training in overweight adolescents

“…In fact, polymorphisms in the gene encoding β2 adrenergic receptor (ADRB2) may change the thermogenic effects of catecholamines, being associated with the presence of obesity and weight regain 7,8 , and may also alter lipolysis 9 . Therefore, allelic variants in genes associated with energy expenditure may negatively influence the reduction of adipose tissue 10 and weight reduction 11 .…”

Influence of Beta-2-Adrenergic Receptor Gln27Glu Polymorphism on the Autonomic Heart Rate Modulation in Young Sedentary and Physically Active Women

“…Considering that the participation and function of β2-AR have been widely recognized, a large amount of research is being done regarding the physiological and physiopathological relevance of polymorphisms of receptors in cardiac insufficiency [9], sistemic arterial hypertension [10], obesity [11][12][13] and metabolic syndromes [14].…”