Alpha2B-adrenergic receptor deletion polymorphism and cardiac autonomic nervous system responses to exercise in obese women.
Int J Obes (Lond)
; 30(2): 214-20, 2006 Feb.
Article
en En
| MEDLINE
| ID: mdl-16247508
OBJECTIVE: To investigate the association of short form (Glu9/Glu9) of the 12Glu9 deletion polymorphism of the alpha2B-adrenergic receptor (alpha2B-AR) gene polymorphism with the cardiac autonomic responsiveness during sustained isometric handgrip exercise. DESIGN: Cross-sectional clinical study. SUBJECTS: In all, 97 normotensive obese women (body mass index (BMI) = 33.2 kg/m2). Of these, 78 (80.41%) were genotyped as Glu12/Glu12, 13 (13.40%) as Glu12/Glu9 and six (6.19%) as Glu9/Glu9 form. MEASUREMENTS: The sympathovagal balance was assessed by means of power spectral analysis of heart rate variability at rest and during sustained isometric handgrip exercise at 30% of maximal voluntary handgrip contraction for 3 min. Two spectral components were analysed: low-frequency component reflecting sympathetic efferent activity and high-frequency power (HFnu) reflecting parasympathetic modulation. In addition, a normalized low-frequency power (LFnu) and HFnu were analysed. Genotypes were determined by polymerase chain reaction followed by agarose gel electrophoresis. RESULTS: There were no differences in baseline measurements among groups. The absolute level of LFnu throughout handgrip exercise was significantly lower in Glu9/Glu9 subjects compared with other genotypes, while the decline of absolute HFnu was significantly smaller compared with Glu12/Glu12 genotype. CONCLUSION: These findings suggest that 12Glu9 deletion polymorphism of the alpha2B-AR gene (Glu9/Glu9 genotype) might result in reduced autonomic responsiveness by altering cardiac sympathetic and vagal function during sustained handgrip exercise in normotensive obese women.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Polimorfismo Genético
/
Sistema Nervioso Autónomo
/
Ejercicio Físico
/
Receptores Adrenérgicos alfa 2
/
Corazón
/
Obesidad
Límite:
Adult
/
Female
/
Humans
Idioma:
En
Revista:
Int J Obes (Lond)
Año:
2006
Tipo del documento:
Article
País de afiliación:
Brasil