title: Modifying effects of the R389G beta1-adrenoceptor polymorphism on resting heart rate and blood pressure in patients with obstructive sleep apnoea.
abstract: OSA (obstructive sleep apnoea) stimulates sympathetic nervous activity and elevates resting HR (heart rate) and BP (blood pressure). In the present study in a cohort of 309 untreated OSA patients, the resting HR and BP during the daytime were correlated with AHI (apnoea/hypopnea index) and compared with patients with R389R (n = 162), R389G (n = 125) and G389G (n = 22) genotypes of the beta1-adrenoreceptor R389G polymorphism. We analysed the impact of the genotype on the decline of HR and BP in a subgroup of 148 patients (R389R, n = 86; R389G, n = 54; G389G, n = 8) during a 6-month follow-up period under CPAP (continuous positive airway pressure) therapy during which cardiovascular medication remained unchanged. In untreated OSA patients, we found an independent relationship between AHI and resting HR (beta = 0.096, P < 0.001), systolic BP (beta = 0.09, P = 0.021) and diastolic BP (beta = 0.059, P = 0.016). The resting HR/BP, however, did not differ among carriers with the R389R, R389G and G389G genotypes. CPAP therapy significantly reduced HR [-2.5 (-1.1 to -4.0) beats/min; values are mean difference (95% confidence intervals)] and diastolic BP [-3.2 (-1.5 to -5.0) mmHg]. The decline in HR was more significantly pronounced in the R389R group compared with the Gly(389) carriers [-4.1 (-2.3 to -5.9) beats/min (P < 0.001) compared with -0.2 (2.1 to -2.6) beats/min (P = 0.854) respectively; Student's t test between groups, P = 0.008]. Diastolic BP was decreased significantly (P < 0.001) only in Gly389 carriers (R389G or G389G) compared with R389R carriers [-5.0 (-2.3 to -7.6) mmHg compared with -2.0 (0.4 to -4.3) mmHg respectively]. ANOVA revealed a significant difference (P = 0.023) in HR reduction between the three genotypes [-4.1 (+/-8.4) beats/min for R389R, -0.5 (+/-9.3) beats/min for R389G and +1.9 (+/-7.2) beats/min for G389G]. In conclusion, although the R389G polymorphism of the beta1-adrenoceptor gene did not influence resting HR or BP in untreated OSA patients, it may modify the beneficial effects of CPAP therapy on these parameters.
authors.affiliation: Medical Clinic 2, Cardiology and Angiology, St Josef Hospital/Bergmannsheil, Ruhr University, Bochum, Germany. jan.boergel@ruhr-uni-bochum.de
authors.forename: Jan
authors.initials: J
authors.lastname: Börgel
authors.forename: Tino
authors.initials: T
authors.lastname: Schulz
authors.forename: Nina K
authors.initials: NK
authors.lastname: Bartels
authors.forename: Jörg T
authors.initials: JT
authors.lastname: Epplen
authors.forename: Nikolaus
authors.initials: N
authors.lastname: Büchner
authors.forename: Lars Christian
authors.initials: LC
authors.lastname: Rump
authors.forename: Anika
authors.initials: A
authors.lastname: Huesing
authors.forename: Bernd M
authors.initials: BM
authors.lastname: Sanner
authors.forename: Andreas
authors.initials: A
authors.lastname: Mügge
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000235:genetics*; D045422:Continuous Positive Airway Pressure; D005260:Female; D005500:Follow-Up Studies; D005838:Genotype; D006339:Heart Rate / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D017286:Polysomnography; D018342:Receptors, Adrenergic, beta-1 / Q000235:genetics*; D020181:Sleep Apnea, Obstructive / Q000235:genetics* / Q000503:physiopathology / Q000628:therapy
chemical_list: D018342:Receptors, Adrenergic, beta-1