OS 31-02 ANTIHYPERTENSIVE RESPONSE TO BISOPROLOL WAS NOT RELATED TO POLYMORPHISMS IN ADRB1 Or CYP2D6 IN CHINESE HYPERTENSIVE PATIENTS.

OBJECTIVE: The blood pressure (BP) response to antihypertensive drugs varies considerably between different patients. The response to some beta-blockers has been associated with polymorphisms in the beta1-adrenergic receptor (ADRB1) or cytochrome P450 2D6 (CYP2D6) genes. We examined the effects of common polymorphisms in ADRB1 and CYP2D6 on the response to bisoprolol in 100 Chinese patients.

DESIGN AND METHOD: Chinese patients with primary hypertension with sitting clinic systolic BP (SBP) 140-169 mmHg and/or diastolic BP (DBP) 90-109 mmHg after placebo run-in were treated with open-label bisoprolol 2.5 mg daily. Other antihypertensive treatments were discontinued except for amlodipine which was continued if necessary to achieve BPs in the defined range at the end of the run-in. Clinic and ambulatory BP (ABP) were measured after the placebo run-in and after 6 weeks treatment. Patients were genotyped for the Gly389Arg and Ser49Gly polymorphisms in ADRB1 and the CYP2D6*10 polymorphism.

RESULTS: After 6 weeks of treatment with bisoprolol 2.5 mg daily, reductions in clinic BP and heart rate were 14.3 ± 10.9/8.4 ± 6.2 mmHg (p < 0.01) and 6.3 ± 7.6 beats/min (p < 0.01), respectively, and there were similar reductions in the ABP and heart rate values. Allele frequencies of the ADRB1 Gly389Arg and Ser49Gly and CYP2D6*10 variants were 0.24, 0.18, and 0.42, respectively. In 97 patients (age 55 ± 11 years, 59% male) with complete data, the reductions in SBP were related to the baseline SBP values but not to age, sex, body weight or concomitant therapy with amlodipine. Reductions in DBP and heart rate were not significantly related to any of these phenotype variables. There was no significant association of the ADRB1 polymorphisms or haplotypes or the CYP2D6*10 polymorphism with the clinic or ABP responses to bisoprolol.

CONCLUSIONS: Reductions in BP and heart rate with bisoprolol treatment were not related to the common polymorphisms in ADRB1 and CYP2D6 in Chinese hypertensive patients.