| 1. |
- Hallberg, Pär, et al.
(författare)
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Adipocyte-derived leucine aminopeptidase genotype and response to antihypertensive therapy
- 2003
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Ingår i: BMC Cardiovascular Disorders. - : Springer Science and Business Media LLC. - 1471-2261 .- 1471-2261. ; 18:3, s. 11-
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Tidskriftsartikel (refereegranskat)abstract
- BackgroundAdipocyte-derived leucine aminopeptidase (ALAP) is a recently identified member of the M1 family of zinc-metallopeptidases and is thought to play a role in blood pressure control through inactivation of angiotensin II and/or generation of bradykinin. The enzyme seems to be particularly abundant in the heart. Recently, the Arg528-encoding allele of the ALAP gene was shown to be associated with essential hypertension.MethodsWe evaluated the influence of this polymorphism on the change in left ventricular mass index in 90 patients with essential hypertension and echocardiographically diagnosed left ventricular hypertrophy, randomised in a double-blind study to receive treatment with either the angiotensin II type I receptor antagonist irbesartan or the beta1-adrenoceptor blocker atenolol for 48 weeks. Genyotyping was performed using minisequencing.ResultsAfter adjustment for potential covariates (blood pressure and left ventricular mass index at baseline, blood pressure change, age, sex, dose and added antihypertensive treatment), there was a marked difference between the Arg/Arg and Lys/Arg genotypes in patients treated with irbesartan; those with the Arg/Arg genotype responded on average with an almost two-fold greater regression of left ventricular mass index than patients with the Lys/Arg genotype (-30.1 g/m2 [3.6] vs -16.7 [4.5], p = 0.03).ConclusionsThe ALAP genotype seems to determine the degree of regression of left ventricular hypertrophy during antihypertensive treatment with the angiotensin II type I receptor antagonist irbesartan in patients with essential hypertension and left ventricular hypertrophy. This is the first report of a role for ALAP/aminopeptidases in left ventricular mass regulation, and suggests a new potential target for antihypertensive drugs.
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| 2. |
- Hallberg, Pär, et al.
(författare)
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B2 bradykinin receptor (B2BKR) polymorphism and change in left ventricular mass in response to antihypertensive treatment : results from the Swedish Irbesartan Left Ventricular Hypertrophy Investigation versus Atenolol (SILVHIA) trial
- 2003
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Ingår i: Journal of Hypertension. - : Lippincott Williams & Wilkins. - 0263-6352 .- 1473-5598. ; 21:3, s. 621-4
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Hypertension is associated with a number of adverse morphologic and functional changes in the cardiovascular system, including left ventricular (LV) hypertrophy. Studies have demonstrated that bradykinin, through the B2 bradykinin receptor (B2BKR), mediates important cardiovascular effects that may protect against LV hypertrophy. Recently, a +9/-9 exon 1 polymorphism of the B2BKR was shown to be strongly associated with LV growth response among normotensive males undergoing physical training. We aimed to clarify whether the processes found in exercise-induced LV growth in normotensive people also occur in pathological LV hypertrophy. DESIGN AND METHODS: We determined the B2BKR genotype of 90 patients with essential hypertension and echocardiographically diagnosed LV hypertrophy, included in a double-blind study to receive treatment for 48 weeks with either the angiotensin II type 1 (AT1) receptor antagonist irbesartan or the beta1-adrenoceptor antagonist atenolol. RESULTS: B2BKR +9/+9 genotypes responded poorly in LV mass regression, independent of blood pressure reduction or treatment, as compared to the other genotypes (adjusted mean change in LV mass index = -10.0 +/- 4.6 versus -21.6 +/- 2.2 g/m2, P = 0.03). CONCLUSIONS: Our results suggest an impact of the B2BKR polymorphism on LV mass regression during antihypertensive treatment.
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| 3. |
- Hallberg, Pär, et al.
(författare)
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The CYP2C9 genotype predicts the blood pressure response to irbesartan : results from the Swedish Irbesartan Left Ventricular Hypertrophy Investigation vs Atenolol (SILVHIA) trial
- 2002
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Ingår i: Journal of Hypertension. - : Lippincott Williams & Wilkins. - 0263-6352 .- 1473-5598. ; 20:10, s. 2089-2093
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The cytochrome P450 CYP2C9 enzyme (CYP2C9) metabolizes many clinically important drugs, for example, phenytoin, warfarin and the angiotensin II type 1 (AT(1)) receptor antagonists, losartan and irbesartan. Single nucleotide polymorphisms in the CYP2C9 gene result in the expression of three important variants, CYP2C9*1(wild-type), CYP2C9*2 and CYP2C9*3, the last two exhibiting reduced catalytic activity compared with the wild-type. The CYP2C9 genotype is known to determine sensitivity to and dose requirements for both warfarin and phenytoin, and also the rate of metabolism of losartan. However, its influence on clinical response to treatment with the AT(1) receptor antagonist, irbesartan, has not been investigated. OBJECTIVE: To determine whether the CYP2C9genotype influences the blood pressure-decreasing response to antihypertensive treatment with irbesartan. DESIGN AND METHODS: One hundred and two patients with essential hypertension and left ventricular hypertrophy were allocated randomly to groups to receive double-blind treatment with either irbesartan (n = 49) or the beta(1)-adrenergic receptor blocker, atenolol ( n= 53). Blood pressure was measured before and after 12 weeks of treatment. genotyping was performed using solid-phase minisequencing. RESULTS: The diastolic blood pressure (DBP) response differed in relation to the CYP2C9 genotype in patients given irbesartan: the reduction in patients with genotype CYP2C9*1/CYP2C9*1 (n = 33) was 7.5% and that with CYP2C9*1/CYP2C9*2 (n = 12) was 14.4% ( P= 0.036). A similar trend was seen for systolic blood pressure. In contrast, no relation was seen between the CYP2C9 genotype and blood pressure response to atenolol, a drug not metabolized via CYP2C9. CONCLUSIONS: The CYP2C9 genotype seems to predict the DBP response to irbesartan, but not to atenolol, in patients with essential hypertension.
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| 4. |
- Hallberg, Pär, et al.
(författare)
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Transforming growth factor beta1 genotype and change in left ventricular mass during antihypertensive treatment : results from the Swedish Irbesartan Left Ventricular Hypertrophy Investigation versus Atenolol (SILVHIA)
- 2004
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Ingår i: Clinical Cardiology. - : Wiley. - 0160-9289 .- 1932-8737. ; 27:3, s. 169-73
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Angiotensin II, via the angiotensin II type 1 (AT1) receptor, may mediate myocardial fibrosis and myocyte hypertrophy seen in hypertensive left ventricular (LV) hypertrophy through production of transforming growth factor beta1 (TGF-beta1); AT1-receptor antagonists reverse these changes. The TGF-beta1 G + 915C polymorphism is associated with interindividual variation in TGF-beta1 production. No study has yet determined the impact of this polymorphism on the response to antihypertensive treatment. HYPOTHESIS: We aimed to determine whether the TGF-beta1 G + 915C polymorphism was related to change in LV mass during antihypertensive treatment with either an AT1-receptor antagonists or a beta1-adrenoceptor blocker. The polymorphism was hypothesized to have an impact mainly on the irbesartan group. METHODS: We determined the association between the TGF-beta1 genotype and regression of LV mass in 90 patients with essential hypertension and echocardiographically diagnosed LV hypertrophy, randomized in a double-blind study to receive treatment for 48 weeks with either the AT1-receptor antagonist irbesartan or the beta1-adrenoceptor blocker atenolol. RESULTS: Irbesartan-treated patients who were carriers of the C-allele, which is associated with low expression of TGF-beta1, responded with a markedly greater decrease in LV mass index (LVMI) than subjects with the G/G genotype (adjusted mean change in LVMI -44.7 g/m2 vs. -22.2 g/m2, p = 0.007), independent of blood pressure reduction. No association between genotype and change in LVMI was observed in the atenolol group. CONCLUSIONS: The TGF-beta1 G + 915C polymorphism is related to the change in LVMI in response to antihypertensive treatment with the AT1-receptor antagonist irbesartan.
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