Amlodipine lowers blood pressure without affecting cerebral blood flow as measured by single photon emission computed tomography in elderly hypertensive subjects

Pandita-Gunawardena, N. D.; Clarke, Simon

doi:10.1093/ageing/28.5.451

Cited by 23 publications

(15 citation statements)

References 24 publications

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“…[34][35][36] However, this has not been a finding in all studies, 19,20 which may reflect methodological or small sample sizes in some studies. 19,20 Our study has specific features which add to understanding of the effects of BP lowering on CBF.…”

Section: Discussionmentioning

confidence: 99%

Intensive Blood Pressure Lowering Increases Cerebral Blood Flow in Older Subjects With Hypertension

Tryambake

He²,

Firbank³

et al. 2013

Hypertension

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Abstract-Hypertension is associated with reduced cerebral blood flow (CBF). Intensive (<130/80 mm Hg) blood pressure (BP) lowering in older people might give greater reduction in cardiovascular risk, but there are concerns that this might produce hypoperfusion which may precipitate falls and possibly stroke. We determined the effect of intensive compared with usual BP lowering on CBF in hypertensive older subjects. Individuals aged >70 years with a history of systolic hypertension on 1 or no BP lowering drugs were recruited from primary care (n=37; age, 75±4 years; systolic BP, >150 mm Hg) and randomized to receive intensive (target BP, <130/80 mm Hg) or usual (target BP, <140/85 mm Hg) BP lowering for 12 weeks, with reviews every 2 weeks. CBF, determined using 3T arterial spin labeling MRI, and 24-hour ambulatory BP were performed at baseline and after 12 weeks of treatment. Baseline BP (ambulatory or in clinic) and baseline gray matter CBF were not significantly different between the groups. After treatment, BP was reduced significantly in both groups but fell more in the intensive group (26/17 versus 15/5 mm Hg; P<0.01). Over the same period, gray matter CBF increased significantly in the intensive group (7±11 mL/min per 100 g; P=0.

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Section: Discussionmentioning

confidence: 99%

Intensive Blood Pressure Lowering Increases Cerebral Blood Flow in Older Subjects With Hypertension

Tryambake

He²,

Firbank³

et al. 2013

Hypertension

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“…[7][8][9][10][11][12][13] However, the effects of these medications on cerebral blood flow during orthostatic stress have not been established, particularly in elderly patients with systolic hypertension.…”

Section: Discussionmentioning

confidence: 99%

Antihypertensive Therapy Increases Cerebral Blood Flow and Carotid Distensibility in Hypertensive Elderly Subjects

Lipsitz

Gagnon²,

Vyas³

et al. 2005

Hypertension

100

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Abstract-Many physicians are reluctant to lower blood pressure to recommended levels in elderly hypertensive patients because of concern about producing cerebral hypoperfusion. Because hypertension is associated with potentially reversible structural and functional alterations in the cerebral circulation that may improve with treatment, we investigated whether long-term pharmacological reduction of systolic blood pressure will improve, rather than worsen, cerebral blood flow and its regulation. Three groups of elderly subjects 65 years of age or older were studied prospectively: normotensive subjects (Nϭ19), treated hypertensive subjects with systolic pressure Ͻ140 mm Hg (Nϭ18), and uncontrolled hypertensive subjects with systolic pressure Ͼ160 mm Hg at entry into the study (Nϭ14).We measured beat-to-beat blood flow velocity in the middle cerebral artery (transcranial Doppler ultrasonography), finger arterial pressure (photoplethysmography), and pulsatile distensibility of the carotid artery (duplex Doppler ultrasonography) at baseline and after 6 months of observation or antihypertensive therapy. After baseline hemodynamic measurements, uncontrolled hypertensive subjects underwent aggressive treatment with lisinopril with or without hydroclorothiazide or, if not tolerated, nifedipine or an angiotensin receptor blocker to bring their systolic pressure Ͻ140 mm Hg for 6 months. The other 2 groups were observed for 6 months. After 6 months of successful treatment, uncontrolled hypertensive subjects had significant increases in cerebral blood flow velocity and carotid distensibility that was not seen in the other groups. Treatment reduced cerebrovascular resistance and did not impair cerebral autoregulation. Therefore, judicious long-term treatment of systolic hypertension in otherwise healthy elderly subjects does not cause cerebral hypoperfusion. Key Words: aging Ⅲ angiotensin-converting enzyme inhibitor Ⅲ brain Ⅲ hemodynamics Ⅲ ultrasonography A lthough the treatment of systolic hypertension has been shown in prospective randomized controlled trials to reduce cardiovascular morbidity and mortality in subjects up to age 80, many physicians are reluctant to lower systolic blood pressure (BP) to the recommended level of 140 mm Hg or lower in elderly patients, because of concern that aggressive treatment may cause cerebral hypoperfusion and associated syncope, falls, or cognitive dysfunction. 1,2 Because hypertension is associated with potentially reversible structural and functional changes in the cerebral circulation, we hypothesized that long-term BP reduction would improve, rather than worsen, cerebral blood flow and its regulation. Therefore, we conducted the current study to determine the effects of systolic BP reduction over 6 months on cerebral perfusion in elderly hypertensive patients. We also examined structural and functional changes in the cerebral vasculature potentially affected by BP-lowering, including carotid distensibility and cerebral autoregulation. Methods DesignThe study was a prospective 3-gro...

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“…* Maximum of BP and CBFV respectively. type 1 receptor) antagonist are confirmed [37][38][39][40][41][42]. Thus elderly subjects with hypertension, whether controlled or uncontrolled with antihypertensive medication, retain cerebral autoregulatory capacity [43].…”

Section: Figure 3 Representative Continuous Recordings Of Bp and Cbfvmentioning

confidence: 92%

Dynamic cerebral autoregulatory capacity is affected early in Type 2 diabetes

et al. 2008

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Type 2 diabetes is associated with an increased risk of endothelial dysfunction and microvascular complications with impaired autoregulation of tissue perfusion. Both microvascular disease and cardiovascular autonomic neuropathy may affect cerebral autoregulation. In the present study, we tested the hypothesis that, in the absence of cardiovascular autonomic neuropathy, cerebral autoregulation is impaired in subjects with DM+ (Type 2 diabetes with microvascular complications) but intact in subjects with DM- (Type 2 diabetes without microvascular complications). Dynamic cerebral autoregulation and the steady-state cerebrovascular response to postural change were studied in subjects with DM+ and DM-, in the absence of cardiovascular autonomic neuropathy, and in CTRL (healthy control) subjects. The relationship between spontaneous changes in MCA V(mean) (middle cerebral artery mean blood velocity) and MAP (mean arterial pressure) was evaluated using frequency domain analysis. In the low-frequency region (0.07-0.15 Hz), the phase lead of the MAP-to-MCA V(mean) transfer function was 52+/-10 degrees in CTRL subjects, reduced in subjects with DM- (40+/-6 degrees ; P<0.01 compared with CTRL subjects) and impaired in subjects with DM+ (30+/-5 degrees ; P<0.01 compared with subjects with DM-), indicating less dampening of blood pressure oscillations by affected dynamic cerebral autoregulation. The steady-state response of MCA V(mean) to postural change was comparable for all groups (-12+/-6% in CTRL subjects, -15+/-6% in subjects with DM- and -15+/-7% in subjects with DM+). HbA(1c) (glycated haemoglobin) and the duration of diabetes, but not blood pressure, were determinants of transfer function phase. In conclusion, dysfunction of dynamic cerebral autoregulation in subjects with Type 2 diabetes appears to be an early manifestation of microvascular disease prior to the clinical expression of diabetic nephropathy, retinopathy or cardiovascular autonomic neuropathy.

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Amlodipine lowers blood pressure without affecting cerebral blood flow as measured by single photon emission computed tomography in elderly hypertensive subjects

Abstract: Amlodipine was a well-tolerated and effective antihypertensive agent, and did not reduce regional cerebral blood flow in elderly hypertensive patients.

Cited by 23 publications

References 24 publications

Intensive Blood Pressure Lowering Increases Cerebral Blood Flow in Older Subjects With Hypertension

Intensive Blood Pressure Lowering Increases Cerebral Blood Flow in Older Subjects With Hypertension

Antihypertensive Therapy Increases Cerebral Blood Flow and Carotid Distensibility in Hypertensive Elderly Subjects

Dynamic cerebral autoregulatory capacity is affected early in Type 2 diabetes

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