Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We surveyed 1,545 subjects--recruited into the UK Medical Research Council elderly hypertension treatment trial between 1982 and 1987--to detect incident cases of dementia, identifying 50 cases of dementia, including 31 cases of probable or possible Alzheimer's disease (AD). These we compared with 223 unimpaired, unmatched controls from the same population for exposure to familial, cardiovascular, educational, and geographic risk factors for dementia. Our study confirms the association of family history of dementia with dementia (odds ratio [OR] = 4.36) and AD (OR = 4.69), and of advanced age with dementia (OR = 2.81). Rural residence exerted a protective effect for dementia (OR = 0.21) and AD (OR = 0.28). We report near-significant associations between AD and dementia and several cardiovascular risk factors (ECG ischemia, systolic hypertension, and smoking) among subjects lacking a family history of dementia. We postulate the existence of a nonfamilial form of dementia transcending traditional categories of multi-infarct dementia and AD, more common among urban residents, and mediated through vascular pathology. Risk factors reported elsewhere but not confirmed in this study were advanced maternal age and winter season of birth.
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PMID:Risk factors for Alzheimer's disease and dementia: a case-control study based on the MRC elderly hypertension trial. 829 99

Eptastigmine is a new cholinesterase inhibitor, which may be potentially useful for the symptomatic treatment of Alzheimer's disease. A preliminary evaluation of its pharmacodynamic and pharmacokinetic profiles in the elderly has now been made in 6 healthy subjects (63-84 years of age) given 30 mg eptastigmine as a single oral dose. Blood was collected prior to and 1, 2, 3, 4, 6, 8, and 12 h after eptastigmine administration for measurement of cholinesterase inhibition in plasma and red blood cells and the plasma drug concentrations. The maximum plasma cholinesterase inhibition was 17%, which was reached 2.7 h after treatment. In red cells the maximum inhibition of the enzyme was 29% after 3.8 h. The estimated half-time of cholinesterase recovery was 12.4 h in plasma and 13.6 h in red blood cells. The peak plasma concentration of eptastigmine of 0.86 ng.ml-1 was reached after 1.4 h. Following absorption the drug was rapidly distributed into tissues (t1/2 alpha = 0.44 h) and then eliminated with a half-life of 12.1 h. The drug was well tolerated in all but one subject, who showed bradycardia with hypertension and nausea for about 2 h after the dose. The results indicate that oral administration of eptastigmine to elderly subjects produces long lasting inhibition of cholinesterase activity in plasma and in red blood cells.
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PMID:Pharmacodynamics and pharmacokinetics of eptastigmine in elderly subjects. 829 73

To elucidate a definite prevalence of dementia and its risk factors in the senescence, 887 subjects aged 65 years or over of Hisayama residents (94.6% of the whole population in the same age-range) were examined from May to December, 1985, as to whether he or she has suffered dementia. Karasawa's "Clinical criteria for the severity of dementia", Hasegawa's Dementia Scale and Hachinski's ischemic score were used as a procedure to identify demented persons. Out of 887 examined, 59 subjects were diagnosed to have had dementia (6.7%) with female to male ratio being 1.2. The prevalence rates of dementia increased with advanced age decades and sharply grew up over tha age of 80 years. Brain morphology in 50 of the 59 dementias was re-evaluated by autopsy and/or CT scan, during a 55-month follow-up period from January 1986 to July 1990. Coincidence rate between clinical evaluation and morphological diagnosis was 90.5% for vascular dementia (VD), 62.5% for senile dementia of Alzheimer type (SDAT), and 28.6% for other or ill-defined dementia (Others). Misdiagnosis of clinical evaluation for VD was mainly due to uncertain history of head trauma, while the subjects suffering from atypical stroke tended to be diagnosed as SDAT. Out of the 21 cases who were initially diagnosed as having other or ill-defined dementia, 8 were re-evaluated as VD, and 7 as SDAT later. Most cases who were finally diagnosed as having VD had multi-infarcts without an episode of stroke attack, while those who were classified to SDAT had less severely undergone dementia. The final type-specific prevalence of dementia was 56% for VD, 26% for SDAT and 18% for Others, respectively. The ratio of VD to SDAT was 2.2, indicating more frequent VD than SDAT. Retrospective case-control study on risk factors of VD was performed using selected parameters obtained at examinations in 1973 or 1978, comparing 27 VD cases and 789 non-demented cases. As a consequence, aging, hypertension, electro-cardiographic abnormalities (Minnesota code 3-1 and/or 4-1, 2, 3) and high hematocrit were taken as important risk factors for VD. These risk factors were very similar to those for lacunar infarcts among Hisayama residents. The difficulty of epidemiologic study on dementia in general population and the accuracy of diagnosis for type of dementia were discussed.
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PMID:[Epidemiologic and clinico-pathologic study on senile dementia in a Japanese community, Hisayama]. 833 7

We investigated whether cigarette smoking is negatively associated with Alzheimer's disease (AD) in a population-based, frequency-matched, case-control study of 152 AD patients and 180 controls. Ever having smoked was associated with lower risk of AD (adjusted odds ratio = 0.61; 95% confidence interval: 0.37-0.99). Additional multivariate analyses demonstrated that education and history of hypertension modified this association. The direction of the modification was for higher education level and history of hypertension to further reduce the risk. The "dose-response" pattern showed the greatest risk reduction among those who smoked least and suggests a biologic mechanism of a dose-dependent up-regulation of nicotinic (cholinergic) brain receptors. These data, although consistent with current opinion about pathophysiology of AD, do not suggest smoking should be used as a preventive strategy for AD.
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PMID:Relationship between cigarette smoking and Alzheimer's disease in a population-based case-control study. 843 92

This study examined associations of psychosocial factors with cardiovascular reactivity in two groups of men and women--spouse caregivers of individuals with Alzheimer's disease (M age = 69.4 N = 82) and controls (M age = 68.5, N = 78) group-matched for age and gender. Cardiovascular responses to an emotional task (speech sample about one's spouse) yielded higher systolic and diastolic blood pressures (SBP, DBP) than a spoken cognitive task, which in turn yielded higher BPs and heart rate (HR) than the baseline rest period. HR was greater in response to the two tasks than in response to the baseline period, but it did not differ across tasks. Regression models of SBP, DBP, and HR reactivity in response to the two tasks demonstrated that after controlling for hypertension and gender, combinations of hostility, anger expression, avoidance coping, Type A behavior and Expressed Emotion (criticism) explained more reactivity in response to the emotional (8-12%) than the cognitive task (4-7%). Caregivers were more reactive than controls only if they were hypertensive. Psychosocial factors may be as important in explaining reactivity in older adults as in younger adults.
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PMID:Psychosocial factors associated with cardiovascular reactivity in older adults. 847 31

To study the relationship between vascular factors and white matter low attenuation of the brain (WMLA), computer tomography findings of 251 patients were re-interpreted. Clinical data on patients were collected from the hospital records. It was possible to obtain sufficient clinical data on 204 patients who were included in the study. WMLA changes, on computer tomography, were found in 51.5% of patients. WMLA was most commonly present in patients with vascular (69.8%) and combined (69.2%) dementia. The occurrence of WMLA did not differ between patients with Alzheimer's disease (26.7%) and those without dementia (35.9%). Arterial hypertension, coronary heart disease, or diabetes were not associated with WMLA. Heart failure and orthostatic hypotension, were found to be more commonly present in patients with than in those without WMLA (34.0% vs 14.3%, p = 0.0012; 10.0% vs 2.0%, p = 0.036). Both systolic and diastolic low blood pressure values were associated with WMLA unlike hypertensive blood pressure values. Atrial fibrillation in electrocardiography was associated with WMLA, while neither left ventricular hypertrophy nor myocardial infarction was. When several explanatory variables were adjusted by logistic regression analysis, age, heart failure, and systolic blood pressure below 130 predicted WMLA. In conclusion, the association between WMLA and vascular factors with hemodynamic significance suggests that cerebral hypoperfusion may contribute to the genesis of WMLA.
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PMID:Relationship between vascular factors and white matter low attenuation of the brain. 850 57

Vascular dementia is the most common cause of dementia in the elderly after Alzheimer's disease. Many forms of vascular dementia have been described: multi-infarct dementia, lacunar dementia, Binswanger's subcortical encephalopathy, cerebral amyloid angiopathy, white matter lesions associated with dementias, single infarct dementia, dementia linked to hypoperfusion and haemorrhagic dementia. The difficulty of diagnosing vascular dementia must not be underestimated and an international consensus is needed for epidemiological studies. The NINCDS-AIREN group has recently published diagnostic criteria. The State of California Alzheimer's Disease Diagnostic and Treatment Centers also proposed some which differ from the NINCDS-AIREN criteria in considering only ischaemic vascular dementia and not other mechanisms such as haemorrhagic or hypoxic lesions. Most studies stress hypertension as the most powerful risk factor for all forms of vascular dementia. The incidence rate ranges from 7 per 1000 person-years in normal volunteers to 16 per 1000 person-years in hypertensive patients. No therapeutic attempt has influenced the course of the disease once the dementing condition is established. The only effective approach is preventive treatment. The objective of the SYST-EUR Vascular Dementia project is to confirm that the treatment of isolated systolic hypertension is able to reduce its incidence.
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PMID:Assessing vascular dementia. 853 23

The heterogeneity of vascular dementia depends on the cause, size, location and nature of the vascular lesions (36, 62). Magnetic resonance imaging (MRI) techniques are of major interest to detect the vascular origin of dementia: the lack of focal lesions or leukoencephalopathy excludes the vascular origin of dementia (36). Occlusions of large extra-cerebral arteries usually lead to cortical or large subcortical infarcts or both (28). Dementia may be due to multiple infarcts or to a single infarct located in a strategic area (47). Lacunar infarcts are due to the occlusion of one single deep perforator with a thickening of the arterial wall due to lipohyalinosis (25), usually in a patient with arterial hypertension; lacunes are located in a territory supplied by the deep perforators. They appear as hyperintense in T2-weighted sequences and hypo-intense in T1-weighted sequences. Old small hemorrhages have the same appearance than infarcts on CT-scans but their center appears hypo-intense in T2-weighted sequences. In normal subjects, age and arterial hypertension are risk factors for hemispheric white matter hyperintensities (59, 60). Their vascular origin is likely because of the evidence of lesions of the wall of deep perforators (17, 21), their association with lacunes (17, 21, 30, 37) or deep hemorrhages (30, 32, 37), and their frequency in amyloid angiopathy (26). Their prevalence is higher in vascular dementia than in Alzheimer's disease (59). They sometimes fulfill criteria for Binswanger's disease (5). Even after exclusion of predisposing factors they remain frequent in healthy subjects over 50 years (39, 56); however, whether they herald subsequent dementia remains unsettled.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Magnetic resonance imaging in vascular dementia]. 854 1

Bayes' theorem describes the effect of new information (e.g., a test result) on the probability of an outcome (e.g., a disease). Likelihood ratios for separate tests can be combined to assess the joint effect of their results on disease probability. This approach has been used to develop a test package for Alzheimer's disease that consists of some simple cognitive tests (Paired Associate Learning Test, Trailmaking Test, and Raven's Progressive Matrices) combined with age and family history of dementia. A total of 1,454 subjects who had been recruited into the Medical Research Council Elderly Hypertension Trial between 1983 and 1985 completed cognitive tests at entry to the trial (when they were without signs of dementia) and 1 month later. Their dementia status was ascertained in 1990-1991. The test package identified 52% of Alzheimer's disease cases with a 9% false-positive rate or 90% of Alzheimer's disease cases with a 29% false-positive rate. The author proposes the use of a similar test package in conjunction with a test for apolipoprotein E e4 status, which is a powerful risk factor for late-onset Alzheimer's disease, as a likelihood ratio approach to the prospective identification of Alzheimer's disease cases. This approach could be followed by ethically sound trials of new therapeutic agents for subjects who have a high probability of developing Alzheimer's disease.
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PMID:Predicting the onset of Alzheimer's disease using Bayes' theorem. 856 Nov 65

With the advancement of technical progress, especially with respect to magnetic resonance imaging, patchy cerebral white matter lesions (WML) are being found with increasing frequency. The (differential) diagnosis between the two main dementias of old age, (senile) dementia of the Alzheimer type ([S]DAT) and vascular dementia (VD) is made more frequently in favour of the latter, since the detection of WML leads to support a vascular origin for dementia. The present article reviews the literature concerning X-ray computed tomography (CT) and magnetic resonance imaging (MRI) in these disorders. For comparison purposes some methodological problems must be taken into account including different scoring systems for WML severity, differences in imaging techniques and in the criteria for the selection of patients and controls. A great number of studies demonstrates a strong association of frequency and severity of WML with increasing age and presence of cerebrovascular risk factors such arterial hypertension. Some studies revealed an association with neuropsychiatric deficits including gait disorders, urinary incontinence, affective lability and reduced attention and information processing speed. In CT studies, about 30% of patients with (S)DAT had WML but 36-88% in MR studies. However, only few studies controlled for the presence of cerebrovascular risk factors. More recent studies - with improved techniques - revealed a higher frequency of (slight or moderate) WML in the (S)DAT group compared to controls. The prevalence of WML in VD patients was 75-97% in CT studies and about 100% in MR studies. Therefore, without the presence of WML, the diagnosis of VD is currently in doubt. A number of in vivo investigations proved consistently - and with different methods - that cerebral blood flow was reduced in WML regions. As shown in some studies the neuropathologic correlates of WML have in common that the relative tissue water content is increased: This includes inflammation, gliosis, complete and incomplete infarctions, dilation of the perivascular (Virchow-Robin) spaces with myelin atrophy. Thus the finding of WML in watershed areas can be understood. Three case reports serve to illustrate the problems pointed out. In conclusion, the occurrence of WML is an unspecific finding which is observed in up to 50% of the elderly. Diagnostic classification as "vascular lesions" or signs of "vascular encephalopathy" or VD based on CT or MRI alone, should not be made.
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PMID:[Patchy changes in white matter in cranial computerized and magnetic resonance tomography--significance for (differential) diagnosis of dementia of the Alzheimer type and vascular dementia]. 857 17


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