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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

During recent decades the importance of perceiving isolated systolic hypertension (ISH) in cardiovascular pathophysiology has been changed from a benign condition to the major cardiovascular risk factor. Aging is per se associated with the deterioration in arterial compliance through both structural and functional changes in large arteries which mainly involves the intima and media. The observed changes result in a decrease of the lumen-to-wall ratio, the overall lumen cross-sectional area and an increase of arterial stiffness which especially involve the aorta and other elastic arteries. In addition to the structural changes in vessel walls, aging is associated with certain functional changes such as an increase in sympathetic system activity probably due to the age-related decreased sensitivity of beta-receptors. While the function of arterial wall alpha-receptors remains intact, in elderly subjects a shift towards arterial vasoconstriction can be observed. In many of the published studies the definition of ISH was based on the criterion 160/95 mm Hg or 160/90 mm Hg while in recognition of the high risk associated with systolic blood pressure (SBP) the WHO/ISH guidelines and Report of the Sixth Joint National Committee on Hypertension indicated that ISH should be diagnosed with SBP as > or =140 mm Hg and diastolic BP (DBP) as <90 mm Hg. Thus the setting down of normal values of SBP will lead to an earlier diagnosis and treatment of ISH. Several prospective studies, such as the US Hypertension Detection and Follow-up Programme, confirmed this and the Multiple Risk Factor Intervention Trial demonstrated that for any given level of DBP, higher SBP was associated with an increase in cardiovascular risk. Moreover, data from the Framingham Study show that ISH was associated not only with increased mortality but also cardiovascular morbidity. Risk of non-fatal stroke and myocardial infarction was increased three and two-times respectively in the presence of ISH. Three major up-to-date studies that included patients with ISH have been published. In concordance to the previously published SHEP and MCR trials, the most recent, the Systolic Hypertension in the Elderly Trial (SYST-EUR), demonstrated that active treatment significantly reduces the risk of stroke and all fatal and non-fatal cardiac end-points, including sudden death. Of note, these benefits were demonstrated with new anti-hypertensive classes such as dihydropiridyne calcium channel blocker (nitrendipine) and the angiotensin-converting enzyme inhibitor (enalapril). The necessity to carefully balance the benefits and risks of anti-hypertensive therapy in the elderly indicates that patients with suspected ISH should undergo careful BP measurements on at least three different occasions before the diagnosis is established and an orthostatic reaction should be evaluated. If non-pharmacological procedures fail, drug therapy should be considered, especially in elderly patients with a SBP over 160 mm Hg, since their risk of complications is markedly higher. Pharmacological treatment should also be strongly considered in patients with a SBP between 140 and 160 mm Hg with such concomitant cardiovascular risk factors as diabetes, angina pectoris, and left ventricular hypertrophy. The drug regimen should be simple, starting with a low dose of a single drug that is titrated slowly. The selection of the first-line anti-hypertensive agent should be based on a careful assessment of pathophysiological and clinical parameters in each individual geriatric patient.
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PMID:Isolated systolic hypertension: pathophysiology, consequences and therapeutic benefits. 978 91

This paper briefly reviews the epidemiological evidence that hypertension is a major cardiovascular risk factor. It also summarizes the data from controlled intervention trials that show antihypertensive treatment to be accompanied by a reduction in cardiovascular morbidity and mortality. The inability of antihypertensive treatment to offer full protection to the hypertensive individual is then discussed, together with the therapeutic strategies to increase the benefits, particularly with respect to limiting end-organ damage and reduction of cardiovascular events. In this context, emphasis is given to the potential additional benefit conferred by control of 24-h blood pressure and to the compliance advantage of using drugs with a long duration of action. The longevity of the blood pressure lowering effect can compensate for delayed or missed drug consumption, a frequent phenomenon in the chronically treated hypertensive patient.
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PMID:Clinical benefits of a consistent reduction in blood pressure. 985 82

Obese hypertensive patients with cardiovascular risk factor clustering have increased plasma nonesterified fatty acid levels and are at high risk for atherosclerotic events. Our previous studies demonstrated that oleic acid induces a mitogenic response in rat aortic smooth muscle cells (RASMCs) through protein kinase C (PKC)- and extracellular signal-regulated kinase (ERK)-dependent pathways. In the present study we investigated the possibility that the generation of reactive oxygen species (ROS) constitutes a critical component of the oleic acid-induced mitogenic signaling pathway in RASMCs. We studied the effect(s) of oleic acid on the generation of ROS using the oxidant-sensitive fluoroprobe 2',7'-dichlorofluorescin diacetate. Relative fluorescence intensity and fluorescent images were obtained with laser confocal scanning microscopy from 1 to 5 minutes, since preliminary studies demonstrated that the peak fluorescence intensity occurred within 5 minutes. Oleic acid (100 micromol/L) induced a time-dependent increase of cell fluorescence that was >8-fold of that seen in control cells at 5 minutes. This was blocked by catalase, which suggests that H2O2 was the principal ROS. The oleic acid-induced increases in H2O2 were blocked when PKC was inhibited with the use of bisindolylmaleimide and when PKC activity was downregulated by exposing RASMCs to phorbol 12-myristate 13-acetate for 24 hours. Stearic and elaidic acids, which are weak PKC activators, did not significantly increase H2O2 production. The increase of H2O2 in response to oleic acid was inhibited by the antioxidant N-acetylcysteine. N-Acetylcysteine also completely blocked ERK activation and the increase of thymidine incorporation in response to oleic acid. The data suggest that generation of H2O2 in RASMCs exposed to oleic acid is PKC dependent. Moreover, H2O2 production emerges as a critical intermediary event in the oleic acid-mediated mitogenic signaling pathway between the activation of PKC and ERK. These observations raise the possibility that the elevated plasma nonesterified fatty acids, including oleic acid, in obese hypertensive patients contribute to vascular growth and remodeling by a PKC-dependent mechanism to generate ROS that subsequently activate ERK.
Hypertension 1998 Dec
PMID:Reactive oxygen species are critical in the oleic acid-mediated mitogenic signaling pathway in vascular smooth muscle cells. 985 64

Hypertension is a very important cardiovascular risk factor and directly leads to major atherosclerotic cardiovascular diseases, including coronary artery disease, stroke cardiac failure and peripheral artery disease. Hypertension tends to cluster with other atherogenic risk factors like dyslipidemia, insulin resistance, obesity and others. The association between hypertension and dyslipidemia is very frequent and the risk is more than additive and its possible pathogenesis may be of a common mechanism. Insulin resistance is the main cause of both risk factors. Endothelium dysfunction is present in arterial hypertension and dyslipidemia and the pathogenesis of atherosclerosis. The treatment of hypertensive patients must be individualized to accommodate both the concomitant dyslipidemia and other atherogenic factors.
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PMID:[Hypertension and dyslipidemia]. 988 66

There is a direct relationship between obstructive sleep apnea and high blood pressure, ischemic heart disease and cerebrovascular disorders. Obstructive sleep apnea, defined as an intermittent complete or partial upper airway obstruction during sleep, occurs in approximately 4% of adults, although some authors suggest a 9% prevalence in women and 24% in men. Due to its high frequency, this condition must be considered as another cardiovascular risk factor that should be prevented and adequately treated.
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PMID:[Cardiovascular manifestations of obstructive sleep apnea. Effects of the treatment]. 992 17

The use of data from ambulatory blood pressure monitoring has the potential to shift how we think about assessing the cardiovascular risk factor of blood pressure. Group mean 24 h, 12 h, 8 h, and hourly blood pressures for two recordings are highly reproducible. A single 24 h ambulatory blood pressure data set correlates better to echocardiographic left ventricular wall thickness than does the average blood pressure of multiple office measurements and than does a single-office visit measurement. Both blunted and excessive nocturnal declines in blood pressure have been associated with more target-organ damage than that with a normal nocturnal decline in blood pressure. Ambulatory blood pressure monitoring has proven to be an indispensable tool in development of drugs. Unfortunately, movement, environmental noise, and excessive vibration interfere with measurement of ambulatory blood pressure. The devices are less accurate for patients with dysrhythmias. False data resulting in incorrect medical decisions might be the most important problem with ambulatory blood pressure monitoring. Reproducibility of individual ambulatory blood pressure data sets is poor. For an individual patient, it might be difficult to detect white-coat hypertension, determine dipping status, and assess a drug's effect. The use of a single ambulatory monitoring record can be inadequate for diagnosing a patient as hypertensive or normotensive. Portable noninvasive ABPM devices would provide more interpretable information if they included an activity detector, a body-position detector, and facilities for performing continuous electrocardiography and measurements of blood pressure. Devices should perform accurately when someone is engaged in vigorous activity. Perhaps detection of sleep and emotional arousal would complete the requirements for an ideal monitor.
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PMID:Ambulatory blood pressure monitoring: test reproducibility and its implications. 1021 59

We investigated the influence of major cardiovascular risk factors (smoking, hypercholesterolemia, diabetes mellitus) on the association between angiotensin-converting enzyme (ACE) gene insertion (I)/deletion (D) polymorphism and echocardiographic left ventricular mass in 225 patients with sustained hypertension, assessed by ambulatory blood pressure monitoring. When the study population was analyzed as a whole, the 3 ACE genotypes did not differ in left ventricular mass (II, 47 g/m2.7; ID, 49 g/m2.7; DD, 51 g/m2.7; p = NS). No difference was found in subjects (n = 135) in whom at least 1 major cardiovascular risk factor was present (II, 51 g/m2.7; ID, 51 g/m2.7; DD: 52 g/m2.7; p = NS). In contrast, in the absence of cardiovascular risk factors, DD subjects (n = 32) exhibited left ventricular mass index higher than non-DD (ID/II) subjects (n = 75; p <0.05). After controlling for age and sex, in the absence of cardiovascular risk factors, the risk of left ventricular hypertrophy was 3.8-fold higher in DD than in non-DD patients (odds ratio 3.8; 95% confidence interval 1.2 to 12.1, p <0.02). We conclude that in the present setting of patients with established sustained systemic hypertension, the absence of risk factors potentially affecting cardiovascular adaptation allows for the detection of a positive association between homozygosity for the D allele of the ACE gene and left ventricular hypertrophy.
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PMID:Cardiovascular risk factors, angiotensin-converting enzyme gene I/D polymorphism, and left ventricular mass in systemic hypertension. 1021 83

Apolipoprotein(a) [apo(a)] is the specific apolipoprotein of lipoprotein(a) [Lp(a)], a recognized cardiovascular risk factor. Apo(a) is characterized by a high genetic polymorphism with at least 34 isoforms in plasma. Recent studies have shown that in atherothrombosis apo(a) polymorphism could play a role independent of Lp(a) levels. In particular, apo(a) phenotypes seem to have their highest predictive value for coronary heart disease, when apo(a) isoforms are detected by high resolution phenotyping methods and when an adequate operative cut-off of apo(a) polymorphism is used. A strong association between apo(a) phenotypes and coronary heart disease has been also found in hypertensive, diabetic, and uremic patients. Moreover, apo(a) phenotypes seem to correlate well with the severity of coronary atherosclerosis and the age of clinical onset of coronary heart disease. These studies suggest that apo(a) polymorphism may have a great clinical usefulness in a primary prevention setting, since apo(a) phenotypes could be used together with Lp(a) levels as strong genetic predictors of atherothrombosis. The analysis of apo(a) polymorphism appears to be particularly useful in healthy subjects with a family history of atherothrombotic diseases, in patients with diseases at high cardiovascular risk (diabetes, hypertension, hypercholesterolemia) and in subjects with conditions modifying Lp(a) levels.
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PMID:Genetics and cardiovascular risk: a role for apolipoprotein(a) polymorphism. 1037 86

The relation of insulin resistance to cardiovascular risk, particularly for coronary artery disease (CAD), has been well established in many prospective studies. The clustering of insulin resistance and/or hyperinsulinemia, hypertriglyceridemia, hypertension, and low HDL is now considered a feature of the insulin resistance syndrome. However, the association is complex and the pathways by which elevated insulin adversely affects both CAD risk factors and the risk of developing CAD have yet to be elucidated. Postprandial lipemia may be a mechanistic link between insulin resistance and CAD. Hyperinsulinemia appears to be a weak, but positive, independent cardiovascular risk factor. The strongest relations are seen in middle-aged rather than older persons and at higher elevations of plasma insulin levels. Individuals with type 2 diabetes have a risk of myocardial infarction (MI) equivalent to that of nondiabetic persons who have had a previous MI. Given the relatively weak association between duration of diabetes and severity of hyperglycemia and cardiovascular disease, common antecedents may underlie both CAD and type 2 diabetes.
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PMID:Epidemiology of insulin resistance and its relation to coronary artery disease. 1041 52

Hypertension is a major cardiovascular risk factor in diabetic subjects. Recent trials have suggested that blood pressure objectives should be < or = 140/80 mmHg. However, there is currently no evidence supporting any particular preferential drug strategy for this treatment objective.
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PMID:[Contribution of arterial hypertension to vascular risk in diabetic patients]. 1042 90


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