Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0085580 (essential hypertension)
 14,686 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ten patients with adult-onset diabetes in whom diabetes antedated the appearance of hypertension were evaluated. These patients had evidence of diabetic autonomic neuropathy, including significant orthostatic hypotension (four patients), impotence (three patients), and evidence of diabetic peripheral sensorimotor neuropathy (nine patients) in clinical testing and nerve conduction study results. Baroreflex function was evaluated by multiple hemodynamic tests, including inhalation of amyl nitrite and intravenous administration of phenylephrine, before and after parasympathetic blockade with atropine, and the cold pressor test; results were compared with results in normal control subjects, patients with essential hypertension, and two subgroups of uremic patients undergoing maintenance hemodialysis. Baroreflex function was significantly abnormal in the diabetic patients and was consistent with combined parasympathetic and sympathetic motor nerve (efferent) dysfunction in the baroreflex arc. There was a significant inverse correlation between the degree of orthostatic hypotension in the diabetic patients and their baroreflex response to phenylephrine (r = -0.680, p less than 0.05). There was no significant correlation between supine hypertension in the patients with diabetes and any of the hemodynamic or biochemical parameters examined. The results suggest that orthostatic hypotension in these patients is related to baroreflex dysfunction. However, baroreflex dysfunction does not appear to be a factor in the development of hypertension in these patients, although more studies with normotensive diabetic patients are needed to confirm this point.
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PMID:Baroreflex dysfunction in patients with adult-onset diabetes and hypertension. 613 Jul 1

Patients with diabetes mellitus may have any one of several forms of hypertension. These include essential hypertension, systolic hypertension of three varieties, the hypertension associated with diabetic nephropathy ("diabetic hypertension"), and the hypertension associated with neuropathy (supine hypertension with orthostatic hypotension). Because there are differences in the hypertensive mechanisms in each of these hypertensions, the use of antihypertensive medications should be tailored to the type of hypertension present. In this review, the rationale for treating hypertension in the diabetic will be discussed, the mechanisms of action and potential side effects of antihypertensive drugs peculiar to the diabetic will be outlined, and specific antihypertensive therapy programs based on the mechanisms involved in producing each of the hypertensions will be detailed.
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PMID:The hypertensions of diabetes. 714 May

Complications of insulin-dependent diabetes mellitus (IDDM) are a major cause of morbidity and mortality; however, the mechanisms of their development are still to be elucidated. Genetic susceptibility contributes to the pathogenesis of nephropathy in IDDM. Enhanced G-protein activation, a cellular phenotype observed in cultured cells from patients with essential hypertension, was recently documented in IDDM subjects with nephropathy. A C825T polymorphism was recently described in GNB3, the gene encoding the beta 3 subunit of heterotrimeric G-proteins. This genetic variant has been associated with enhanced G-protein activation. The 825T allele was observed more frequently in a group with essential hypertension. We analyzed the role of the C825T polymorphism in the predisposition to diabetic complications in IDDM. In this study, we investigated the frequency of this polymorphism in a large case-control study and found no association of the 825T allele with diabetic nephropathy, retinopathy, and neuropathy.
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PMID:The C825T polymorphism in the G-protein beta3 subunit gene and diabetic complications in IDDM patients. 1132 58

Orthostatic hypertension--a rise in blood pressure upon assuming upright posture-is an underappreciated and understudied clinical phenomenon. There is currently no widely agreed-upon definition of clinical orthostatic hypertension, the current definitions being operational within the context of particular studies. The underlying pathophysiology is thought to involve activation of the sympathetic nervous system, but the actual etiology is poorly understood. Orthostatic hypertension is observed in association with a variety of other clinical conditions, including essential hypertension, dysautonomias, and type 2 diabetes mellitus. Orthostatic hypertension has been associated with increased occurrence of silent cerebrovascular ischemia and possibly with neuropathy in type 2 diabetes. So, appreciation of the true incidence of orthostatic hypertension, elucidation of the underlying pathophysiology, and an understanding of potentially effective treatment approaches and their associated risks and benefits might all have major clinical significance. Orthostatic hypertension is an aspect of hypertension that is in need of further focused investigation.
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PMID:Orthostatic hypertension: when pressor reflexes overcompensate. 1693 77

Sensorimotor deficits in patients with essential hypertension may be due to impaired nerve function. Cutaneous sensory thresholds, median nerve sensory and motor conduction velocities, and median nerve sensory action potential amplitudes were assessed in 30 patients with unmedicated essential hypertension and 29 normotensives. Cutaneous sensory thresholds were higher and sensory action potential amplitudes smaller in hypertensives than normotensives whereas sensory and motor nerve conduction velocities did not differ between groups. These data suggest that hypertension may reduce the number of active sensory nerve fibers without affecting myelination. Sensory action potential amplitudes were inversely related to cutaneous sensory thresholds, suggesting that subclinical axonal neuropathy of sensory afferents may help account for perceptual deficits that characterize hypertension.
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PMID:Cutaneous sensibility and peripheral nerve function in patients with unmedicated essential hypertension. 1791 Jul 31

Diabetes mellitus is associated with an increased risk of cardiovascular disease, even in the presence of intensive glycemic control. Substantial clinical and experimental evidence suggest that both diabetes and insulin resistance cause a combination of endothelial dysfunctions, which may diminish the anti-atherogenic role of the vascular endothelium. Both insulin resistance and endothelial dysfunction appear to precede the development of overt hyperglycemia in patients with type 2 diabetes. Therefore, in patients with diabetes or insulin resistance, endothelial dysfunction may be a critical early target for preventing atherosclerosis and cardiovascular disease. Microalbuminuria is now considered to be an atherosclerotic risk factor and predicts future cardiovascular disease risk in diabetic patients, in elderly patients, as well as in the general population. It has been implicated as an independent risk factor for cardiovascular disease and premature cardiovascular mortality for patients with type 1 and type 2 diabetes mellitus, as well as for patients with essential hypertension. A complete biochemical understanding of the mechanisms by which hyperglycemia causes vascular functional and structural changes associated with the diabetic milieu still eludes us. In recent years, the numerous biochemical and metabolic pathways postulated to have a causal role in the pathogenesis of diabetic vascular disease have been distilled into several unifying hypotheses. The role of chronic hyperglycemia in the development of diabetic microvascular complications and in neuropathy has been clearly established. However, the biochemical or cellular links between elevated blood glucose levels, and the vascular lesions remain incompletely understood. A number of trials have demonstrated that statins therapy as well as angiotensin converting enzyme inhibitors is associated with improvements in endothelial function in diabetes. Although antioxidants provide short-term improvement of endothelial function in humans, all studies of the effectiveness of preventive antioxidant therapy have been disappointing. Control of hyperglycemia thus remains the best way to improve endothelial function and to prevent atherosclerosis and other cardiovascular complications of diabetes. In the present review we provide the up to date details on this subject.
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PMID:Endothelial dysfunction in diabetes mellitus. 1820 Aug 6

Bilateral optic disc swelling requires following a number of steps from discovery to causal diagnosis. First, it is necessary to differentiate between true optic disc swelling and disc elevation without true swelling. Then fundus examination, visual acuity and visual field, fluorescein angiography, and optical coherence tomography are performed in order to differentiate papilledema secondary to increased intracranial pressure from optic disc swelling secondary to optic neuropathy. Even if the most frequent etiology is idiopathic intracranial hypertension, the clinician must check for the absence of any signs or symptoms related to hypertension secondary to a cerebral tumor or to cerebral venous thrombosis. Fortunately, modern imaging techniques have facilitated the differential diagnoses of optic disc swelling, and the combination of magnetic resonance imaging (MRI) and magnetic resonance venography appears to be necessary each time the diagnosis of idiopathic hypertension is suggested.
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PMID:[Diagnosing bilateral papilledema]. 2049 84