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Query: UMLS:C0011860 (type 2 diabetes)
 57,723 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The clinical coincidence of hypertension, obesity and non insulin diabetes mellitus (NIDDM) has long been recognized. Increasing interest has also been recently focused on the possible role of insulin and insulin resistance in mediating this association. There is also evidence that hyperglycemia per se may have a role in the pathogenesis of hypertension and atherosclerosis in NIDDM patients. Glucose is a determinant to cellular ion homeostasis, promoting an increase of intracellular calcium and suppressing intracellular free magnesium and pH. Moreover, hyperglycemia promotes glycosilation of proteins and the consequent accumulation of advanced glycosilation end products in tissues. It has recently been suggested that iter is a cellular ionic basis for the clinical and epidemiological linkage of hypertension, left ventricular hypertrophy (LVH), obesity and non insulin dependent diabetes mellitus (NIDDM). These clinical conditions may be different expressions of a common underlying defect in ion handling, displayed by elevated cytosolic free calcium and suppressed free magnesium levels. Therapeutically, reversal of this excess free calcium accumulation and/or free magnesium deficit with ion specific agents, such as calcium channel blocker drugs, may thus ameliorate not only the elevated blood pressure of hypertension but also the concurrent cardiac, vascular and metabolic aspects of the hypertensive states.
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PMID:Diabetes, hypertension and atherosclerosis: pathophysiological role of intracellular ions. 820 15

Parathyroid hypertensive factor (PHF) in rats: PHF is an endogenous hypertensive substance which was originally associated with hypertension in spontaneously hypertensive rats (SHR). In this model, PHF was shown to act by increasing intracellular calcium levels in vascular smooth muscle and was linked with a characteristic pattern of abnormalities in overall calcium regulation. The action of PHF was blocked by calcium antagonists, suggesting that the effect of PHF was to increase extracellular calcium uptake. In SHR the parathyroid glands were shown to be the site of PHF secretion. This secretion was inhibited by an increase in dietary calcium. PHF was further shown to be unique to low-renin forms of hypertension, that is, those forms of hypertension characterized by abnormalities in calcium metabolism. PHF in humans: PHF was subsequently found in human low-renin salt-sensitive hypertension. As in SHR, calcium supplementation can lower PHF levels in humans. Similarly, there is circumstantial evidence for the parathyroid origin of PHF in humans. In human hypertensive patients, the presence of PHF has been shown to predict a favorable therapeutic response to calcium channel blockade. Recently, many of the abnormalities in calcium metabolism present in low-renin hypertension have also been described in other disease states. Notable among these diseases is non-insulin dependent diabetes mellitus. A survey of human non-insulin dependent diabetes mellitus has revealed that PHF was present in a disproportionate number of these patients independently of the blood pressure level. The significance of this latter finding needs to be explored, but PHF may prove to have relevance in diseases other than hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Clinical aspects of parathyroid hypertensive factor. 820 59

Systemic arterial hypertension is not merely a simple haemodynamic abnormality. It is as frequently as in 80% associated with metabolic deviations such as impaired glucose tolerance or NIDDM, obesity, hyperuricaemia, hyperlipoproteinaemia, rapid development of atherosclerosis. This cluster of different symptoms with higher BP readings is too frequent to be incidental. We speak therefore of hypertensive metabolic syndrome which is close to or identical with Reaven's syndrome X or familial dyslipidaemic hypertension. The common pathogenetic basis of the listed metabolic deviations and hypertension is probably genetic or acquired reduction of tissue sensitivity, in particular striated muscle sensitivity to the physiological action of insulin. The consequence of this insulin resistance and the effort to maintain euglycaemia is a compensating adaptational risk of plasma insulin. Hyperinsulinism in addition to an increased synthesis of triacylglycerols, VLDL and LDL lipoproteins can promote the rise of BP by a complex mechanism: it stimulates the activity of the sympathetic nervous system, it promotes sodium retention in the kidneys, it affects transmembrane transport mechanisms for electrolytes and an increase of intracellular sodium and calcium, it stimulates hypertrophy and remodelling of the vascular wall and hastens the development of atherosclerosis. Hyperinsulinaemia is also associated with resistance of hypertonic patients to antihypertensive treatment. Its reduction by non-pharmacological procedures (reduction of body weight, physical activity etc.) restore the effectiveness of antihypertensive drugs. Insulin resistance is most probably a genetically conditioned abnormality which has multiple phenotypic manifestations, depending how this congenital disposition is amplified or associated with other genetic abnormalties or external and internal factors.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[The hypertensive metabolic syndrome]. 821 36

Non-insulin dependent diabetes mellitus (NIDDM) and hypertension are common diseases which are independently associated with insulin resistance/hyperinsulinemia, dyslysidemia, abnormalities of platelet function, and accelerated atherogenesis. The interaction of these independent risk factors is poorly understood. Recently, low density lipoprotein (LDL) receptors have been described, in platelets, and LDL elevates [Ca2+]i in these cells. In this study we have evaluated platelet [Ca2+]i responsiveness to LDL and arginine vasopressin (AVP) in NIDDM patients with (n = 28) and without (n = 13) concomitant hypertension, as well as in normal nondiabetic controls (n = 13). Platelet [Ca2+]i concentration-response curves to LDL for both NIDDM and hypertensive NIDDM were shifted significantly to the left when compared to the normotensive, nondiabetic controls. By contrast, no differences were seen in [Ca2+]i responses to 10 mumol/L AVP among any of the groups. To determine the possible role of hyperinsulinemia in this accentuated [Ca2+]i response to LDL, we measured basal and LDL-stimulated [Ca2+]i in platelets of normal volunteers after insulin treatment (0-100 mU/mL for 30 and 90 min). Insulin did not alter baseline or LDL-stimulated (150 mg/mL) platelet [Ca2+]i. Thus, an enhanced platelet [Ca2+]i response to LDL is characteristic of diabetes, independently of blood pressure. As such, it may also help to explain the enhanced platelet aggregation, endothelial dysfunction, and accelerated atherosclerosis of NIDDM.
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PMID:Increased platelet cytosolic calcium responses to low density lipoprotein in type II diabetes with and without hypertension. 830 68

The mitochondrial enzyme FAD-linked glycerophosphate dehydrogenase (m-GDH) is thought to play a key role in the glucose-sensing mechanism of the insulin-producing B-cell. It catalyses a rate-limiting step of the glycerol phosphate shuttle in pancreatic islets. Its activation by Ca2+ accounts for the preferential stimulation of oxidative glycolysis and, hence, pyruvate oxidation in glucose-stimulated islets. Reduced activity of m-GDH was recently observed in islet, but not liver, homogenates from rats injected with streptozotocin during the neonatal period and in two models of inherited diabetes, i.e. GK rats and db/db mice. In the streptozotocin-injected and GK rats the m-GDH islet defect coincided, in intact islets, with an abnormally low ratio between oxidative and total glycolysis. Decreased activity of m-GDH in T-lymphocytes was also observed in 12 of 32 type 2 (non-insulin-dependent) diabetic patients, but only once among 26 other subjects including 11 healthy volunteers, 9 non-diabetics and 6 patients with either type 1 (insulin-dependent) or symptomatic diabetes. In the T-lymphocytes of type 2 diabetics the m-GDH deficiency occasionally coincided with an abnormally high ratio between glutamate-pyruvate and glutamate-oxaloacetate transaminase activities, as also observed in islets from streptozotocin-injected or GK rats. It is speculated that an islet m-GDH defect could represent a far from uncommon factor contributing to the pathogenesis of type 2 diabetes mellitus.
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PMID:Is type 2 diabetes due to a deficiency of FAD-linked glycerophosphate dehydrogenase in pancreatic islets? 832 24

Liquorice extract has been claimed to induce inhibition of the activity of 11 beta-hydroxysteroid dehydrogenase which converts cortisol to cortisone. This enzyme is thought to protect the mineralocorticoid receptor from being occupied by endogeneous glucocorticoids in the kidney. Based on these hypotheses, we investigated the effect of low-dose glycyrrhizine on hyperkalemia due to hyporeninemic hypoaldosteronism in eight subjects with NIDDM. The mean serum potassium concentration decreased from 5.3 +/- 0.3 (SD) mEq/1 to 4.9 +/- 0.2 mEq/1 when 15 g of calcium polystyrene sulfonate, a potassium-binding resin, was given per day, and it decreased significantly to 4.4 +/- 0.4 mEq/1 with 150 mg/day of glycyrrhizine therapy. Changes in fasting plasma glucose and hemoglobin A1c were not significant. These data support the assumption that liquorice extract can be used safely in the therapy for treating hyperkalemia due to selective hypoaldosteronism in diabetes mellitus subjects.
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PMID:Effect of glycyrrhizine on hyperkalemia due to hyporeninemic hypoaldosteronism in diabetes mellitus. 833 14

Non-insulin-dependent diabetes mellitus (NIDDM, type 2 diabetes) is a disorder of glucose homeostasis characterized by hyperglycaemia, peripheral insulin resistance, impaired hepatic glucose metabolism, and diminished glucose-dependent secretion of insulin from pancreatic beta-cells. Glucagon-like-peptide-1(7-37) (GLP-1) is an intestinally derived hormone that may be useful for the treatment of NIDDM because it acts in vivo to increase the level of circulating insulin, and thus lower the concentration of blood glucose. This therapeutic effect may result from the ability of GLP-1 to compensate for a defect in the glucose signalling pathway that regulates insulin secretion from beta-cells. In support of this concept we report here that GLP-1 confers glucose sensitivity to glucose-resistant beta-cells, a phenomenon we term glucose competence. Induction of glucose competence by GLP-1 results from its synergistic interaction with glucose to inhibit metabolically regulated potassium channels that are also targeted for inhibition by sulphonylurea drugs commonly used in the treatment of NIDDM. Glucose competence allows membrane depolarization, the generation of action potentials, and Ca2+ influx, events that are known to trigger insulin secretion.
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PMID:Pancreatic beta-cells are rendered glucose-competent by the insulinotropic hormone glucagon-like peptide-1(7-37). 838 Dec 11

In NIDDM, first-phase insulin release to glucose is (almost) absent. However, in contrast to older studies which suggested that in NIDDM the B-cell is "blind" for glucose, recent evidence indicates that the B-cell is not insensitive for glucose as far as second phase release is concerned. This suggests that the metabolism of glucose is probably not deranged in NIDDM, since glucose leads to insulin release after it has been metabolized. Hyperglycaemia itself has a deleterious effect on insulin release, so-called glucose toxicity. Various mechanisms have been proposed, whereby hyperglycaemia may diminish insulin release: inhibition of Ca2+ mobilization from the endoplasmic reticulum by glucose-6-phosphate, Ca2+ uptake in the ER by glucose and inhibitory effects of protein kinase C. Whatever may prove to be the underlying mechanism(s), glucose toxicity is unlikely to be the only cause of insulin secretory disturbances in NIDDM, since the glucose level would have to be elevated before it could be toxic. Non-insulin-dependent diabetes mellitus (NIDDM) is characterized by both defects in insulin action and insulin secretion. With regard to the defects in insulin release, much research has originated from two (partly) opposing hypotheses, namely the presence of pancreatic B-cell glucose blindness and the hypothesis of pancreatic B-cell glucose toxicity in NIDDM.
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PMID:Defects in insulin secretion in NIDDM: B-cell glucose insensitivity or glucose toxicity? 844 21

Nicardipine is a second generation dihydropyridine calcium antagonist which selectively inhibits vascular smooth muscle contraction. In elderly patients, the drug has demonstrated clinical efficacy in the management of hypertension, angina pectoris and ischaemia-related cerebrovascular disease. In particular, nicardipine effectively controls blood pressure in elderly hypertensive patients with or without coexistent disease. In noncomparative trials, a regimen containing nicardipine has been associated with an improvement of symptoms in hypertensive patients with concurrent coronary artery, cerebrovascular or peripheral vascular disease, while in essentially 'healthy' elderly hypertensive patients, nicardipine monotherapy has resulted in improved indices of mobility and cognitive function. As yet, however, there is no evidence that nicardipine (and/or other calcium channel antagonists) decreases cardiovascular morbidity and mortality in elderly patients, as has been demonstrated for more established antihypertensive therapies, namely diuretics and/or beta-blockers. The pharmacokinetic properties of nicardipine in elderly hypertensive patients appear to be similar to those in younger patients. The main adverse events associated with nicardipine in the elderly are related to the vasodilator properties of the drug and include pedal oedema, headache and flushing. However, the drug does not exacerbate spontaneous postural hypotension in the elderly, nor does it adversely affect the coronary artery disease risk profile, even in patients with type II diabetes mellitus. In summary, widespread clinical experience in the elderly indicates that nicardipine monotherapy or a regimen containing nicardipine is useful for the treatment of hypertension, particularly in patients with coexistent coronary artery, cerebrovascular or peripheral vascular disease. Nicardipine monotherapy has also demonstrated efficacy in angina pectoris and shown promise in the management of ischaemia-related cerebrovascular diseases, notably subarachnoid haemorrhage.
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PMID:Nicardipine. A review of its pharmacology and therapeutic efficacy in older patients. 847 49

There is accumulating evidence that insulin resistance, glucose intolerance, and hyperinsulinemia exist in people with high blood pressure, and it has been suggested that insulin resistance and hyperinsulinemia may be of great importance in the origin of hypertension and its ultimate clinical course. Of importance are the recent observations that persons with normal glucose tolerance, selected on the basis of hyperinsulinemia, had higher blood pressure than matched individuals with normoinsulinemia. Hypertension in in insulin-resistant states generally has been attributed to hyperinsulinemia, with resulting increases in sympathetic nervous system activity. However, recent data from our laboratory suggest that cellular insulin resistance rather than hyperinsulinemia per se may lead to hypertension. The basic tenet proposed in this article is that a deficiency of insulin at the cellular level represents a common mechanism that is involved in the development of hypertension in both type I and type II diabetes mellitus. Insulin has an important role in the modulation of cellular calcium metabolism. Decreased insulin action on vascular smooth muscle cells may contribute both to hypertension and to accelerated atherosclerosis. Recent observations suggest that an impaired cellular response to insulin predisposes to increased vascular smooth muscle tone (the hallmark of hypertension in the diabetic state). For example, recently reported studies from our laboratory demonstrate that insulin attenuates the vascular contractile response to phenylephrine, serotonin, and potassium chloride. Thus, it appears that insulin normally modulates (attenuates) vascular smooth muscle contractile responses to vasoactive factors, and insulin resistance should accordingly be associated with enhanced vascular reactivity.
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PMID:Vascular insulin abnormalities, hypertension, and accelerated atherosclerosis. 850 34


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