Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011860 (type 2 diabetes)
 57,723 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In the setting of an outpatient diabetic clinic, we determined whether macrovascular disease in patients with diabetes mellitus is associated with hyperhomocysteinemia (elevated plasma homocysteine [H(e)] concentrations) following a methionine load. Methionine-load tests were performed in 18 healthy controls, 11 diabetics without vascular disease (five insulin-dependent [IDDM] and six non-insulin-dependent [NIDDM]); and 17 diabetics with vascular disease (five IDDM and 12 NIDDM). All subjects were male, and there was no significant difference in mean age among the three groups. We measured plasma H(e) concentrations before and 2, 4, 6, 8, and 24 hours after an oral methionine load. Hyperhomocysteinemia (peak plasma H(e) concentration > control mean +/- 2 SD) occurred with significantly greater frequency (seven of 18, 39%) in patients with NIDDM as compared with age-matched controls (7%), being more common in those with macrovascular disease (five of 12, 41%). The area under the curve (AUC) over 24 hours, reflecting the total period of exposure to H(e), was also elevated with greater frequency in patients with NIDDM and macrovascular disease (33%) as compared with controls (0%). We conclude that hyperhomocysteinemia is associated with macrovascular disease in a significant proportion of patients with NIDDM. Further investigation of this association may determine whether hyperhomocysteinemia contributes to the increased frequency and accelerated clinical course of vascular disease in patients with diabetes mellitus.
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PMID:Hyperhomocysteinemia following a methionine load in patients with non-insulin-dependent diabetes mellitus and macrovascular disease. 854 71

The prevention of coronary artery disease is based on the control of several factors associated with a disease or clinical condition and suspected to play a pathogenetic role, defined as 'risk factors'. Smoking is a powerful risk factor for coronary artery disease, with risk of events increasing in relation to the number of cigarettes smoked daily. Smoking cessation is associated within 3-4 years, with a significant reduction in cardiovascular risk. Hyperlipidaemia is a powerful predictor of coronary disease with a strong, independent, continuous and graded positive association between cholesterol levels and risk of coronary events. Several large studies have shown the benefit of cholesterol reduction, and there is clear evidence of the efficacy of statins in the reduction of events in primary and secondary prevention. Hypertension is a significant, strong and independent risk factor for coronary artery disease morbidity and mortality and the reduction of events and mortality by antihypertensive treatment is well documented. Obesity is associated with an increase in all-cause mortality and cardiovascular mortality, with a particularly high risk for subjects with central obesity. Central obesity is also part of the so-called 'metabolic X syndrome' including insulin resistance, which appears to be associated with a particularly high risk of coronary artery disease. Type 1 and type 2 diabetes mellitus are associated with an increased risk of cardiovascular disease, especially in women. Several studies have shown that good metabolic control and multifactorial risk factor reduction significantly lower the coronary risk in these patients. Recent evidence is accumulating that some clotting factors (fibrinogen, factor VII, von Willebrand factor) and fibrinolytic factors (t-PA and PAI-1) are associated with an increased risk of coronary artery disease. The European Concerted Action on Thrombosis (ECAT) showed that the levels of fibrinogen, von Willebrand factor antigen, and t-PA antigen are independent predictors of subsequent coronary syndromes in patients with angina pectoris, and that low fibrinogen is associated with a low risk of events despite high cholesterol levels. Post-menopausal status is associated with increased risk of coronary artery disease, particularly when menopause is premature (before the age of 45) or abrupt (surgical). There is strong, thought not yet completely definite evidence that post-menopausal hormone replacement therapy may significantly reduce the risk of events and improve survival. Hyperhomocysteinaemia is an emerging risk factor independently associated with an increased risk of coronary artery disease, cerebral vascular disease, and peripheral vascular disease. The administration of vitamin B6, B12 or folate seems to be useful and is currently under further evaluation. Recently, attention has been focused on the correlation between coronary artery disease and genetic factors, such as ACE gene polymorphism or the gene polymorphism for the IIIa-moiety of the platelet fibrinogen receptor IIb-IIIa. In primary prevention, control of the major risk factors mainly in patients with clustered factors will substantially reduce the risk of ischaemic events. Secondary prevention of CHD is based on: aggressive behavioural advice, blood pressure reduction in hypertensives, good metabolic control of diabetes, and cholesterol reduction. Aspirin, beta-blockers, ACE inhibitors, and oral anticoagulants, may be useful in selected patients.
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PMID:Classical risk factors and emerging elements in the risk profile for coronary artery disease. 951 44

The missense mutation in the 677th nucleotide (C677T) of methylenetetrahydrofolate reductase gene causes substitution of valine (V) for alanine (A) resulting in three genotypes VV, VA and AA. The VV genotype causes hyperhomocysteinemia and may be a risk factor for coronary artery disease. We determined genotypes by polymerase chain reaction and subsequent restriction fragment length analysis and compared them in 84 patients with type 2 diabetes and in 115 non-diabetic subjects with and without coronary disease. Fractional urinary excretion rate of albumin was assessed by nephelometry. The VV, VA, and AA frequencies in the diabetic and in the control groups were 0.095, 0.357, 0.548 and 0.061, 0.417, 0.522, respectively (p = NS, diabetic vs. controls, chi2 test). Genotype frequencies did not differ in either diabetic or control subjects between those with or those without coronary disease (chi2 test). The fractional urinary excretion rate of albumin (mean +/-SD) in diabetic patients with the VV genotype i.e. 1.59 +/-0.71 was lower (Kruskall-Wallis test p = 0.002) than in the other genotypes i.e. VA 5.98 +/-9.75 and AA 3.75 +/-4.77, respectively (post-hoc Mann-Whitney test VV vs. VA p = 0.005 and VV vs. AA p = 0.054, respectively). We found that in patients with type 2 diabetes the methylenetetrahydrofolate reductase VV genotype was associated with a low urinary albumin excretion but not with coronary artery disease or diabetes per se.
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PMID:Mutation C677T of methylenetetrahydrofolate reductase gene is not associated with coronary artery disease, but possibly with albuminuria, in type 2 diabetic patients. 980 73

TNF-alpha (so-called cachectin), IL-1 and 6 are important regulating agents in the homeostasis of energy in the organism, as among others they control processes of apoptosis and thus also the volume of adipose and muscular tissues. They are produced not only in immunocompetent cells but also in adipocytes and muscle cells. The cytokine system is then activated not only in tumours and infections but elevated values were found also in obesity, NIDDM, in myocardial infarction and in advanced decompensated cardiac patients. By acting on phosphorylation of IRS-1 and PI-3 kinase TNF-alpha promotes significantly insulin resistance, causes deterioration of diabetes, as well as elevated body temperature, sleepiness and anorexia. In a group of 65 patients, mostly with android obesity, in hyperleptinaemic and insulin resistant probands with coronarographically confirmed microvascular angina pectoris (n = 22) or IHD, mostly after a myocardial infarction (n = 43) with one or more significant stenoses on the epicardial coronary arteries in half the patients positive or elevated TNF-alpha was found and in 28% also IL-6. This increase did not correlate however with BMI, the percentage of body fat, IRI and C peptide levels nor with cortisol and leptin levels. Insulin resistant subjects had more frequently elevated homocysteine and Lp(a) values which are further two independent risk factors of atherothrombogenesis. Hyperhomocysteinaemia can be favourably influenced by vitamin fortification of the diet or by administration of folate and pyridoxine (1 tablet per day) involving negligible financial costs.
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PMID:[Relation between cytokines (TNF-alpha, IL-1 and 6) and homocysteine in android obesity and the phenomenon of insulin resistance syndromes]. 1042 20

Non-insulin-dependent diabetes mellitus (NIDDM) and hyperhomocysteinemia are both associated with premature vascular disease. We tested the hypothesis that homocysteine is associated with vascular disease and other diabetic complications in patients with NIDDM. The current investigation is a cross-sectional analysis of baseline variables for participants in the Appropriate Blood Pressure Control in Diabetes (ABCD) Trial. Men and women aged 40 to 74 years with NIDDM and a mean diastolic blood pressure (BP) of 80 mm Hg or higher were eligible. We measured serum levels of total homocysteine (tHcy), cystathionine, and methylmalonic acid (MMA) and correlated these values with clinical and other laboratory measures of the complications of diabetes mellitus in 452 subjects. tHcy was higher in males than in females and correlated with the duration of hypertension and systolic BP. tHcy was significantly correlated with MMA (r = .35, P < .0001) and cystathionine (r = .53, P < .0001) levels and inversely correlated with serum B12 (r = -.23, P < .0001) and folate (r = -.18, P < .0001). It was significantly correlated with serum creatinine (r = .28, P < .0001 for males and r = .39, P < .0001 for females) and inversely correlated with creatinine clearance (r = -.19, P < .005 for males and r = -.30, P < .0001 for females). tHcy was not increased in subjects with cardiovascular disease or retinopathy, but it was increased in those with neuropathy (10.3 v 9.3 micromol/L, P < .05) and macroalbuminuria (11.0 v 9.2 micromol/L, P < .005). Of these subjects, 2.2% met the criteria for vitamin B12 deficiency and 1% met the criteria for folate deficiency. We conclude that elevations of tHcy in this population appear to be the result of a combination of vitamin deficiency and decreased renal function and do not appear to be a predictor of cardiovascular disease.
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PMID:Total homocysteine is associated with nephropathy in non-insulin-dependent diabetes mellitus. 1048 47

Microalbuminuria is a strong indicator of the risk of future cardiovascular disease and renal dysfunction. Slightly increased levels of homocysteine, an independent risk factor for atherothrombotic disease, have recently been found to be associated with the presence of (micro)albuminuria. However, it is unknown whether increased homocysteine levels precede the occurrence of (micro)albuminuria. Normoalbuminuric subjects (n=316, 66 with non-insulin-dependent diabetes mellitus [NIDDM]) of an age-stratified, sex-stratified, and glucose tolerance-stratified sample of a population-based cohort study were investigated at baseline and after a mean follow-up duration of 6.1 years. Development of (micro)albuminuria was defined as a mean albumin-to-creatinine ratio >2.0 mg/mmol at the follow-up examination. The cumulative incidence of (micro)albuminuria was 14. 0% (9.7 % to 18.3%) among nondiabetic subjects and 22.7% (12.9% to 32.5%) among NIDDM patients. Age-adjusted, sex-adjusted, and glucose tolerance status-adjusted logistic regression analyses showed development of (micro)albuminuria to be significantly associated with baseline homocysteine levels >19.0 micromol/L compared with homocysteine levels <9.1 micromol/L (odds ratio [OR] 5.1, 95% CI 1.1 to 23.0). For homocysteine levels of 9.1 to 14.0 micromol/L and 14.1 to 19.0 micromol/L, the values were OR 1.2 (95% CI 0.5 to 3.0) and OR 1.8 (95% CI 0.6 to 5.3), respectively. Additional adjustment for baseline insulin resistance, blood pressure, body mass index, presence of cardiovascular disease and retinopathy, current smoking, or estimates of glomerular filtration rate did not materially affect the results. Substituting homocysteine levels as a continuous variable for categories of homocysteine levels showed that a 5-micromol/L increase of the homocysteine level was associated with an increased risk of developing (micro)albuminuria (OR 1.38, 95% CI 0.97 to 1.95). Analyses performed in nondiabetic and diabetic subjects separately gave similar results among nondiabetic subjects. Among diabetic subjects, the association between homocysteine level and (micro)albuminuria could not be estimated, because there was an insufficient number of diabetic subjects with high homocysteine levels. Hyperhomocysteinemia is an independent determinant of the development of (micro)albuminuria among nondiabetic subjects, even after adjustment for estimates of glomerular filtration rate. We could neither confirm nor reject an association between homocysteine levels and the development of (micro)albuminuria among NIDDM subjects. These data suggest that homocysteine may play a pathophysiological role in the development of (micro)albuminuria.
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PMID:Serum homocysteine levels are associated with the development of (micro)albuminuria: the Hoorn study. 1114 36

Stroke is a major cause of morbidity and mortality. Risk factors for stroke have been determined through prospective epidemiologic study. Control of risk factors has been demonstrated to reduce stroke incidence, either through controlled trials or inferred from observational studies. In the past few years, new approaches to the treatment of established risk factors have been discovered. These include aggressive control of hypertension in diabetes patients, prevention of type 2 diabetes through lifestyle modification, carotid endarterectomy for moderate symptomatic carotid stenosis, encouragement of a high level of physical activity, and control of abdominal obesity and elevated body mass index. In addition, new strategies for stroke prevention have been identified, including encouragement of a diet high in fruits, vegetables, whole grains, and omega-3 fatty acids, the use of vitamins B12, B6, and folic acid in hyperhomocysteinemia, and moderate alcohol consumption. Clinical trial data support the use of hydroxy-methyl-coenzyme A inhibitors in patients with coronary artery disease, and ramipril in high-risk patients with coronary artery disease and diabetes, for the primary prevention of stroke. New risk factors for stroke are being investigated, including the role of chronic inflammation and infection, and these may provide future strategies for stroke prevention.
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PMID:Prevention of strokes. 1138 98

Hyperhomocysteinemia is a well established risk factor for cardiovascular disease, and multiple factors likely lead to abnormal regulation of plasma homocysteine in patients with diabetes. To examine a possible role for insulin and glucose in homocysteine metabolism, we examined the activity of two important enzymes of homocysteine metabolism in hepatocytes. In various tissues of six mice, methylene tetrahydrofolate reductase (MTHFR) activity was present in all tissues tested and the highest concentration (per gram) was in the brain. In contrast, cystathionine beta-synthase (CBS) activity appeared to be present only in the liver and to a small extent in the kidney. Using HEP G2 cells in culture, MTHFR activity was 3.3+/-0.8 nmol/h when the glucose concentration in the medium was 100 mg/dl and fell to 2.3+/-0.3 nmol/h when glucose was increased to 300 mg/dl. MTHFR activity was 3.4+/-0.3 nmol/h when cells were exposed to an insulin concentration of 5 mU/ml and fell to 2.8+/-0.3 nmol/h when insulin concentration was increased to 200 mU/ml (P<0.01). In contrast CBS activity increased from 0.017 to 0.13 U/ml by increasing the glucose concentration in the medium (P<0.01), but decreased from 0.04 to 0.02 (P<0.01) when the insulin concentration was increased from 5 to 200 mU/ml, respectively. We conclude that CBS and MTHFR have different tissue distributions, with CBS being present predominantly in liver and kidney, and MTHFR found in many tissues. In addition, both insulin and glucose affect the activity of the two enzymes when added to hepatocytes in vitro. If such effects occur in humans with hyperglycemia and hyperinsulinemia, then alterations in homocysteine metabolism may contribute to the accelerated macrovascular disease associated with insulin resistance or type 2 diabetes.
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PMID:The effect of glucose and insulin on the activity of methylene tetrahydrofolate reductase and cystathionine-beta-synthase: studies in hepatocytes. 1158 7

Hyperhomocysteinemia is recognised as a risk factor of ischaemic heart disease and vascular complications of arterial hypertension. Methylenetetrahydrofolate reductase (MTHFR) gene C677T polymorphism is associated with hyperhomocysteinaemia. The aim of the study was the assessment of an association of the above polymorphism with type 2 diabetes with special attention to myocardial infarction and arterial hypertension accompanying diabetes. The study group consisted of 172 type 2 diabetics. 172 control subjects with normal glucose tolerance were age and sex matched to patients with diabetes. C677T polymorphism in MTHFR gene locus was detected using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) method. CT and TT genotypes were found more often among diabetics (OR 1.83, 95% CI 1.16-2.89; p < 0.01). This finding may be secondary to the excess of T allele bearers among diabetics with myocardial infarction when compared to diabetics without infarction and to control group. Upon obtained results the potential role of genotypes CT and TT as risk factors of myocardial infarction among patients with type 2 diabetes could not be excluded (OR 2.33, 95% CI 0.93-5.8; p = 0.07). Genotypes containing T allele are not associated with diabetes type 2 and concomitant arterial hypertension (OR 1.45, 95% CI 0.89-2.57; p = 0.14). A confirmation in further studies is needed for the presented findings.
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PMID:[Methylenetetrahydrofolate reductase gene polymorphism in patients with type 2 diabetes]. 1192 64

Accelerated atherosclerosis is common in diabetes mellitus, although its extent is not always related to its strong association with classical cardiovascular risk factors. Diabetic patients, especially with type 2 diabetes, are prone to cardiovascular disease which is the leading cause of death in this population. Recent clinical studies among general population have shown that an even mild increase of homocysteinemia play an important role in the progression of atherosclerosis, either in coronary or peripheral arteries. An increasing amount of in vitro data is providing evidence that excess of homocysteine has a toxic effect on the arterial wall. This aminoacid thus appears to be not only a risk marker but also an emerging cardiovascular risk factor. The measurement of plasma homocysteine contributes to the identification, among the diabetic population, of patients at high cardio-vascular risk, with the aim of improving their global management. Moreover the addition of group B vitamins provides an easy and low-cost treatment to lower hyperhomocysteinemia.
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PMID:[Clinical relevance of homocysteine monitoring in the diabetic patient]. 1252 34


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