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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

In clinical trials, all lipid-lowering agents have been associated with mild, asymptomatic elevations of alanine aminotransferase (ALT) and asparate aminotransferase enzymes. This, along with the fact that 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitors are hepatotoxic in some animals, led the US Food and Drug Administration (FDA) to recommend monitoring of liver enzymes for all lipid-lowering agents, except the bile acid sequestrants. Because the drugs act by different mechanisms, ALT elevations may be a pharmacodynamic effect related to lipid lowering, rather than a direct effect of the drug. Animal studies support this assumption. ALT elevations of 3 times the upper limit of normal occur in <3% of patients in clinical trials of lipid-lowering drugs. The elevations are transient and often dose-related, and they usually revert to normal while continuing therapy and have never been associated with hepatotoxicity. Confounding factors include alcohol, acetaminophen, and pre-existing liver disease, such as chronic hepatitis C and type II diabetes with fatty liver, which are both associated with mild, intermittent elevations of ALT. The more important issue is whether or not lipid-lowering agents are hepatotoxic. There are case reports of hepatotoxicity (cholestasis, jaundice, hepatitis, chronic active hepatitis, fatty liver, cirrhosis and acute liver failure) with all of the drugs, except cholestyramine. To date there are just 5 cases of documented liver failure linked to lovastatin. There is no evidence that monitoring reduces the rate of hepatotoxicity. Mild elevations of ALT that occur with many drugs, including HMG-CoA reductase inhibitors, do not predict hepatotoxicity. Liver enzyme elevations appear to be a class characteristic of lipid-lowering agents. Hepatotoxicity is a rare idiosyncratic reaction, occurring only with sustained released nicotinic acid.
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PMID:Defining patient risks from expanded preventive therapies. 1085 89

The hypertriglyceridemia attends the physiopathology of the atherosclerosis by various mechanisms: association of low levels of high density lipoprotein-cholesterol (HDL-c), modification of quality of low density lipoprotein-cholesterol (LDL-c), influence on hemostatic processes, association with other hazard's factors (obesity, hypertension, etc.). The hypertriglyceridemia distinguishes in primary and secondary. In primary forms the origin is essentially genetic, while the secondary ones are metabolic consequence of various pathologies (renal, thyroid, diabetes mellitus etc.). The hypertriglyceridemia's treatment is founded on a correct feeding and/or on eventual use of drugs. Apart from the secondary forms, in which is obligatory to treat at first the basal disease, the pharmacological therapy of the hypertriglyceridemia is suggested only in resistant cases to alone dietetic therapy and overall in presence of other factors of atherothrombotic hazard. The most utilized drugs are: omega-3 fatty acids, the nicotinic acid and its derivatives, the fibrates and the statins. The stronghold of alpha-glucosidases inhibitors is the acarbose. It reduces the biosynthesis of very low density lipoproteins (VLDL) by the reduction of substrata with an improvement of glucidic metabolism. Atorvastatin and cerivastatin develop a greater action to reduce serum levels of triglycerides as to the foregoing ones because of the better selectivity of receptor binding, the greater halflife and inhibition of the apolipoprotein's B100 synthesis.
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PMID:[Treatment of hypertriglyceridemia. Current aspects]. 1093 25

Nicotinamide, the amide derivative of nicotinic acid, has over the past forty years been given at high doses for a variety of therapeutic applications. It is currently in trial as a potential means of preventing the onset of Type I (insulin-dependent) diabetes mellitus in high-risk, first-degree relatives. Nicotinamide is for regulatory purposes classed as a food additive rather than a drug and has not therefore required the formal safety evaluation normally expected of a new therapy. Because the safety of treatment with megadoses of vitamins cannot be assumed, a full literature review has been undertaken. The therapeutic index of nicotinamide is wide but at very high doses reversible hepatotoxicity has been reported in animals and humans. Minor abnormalities of liver enzymes can infrequently occur at the doses used for diabetes prevention. There is no evidence of teratogenicity from animal studies and nicotinamide is not in itself oncogenic; at very high doses it does however potentiate islet tumour formation in rats treated with streptozotocin or alloxan. There is no evidence of oncogenicity in man. Growth inhibition can occur in rats but growth in children is unaffected. Studies of its effects on glucose kinetics and insulin sensitivity are inconsistent but minor degrees of insulin resistance have been reported. The drug is well tolerated, especially in recent studies which have used relatively pure preparations of the vitamin. Experience to date therefore suggests that the ratio of risk to benefit of long-term nicotinamide treatment would be highly favourable, should the drug prove efficacious in diabetes prevention. High-dose nicotinamide should still, however, be considered as a drug with toxic potential at adult doses in excess of 3 gm/day and unsupervised use should be discouraged.
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PMID:Safety of high-dose nicotinamide: a review. 1112

Patients with type 2 diabetes (formerly known as non-insulin-resistant diabetes) have a significantly increased risk of developing cardiovascular disease. Once clinical cardiovascular disease develops, these patients have a poorer prognosis than normoglycemic patients. By inducing endothelial changes, hyperglycemia contributes directly to atherosclerosis. Type 2 diabetes is also associated with atherogenic dyslipidemias. This form of diabetes, or the precursor state of insulin resistance, commonly occurs as a metabolic syndrome (formerly known as syndrome X) consisting of hypertension, atherogenic dyslipidemia and a procoagulant state, in addition to the disorder of glucose metabolism. All cardiovascular risk factors except smoking are more prevalent in patients with type 2 diabetes. In addition to exercise, weight control, aspirin therapy and blood pressure control, therapy to modify lipid profiles is usually necessary. The choice of agent or combination of statin, bile acid sequestrant, fibric acid derivative and nicotinic acid depends on the lipid profile and characteristics of the individual patient.
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PMID:Attenuating cardiovascular risk factors in patients with type 2 diabetes. 1114 70

Cardiovascular disease (CVD) is the leading cause of death and disability in the United States and in most industrialized nations. Major breakthroughs to modern day cardiovascular/lipid research have been attributed to the findings of the Framingham Heart Study and Gofman and colleagues who made associations between lipoprotein levels (LDL, VLDL and HDL) and CVD. Unfortunately, half of all CVD patients have none of the established coronary risk factors (hypertension, hypercholesterolemia, cigarette smoking, diabetes mellitus, obesity) and new strategies for identifying patients need be considered. Although there remains little disagreement regarding the necessity to lower elevated plasma cholesterol levels, there remains much controversy regarding appropriate dietary means of accomplish this goal. The National Cholesterol Education Program (1993) proposed a dietary reduction (Step I and Step II diets) to the percent saturated fat and cholesterol consumed by at-risk patients. Many currently question about the effectiveness of these diets and an alternative diet, replacing saturated fats by monounsaturated fats (olive oil), has attracted recent attention. While diet modification is considered the foundation of primary treatment, other interventions are frequently required. Although early drug trials demonstrated that agents such as nicotinic acid, clofibrate, gemfibrozil, bile acid-binding resins generally slowed progression of atherosclerotic lesions, lowered plasma cholesterol levels and decreased mortality from CVD, the greatest advance to current drug therapy involved the discovery of the "statins" (HMG-CoA reductase inhibitors). In the current work, mechanisms for vascular dysfunction resulting in myocardial ischemia were explored and potential nutritional (dietary) and pharmacologic interventions were reviewed.
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PMID:Cardiovascular disease: a historic perspective. 1123 77

Effects of endogenously derived free fatty acids (FFAs) on rates of gluconeogenesis (GNG) (determined with 2H2O), glycogenolysis (GL), and endogenous glucose production (EGP) were studied in 18 type 2 diabetic patients and in 7 nondiabetic control subjects under three experimental conditions: 1) during an 8-h fast (from 16-24 h after the last meal), when plasma FFA levels increased slowly; 2) during 4 h (from 16-20 h) of nicotinic acid (NA) administration (fasting plus NA), when plasma FFAs decreased acutely; and 3) during 4 h (from 20-24 h) after discontinuation of NA (FFA rebound), when plasma FFAs increased acutely. During fasting, FFAs increased from 636 to 711 micromol/l in type 2 diabetic patients and from 462 to 573 micromol/l in control subjects (P < 0.04), but GNG did not change in diabetic patients (6.9 vs. 6.5 micromol x kg(-1) x min(-1), P > 0.05) or in control subjects (5.1 vs. 5.4 micromol x kg(-1) x min(-1), P > 0.05). During fasting plus NA, FFAs decreased in diabetic patients and control subjects (from 593 to 193 and from 460 to 162 micromol/l, respectively); GNG decreased (from 6.1 to 4.2 and from 4.7 to 3.5 micromol x kg(-1) x min(-1)), whereas GL decreased in diabetic patients (from 5.3 to 4.4 micromol x kg(-1) x min(-1)) but increased in control subjects (from 5.4 to 7.2 micromol x kg(-1) min(-1)). During the FFA rebound, FFAs increased in diabetic patients and control subjects (from 193 to 1,239 and from 162 to 1,491 micromol/l, respectively); GNG increased (from 4.2 to 5.4 and from 3.4 to 5.3 micromol x kg(-1) x min(-1) respectively), and GL decreased (from 4.4 to 3.4 and from 7.3 to 4.3 micromol x kg(-1) x min(-1), respectively). In summary, during an extended overnight fast, increasing plasma FFA levels stimulated GNG, whereas decreasing FFA levels inhibited GNG in both diabetic and control subjects; 20 h after the last meal, approximately one-third of GNG in both diabetic and control subjects was dependent on FFAs; and autoregulation of EGP by GL in response to decreasing GNG was impaired in diabetic patients.
Diabetes 2001 Apr
PMID:Effects of free fatty acids on gluconeogenesis and autoregulation of glucose production in type 2 diabetes. 1128 46

There is now much interest in the mechanisms by which altered lipid metabolism might contribute to insulin resistance as is found in Syndrome X or in Type II diabetes. This review considers recent evidence obtained in animal models and its relevance to humans, and also likely mechanisms and strategies for the onset and amelioration of insulin resistance. A key tissue for development of insulin resistance is skeletal muscle. Animal models of Syndrome X (eg high fat fed rat) exhibit excess accumulation of muscle triglyceride coincident with development of insulin resistance. This seems to also occur in humans and several studies demonstrate increased muscle triglyceride content in insulin resistant states. Recently magnetic resonance spectroscopy has been used to demonstrate that at least some of the lipid accumulation is inside the muscle cell (myocyte). Factors leading to this accumulation are not clear, but it could derive from elevated circulating free fatty acids, basal or postprandial triglycerides, or reduced muscle fatty acid oxidation. Supporting a link with adipose tissue metabolism, there appears to be a close association of muscle and whole body insulin resistance with the degree of abdominal obesity. While causal relationships are still to be clearly established, there are now quite plausible mechanistic links between muscle lipid accumulation and insulin resistance, which go beyond the classic Randle glucose-fatty acid cycle. In animal models, dietary changes or prior exercise which reduce muscle lipid accumulation also improve insulin sensitivity. It is likely that cytosolic accumulation of the active form of lipid in muscle, the long chain fatty acyl CoAs, is involved, leading to altered insulin signalling or enzyme activities (eg glycogen synthase) either directly or via chronic activation of mediators such as protein kinase C. Unless there is significant weight loss, short or medium term dietary manipulation does not alter insulin sensitivity as much in humans as in rodent models, and there is considerable interest in pharmacological intervention. Studies using PPARgamma receptor agonists, the thiazolidinediones, have supported the principle that reduced muscle lipid accumulation is associated with increased insulin sensitivity. Other potent systemic lipid-lowering agents such as PPARalpha receptor agonists (eg fibrates) or antilipolytic agents (eg nicotinic acid analogues) might improve insulin sensitivity but further work is needed, particularly to clarify implications for muscle metabolism. In conclusion, evidence is growing that excess muscle and liver lipid accumulation causes or exacerbates insulin resistance in Syndrome X and in Type II diabetes; development of strategies to prevent this seem very worthwhile.
Exp Clin Endocrinol Diabetes 2001
PMID:Triglycerides, fatty acids and insulin resistance--hyperinsulinemia. 1145 39

Elevated total plasma homocysteine has been established as an independent risk factor for thrombosis and cardiovascular disease. A strong relationship between plasma homocysteine levels and mortality has been reported in patients with angiographically confirmed coronary artery disease. Homocysteine is a thiol containing amino acid. It can be metabolised by different pathways, requiring various enzymes such as cystathionine beta-synthase and methylenetetrahydrofolate reductase. These reactions also require several co-factors such as vitamin B6 and folate. Medications may interfere with these pathways leading to an alteration of plasma homocysteine levels. Several drugs have been shown to effect homocysteine levels. Some drugs frequently used in patients at risk of cardiovascular disease, such as the fibric acid derivatives used in certain dyslipidaemias and metformin in type 2 (non-insulin-dependent) diabetes mellitus, also raise plasma homocysteine levels. This elevation poses a theoretical risk of negating some of the benefits of these drugs. The mechanisms by which drugs alter plasma homocysteine levels vary. Drugs such as cholestyramine and metformin interfere with vitamin absorption from the gut. Interference with folate and homocysteine metabolism by methotrexate, nicotinic acid (niacin) and fibric acid derivatives, may lead to increased plasma homocysteine levels. Treatment with folate or vitamins B6 and B12 lowers plasma homocysteine levels effectively and is relatively inexpensive. Although it still remains to be demonstrated that lowering plasma homocysteine levels reduces cardiovascular morbidity, surrogate markers for cardiovascular disease have been shown to improve with treatment of hyperhomocystenaemia. Would drugs like metformin, fibric acid derivatives and nicotinic acid be more effective in lowering cardiovascular morbidity and mortality, if the accompanying hyperhomocysteinaemia is treated? The purpose of this review is to highlight the importance of homocysteine as a risk factor, and examine the role and implications of drug induced modulation of homocysteine metabolism.
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PMID:Drugs affecting homocysteine metabolism: impact on cardiovascular risk. 1189 29

The 2 principal approaches to management of dyslipidemias are lifestyle intervention and lipid-modifying drug therapy. Recent revisions to the American Heart Association's dietary guidelines for reducing cardiovascular disease emphasize an overall healthy eating pattern and maintenance of appropriate body weight, together with achieving a desirable blood pressure and a desirable lipoprotein profile. New National Cholesterol Education Program treatment guidelines include a scoring system for calculating coronary heart disease (CHD) risk that is adapted from the Framingham Heart Study, as well as a category of CHD risk equivalents (e.g., diabetes) that will encourage more aggressive therapeutic intervention for individuals at high short-term risk for CHD, even in the absence of clinically evident coronary disease. Classes of lipid-modifying drugs include bile acid sequestrants (resins), fibrates, and statins, with each class exerting different effects on the lipid profile. Nicotinic acid (niacin) is also an approved lipid-modifying agent. The armamentarium for treating lipid disorders and atherosclerosis now includes statins that can decrease low-density lipoprotein (LDL) cholesterol levels by up to 55%, as well as a resin with improved tolerability. In patients with high levels of LDL cholesterol and triglycerides, together with low concentrations of high-density lipoprotein cholesterol, combination therapy may be effective. Moreover, researchers are currently investigating the development of drugs directed at molecular targets, including cholesterol esterification and accumulation in macrophage foam cells (e.g., inhibiting acyl-coenzyme A : cholesterol acyltransferase), degradation of atherosclerotic plaque (e.g., decreasing the expression of matrix metalloproteinases), and reverse cholesterol transport (e.g., stimulating ATP-binding cassette transporter A1).
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PMID:Management of dyslipidemia. 1204 90

Diabetes mellitus ia very common disease with a high cardiovascular morbidity and mortality. This articles reviews the types of lipid disorders that can accompany diabetes mellitus and the evidence that treatment of dyslipidaemia improves primary and secondary endpoints, i.e. lipid levels, cardiovascular events, and mortality. Specific lipid-lowering strategies are discussed, including diet and exercise, treatment of hyperglycaemia, and the use of lipid-lowering therapy such as statins, fibric acid derivatives, bile acid sequestrants, nicotinic acid and its derivatives, fish oil and hormone replacement therapy. An approach to the patient with diabetes mellitus and dyslipidaemia is provided.
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PMID:Lipids and diabetes mellitus: a review of therapeutic options. 1236 20


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