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

The objective of this study was to assess the role of free fatty acids (FFAs) as insulin secretagogues in patients with type 2 diabetes. To this end, basal insulin secretion rates (ISR) in response to acute increases in plasma FFAs were evaluated in patients with type 2 diabetes and in age- and weight-matched nondiabetic control subjects during 1) intravenous infusion of lipid plus heparin (L/H), which stimulated intravascular lipolysis, and 2) the FFA rebound, which followed lowering of plasma FFAs with nicotinic acid (NA) and was a consequence of increased lipolysis from the subject's own adipose tissue. At comparable euglycemia, diabetic patients had similar ISR but higher plasma beta-hydroxybutyrate (beta-OHB) levels during L/H infusion and higher plasma FFA and beta-OHB levels during the FFA rebound than nondiabetic control subjects. Correlating ISR with plasma FFA plus beta-OHB levels showed that in response to the same changes in FFA plus beta-OHB levels, diabetic patients secreted approximately 30% less insulin than nondiabetic control subjects. In addition, twice as much insulin was secreted during L/H infusion as during the FFA rebound in response to the same FFA/beta-OHB stimulation by both diabetic patients and control subjects. Glycerol, which was present in the infused lipid (272 mmol/l) did not affect ISR. We concluded that 1) assessment of FFA effects on ISR requires consideration of effects on ISR by ketone bodies; 2) ISR responses to FFA/beta-OHB were defective in patients with type 2 diabetes (partial beta-cell lipid blindness), but this defect was compensated by elevated plasma levels of FFAs and ketone bodies; and 3) approximately two times more insulin was released per unit change in plasma FFA plus beta-OHB during L/H infusion than during the FFA rebound after NA. The reason for this remains to be explored.
Diabetes 1999 Mar
PMID:Effects of fatty acids and ketone bodies on basal insulin secretion in type 2 diabetes. 1007 59

To obtain optimal image quality in myocardial viability studies, it is recommended that 18F-fluordeoxyglucose (18F-FDG) studies be performed with hyperinsulinaemic glucose clamping. 18F-FDG imaging after oral administration of acipimox, a nicotinic acid derivative, results in comparable image quality to clamping. Twenty consecutive patients (7 with diabetes mellitus) with angiographically confirmed coronary artery disease and similar demographic/clinical profiles were randomly allocated to gated cardiac 18F-FDG-PET with a standard euglycaemic hyperinsulinaemic clamp protocol or using a combination of oral administration of acipimox and the insulin clamp technique. The image quality, expressed as the myocardial-to-blood pool activity ratio, was superior in the combined protocol compared with the insulin clamping technique alone (3.37 +/- 1.46 vs 2.27 +/- 0.62, P = 0.037). Although there were no significant differences in plasma insulin and free fatty acids concentrations between the two protocols, plasma glucose concentrations obtained with the standard protocol were elevated compared with the combined protocol (11.1 +/- 3.7 vs 6.3 +/- 3.0 mM during clamping; 10.2 +/- 3.3 vs 5.5 +/- 3.0 mM during acquisition). We conclude that gated 18F-FDG-PET imaging after oral administration of acipimox plus insulin clamping yields image quality superior to that obtained with clamping alone.
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PMID:Combined hyperinsulinaemic glucose clamp and oral acipimox for optimizing metabolic conditions during 18F-fluorodeoxyglucose gated PET cardiac imaging: comparative results. 1058 93

The 'metabolic syndrome' is a special clinical entity characterized by upper body segment obesity (android obesity), together with one or more of a constellation of metabolic disorders that includes glucose intolerance, which may amount to frank diabetes mellitus, hypertension, cardiovascular lesions, hyperuricemia, and dyslipidemias (hypercholesterolemia, hypertriglyceridemia and reduced serum HDL). Recently, lipoprotein (Lp) (a) proved to be a new member in this syndrome. Lp(a) has the distinctive feature of containing apolipoprotein (a), which is a glycoprotein linked to apo B100, and has a similarity to plasminogen; it is also structurally related to LDL. Lp(a) is a macromolecular complex which is genetically determined, and has been identified as an independent risk factor for premature coronary artery disease (CAD). It is elevated in diabetic and non-diabetic android obese subjects, and aggravates the atherogenic effect of diabetes mellitus. Lp(a) is poorly influenced either by dietary measures or by hypolipidemic drugs. Unfortunately, few pharmacologic agents, such as niacin, nicotinic acid, sex hormones (estrogen and testosterone), alcohol and neomycin, affect Lp(a).
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PMID:Lipoprotein (a) in android obesity and NIDDM: a new member in 'the metabolic syndrome'. 1066 39

Nicotinamide adenine dinucleotide (NAD) and its derivatives NADH, NADP and NADPH have regulatory functions in the generation of triose phosphates and pyruvate from glucose. In many studies of the influence of the diabetic state on relationships between pyridine nucleotide and glucose metabolism, the focus has been on the sorbitol pathway. Less attention has been paid to other aspects of the role of pyridine nucleotides in pyruvate formation from glucose, in particular the effects of the NAD precursors nicotinamide and nicotinic acid on glucose metabolism. This paper reviews current knowledge of the involvement of pyridine nucleotides and their precursors in glucose catabolism in the normal and diabetic state. Reference is also made to the following three current hypotheses for mechanisms underlying diabetic microangiopathy: 1. Chronic glucose overutilization, caused by hyperglycemia, in tissues which lack insulin receptors and therefore are freely permeable to glucose. 2. Enhancement of sorbitol pathway activity with an ensuing decrease in the ratio of NAD/NADH. 3. Enhanced utilization of both glucose and pyridine nucleotides in formation of triose phosphates and pyruvate. Therapy with NAD precursors like nicotinamide might have corrective effects on these proposed biochemical aberrations, thereby retarding progression of microangiopathy.
Diabetes Metab Res Rev
PMID:Pyridine nucleotides in glucose metabolism and diabetes: a review. 1070 37

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


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