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

Factors involved in blood-oxygen transport were studied in 46 pregnant women during the first trimester. All had type 1 (insulin-dependent) diabetes and comparisons were made with similar measurements from 19 non-diabetic pregnant women, also in the first trimester. The concentration of hemoglobin A1c (HbA1c) was significantly increased (7.6% versus 4.4%, p less than 0.01) and arterial oxygen saturation was decreased (0.95 versus 0.98 mol/mol, p less than 0.01) in the pregnant diabetics compared with the non-diabetics. The hemoglobin concentration was significantly elevated in the diabetic women (12.9 versus 12.1 g/100 ml, p less than 0.01). Even though the red cell 2,3-diphosphoglycerate content was the same in the two groups, and pH was significantly lower in the diabetic women, hemoglobin-oxygen affinity was slightly increased in the diabetic patients (P50 at actual pH: 26.2 versus 26.7 mmHg, p less than 0.05; P50 at pH 7.40: 27.0 versus 28.0 mmHg, p less than 0.01). The study has demonstrated certain modifications in the blood oxygen transport system in the first trimester of pregnancy of diabetic women that are possibly related to the presence of excess amounts of glycosylated hemoglobin with increased oxygen affinity. This disturbance in maternal oxygen transport, particularly when associated with diabetic vascular disease, may lead to episodes of fetal hypoxia. Such fetal hypoxia may be a pathogenetic factor for the development of congenital malformations in the outcome of diabetic pregnancy.
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PMID:Blood-oxygen transport in first trimester of diabetic pregnancy. 674 58

Erythrocyte deformability measured as filtration index is clearly diminished in diabetics, thus possibly contributing to diabetes-associated microvascular complications. Moreover, the erythrocyte sorbitol level in IDD is clearly higher than that of non-diabetics, suggesting an alteration in the polyol pathway as possible determinant of diabetes-associated complications. Following this line of research, intracellular sorbitol as well as glucose, inositol, galactitol, mannitol and 2,3-diphosphoglycerate have been studied in 21 diabetics and in 14 controls matched for age and sex. In addition to confirming the high levels of intraerythrocytic glucose and sorbitol in diabetic subjects, statistically significant correlations have been demonstrated between sorbitol and filtration index, between plasma glucose, intracellular glucose level and glycosylated hemoglobin, suggesting a relationship between metabolic control and hemorheologic alterations in diabetes.
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PMID:Role of red cell sorbitol as determinant of reduced erythrocyte filtrability in insulin-dependent diabetics. 675 60

Several hematologic abnormalities have been defined in patients with diabetes mellitus, despite the lack of classic hematologic pathologic findings in this condition. Studies of the erythrocyte and the formation of hemoglobin A1c have provided a means of documenting glycemia and a model reaction for diabetic sequelae through postsynthetic protein modification. Oxygen affinity has been noted to be abnormal in the diabetic erythrocyte, concomitant with a decreased concentration of inorganic phosphorus, glycosylation of the 2,3-diphosphoglycerate binding site or preexisting vascular disease. Red cell membrane viscosity has also been documented to be increased in the hyperglycemic subject. Abnormalities in the polymorphonuclear leukocyte have been described, involving the properties of adherence, random migration, chemotaxis, phagocytosis and killing. Certain metabolic abnormalities are also present in this cell type. The lymphocyte has been shown to have abnormal metabolic properties, mitogen responses and cell surface properties in diabetes both in animals and human subjects. Certain subpopulations of lymphocytes appear to be especially vulnerable to changes concomitant with diabetes mellitus. In vitro abnormalities of platelet behavior have been widely studied, although the in vivo significance of these findings remains controversial. Studies of the fluid phase of coagulation have suggested the existence of a hypercoagulable state in hyperglycemic subjects. The clinical significance of most of these findings remains to be defined. Nevertheless, the observation that many of the abnormalities described are reversible when hyperglycemia is corrected has given impetus to the development of improved systems of glucose "control" for diabetic patients.
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PMID:Hematologic alterations in diabetes mellitus. 700 87

The relationship between blood glucose and glycosylated haemoglobin (HbAlc) had been investigated during an 8 week period in 53 Type 1 (insulin-dependent) diabetic women studied during the third trimester of pregnancy. Blood glucose estimations (fasting and 2h post-prandially) were made an average of 41 times in each patient during this period and HbAlc was determined once at the end of the study. There was a significant correlation between both the mean blood glucose over the preceding 8 weeks and the standard deviation of the fasting blood glucose with HbAlc (r = 0.69, p less than 0.001; r = 0.46, p less than 0.001, respectively). A "glycosylation index" was calculated for each patient (HbAlc divided by the mean blood glucose value). There was a significant correlation between the "glycosylation index" and duration of diabetes (r = 0.68, p less than 0.001). In contrast, there was no correlation between red cell 2,3-diphosphoglycerate and HbAlc or "glycosylation index". These findings suggest that increasing duration of diabetes influences the post-translational formation of HbAlc and that isolated HbAlc values need to be interpreted with caution in the pregnant diabetic.
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PMID:Relationship between glycosylation of haemoglobin and the duration of diabetes: a study during the third trimester of pregnancy. 706 Aug 48

The content of 2,3-diphosphoglycerate (2,3-DPG) was studied in the red blood cells of 145 patients with diabetes mellitus. A significant (P less than 0.001) increase in 2,3-DPG (8.10 +/- 0.42 mc mol/l of red blood cells) was seen in the diabetic patients as compared with that of the healthy subjects (4.50 +/- 0.40 mc mol/l ml of red blood cells). A rice in 2,3-DPG concentration is not dependent on the patients' age, duration, severity and type of the disease. The determination of a 2,3-DPG level maybe used for evaluation of tissue hypoxia in patients with diabetes mellitus.
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PMID:[Assessment of the 2,3-diphosphoglycerate content of erythrocytes in diabetes mellitus]. 714 79

Lipemic plasma with marked elevations of plasma triglyceride levels (3221 +/- 1590 mg/dl) and fasting chylomicronemia was observed in nine patients with uncontrolled non-insulin-dependent diabetes mellitus. Every case had hypertriglyceridemic relatives, suggesting that the very high triglyceride values seen resulted from the coexistence of diabetes with a familial form of hypertriglyceridemia. A number of clinical and biochemical features observed in the diabetic patients and also in a group of nondiabetic controls with comparable degrees of hypertriglyceridemia suggests that these manifestations are related to high plasma triglyceride levels rather than to the diabetes per se. Chronic abdominal pain, mental confusion, and memory loss improved with lipid-lowering therapy and clearing the plasma of chylomicrons. Pulmonary function tests, red cell 2,3-diphosphoglycerate, and hemoglobin oxygen affinity were normal; the mild hypoxemia observed is believed to be an artifact. It is suggested that a syndrome due to chylomicronemia can occur in uncontrolled non-insulin-dependent diabetic patients, who in addition have a familial form of hypertriglyceridemia. To prevent manifestations of this syndrome in these patients, specific lipid-lowering therapy may be required in addition to control of their diabetes.
Diabetes Care
PMID:Chylomicronemia syndrome in diabetes mellitus. 734 82

Nerve ischemia/hypoxia has been linked to the pathogenesis of diabetic complications. Red blood cell 2,3-diphosphoglycerate is an important regulator of peripheral tissue oxygenation; however, the relationship between 2,3-diphosphoglycerate concentration and diabetic complications has not been studied in detail. This investigation focused on the relationship between red blood cell 2,3-diphosphoglycerate and diabetic neuropathy, by measuring motor nerve conduction velocity and sciatic nerve blood flow in streptozotocin-induced diabetic rats. The effect of treatment with niceritrol, a nicotinic acid derivative that acts as a vasodilator and reduces serum lipid concentrations, on 2,3-diphosphoglycerate concentration and diabetic neuropathy was also examined. Untreated diabetic rats had significantly lower concentrations of red blood cell 2,3-diphosphoglycerate, higher concentrations of serum total cholesterol and triglyceride, as well as reduced motor nerve conduction velocity and sciatic nerve blood flow, compared to untreated normal rats. Niceritrol prevented these abnormalities without correcting hyperglycemia in diabetic rats, but had no effect on these parameters in normal rats. Red blood cell 2,3-diphosphoglycerate concentration and motor nerve conduction velocity showed a positive correlation with sciatic nerve blood flow and 2,3-diphosphoglycerate, respectively. These observations suggest that ischemia/hypoxia plays an important role in the development of diabetic neuropathy, and that niceritrol has a therapeutic effect on this condition by improving endoneurial ischemia/hypoxia.
J Diabetes Complications
PMID:Niceritrol prevents the decrease in red blood cell 2,3-diphosphoglycerate and neuropathy in streptozotocin-induced diabetic rats. 754 76

Streptozotocin induced diabetes in rats was accompanied by development of hyperglycemia, by increase in the rate of hemoglobin and albumin glycosylation in blood and by elevation of 2,3-diphosphoglycerate content in erythrocytes. Alterations of the dissociation properties and the decrease in Hb P50 value suggested the reduced affinity of hemoglobin to oxygen. Injection of nicotinamide, which is involved in NAD+ biosynthesis, caused a decrease of glucose content in blood, stabilized the content of 2,3-diphosphoglycerate and of glycosylated hemoglobin in erythrocytes. Nicotinamide appears to decrease the rate of hemoglobin glycosylation and enhanced the tissue oxygen utilization under hypoxic conditions.
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PMID:[Correcting effect of nicotinamide on hemoglobin glycosylation in streptozotocin diabetes in rats]. 777 Oct 89

Insulin administration can cause or worsen experimental and human diabetic neuropathy ("insulin neuritis"). In this study, we tested the hypothesis that insulin administration impairs tissue oxygenation. We infused insulin under nonhypoglycemic conditions and evaluated its effect on endoneurial oxygen tension, nerve blood flow, and the oxyhemoglobin dissociation curve of peripheral nerve in normal and diabetic rats. Intravenous insulin infusion resulted in a dose-dependent reduction in endoneurial oxygen tension in normal nerves (from 26% at 0.04 U/kg insulin to 55% at 32 U/kg). The nerves of rats with streptozotocin-induced diabetes were resistant, but with control of hyperglycemia this susceptibility to the endoneurial hypoxic effect of insulin returned. The reduction in endoneurial oxygen tension regressed with glycosylated hemoglobin (Y = 53.8-2.7X, where Y = %reduction in endoneurial oxygen tension and X = HbA1; r = 0.87; P = < 0.001). Diabetes or insulin administration resulted in only minimal and physiologically insignificant alterations in the oxygen dissociation curve and 2,3-diphosphoglycerate of sciatic nerve. Instead, insulin administration resulted in a reduction in nerve nutritive blood flow and an increase in arteriovenous shunt flow. When the latter was eliminated by the closure of arteriovenous shunts (infusion of 5-hydroxytryptamine), endoneurial oxygen reverted to normal. These findings indicate a deleterious vasoactive effect of insulin and may explain the development of insulin neuritis.
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PMID:Hypoxic effect of exogenous insulin on normal and diabetic peripheral nerve. 802 30

We describe a new alpha chain mutant accidentally found in a diabetic patient. The propositus is being treated for diabetes mellitus II with 4% glycated hemoglobin (Hb A1C). The variant, named Hb Gouda, is not detectable by starch gel electrophoresis but appears as a shoulder before the Hb A fraction during the chromatographic separation of Hb A1C. The hematological analysis revealed normal parameters with a normal serum iron value. No anomalies were reported in connection with Hb Gouda. The tryptic peptide map and sequencing of the alpha T-9 peptide revealed the substitution of a histidine by a glutamine at position 72. By selective amplification and sequencing of both the alpha genes, we have assigned the new mutation to the alpha 2 gene. Position 72 of the alpha chain is a moderately conserved site located between two non-conserved amino acids. This site is not involved in heme, dimer or tetramer contacts, or in Bohr effect or in 2,3-diphosphoglycerate binding.
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PMID:HB Gouda [alpha 72(EF1)His-->Gln], a new silent alpha chain variant. 874 29


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