Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A functional arterial spasm, revealed by reduced post-ischemic response, is present in diabetic subjects with no overt evidence of vascular damage. The administration of three different antioxidant agents, vitamin C, thiopronine and glutathione, produces an increase of basal blood flow in both diabetic and normal subjects, and ameliorates significantly the vascular functional response in diabetes. These data suggest that free radicals may play a role in the regulation of arterial resistance in humans, and that a de-regulation of their action may be involved in the development of arterial dysfunction in diabetes.
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PMID:Evidence for a possible role of oxygen free radicals in the abnormal functional arterial vasomotion in insulin dependent diabetes. 226 37

Hyperglycemia and/or hypoinsulinemia have been found to inhibit L-ascorbic acid cellular transport. The resultant decrease in intracellular ascorbic acid may de-inhibit aryl sulfatase B and increase degradation of sulfated glycosaminoglycans (sGAG). This could lead to a degeneration of the extracellular matrix and result in increased intimal permeability, the initiating event in atherosclerosis. The present studies show that the glucose transport inhibitor cytochalasin B blocked the uptake of 3H-2-deoxy-D-glucose (2.5 mg%) by mouse 3T3 fibroblasts. Cytochalasin B also blocked the uptake of 14C-L-ascorbic acid (1.25 mg%). The results of these studies further support the hypothesis that glucose and ascorbate share a common transport system. This may have important implications concerning the vascular pathology associated with diabetes mellitus.
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PMID:Effect of cytochalasin B on the uptake of ascorbic acid and glucose by 3T3 fibroblasts: mechanism of impaired ascorbate transport in diabetes. 230 70

Normal and streptozotocin diabetic female Wistar rats were given vitamin C (VC) at 0.3% or 1.0% (w/w) in the diet: 1% dietary VC resulted, in 12-24 hr, in significant increases in serum ascorbate levels and lens ascorbate concentrations in normal rats. The increase was biphasic, with VC concentrations falling to a lower level which was still significantly elevated compared to controls in the period of 1.7-4 days for serum and 1.7-5 days for lenticular VC. At the end of 10 weeks the rats were examined for weight gain or loss, general body condition and cataracts. At the time of killing, blood was collected for measurement of serum glucose. Alpha-crystallin levels were determined in vitreous and aqueous humours using a radioimmunoassay. One lens from each rat was fixed for either scanning electron microscopy or light microscopy; the other lens was homogenized in 8 M guanidinium chloride for adenosine triphosphate analysis. In normal rats, a small amount of gamma-crystallin was found in the vitreous humour, and an even smaller amount in the aqueous humour. Diabetes caused a five-fold increase in the vitreous humour and a 2.5-fold increase in gamma-crystallin in the aqueous humour. Diabetes also led to a significant worsening in general body condition, loss of body weight, formation of cataracts, and decrease in lens adenosine triphosphate levels. Addition of VC to the diet of diabetic animals resulted in reduction in cataracts and a decrease of gamma-crystallin leakage into the aqueous and vitreous humours. VC had no effect on lens adenosine triphosphate levels.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Modelling cortical cataractogenesis. XI. Vitamin C reduces gamma-crystallin leakage from lenses in diabetic rats. 240 46

A questionnaire measuring food frequency was validated against 7-day records of food intake in a group of 30 children, 2-16 years of age. Special emphasis was given to the ability of the questionnaire to estimate frequency of intake of foods of particular interest in diabetes mellitus. Fifteen children had insulin-dependent diabetes; 15 were healthy. Comparison of the two methods regarding frequency of foods with high content of sucrose, protein, fat, fibres, nitrite or vitamin C showed a correlation of 0.52-0.76. The frequency of intake of some staple foods was often overestimated by the questionnaire, while the frequency of meat, sausage and some sweet snacks was underestimated. The use of the questionnaire to identify high or low consumers of the mentioned nutrients showed a rather low sensitivity (0.38-0.50), but a high specificity (0.86-1.0) when compared with results of the 7-day record. In our limited sample of subjects no systematic differences were found comparing sexes or diabetic and healthy children. A food frequency questionnaire may, in spite of some important reservations, be a useful tool for screening purposes when more time-consuming and resource-demanding methods cannot be used.
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PMID:Estimating children's eating habits. Validity of a questionnaire measuring food frequency compared to a 7-day record. 260 11

Plasma total ascorbate status measured by 2.4 dinitrophenyl hydrazine method showed that diabetics (N = 100) had significantly lower plasma total ascorbate compared with 45 age and sex matched non-diabetic controls; 0.34 +/- 0.16 mg/dl vs 0.68 +/- .06 mg/dl, P less than 0.001) regardless of presence or absence of retinopathy and irrespective of mode of treatment. The finding unique to this study was that plasma total ascorbate status in diabetics with retinopathy (0.19 +/- 0.07 mg/dl) was significantly lower than that of uncomplicated diabetics (0.49 +/- 0.06 mg/dl; P less than 0.001). Plasma Glucose had no correlation with plasma ascorbate levels and effect of duration of Diabetes Mellitus (DM) on ascorbate status in diabetics was ambiguous. Diabetics had abnormally fragile cutaneous capillaries detected by Hess test. The incidence of capillary fragility was more in patients with retinopathy. Hess test can be used as an easy and non-invasive test to assess plasma ascorbate status to detect microvascular involvement in DM. The experience of this study reflects that the two distinct microvascular lesions in diabetes, i.e. abnormal dermal capillary fragility and retinopathy may have a common link to ascorbic acid deficiency. An early switching on of the supplementation of ascorbic acid may retard the development of microvascular complications in diabetes.
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PMID:Role of plasma ascorbate in diabetic microangiopathy. 262 96

This review has discussed some metabolic and endocrine changes that can be associated with a stress type of metabolism, diabetes, obesity, hypertension, smoking and the consumption of diets rich in fat and refined sugar, or poor in ascorbate. These are some of the risk factors associated with premature atherosclerosis, coronary thrombosis and stroke. It has been proposed that an increased control of metabolism by the 'stress' or counter-regulatory hormones, relative to insulin, is a common feature of these risk factors. Particular emphasis was placed upon the action of the glucocorticoids which can produce insulin insensitivity, leading to hyperglycaemia, hypertriglyceridaemia, hypercholesterolaemia and hyperinsulinaemia. Furthermore, glucocorticoids can decrease energy expenditure and, together with insulin, promote energy deposition. These observations provide a partial explanation for the metabolic changes that can accompany the risk factors and clarify why they interact in promoting atherosclerosis.
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PMID:Possible connections between stress, diabetes, obesity, hypertension and altered lipoprotein metabolism that may result in atherosclerosis. 268 77

Tissues sequester vitamin C in concentrations exceeding that present in plasma. The transmembrane transport mechanisms have been shown to be influenced by the concentration of glucose in vitro. On this basis an impairment of tissue vitamin C status may be present in diabetes mellitus. Recent evidence in support of this hypothesis, first proposed by Mann in 1974, is reviewed.
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PMID:Altered vitamin C transport in diabetes mellitus. 305 Mar 88

Plasma and buffy layer vitamin C concentrations have been measured in insulin dependent and non-insulin dependent diabetic patients and the results compared with age and gender matched non-diabetic controls. No differences were found between the controls and the diabetics nor between the different types of diabetes, although patients who had had clinical diabetes for longer had higher plasma vitamin C values than patients in whom the disease was not long standing. There were no significant changes in the distribution of vitamin C between plasma and white cells in the diabetic nor in patients with marked hyperglycaemia. We conclude that the vitamin C intakes of the majority of diabetic patients we studied, who are probably typical of diabetics receiving hospital treatment in the United Kingdom, are adequate and are sufficient to maintain satisfactory plasma and buffy layer vitamin C concentrations. These findings are discussed in the light of reports which have shown lower levels of vitamin C in the blood of diabetic patients and competition between vitamin C and glucose for transport across the cell membrane.
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PMID:Blood vitamin C concentrations in patients with diabetes mellitus. 319 19

The prevalence and incidence of diabetes mellitus in the age group zero to 14 years in Western Australia were determined from a survey by means of Schools Health Services. Additional information from the State's computer-linked hospital records system, the State's only children's hospital, diabetic clinics and physicians enabled virtually complete ascertainment of cases of childhood diabetes. Only 60% of school-age diabetic children were known to school nurses before the survey, but the nurses were able to identify two-thirds of the remainder during the survey. Among non-Aboriginal children, the prevalence of diabetes in the age group zero to 14 years was 0.59 per 1000 children and the incidence was 12.3 per 100,000 children per year. These rates are somewhat lower than those that have been reported from the United Kingdom and North America, and substantially lower than the rates that were reported from Scandinavia. All but one of the diabetic children who were identified required insulin and were assumed to be insulin-dependent. An excess of boys was found. None of 8715 Aboriginal or part-Aboriginal children had insulin-dependent diabetes mellitus, which indicates that this racial group has a low prevalence of this condition. In case--control studies, which used questionnaires for parents, no significant trends were found in relation to the history of immunizations or of specific viral illnesses except for a past history of varicella which was less frequent in diabetic children. A past history of established breast-feeding (of more than one week) was less frequent in diabetic children, as was the ingestion of vitamin C supplements before the onset of diabetes. Some evidence for a seasonality of onset was obtained. The diabetic children were absent from school for more days and had more admissions to hospital than did non-diabetic children. The majority of diabetic children were prescribed insulin twice a day or more often (84%); performed home blood-glucose monitoring (74%); and attended hospital diabetic clinics (91%).
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PMID:Diabetes in Western Australian children: descriptive epidemiology. 334 23

As part of an exploratory study of nutrition and senile cataract relationships between biochemical markers of nutritional status and senile cataract were examined in 112 subjects aged 40-70 y. Seventy-seven subjects had a cataract in at least one lens. Blood levels were determined for total carotenoids, vitamin A, vitamin D, vitamin E, vitamin C, riboflavin, thiamin, vitamin B-6, zinc, copper, selenium, and magnesium. Subjects were grouped into quintiles for each nutrient. Logistic regression was used to estimate the odds ratios (ORs) for cataract among subjects in the highest quintile and the middle three quintiles relative to subjects in the lowest quintile. ORs were adjusted for age, sex, race, and presence of diabetes. Results suggest that risk of cortical cataract was reduced for subjects in the highest quintile of vitamin D and total carotenoids and that persons with cataract may have lower levels of vitamin C and higher levels of vitamin B-6 and Se.
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PMID:Nutritional status in persons with and without senile cataract: blood vitamin and mineral levels. 338 22


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