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Query: UMLS:C0011854 (type 1 diabetes)
 20,749 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The influence of insulin on plasma and bone mineral homeostasis was studied in the BB rat model, which develops an autoimmune form of diabetes at the age of about 100 days. Untreated diabetes of short duration resulted in hypercalciuria and intestinal calcium malabsorption despite increased free concentrations of serum 1,25-dihydroxyvitamin D. The concentrations of two vitamin D-dependent calcium-binding proteins were also decreased: a low duodenal calbindin-D 9K concentration corresponding to the low intestinal active calcium absorption and a low serum osteocalcin concentration, corresponding to a low bone formation and highly correlated with serum IGF-I concentration. Indeed, on bone histology a very low number of osteoblasts and low osteoblast activity (osteoid formation and mineral apposition rate) were observed. Similar abnormalities persisted in rats with long-standing diabetes resulting in markedly decreased bone mass and increased brittleness of bone. Diabetes therefore resulted in low-turnover osteoporosis. Several hormones (testosterone, growth hormone and 1,25-dihydroxyvitamin D) and growth factors (IGF-I and its binding proteins) with known effects on bone were markedly decreased in diabetic rats. A continuous infusion of testosterone, GH or 1,25-(OH)2D3 for 14 d by miniosmotic pumps could not improve the biochemical or histomorphometric abnormalities. Insulin infusion for 2 weeks, however, rapidly increased and overcorrected the number of osteoblasts, normalized serum osteocalcin and IGF-I concentrations but could not yet normalize bone mineralization. Continuous infusion of IGF-I alone did not improve the osteoblast number of osteocalcin but markedly stimulated bone mineralization. From these data we can conclude that both insulin and IGF-I are potent bone growth factors but with different mode of action. In human type 1 diabetes, a similar decrease in serum osteocalcin and IGF-I was observed. A reduction of regional bone mass, both in long and trabecular bones, is frequently observed in human diabetes. Cumulative data from case control studies indicate that the life-time fracture risk is increased in diabetes.
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PMID:Diabetic bone disease. Low turnover osteoporosis related to decreased IGF-I production. 146 60

Insulin-dependent diabetes mellitus (IDDM) is a chronic metabolic disorder which can induce alterations in bone metabolism (osteopenia) and/or in mineral homeostasis, mainly during growth. Some data suggest that these alterations may be related to low serum magnesium values found in IDDM that induce a functional hypoparathyroid state. In this paper, some aspects are revised relating to altered magnesium and mineral homeostasis in children with IDDM and their possible relationships. The role of osteocalcin, a specific osteoblast protein product, as a biochemical marker of diabetic osteopenia is also discussed. In addition, on the basis of personal experience, it is shown that the deranged parathyroid hormone-vitamin D axis in IDDM is reversed after normalization of magnesium serum levels by oral magnesium. Thus available data suggest that hypomagnesaemia is involved in the genesis of the altered mineral metabolism in children with IDDM.
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PMID:The parathyroid hormone- 1,25-dihydroxyvitamin D endocrine system and magnesium status in insulin-dependent diabetes mellitus: current concepts. 159 Nov 43

To evaluate the relationship between insulin and hormonal vitamin D system we compared the serum concentrations of 1.25 dihydroxyvitamin D (1.25 D) in a group of 56 patients with insulin dependent diabetes mellitus (IDDM) with those from a control population of 26 healthy individuals. We did not find overall significant differences in 1.25 D levels between diabetic patients and control individuals (32.6 +/- 12 vs 35.4 +/- 9 pg/ml), but there were differences between the different patient subgroups depending on the duration of the disease. The dose of insulin and the 1.25 D levels were linearly correlated (r = 0.3693, p = 0.0051). The patients with IDDM had normal 1.25 D levels. Exogenous insulin administration may have relevance for the interpretation of these results.
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PMID:[Serum 1,25-dihydroxyvitamin D in insulin-dependent diabetes mellitus]. 225 May 44

Recent studies indicate that serum levels of osteocalcin, a 49-aminoacid bone matrix protein, are a biochemical marker of bone formation. In order to study bone metabolism in diabetes mellitus, in 28 patients with Type 1 (insulin-dependent) diabetes mellitus, in 38 patients with Type 2 (non-insulin-dependent) diabetes mellitus and two control groups, matched for Type 1 and Type 2 diabetic patients, respectively, serum levels of osteocalcin, parathyroid hormone and 25 hydroxy vitamin D were measured by radioimmunoassay. Whereas in Type 1 diabetic patients and control subjects serum levels of osteocalcin and 25 hydroxy vitamin D were not statistically different, serum osteocalcin and 25 hydroxy vitamin D levels were significantly decreased in Type 2 diabetic patients when compared with corresponding control subjects (p less than 0.03 and p less than 0.001, respectively). Independent of the type of diabetes, serum parathyroid hormone levels were comparable in diabetic patients and matched control subjects. Serum osteocalcin levels were significantly lower in Type 1 diabetic patients with retinopathy and/or proteinuria than in Type 1 diabetic patients without microangiopathy (p less than 0.05). Whereas serum parathyroid hormone levels in Type 2 diabetic patients with retinopathy and/or proteinuria were significantly increased (p less than 0.02), 25 hydroxy vitamin D levels were decreased (p less than 0.02) when compared with Type 2 diabetic patients without microangiopathy. Our data give evidence of a vitamin D deficiency and a decreased bone formation in patients with Type 2 diabetes mellitus. In Type 1 diabetes mellitus bone formation as reflected by serum osteocalcin levels is influenced by the presence or absence of microangiopathic complications.
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PMID:Serum osteocalcin levels in diabetes mellitus: analysis of the type of diabetes and microvascular complications. 326 86

The degree of diabetic osteopenia and serum vitamin D metabolite levels were measured in 14 type 1 (insulin-dependent) and 168 type 2 (non-insulin-dependent) diabetic patients. Based on six indices obtained by microdensitometry, we found the bone mass in 28.6% of type 1 and 26.2% of type 2 diabetic patients to be decreased and in 14.3% and 11.9%, respectively, the decrease was severe. Our method of analysis of bone mass has shown that diabetic osteopenia differs from typical osteoporosis in character. In addition, serum 24,25-dihydroxyvitamin D was significantly decreased both in type 1 and in type 2 diabetes (p less than 0.01), but 1,25-dihydroxyvitamin D was significantly decreased only in type 1 diabetes (p less than 0.01) compared to the controls, being lower than that in type 2 diabetes (p less than 0.05). On the other hand, 25-hydroxyvitamin D was similar to that of the controls, in both types of diabetes.
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PMID:Osteopenia and circulating levels of vitamin D metabolites in diabetes mellitus. 387 11

Vitamin D has been shown to modulate the immune system thereby preventing the development of diabetes in NOD mice. Since the vitamin D binding protein (DBP) is the main transporter for vitamin D and DBP has immunomodulatory properties itself, we investigated three polymorphic sites within the DBP gene as candidates for type 1 diabetes susceptibility for the first time. 152 Caucasian families with at least one affected offspring were genotyped for intron 8 [(TAAA)n repeat] and exon 11 (HaeIII, StyI) polymorphisms. Transmission disequilibrium testing was used to detect preferential transmission to affected offspring. We found no significant transmission disequilibrium for DBP alleles. The strongest deviation from expected values was observed for the "10" allele (relative risk = 0.57, transmitted 13 of 36 times (corrected p = 0.249)). Although we cannot exclude an association of the studied DBP alleles with type 1 diabetes at present, these data do not suggest their contribution to this disease in Germans.
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PMID:Vitamin D binding protein alleles and susceptibility for type 1 diabetes in Germans. 1059 71

Five cases of severe myopathy associated with vitamin D deficiency are described. Each patient was confined to a wheelchair because of weakness and immobility. Two were elderly, 1 was a 37-year-old African American with type 1 diabetes mellitus, 1 was being treated for carcinoid syndrome, and 1 was severely malnourished due to poor oral intake. In each, weakness had previously been attributed to other causes, including old age, concomitant diabetic neuropathy, or general debility. Correct diagnosis was made initially by a high index of suspicion, following the demonstration of clinical proximal myopathy; confirmation was made by the demonstration of low 25-hydroxyvitamin D and elevated parathyroid hormone concentrations. Treatment with vitamin D caused a resolution of body aches and pains and a restoration of normal muscle strength in 4 to 6 weeks. Four patients became fully mobile and had normal 25-hydroxyvitamin D concentrations, and the fifth also became mobile. In the 4 fully recovered cases, parathyroid hormone levels on follow-up were lower but still elevated. This finding suggests a degree of autonomy of parathyroid secretion known to occur in cases of long-standing vitamin D deficiency. Myopathy, due to chronic vitamin D deficiency, probably contributes to immobility and ill health in a significant number of patients in the northern United States. An awareness of this condition may significantly improve mobility and quality of life in patient populations vulnerable to vitamin D deficiency.
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PMID:Severe myopathy associated with vitamin D deficiency in western New York. 1078 15

Vitamin D has been shown to exert manifold immunomodulatory effects. Because type 1 diabetes is regarded to be immune-mediated and vitamin D prevents the development of diabetes in the NOD mouse, we investigated the role of the vitamin D receptor (VDR) gene as a candidate for type 1 diabetes susceptibility. A total of 152 Caucasian families with at least one affected offspring were genotyped for four VDR restriction-site polymorphisms (FokI, BsmI, ApaI, and TaqI). Whereas the BsmI, ApaI, and TaqI polymorphisms are in strong linkage disequilibrium with each other, no significant linkage disequilibrium with the FokI site was observed. Extended transmission disequilibrium testing (ETDT) was used to detect preferential transmission of allelic combinations to affected offspring. We found significant haplotype-wise ETDT results for the BsmI/ApaI/TaqI (chi2 = 18.886, df = 7, P = 0.0086), the BsmI/TaqI (chi2 = 8.373, df = 3, P = 0.0389), and theApaI/TaqI (chi2 = 17.182, df = 3, P = 0.0006) haplotypes. The "At" and "Bt" alleles confer an increased risk, whereas "AT" and "at" are protective. The combination with the strongest susceptibility was the "BAt" haplotype (64% transmitted, P = 0.0106). Analysis of the FokI site does not provide more information on susceptibility (FokI/BsmI/ApaI/TaqI [chi2 = 24.702, df = 15, P = 0.0541]). These findings suggest a linkage of VDR itself or a nearby gene with type 1 diabetes susceptibility in Germans, confirming respective observations previously made in Indian Asians.
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PMID:Vitamin D receptor allele combinations influence genetic susceptibility to type 1 diabetes in Germans. 1086 75

We examined whether 1,25 dihydroxyvitamin D(3) (1,25 D(3)), the active form of vitamin D involved in the regulation of the immune system, may also protect human pancreatic islet cells from destruction induced by cytokines. In this study, we specifically investigated the effect of 1,25 D(3) on oxidative stress and major histocompatibility complex (MHC) induction, both implicated in cytokine-induced islet cell dysfunction and destruction. We also investigated the effects of 1,25 D(3) on interleukin (IL)-6, a pleiotropic cytokine implicated in the pathogenesis of immunoinflammatory disorders. Human pancreatic islets, isolated from heart-beating donors, were treated with a combination of three cytokines, IL-1beta+tumor necrosis factor alpha+interferon gamma, in the presence or absence of vitamin D, and compared with with untreated control cells. Metabolic activity was assessed by cell viability and insulin content. Oxidative stress was estimated by heat shock protein 70 (hsp70) expression, cell manganese superoxide dismutase (MnSOD) activity and nitrite release, a reflexion of nitric oxide (NO) synthesis. Variation of immunogenicity of islet preparations was determined by analysis of the MHC class I and class II transcripts. Inflammatory status was evaluated by IL-6 production. After 48 h of contact with cytokines, insulin content was significantly decreased by 40% but cell viability was not altered. MHC expression significantly increased six- to sevenfold as well as NO and IL-6 release (two- to threefold enhancement). MnSOD activity was not significantly induced and hsp70 expression was not affected by the combination of cytokines. The addition of 1,25 D(3) significantly reduced nitrite release, IL-6 production and MHC class I expression which then became not significantly different from controls. These results suggest that the effect of 1,25 D(3) in human pancreatic islets cells may be a reduction of the vulnerability of cells to cytotoxic T lymphocytes and a reduction of cytotoxic challenge. Hence, 1,25 D(3) might play a role in the prevention of type 1 diabetes and islet allograft rejection.
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PMID:Beneficial effect of 1,25 dihydroxyvitamin D3 on cytokine-treated human pancreatic islets. 1125 Jun 57

Induced apoptosis of autoreactive T-lymphocyte precursors in the thymus is crucial for the prevention of autoimmune disorders. IGF-I and prolactin, which are lymphocyte growth factors, may have the potential to suppress apoptosis in thymocytes and thus encourage autoimmunity; conversely, dietary fish oil rich in omega-3 fats appears to upregulate apoptosis in lymphocytes. Since whole-food vegan diets may downregulate systemic IGF-I activity, it is proposed that such a diet, in conjunction with fish oil supplementation and treatment with dopamine agonists capable of suppressing prolactin secretion, may have utility for treating and preventing autoimmune disorders. This prediction is consistent with the extreme rarity of autoimmune disorders among sub-Saharan black Africans as long as they followed their traditional quasi-vegan lifestyles, and with recent ecologic studies correlating risks for IDDM and for multiple sclerosis mortality with animal product and/or saturated fat consumption. Moreover, there is evidence that vegan or quasi-vegan diets are useful in the management of rheumatoid arthritis, multiple sclerosis, and possibly SLE. The dopamine agonist bromocryptine exerts anti-inflammatory effects in rodent models of autoimmunity, and there is preliminary evidence that this drug may be clinically useful in several human autoimmune diseases; better tolerated D2-specific agonists such as cabergoline may prove to be more practical for use in therapy. The moderate clinical utility of supplemental fish oil in rheumatoid arthritis and certain other autoimmune disorders is documented. It is not unlikely that extra-thymic anti-inflammatory effects contribute importantly to the clinical utility of vegan diets, bromocryptine, and fish oil in autoimmunity. The favorable impact of low latitude or high altitude on autoimmune risk may be mediated by superior vitamin D status, which is associated with decreased secretion of parathyroid hormone; there are theoretical grounds for suspecting that parathyroid hormone may inhibit apoptosis in thymocytes. Androgens appear to up-regulate thymocyte apoptosis, may be largely responsible for the relative protection from autoimmunity enjoyed by men, and merit further evaluation for the management of autoimmunity in women. It will probably prove more practical to prevent autoimmune disorders than to reverse them once established; a whole-food vegan diet, coupled with fish oil and vitamin D supplementation, may represent a practical strategy for achieving this prevention, while concurrently lowering risk for many other life-threatening 'Western' diseases.
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PMID:Upregulation of lymphocyte apoptosis as a strategy for preventing and treating autoimmune disorders: a role for whole-food vegan diets, fish oil and dopamine agonists. 1146 Nov 85


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