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)

Vitamin D metabolites and vitamin D-binding protein (DBP) were measured in non-diabetic rats and in rats made diabetic with streptozotocin. The animals were studied in the intact state, after gonadectomy and during pregnancy. In male non-diabetic rats the serum concentrations of 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) and DBP decreased after orchidectomy and were restored by treatment with testosterone. In female non-diabetic rats, these parameters increased after ovariectomy. Increased 1,25-(OH)2D3 and decreased DBP concentrations were found during pregnancy in non-diabetic rats. After the induction of diabetes in intact rats of both sexes, the concentration of DBP decreased, but a significant decrease in the concentration of 1,25-(OH)2D3 was found in male animals only. After ovariectomy, however, 1,25-(OH)2D3 decreased also in female diabetic rats. Both orchidectomy and insulin deficiency depressed serum concentrations of 1,25-(OH)2D3 (-22 and -45% respectively) and DBP (-14 and -29% respectively), but the effects of insulin deficiency were greater than those of androgen withdrawal. Moreover, the testosterone concentration was twofold lower in intact male diabetic rats than in non-diabetic animals. Insulin, but not testosterone treatment, however, restored DBP and 1,25-(OH)2D3 concentrations in diabetic rats, and insulin was effective in intact as well as in gonadectomized animals. This study shows that insulin deficiency decreases the concentrations of DBP and 1,25-(OH)2D3 in the rat, and that these decreases are facilitated by androgens, but counteracted by oestrogens.
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PMID:Evidence for an interaction of insulin and sex steroids in the regulation of vitamin D metabolism in the rat. 296 88

Vitamin D metabolites and vitamin D-binding protein were measured in the serum of nonketotic Bantu and Caucasian insulin-requiring diabetic subjects from Zaire and Belgium, respectively. In Caucasian diabetics, whether untreated (N = 18) or insulin treated (N = 26), no abnormalities were found. The Bantu diabetics (N = 20) were more insulin-deficient and had a poorer glucose control than the Caucasians. They presented, compared with Bantu controls, a significant decrease in the serum concentrations of 25-hydroxyvitamin D3 (26 +/- 10 vs. 35 +/- 14 micrograms/L, P less than .01), 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] (38 +/- 15 vs. 58 +/- 17 ng/L, P less than .001), and vitamin D-binding protein (303 +/- 55 vs. 356 +/- 41 mg/L, P less than .001). The decreased concentrations of vitamin D metabolites in the adult Bantu diabetic patients may be partly explained by a concomitant decrease in the concentration of vitamin D-binding protein, possibly due to insulin deficiency. The ratio between the molar concentrations of 1,25-(OH)2D3 and vitamin D-binding protein, used as an index of the free hormonal level, was also decreased, in association with a decreased serum calcium level. In conclusion, no abnormalities in vitamin D metabolism were found in Caucasian insulin-dependent diabetics, whereas low serum 1,25(OH)2D3 concentrations and hypocalcemia were found in poorly controlled Bantu diabetic subjects.
Diabetes 1986 Aug
PMID:Vitamin D metabolites and their binding protein in adult diabetic patients. 373 32

Vitamin D has been shown to increase insulin release from pancreatic islet cells in vitro, and to improve insulin secretion in vitamin D-deficient animals. Few attempts have been made to evaluate this issue directly in humans. We studied 35 otherwise healthy diabetic subjects in the early spring at the seasonal nadir of 25-hydroxyvitamin D [25(OH)D] concentrations (mean 35 +/- 7 nmol/L). Fasting glucose, insulin, C-peptide, and glucagon concentrations, and their responses to Sustacal stimulation were not related to indexes of mineral metabolism. In 20 subjects, a double-blinded, placebo-controlled, crossover trials of 1,25-dihydroxyvitamin D[1,25](OH)2D] treatment (1 micrograms/d for 4 d) had no effect on fasting or stimulated glucose, insulin, C-peptide, or glucagon concentrations. However, insulin and C-peptide responses to Sustacal after 1,25(OH)2D treatment were related to duration of diabetes (r2 = 0.28, P = 0.052 and r2 = 0.25, P = 0.002, respectively) in that short duration correlated with improvement after 1,25(OH)2D treatment. Hence, vitamin D nutrition, or 1,25(OH)2D therapy, had no major effect on glucose homeostasis in non-insulin-dependent diabetes mellitus.
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PMID:Effects of vitamin D on insulin and glucagon secretion in non-insulin-dependent diabetes mellitus. 817 95

Vitamin D is essential for normal insulin secretion in vivo and in vitro. The differential effect of calcium and of the vitamin D endocrine system in the insulin response to secretagogues is still a subject of debate. To study the roles of calcium and the vitamin D system in the in vivo insulin response, GTT and insulin sensitivity tests were conducted in rats presenting vitamin D depletion and hypocalcemia or vitamin D depletion supplemented with calcium alone for 3, 7, or 14 days, vitamin D3 (6.5 nmol/day x 7 days), or 1,25(OH)2D3 (28 pmol/day x 7 days). Serum calcium was 1.28 +/- 0.04 mM in hypocalcemic vitamin D-depleted rats, 1.47 +/- 0.06 (NS), 1.8 +/- 0.2 (P < 0.0002), and 2.04 +/- 0.07 (P < 0.0001) mM after 3, 7, or 14 days, respectively, of calcium supplementation; vitamin D3- or 1,25(OH)2D3-supplemented animals had serum calcium of 2.61 +/- 0.04 or 2.48 +/- 0.05 mM (P < 0.0001 vs. hypocalcemic vitamin D-depleted rats). Rats with hypocalcemia and vitamin D depletion had significantly higher glucose concentrations (P < 0.0005) and lower insulin response during GTT than all other groups (P < 0.001). Differences in insulin sensitivity could not account for differences in response because exogenous insulin administration led to a similar drop in glucose concentrations in all groups, with the nadir averaging 51.7 +/- 2.6% of initial values. To distinguish between calcium and the vitamin D system in the GTT response, rats were treated with a nonhypercalcemic analogue of 1,25(OH)2D3, OCT (28 pmol/day x 4-7 days) with or without dietary calcium.(ABSTRACT TRUNCATED AT 250 WORDS)
Diabetes 1993 Jan
PMID:Calcium is essential in normalizing intolerance to glucose that accompanies vitamin D depletion in vivo. 838 May 63

Vitamin D has been discovered at the beginning of this century. 7-Dehydrocholesterol is converted to vitamin D3 in the skin and after several hydroxylations it is further converted to the active hormonal form, 1 alpha,25-(OH)2D3. Vitamin D stimulates the absorption of calcium and phosphate and is an essential link in bone resorption and formation and calcium metabolism. 1 alpha,25-(OH)2D3 acts through a vitamin D receptor. These receptors are not only present in clinical target organs (kidney, gut, liver) but can also be found in a wide variety of "non-classical" tissues (keratinocytes, cells belonging to the immune system). Moreover, numerous cells (keratinocytes, macrophages) can locally synthetize or can be induced to synthetize 1 alpha,25-(OH)2D3 and these cells are responsive to its action. When these data are combined, a possible paracrine function of 1 alpha,25-(OH)2D3 can be suspected. Via this paracrine function 1 alpha,25-(OH)2D3 can suppress the cellular and humoral immunity. Based on the discovery of these effects on immune cells in vitro it became clear that 1 alpha,25-(OH)2D3 might be an interesting molecule to prevent autoimmune diseases and organ transplantation. This has already been shown in several animal models (Heymann nephritis, diabetes mellitus, experimental allergic-encephalomyelitis, lupus). 1 alpha,25-(OH)2D3 demonstrates however some side-effects (hypercalciuria, hypercalcemia, bone resorption) and for this reason 1 alpha,25-(OH)2D3-analogs are developed with dissociated effects i.e. an activity profile that allows a specific action on non-classical tissues without calcemic effects. Some chemical modifications of the side chain, A and/or CD-ring results in "superanalogs" with 10 to 100-fold more activity on cell differentiation and the immune system then 1 alpha,25-(OH)2D3 but with less calcemic activity in vivo. These biological effects can be explained by differences in pharmacokinetics (low affinity for the plasma vitamin D-binding protein and short extracellular half-life) and increased intracellular activation and gen transactivation. Preclinical research must still be done to select the most potent superanalogs and to find the exact protocols for the prevention and treatment of autoimmune diseases and rejection of transplanted organs.
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PMID:[Immune modulation by vitamin D analogs in the prevention of autoimmune diseases]. 857 69

Vitamin D is absolutely essential for the maintenance of a healthy skeleton. Without vitamin D, children develop rickets and adults exacerbate their osteoporosis and develop osteomalacia. Casual exposure to sunlight is the major source of vitamin D for most people. During exposure to sunlight, ultraviolet B photons photolyze cutaneous stores of 7-dehydrocholesterol to previtamin D3. Previtamin D3 undergoes a thermal isomerization to form vitamin D3. Increased skin pigmentation, changes in latitude, time of day, sunscreen use, and aging can have a marked influence on the cutaneous production of vitamin D3. Once vitamin D3 is formed in the skin or ingested in the diet, it must be hydroxylated in the liver and kidney to 1,25-dihydroxyvitamin D3 [1,25(OH)2D3]. It is now recognized that a wide variety of tissues and cells, both related to calcium metabolism and unrelated to calcium metabolism, are target sites for 1,25(OH)2D3. 1,25(OH)2D3 stimulates intestinal calcium absorption and mobilizes stem cells to mobilize calcium stores from bone. Noncalcemic tissues that possess receptors for 1,25(OH)2D3 respond to the hormone in a variety of ways. Of great interest is that 1,25(OH)2D3 is a potent antiproliferative and prodifferentiation mediator. As a result, 1,25(OH)2D3 and its analogs have wide clinical application in such diverse clinical disorders as rheumatoid and psoriatic arthritis; diabetes mellitus type I; hypertension; cardiac arrhythmias; seizure disorders; cancers of the breast, prostate, and colon; some leukemias and myeloproliferative disorders; chemotherapy-induced hair loss; and skin rejuvenation as well as skin diseases like psoriasis and ichthyosis.
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PMID:Noncalcemic actions of 1,25-dihydroxyvitamin D3 and clinical applications. 857 91

Vitamin D deficiency reduces insulin secretion and still occurs in East London Asians in whom the prevalence of diabetes mellitus is at least four times that of Caucasians. Vitamin D status was assessed in 44 of 65 non-diabetic subjects 'at risk' of diabetes (spot blood glucose level >6.0 mmol/l <2 h post cibum, or>4.6 mmol/l >2 h post cibum on two separate occasions) and in 15 of 60 age and sex-matched 'low-risk' control subjects who attended for oral glucose tolerance test (OGTT) after screening of 877 omnivorous subjects not known to have diabetes. It was found that 95% of at-risk and 80% of low-risk subjects were vitamin D deficient (serum 25-hydroxy-vitamin D <11 ng/ml). Diabetes was present in 16, impaired glucose tolerance in 12 and normoglycaemia in 19 at-risk subjects, imparied glucose tolerance in 2, and normoglycaemia in 13 low-risk subjects. Correlation of 30-min OGTT blood glucose, specific insulin and C-peptide levels with 25-hydroxy-vitamin D concentrations in 44 at-risk subjects were -0.31 (p=0.04), 0.59 (p=0.0001) and 0.44 (p=0.006). In 15 'not-at-risk' subjects 30-min OGTT specific insulin and C-peptide levels correlated with 25-hydroxy-vitamin D, r=0.39 (p=0.04) and 0.16 (p=0.43), respectively. Serum alkaline phosphatase concentration was higher in at-risk than not-at-risk subjects (59.6 vs 46.5 IU/l, p=0.012); corrected calcium concentrations were comparable (2.38 vs 2.39 mmol/l, p=0.7). Following treatment with 100,000 IU vitamin D by i.m. injection, specific insulin, C-peptide [30 min on OGTT] and 25-hydroxy-vitamin D concentrations had risen 8-12 weeks later [mean +/- DS] from 57 +/- 62 to 96.2 +/- 82.4 mU/l [p=0.0017], 1.0 +/- 0.4 to 1.7 +/- 0.8 pmol/ml [p=0.001] and 3.6 +/- 1.8 to 13.5 +/- 7.4 ng/ml [p=0.0001], (but not to low-risk group values of 179 +/- mU/l, 2.7 +/- 1.14 pmol/ml and 8.16 +/- 6.4 ng/ml), respectively. Both total serum alkaline phosphatase and corrected calcium concentrations rose following vitamin D treatment in the at-risk subjects by 11.1 +/- 8.22 (from 44 to 55 IU/l) and 0.15 +/- 0.18, (2.43 to 2.57 mmol/l), respectively (p=0.004). Abnormal glucose tolerance was unchanged by vitamin D treatment. The value of early and sustained repletion with vitamin D in diabetes prophylaxis should be examined in communities where vitamin D depletion is common.
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PMID:Glucose intolerance and impairment of insulin secretion in relation to vitamin D deficiency in east London Asians. 869 Jan 78

Vitamin D status was assessed in 142 elderly Dutchmen participating in a prospective population-based study of environmental factors in the aetiology of non-insulin-dependent diabetes mellitus. Of the men aged 70-88 years examined between March and May 1990, 39% were vitamin D depleted. After adjustment for confounding by age, BMI, physical activity, month of sampling, cigarette smoking and alcohol intake the 1-h glucose and area under the glucose curve during a standard 75-g oral glucose tolerance test (OGTT) were inversely associated with the serum concentration of 25-OH vitamin D (r = -0.23, p < 0.01; r = -0.26, p < 0.01, respectively). After excluding newly diagnosed diabetic patients total insulin concentrations during OGTT were also inversely associated with the concentration of 25-OH vitamin D (r = -0.18 to -0.23, p < 0.05). Hypovitaminosis D may be a significant risk factor for glucose intolerance.
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PMID:Vitamin D, glucose tolerance and insulinaemia in elderly men. 908 75

Vitamin D has important immunomodulatory properties and prevents development of diabetes mellitus in an animal model of insulin-dependent diabetes (IDDM). We have studied the vitamin D receptor locus as a candidate for genetic susceptibility to IDDM in Southern Indian families. We found evidence for an association of one particular vitamin D receptor allele with IDDM susceptibility in this community. Ninety-three South Indian families consisting of available parents and an affected offspring were genotyped for three vitamin D receptor polymorphisms using the restriction enzymes TaqI, ApaI and BsmI as well as an adjacent microsatellite located to 12q14 (D12S85). Transmission disequilibrium testing analysis was used to assess preferential transmission of polymorphic markers and haplotypes with IDDM. There was significant excess transmission of vitamin D receptor alleles containing the BsmI restriction site to affected offspring in these families (p = 0.016). No association was found between D12S85 and IDDM. This study suggests that a polymorphism within or close to the vitamin D receptor gene may modify susceptibility to IDDM in this ethnic group.
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PMID:Allelic variation in the vitamin D receptor influences susceptibility to IDDM in Indian Asians. 926 94

Hypoparathyroidism is a rare disease with hypocalcemia as the leading symptom. In adults, hypocalcemia is mainly due to postoperative hypoparathyroidism. Hypoparathyroidism requires lifelong therapy with vitamin D or metabolites. Genuine vitamin D3 (Vigantol) is the most economic treatment of hypoparathyroidism; however, vitamin D3 has a very long biologic half life with the subsequent danger of chronic vitamin D intoxication. Dihydrotachysterol (A.T.10), an analogue of vitamin D, acts similarly and can be used alternatively. 1,25-dihydroxyvitamin D3 (Rocaltrol), the biologically active metabolite of vitamin D3, is very potent, but bears the danger of causing acute intoxication; it has a short half life and is more expensive than vitamin D3. A further metabolite, 1-hydroxy-vitamin D3 (alfacalcidol, Doss, EinsAlpha) is available for therapeutic use. Clinical intervention trials concerning the best therapy and management of hypoparathyroidism are lacking. We therefore surveyed German physicians treating hypoparathyroidism. Furthermore, we carried out a retrospective study of 45 patients treated in our endocrinology department during the last 8 years and examined whether measurement of 25(OH)-vitamin D3 is helpful in managing hypoparathyroidism. The data from 59 children and 270 adults could be completed in the survey. 1,25-dihydroxyvitamin D3 was the only vitamin D agent that was administered in the treatment of children, whereas in adults 52% were treated with dihydrotachysterol, 28% with genuine vitamin D3, and 20% with 1,25-dihydroxyvitamin D3. There was a positive correlation between serum 25(OH)-vitamin D3 levels and administered vitamin D3 doses. In patients treated with vitamin D3, serum calcium levels correlated significantly with serum 25(OH)-vitamin D3 levels whereas they did not correlate with administered calcium doses. Thus: (1) in Germany dihydrotachysterol is preferred for therapy of hypoparathyroidism in adults and (2) measurement of serum 25(OH)-vitamin D3 may be helpful in assessing efficacy of therapy and compliance in patients treated with vitamin D3.
Exp Clin Endocrinol Diabetes 1997
PMID:Current therapy of hypoparathyroidism--a survey of German endocrinology centers. 928 13


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