24-25-dihydroxyvitamin-d-3 and Diabetes-Mellitus--Type-1

In this prospective controlled study, we examined 25 adults with adequately controlled (HbA1c level < 8.0%) type 1 diabetes mellitus (T1DM) and 49 conditionally healthy adults, intending to reveal the diversity of vitamin D metabolism in the setting of cholecalciferol intake at a therapeutic dose. All patients received a single dose (150,000 IU) of cholecalciferol aqueous solution orally. Laboratory assessments including serum vitamin D metabolites (25(OH)D

Topics: 24,25-Dihydroxyvitamin D 3; 25-Hydroxyvitamin D 2; Administration, Oral; Adult; Calcifediol; Calcitriol; Case-Control Studies; Cholecalciferol; Diabetes Mellitus, Type 1; Female; Glycated Hemoglobin; Humans; Male; Parathyroid Hormone; Prospective Studies; Vitamin D; Vitamin D-Binding Protein; Young Adult

People with type 1 diabetes are at high risk of premature atherosclerosis. Existing evidence suggests that impaired vitamin D metabolism may contribute to the development of atherosclerosis. We tested associations of circulating vitamin D metabolite concentrations with subclinical atherosclerosis among 1,193 participants with type 1 diabetes in the DCCT/EDIC study.. We measured plasma concentrations of 25-hydroxyvitamin D [25(OH)D], 1,25-dihydroxyvitamin D, and 24,25-dihydroxyvitamin D by mass spectrometry at the end of the DCCT. In a staggered cross-sectional design, we tested associations with coronary artery calcium (CAC), measured by computed tomography a median of 10 years later, and with common and internal carotid intima-media thickness (IMT), measured by B-mode ultrasonography on two occasions a median of 4 years later and a median of 10 years later. We hypothesized that lower concentrations of each vitamin D metabolite would be associated with increased risk of CAC and greater carotid IMT. RESULTS At the time metabolites were measured, mean age was 32.4 years and mean duration of diabetes was 7.5 years. The prevalence and severity of CAC tended to be lower-not higher-with lower concentrations of each vitamin D metabolite. For instance, in a fully adjusted multinomial logistic model, a 25 nmol/L lower 25-hydroxyvitamin D was associated with a 0.8-fold decrease in the odds of having higher CAC (95% CI 0.68-0.96, P = 0.01). No vitamin D metabolite was associated with either common or internal mean IMT.. We did not find evidence linking impaired vitamin D metabolism with increased subclinical atherosclerosis in type 1 diabetes.

Topics: 24,25-Dihydroxyvitamin D 3; Adult; Atherosclerosis; Calcium; Carotid Artery Diseases; Carotid Intima-Media Thickness; Coronary Artery Disease; Coronary Vessels; Diabetes Mellitus, Type 1; Female; Humans; Male; Vascular Calcification; Vitamin D

Plasma concentrations of 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, 24,25-dihydroxyvitamin D and vitamin D binding protein were determined in 87 serum samples from 46 Type 1 (insulin-dependent) diabetic children and adolescents at the various stages of puberty. The results were compared with data similarly obtained from healthy pubertal children. The diabetic patients had lower mean 1,25-dihydroxyvitamin D concentrations (p less than 0.05) and higher molar ratios of 24,25-dihydroxyvitamin D to 25-hydroxyvitamin D (p less than 0.05) than their healthy counter parts. In contrast to the reference group, the diabetic patients failed to attain the increase in 1,25-dihydroxyvitamin D normally seen during the pubertal stages of maximal growth velocity. The mean plasma levels of vitamin-D binding protein did not differ between the two groups, and a calculated 'free' 1,25-dihydroxyvitamin D value followed a pattern similar to that of total 1,25-dihydroxyvitamin D throughout puberty for both groups. The results suggest that the regulatory mechanisms of the vitamin D endocrine system are altered in diabetic children at puberty, resulting in a relative decrease in 1,25-dihydroxyvitamin D plasma concentration and increased 24,25-dihydroxyvitamin D levels.

Topics: 24,25-Dihydroxyvitamin D 3; Adolescent; Calcifediol; Calcitriol; Child; Diabetes Mellitus, Type 1; Dihydroxycholecalciferols; Humans; Puberty; Reference Values; Vitamin D; Vitamin D-Binding Protein

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.

Topics: 24,25-Dihydroxyvitamin D 3; Adolescent; Adult; Aged; Bone and Bones; Bone Diseases; Calcifediol; Calcitriol; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Dihydroxycholecalciferols; Female; Humans; Male; Middle Aged; Vitamin D

To assess the relationship between the decreased bone mass observed in young insulin-requiring diabetic patients and vitamin D metabolism, we measured serum 25-hydroxyvitamin D, 24,25-dihydroxyvitamin D, and 1,25-dihydroxyvitamin D concentration in 45 white, insulin-dependent diabetic subjects, 7-18 yr of age. Metacarpal cortical thickness in 87% of these diabetics was below the mean for their respective ages, while 16% had a cortical thickness value greater than 2 sDs below the mean. Serum calcium and phosphate concentrations were normal, immunoreactive parathyroid hormone was in the low normal range, and total serum alkaline phosphatase was elevated compared to age- and sex-matched controls. Circulating 24,25-dihydroxyvitamin D concentrations were significantly elevated, and 1,25-dihydroxyvitamin D was significantly decreased. The increase in 24,25-dihydroxyvitamin D was greater in the diabetics with the most severe bone loss and was maximally increased during the first 5 yr of clinical diabetes. No apparent correlation was seen between metabolic control, as measured by hemoglobin A1C and urine and plasma glucose, and the circulating levels of the vitamin D metabolites. Despite appropriate insulin replacement, alterations in vitamin D metabolism occur in the young insulin-dependent diabetic and could relate to the decrease in cortical bone mass observed in these patients.

Topics: 24,25-Dihydroxyvitamin D 3; Adolescent; Alkaline Phosphatase; Calcifediol; Calcitriol; Child; Diabetes Mellitus, Type 1; Dihydroxycholecalciferols; Humans; Hydroxycholecalciferols; Insulin; Metacarpus; Vitamin D