RÉSUMÉ
@#Introduction: Vitamin D deficiency has been implicated as one of the factors involved in endothelial dysfunction associated with diabetes. This study aimed to evaluate the effects of active vitamin D (alphacalcidol) supplementation on aortic endothelial function in diabetic rats receiving vitamin D-deficient diet. Methods: Streptozotocin-induced diabetic rats were fed with standard diet (D) or vitamin D-deficient diet (DD and DDS) for 10 weeks. Group DDS was then supplemented with 0.2 μg/kg alphacalcidol at the last four weeks of the study duration. Non-diabetic rats were fed with standard diet (N) or vitamin-D deficient diet (ND). At the end of the experiment, the rats were sacrificed, and their aortic rings were harvested for endothelial functional study. Results: Acetylcholine-induced relaxation in aorta of diabetic rats (D and DD) were significantly lower compared to non-diabetic rats (N). In the presence of endothelial nitric oxide synthase blocker (L-NAME), maximal relaxation induced by acetylcholine in aorta of D and DD groups were significantly higher compared to N, ND and DDS groups, indicating involvement of non-nitric oxide (NO) relaxation pathways in diabetes. Four weeks supplementation with alphacalcidol in DDS group significantly improved acetylcholine-induced relaxation and reduced the reliance on non-NO relaxation pathways. Conclusion: The present study suggests that impairment of acetylcholine-induced relaxation in aorta of diabetes and diabetes with vitamin D-deficient diet was largely due to a decrease in NO related pathways, and this was compensated by non-NO pathways. Supplementation with alphacalcidol alleviated endothelial impairment in aorta of diabetic rats with vitamin D-deficient diet.
RÉSUMÉ
This study was performed to estimate the effect of alphacalcidol supplementation or nutrition education on the nutrient intakes, bone mineral density and bone markers in continuous ambulatory peritoneal dialysis (CAPD) patients. The 90 CAPD subjects were randomly assigned to 3 groups (alphacalcidol group: AG, nutrition education group: NG, and control group: CG). Alphacalcidol supplementation(0.5 microgram/day) was carried out for 8 months. Nutrition counseling was performed according to the patient's individual question for the first 6 months and scheduled nutrition education with individual counseling was carried out for the last 2 months. In baseline data, there were no significant differences in age, sex, family number, education years and monthly income except the NG showed significantly less duration of CAPD (p <0.05) compared to other two groups. After intervention all three groups showed tendency of lower intakes. NG revealed less decrease in protein, especially in animal protein, calcium from Ca-P binder, dietary calcium, dietary iron and niacin. NG showed significantly more increase in dry weight (p <0.05) and AG in waist circumference (p <0.001) after intervention. The groups did not show significant differences in the changes of biochemical indices related to bone metabolism. NG revealed more increase in trochanter BMD (p <0.05) compared to other two groups. It seems that nutrition education is more effective in preventing deterioration or improving the bone and general nutrition status.