Objective: To investigate the deficiencey and insufficiency of 25-hydroxyvitamin D3 [25 (OH) D3], 1,25- dihydroxyvitamin D3 [1,25 (OH)2 D3] in patients with diabetic nephropathy (DN), an their association with carotid artery intima-media thickness (IMT) and coronary artery calicfication.
Methods: The concentrations of 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3, and intact parathyroid hormone (iPTH) were determined by radioimmunoassay in 151 DN patients. Based on the level of 25-hydroxyvitamin D3, the patients were divided into Vitamin D deficiency group (Vit-D-D group, <15 ng/mL), insufficiency group (Vit-D-I group, 15-30 ng/mL), and normal group (Vit-D-N group, >30 ng/mL). The association of Vitamin D with IMT and coronary artery calcification was examined through group comparisons, logistic regression analysis and multiple linear regression analysis.
Results: The mean level of 25-hydroxyvitamin D3 was (28 +/- 18.1) ng/mL, with an interquartile range of 16.92 - 35.45 ng/mL. The incidence of 25-hydroxyvitamin D3 insufficiency and deficiency was 47.01% (71/151) and 18.574% (28/151) respectively. The mean level of 1,25-dihydroxyvitamin D3 was (28.93 +/- 33.13) pg/mL, with an interquartile rang of 10.36 - 31.08 pg/mL. The incidence of 1,25-dihydroxyvitamin D3 insufficiency was 77.5% (117/151). Compared with the normal controls, the BMI, 24 h urine protein, CHO and LDL of those with Vitamin D deficiency increased significantly (P < 0.05). IMT ws associated with age, sex, and serum phosphorous. Coronary clcification was negative correlated with 1,25-dihydroxyvitamin D3.
Conclusion: The incidence of vitamin D deficiency and insufficiency in DN patients is high. The patients with vitamin D deficiency have higher urinary protein, CHO and LDL. Corornary artery calcification is reversely correlated with 1,25(OH)2D3.