Changes in Serum 25-Hydroxyvitamin D and Plasma Intact PTH Levels Following Treatment With Ergocalciferol in Patients With CKD
Received 11 December 2006; accepted 9 April 2007. published online 30 May 2007.
Background
Vitamin D insufficiency and deficiency are very common in patients with chronic kidney disease (CKD). The effect of ergocalciferol administration on serum 25-hydroxyvitamin D and plasma intact parathyroid hormone (PTH) levels in these patients is not known.
Study Design
Retrospective study.
Setting & Participants
Patients with CKD stage 3 or 4 who had a serum 25-hydroxyvitamin D level less than 30 ng/mL (<75 nmol/L) and increased plasma intact PTH level were treated with 50,000 IU of ergocalciferol once weekly for 12 weeks and once monthly thereafter for a total of 6 months. Patients were excluded if they had a history of active vitamin D sterol use.
Outcome & Measurements
25-Hydroxyvitamin D and intact PTH were measured at baseline and follow-up.
Results
66 patients met inclusion criteria. Average age was 70.4 ± 1.3 (SE) years (range, 40 to 88 years), and 97% were men. There were 44 patients (66%) with CKD stage 3 and 22 patients (33%) with CKD stage 4. After a median follow-up of 6 months, there was a significant increase in 25-hydroxyvitamin D levels from 16.6 ± 0.7 to 27.2 ± 1.8 ng/mL (41 ± 2 to 68 ± 4 nmol/L; P < 0.05) and a significant decrease in plasma intact PTH levels from 231 ± 26 to 192 ± 25 pg/mL (ng/L; P < 0.05). A multivariate logistic regression model showed that an increase in 25-hydroxyvitamin D level greater than 5 ng/mL (>12 nmol/L) is associated with a significant likelihood of a greater than 30% decrease in plasma intact PTH level (odds ratio, 4.5; 95% confidence interval, 1.5 to 15.1; P < 0.05). Although posttreatment 25-hydroxyvitamin D levels were not different between patients with CKD stages 3 and 4, only patients with CKD stage 3 had a significant decrease in plasma intact PTH levels.
Limitations
This is a retrospective study with mostly male patients.
Conclusions
Results show that ergocalciferol administration has a favorable effect on PTH levels if therapy results in an increase in 25-hydroxyvitamin D levels; this effect is more evident in patients with CKD stage 3.
1Division of Nephrology, Saint Louis Veterans Affairs Medical Center, St Louis, MO
2Division of Nephrology, Saint Louis University, St Louis, MO
3Department of Research and Education, Saint Louis Veterans Affairs Medical Center, St Louis, MO.
Address correspondence to Ziyad Al-Aly, MD, Saint Louis Veterans Administration Medical Center, Division of Nephrology 111B-JC, 915 North Grand Boulevard, St Louis, MO 63106.
ABSTRACT