Serum 25-hydroxyvitamin D predict prognosis in radioiodine therapy of Graves' disease.
OBJECTIVE
To investigate serum 25-hydroxyvitamin D 25(OH)D status and assess the predictability of outcome in patients with Graves' disease (GD) who received a patient-specific calculated dose of radioiodine therapy (RIT).


METHODS
128 patients with GD who received RIT from July 2010 to September 2010 were included. Pre-therapy serum levels of 25(OH)D, calcium, phosphorus, parathyroid hormone, free triiodothyronine, free thyroxine, thyroid stimulating hormone and creatinine were measured. 60 age- and BMI-matched healthy subjects were chosen as the normal control group.


RESULTS
Post-therapy follow-up results revealed that therapy failed in 25.00 % of the patients. Serum 25(OH)D levels were found to be significantly lower in patients who failed in therapy. The prevalence of vitamin D deficiency in GD patients was significantly higher compared with control subjects (56.25 vs. 10.00 %, P < 0.001), and therapy failed in 27 (37.50 %) of these patients whose serum 25(OH)D levels < 20 ng/ml. Out of the 56 patients (43.75 %) in whom serum 25(OH)D levels ≥20 ng/ml, therapy was unsuccessful in only 5 (8.93 %). Cox regression analysis suggested that serum 25(OH)D levels <20 ng/ml might be an independent risk factor for predicting failure of RIT in GD patients (relative risk = 8.83, 95 % confidence interval = 3.34-23.38, P < 0.001).


CONCLUSIONS
Serum 25(OH)D levels were lower in patients who failed than in those who succeeded in RIT of GD. Therefore, serum 25(OH)D < 20 ng/ml might be an independent risk factor for predicting failure of RIT in GD patients.
Department of Gerontology, Huai'an First People's Hospital, Nanjing Medical University, 6 Beijing Xi Road, Huai'an, 223300, Jiangsu, China.
X
X
Li
Department of Urology, Huai'an First People's Hospital, Nanjing Medical University, 6 Beijing Road, Huai'an, 223300, Jiangsu, China.
G
G
Wang
Department of Gerontology, Huai'an First People's Hospital, Nanjing Medical University, 6 Beijing Xi Road, Huai'an, 223300, Jiangsu, China.
Z
Z
Lu
Department of Gerontology, Huai'an First People's Hospital, Nanjing Medical University, 6 Beijing Xi Road, Huai'an, 223300, Jiangsu, China.
M
M
Chen
Department of Gerontology, Huai'an First People's Hospital, Nanjing Medical University, 6 Beijing Xi Road, Huai'an, 223300, Jiangsu, China.
J
J
Tan
Department of Gerontology, Huai'an First People's Hospital, Nanjing Medical University, 6 Beijing Xi Road, Huai'an, 223300, Jiangsu, China. drfangxiaozheng@163.com.
X
X
Fang
D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006111:Graves Disease / Q000097:blood* / Q000188:drug therapy* / Q000532:radiotherapy; D006801:Humans; D007457:Iodine Radioisotopes / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care; D011379:Prognosis; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood
D007457:Iodine Radioisotopes; D014807:Vitamin D; C104450:25-hydroxyvitamin D
25-Hydroxyvitamin D; Graves’ disease; Hyperthyroidism; Prognosis; Radioiodine therapy