Kidney Week

Abstract: SA-PO700

Serum 1,25-Dihydroxyvitamin D Concentrations in Maintenance Hemodialysis Patients: In the Era of CKD-MBD Guideline

Session Information

• Bone and Mineral Metabolism: Clinical - II
  October 27, 2018 | Location: Exhibit Hall, San Diego Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Dialysis

• 701 Dialysis: Hemodialysis and Frequent Dialysis

Authors

• Ishimura, Eiji, Meijibashi Hospital, Matsubara, Osaka 580-0045, Japan

Eiji Ishimura,

• Nakatani, Shinya, Osaka City University Graduate School of Medicine, Osaka, Japan

Shinya Nakatani,

• Okuno, Senji, Shirasagi Hospital, Osaka, OSAKA-FU, Japan

Senji Okuno,

• Ueda, Shuko, Meijibashi Hospital, Matsubara, Osaka 580-0045, Japan

Shuko Ueda,

• Kuwamura, Nobuyuki, Meijibashi Hospital, Matsubara, Osaka 580-0045, Japan

Nobuyuki Kuwamura,

• Nin, Yukihiro, Meijibashi Hospital, Matsubara, Osaka 580-0045, Japan

Yukihiro Nin,

• Makino, Tetsuya, Meijibashi Hospital, Matsubara, Osaka 580-0045, Japan

Tetsuya Makino,

• Kakiya, Ryusuke, Meijibashi Hospital, Matsubara, Osaka 580-0045, Japan

Ryusuke Kakiya,

• Inaba, Masaaki, Osaka City University Graduate School of Medicine, Osaka, Japan

Masaaki Inaba,

Background

In hemodialysis (HD) patients, serum levels of 1,25-dihydroxyvitamin D (1,25D), an active form of vitamin D, are low; however, 1,25D, even in low, was reported to play an important role in HD patients (Ando R et al, J Jap Soc Dial Ther 1996). Currently, little is known about serum 1,25D concentrations in HD patients, particularly in the era of CKD-MBD guideline. We measured serum 1,25D concentrations in stable HD patients, and examined their association with clinical factors.

Methods

A total of 89 HD patients (71±11 year-old, 48 males, HD duration 9.4±7.4 years, 36 with type 2 diabetes) were examined. Serum 1,25D was measured by a 1,25D RIA kit (Ishimura E et al. Kidney Int 1999), and intact PTH by a Elecsys PTH IRMA assay (Kurajoh M et al. Osteoporos Int 2008).

Results

Serum 1,25D concentrations were 14.4±8.0 pg/ml, being lower compared to those of healthy subjects. Serum 1,25D concentrations were significantly higher in males than in females (p=0.045). They were tended to be negatively correlated with age (r=-0.034, p=0.083) and HD duration (r=-0.042, p=0.055). Serum 1,25D concentrations were significantly, negatively associated with intact PTH (r=-0.085,p〈0.001), although they were not with serum calcium or phosphate. There were no significant differences in serum 1,25D between patients with (n=65) and without vitamin D treatment, and between those with (n=12) and without calcimimetics. However, serum 1,25D concentrations in patients with intravenous treatment of maxiacalcitol, an active form of vitamin D, (n=12) were significantly higher than those without (p=0.045). In a multiple regression analysis after adjustment of age, gender, HD duration, and vitamin D treatment, serum 1,25D concentrations were significantly, independently associated with serum intact PTH (β=-0.310, p=0.003) (R²=0.200, p=0.002).

Conclusion

These results indicate that serum 1,25D, even in low, is significantly associated with intact PHT. The results also suggest that, even in the era of CKD-MBD guidelines, a clinical importance of serum 1,25D concentrations may be re-considered for the assessment of CKD-MBD, particularly in regards to prevention of secondary hyperparathyroidism. Intravenous, rather than oral, vitamin D treatment may be useful for treatment of secondary hyperparathyroidism.