Changes in vitamin D binding protein and vitamin D concentrations associated with liver transplantation

Authors


Correspondence

Peter P. Reese, MD, MSCE,

Center for Clinical Epidemiology and Biostatistics

University of Pennsylvania, School of Medicine

917 Blockley Hall, 423 Guardian Drive

Philadelphia, PA 19104-6021, USA

Tel: +617 699 8848

Fax: +215 615 0349

e-mail: peter.reese@uphs.upenn.edu

Abstract

Background

Vitamin D deficiency is associated with fractures, infections and death. Liver disease impairs vitamin D and vitamin D binding protein (DBP) metabolism.

Aims

We aimed to determine the impact of liver transplantation on vitamin D, particularly on DBP and free vitamin D concentrations.

Methods

Serum 25(OH)D, 1,25(OH)2D and DBP concentrations were measured in 202 adults before liver transplantation and 3 months later in 155. Free vitamin D concentrations were estimated from these values. Risk factors for 25(OH)D deficiency (<20 ng/ml) and low 1,25(OH)2D (<20 pg/ml) were examined with logistic regression, and changes in concentrations following transplantation with linear regression.

Results

Pretransplant, 84% were 25(OH)D deficient, 13% had 25(OH)D concentrations <2.5 ng/ml, and 77% had low 1,25(OH)2D. Model for end-stage liver disease score ≥20 (P < 0.005) and hypoalbuminemia (P < 0.005) were associated with low 25(OH)D and 1,25(OH)2D concentrations. Following transplantation, 25(OH)D concentrations increased a median of 17.8 ng/ml (P < 0.001). Albumin increased from a median of 2.7 to 3.8 g/dl (P < 0.001) and DBP from 8.6 to 23.8 mg/dl (P < 0.001). Changes in total 25(OH)D were positively and independently associated with changes in DBP (P < 0.05) and albumin (P < 0.001). Free 25(OH)D concentrations rose from 6.0 to 9.7 pg/ml (P < 0.001). In contrast, total 1,25(OH)2 Dconcentrations rose only by 4.3 pg/ml (P < 0.001) and free 1,25(OH)2 Dconcentrations declined (P < 0.001).

Conclusions

Serum total and free 25(OH)D and DBP concentrations rose substantially following transplantation, while 1,25(OH)2D concentrations showed modest changes and free 1,25(OH)2D decreased. Studies of the effects of vitamin D status on diverse transplant complications are needed.

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