Changes Of The Level Of 25-hydroxyvitamin D In Human Following On-pump Or Off-pump Open Heart Surgery

ObjectiveTo analyze and compare the changes of circulating level of 25-hydroxyvitamin D (25-(OH)D) between on-pump and off-pump open heart surgery.MethodsA total of 18 patients performed on-pump open heart surgery was defined group A, which the pump time was more than 30 minutes. A total of 13 patients performed off-pump open heart surgery was defined group B. The levels of 25-(OH)D were respectively measured in group A and group B on the preoperative day, the end of the surgery and the first postoperative day. In addition, the levels of hematocrit(Hct), alanine aminotransferase (ALT), aspartate amninoransferase (AST), blood urea nitrogen (BUN) and serum creatinine (Cr) were measured to analyse the effects of liver and renal functions and hemodilution on the changes of circulating level of 25-(OH)D.ResultsThere was no significant difference in the preoperative levels of 25-(OH)D between group A and group B (61.49±16.01nmol/L vs 60.15±15.28nmol/L, P>0.05), moreover the levels of both were relatively deficient (The concentration of 25-(OH)D between 52-72nmol/L is defined relatively deficient status). In group A, the levels of 25-(OH)D at the end of the surgery were significantly lower than that of the preoperative day (32.88±10.16nmol/L vs 61.49±16.01nmol/L, P<0.05) and there was no recovery to the level at the end of the surgery on the postoperative day (32.40±9.52nmol/L vs 32.88±10.16nmol/L, P>0.05). In group B, there was no significant difference in the levels of 25-(OH)D among the preoperative day, the end of surgery and the first postperative day (60.15±15.28nmol/L vs 59.49±15.97nmol/L vs 59.23±16.39nmol/L, P>0.05). Compared with the period of the end of the surgery and the first postoperative day, the levels of 25-(OH)D in gruop A were lower than group B (32.88±10.16nmol/L vs 59.49±15.97nmol/L, P>0.05; 32.40±9.52nmol/L vs 59.23±16.39nmol/L, P>0.05). Otherwise, the levels of ALT, AST, BUN, and Cr on the preoperative day were no significant differences between two groups (P>0.05) and all of the levels in group A were significantly higher than gruop B on the first postoperative day (P<0.05). There was no defference in Hct between two groups (P>0.05). The level of Hct was obviously low after bypass in gruop A (P<0.05) and there was no recovery to the level before bypass when the surgery was end(P<0.05). In group B, measured level of Hct at the end of the sugery was a little of lower than that of preoperative period (P<0.05).ConclusionsOn-pump open heart surgery leads to decrease on the level of 25-(OH)D after bypss, which has no obviously recovery on the early first postoperative day. Inversely, off-pump has less adverse effects on the level of 25-(OH)D. Impairment of liver and renal functions and hematocrit offers adverse effects on the level 25-(OH)D.