25-hydroxyvitamin D, 1,25-dihydroxyvitamin D and postoperative outcome in cardiac surgery

Several cohort studies have reported U-shaped or inverse J-shaped associations between circulating 25-hydroxyvitamin D [25OHD] and clinical outcomes.

We aimed to investigate in cardiac surgical patients the association of preoperative 25OHD and 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] levels with the risk of major adverse cardiac and cerebrovascular events (MACCE).

A prospective cohort study of adult cardiac surgical patients in 2012-2013 was used.

The study was conducted at the Heart and Diabetes Center North Rhine-Westphalia, Germany.

A total of 3371 adult patients participated in the study.

None Measurements: The main outcome measure was MACCE until discharge. We categorized vitamin D metabolite levels into subgroups and performed multivariable-adjusted logistic regression analysis to estimate odds ratios (ORs) of MACCE. Moreover, we performed multiple regression analysis to assess the association of 25OHD and circulating 1,25(OH)2D3 with preoperative parameters.

As compared with patients in the 25OHD reference category (75-100 nmol/L), the multivariable-adjusted odds ratios (OR) of MACCE was significantly higher in patients with deficient 25OHD levels (< 30 nmol/L) (OR = 2.06 [95%CI: 1.24-3.43]), but was comparable in patients with 25OHD levels > 100 nmol/L (OR = 1.16 [95% CI: 0.56-2.37]). Poor kidney function was an important predictor of high 25OHD (>100 nmol/L) and low 1,25(OH)2D3 levels. 1,25(OH)2D3 was not independently associated with the incidence of MACCE.

In cardiac surgical patients, deficient but not high 25OHD levels are independently associated with the risk of MACCE. Cohort studies should consider potential interrelationships between kidney function, circulating vitamin D metabolite levels, and clinical outcome.