1,25-Dihydroxyvitamin D fluctuations in cardiac surgery are related to age and clinical outcome*

Crit Care Med. 2012 Jul;40(7):2073-81. doi: 10.1097/CCM.0b013e31824e8c42.

Abstract

Objective: To investigate the interrelationship between cardiac surgery, age, circulating concentrations of the vitamin D hormone 1,25-dihydroxyvitamin D, and clinical outcome.

Design: Prospective, monocentric, two-arm parallel study.

Setting: Tertiary Heart and Diabetes Center in the Federal State of North Rhine-Westphalia, Germany.

Patients: Twenty-nine cardiac surgical patients aged ≤ 65 yrs and 30 patients ≥ 75 yrs.

Measurements: We assessed 1,25-dihydroxyvitamin D and other biochemical parameters of mineral metabolism (calcium, phosphate, 25-hydroxyvitamin D, and parathyroid hormone), various inflammatory markers (C-reactive protein, interleukin-6 and 8), and different immunological parameters (CD4 and CD8 cells, monocyte HLA-DR expression). We collected blood samples preoperatively, immediately after surgery, and on postoperative days 1, 5, and 30. In addition, we assessed adverse outcome until discharge as a composite of myocardial infarction, low cardiac output syndrome, infection, stroke, or in-hospital death.

Results: There were significant transient cardiac surgery-related fluctuations in 1,25-dihydroxyvitamin D and the aforementioned parameters of mineral metabolism, inflammation, and immune status. Compared to younger patients, older patients had consistently lower 1,25-dihydroxyvitamin D and phosphate levels (p = .013 and p = .036, respectively) and significantly higher interleukin 6 and 8 levels (p = .008 and p < .001, respectively). Circulating 1,25-dihydroxyvitamin D was directly related to glomerular filtration rate (R(2) = .227; p < .001) and inversely related to interleukin 6 (R(2) = .105; p = .012). The rate of adverse outcome tended to be higher in older than in younger patients (20.0% vs. 3.5%; p = .081). In risk score-adjusted logistic regression analysis, adverse outcome risk decreased by 7.7% (SE: 3.7%) for each pmol/L increment in 1,25-dihydroxyvitamin D (p = .037).

Conclusions: Circulating 1,25-dihydroxyvitamin D levels fluctuate in relation to cardiac surgery. Low 1,25-dihydroxyvitamin D levels are associated with inflammatory processes and age-related differences in clinical outcome. Future studies should determine whether therapies aimed at treating low 1,25-dihydroxyvitamin D levels can improve the outcome in older cardiac surgery patients.

Publication types

  • Clinical Trial

MeSH terms

  • Age Factors
  • Aged
  • C-Reactive Protein / analysis
  • CD4-CD8 Ratio
  • Calcium / blood
  • Cardiac Output, Low
  • Coronary Artery Bypass*
  • Female
  • Glomerular Filtration Rate
  • HLA-DR Antigens / metabolism
  • Heart Valve Prosthesis Implantation*
  • Humans
  • Intensive Care Units
  • Interleukin-6 / blood
  • Interleukin-8 / blood
  • Length of Stay
  • Logistic Models
  • Male
  • Middle Aged
  • Monocytes / metabolism
  • Myocardial Infarction / epidemiology
  • Outcome Assessment, Health Care*
  • Parathyroid Hormone / blood
  • Phosphates / blood
  • Prospective Studies
  • Surgical Wound Infection / epidemiology
  • Vitamin D / analogs & derivatives*
  • Vitamin D / blood

Substances

  • HLA-DR Antigens
  • Interleukin-6
  • Interleukin-8
  • Parathyroid Hormone
  • Phosphates
  • Vitamin D
  • 1,25-dihydroxyvitamin D
  • C-Reactive Protein
  • 25-hydroxyvitamin D
  • Calcium