Septic patients show significantly lower 1,25-dihydroxy vitamin D levels than trauma patients

Introduction

It is known that 1,25-dihydroxyvitamin D (vitamin D) is involved in expression control of more than 200 genes. Vitamin D affects immunity, endothelial and mucosal functions as well as glucose and calcium metabolism. Moreover, its serum deficiency (<20 ng/ml) is reported to be common in hospitalized patients, especially among patients admitted to the ICU. Our aim was to evaluate vitamin D levels in a selected population of ICU patients and its correlation with admission pathology and outcome.

Methods

Among all patients admitted to our general ICU (February to October 2009), 84 patients were studied, 53 admitted for major trauma and 31 patients admitted for severe sepsis/septic shock. Exclusion criteria were: age <18 years, malnutrition state (BMI <18), pregnancy, breastfeeding, chemotherapy and immunotherapy, every pathology affecting bone and calcium metabolism, vitamin D metabolism derangements for therapies, haematological and solid malignancies, HIV. Vitamin D levels were measured by radioimmunoassay and registered at admission as well demographic data, simplified acute physiology score (SAPS), injury severity score (ISS), length of stay (LOS), outcome. Data are expressed as the mean. Statistical analysis: Mann-Whitney (P < 0.05). The study was approved by the Internal Review Board, which waived the need for informed consent.

Results

Vitamin D levels at admission to the ICU respectively were 14.1 ng/ml in the sepsis group (age 61 years, SAPS 46.9) and 21.88 ng/ml in the trauma group (age 46.7 years, SAPS 36.2, ISS 26.8). To avoid the age-related bias, 23 patients older than 50 years were analysed. Vitamin D levels were found to be 20.9 ng/ml (mean age 66.6, SAPS 43.2, mean ISS 24) (P = 0.0195). No correlations with length of stay, duration of mechanical ventilation or outcome were found.

Conclusions

We confirm a vitamin D inadequacy among patients admitted to the ICU, even in young trauma patients (>20 and <30 ng/ml). However, septic patients showed a significantly lower vitamin D level than trauma patients with the same demographic/clinical characteristics (14.1 vs 20.9 ng/ml; P = 0.0195). Correlations between vitamin D levels, LOS and outcome need to be investigated with larger samples.