Sequential vitamin D and parathyroid hormone measurement in patients with septic shock: Could they be prognostic marker in septic shock?

Aim: Hypocalcemia is a common clinical problem in critically-ill patients and it is associated with increased morbidity and mortality. The aim of this study was to investigate serum calcium, vitamin D and parathyroid hormone (PTH) levels in surviving and non-surviving septic shock patients. Method: Patients with septic shock criteria and who were older than 18 years of age were included, whereas patients with diseases influencing calcium homeostasis were excluded. Demographic and laboratory parameters were recorded prospectively. Results: 41 patients, 20 of which were male were included in the study. The median (min-max) age of study population was 67 (19-88) years. Frequency of hypocalcemia in the study population was 29.2% and 68.2% according to corrected calcium and ionized calcium, respectively. On the day septic shock was diagnosed (day 1), median vitamin D levels of survivors and non-survivors were 8.7 ng/ml (4.3-30.4) and 5.3 ng/ml (1.0-21.7), respectively (p=0.05). On the same day, median PTH levels of survivors and non-survivors were 94 ng/L (16.9-1746) and 49 ng/L (6.6-339), respectively (p=0.042). Although vitamin D levels were suppressed and PTH levels were elevated in non-survivors at day 5, this change was not statistically significant (p=0.19 and p=0.187). Conclusion: Hypocalcemia is frequent in septic shock patients, whereas vitamin D levels were low and PTH levels were high in the diagnosis day. These results suggest that vitamin D is suppressed by septic shock at non-surviving patients during course of septic shock. Parathyroid hormone may be a marker for worse outcome in critically ill patients.