Changes in the calcium-parathyroid hormone-vitamin d axis and prognosis for critically ill patients: a prospective observational study.
OBJECTIVE
Vitamin D deficiency is prevalent in critically ill patients and may contribute to suboptimal clinical outcomes, but little is known about alterations of the calcium-parathyroid hormone (PTH)-vitamin D axis and prognosis in these individuals.


METHODS
A prospective observational study was conducted on 216 patients admitted to a university-affiliated, tertiary-care medical intensive care unit(MICU) between June 2011 and December 2012. Serum levels of 25-hydroxyvitamin D, ionised calcium and intact PTH were determined within 24 h of MICU admission. The primary end point was all-cause hospital mortality within 90-days of admission.


RESULTS
95 patients (44%) showed 25-hydroxyvitamin D deficiency. Patients deficient in vitamin D showed significantly higher Acute Physiology and Chronic Health Evaluation II (APACHE II) score, rate of positive blood culture, incidence of multiple organ dysfunction syndrome, and 90-day mortality rate than did patients with vitamin D insufficiency or sufficiency (P<0.05), as well as lower levels of serum IgG. 25-Hydroxyvitamin D deficiency was identified as an independent risk factor for mortality (OR = 3.018, 95%CI 1.329-6.854, P = 0.008). Hypovitaminosis D in PTH-responders was associated with higher mortality than was the same condition in non-responders (P<0.05).


CONCLUSIONS
These results suggest that vitamin D deficiency is prevalent among MICU patients, suggesting a significant derangement of the calcium-PTH-vitamin D axis in critically ill patients. Vitamin D deficiency is an independent risk factor for 90-day mortality, and hypovitaminosis D in PTH-responders is associated with higher mortality than is the same condition in non-responders.
Intensive Care Unit, First Affiliated Hospital of Guangxi Medical University, Nanning, China.
Jieyu
J
Hu
Zuojie
Z
Luo
Xiaoqin
X
Zhao
Qiang
Q
Chen
Zhaoyan
Z
Chen
Hua
H
Qin
Yingfen
Y
Qin
Xinghuan
X
Liang
Yingjun
Y
Suo
D018806:APACHE; D002118:Calcium / Q000097:blood*; D016638:Critical Illness; D005260:Female; D006801:Humans; D015994:Incidence; D007362:Intensive Care Units; D008297:Male; D008875:Middle Aged; D009102:Multiple Organ Failure / Q000097:blood / Q000209:etiology / Q000401:mortality; D010281:Parathyroid Hormone / Q000097:blood*; D011379:Prognosis; D011446:Prospective Studies; D011863:Radioimmunoassay; D012307:Risk Factors; D015996:Survival Rate; D062606:Tertiary Care Centers; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood / Q000150:complications / Q000453:epidemiology*
D010281:Parathyroid Hormone; D014807:Vitamin D; C104450:25-hydroxyvitamin D; D002118:Calcium