Vitamin D binding protein, but not vitamin D or vitamin D-related peptides, is associated with septic shock mortality.

BACKGROUND: The aim of this study was to assess the prognostic value of vitamin D, vitamin D binding protein (VDBP) and vitamin D-related peptides in septic shock patients in relation to hospital mortality. METHODS: This is a single-center, prospective, observational study that included all consecutive patients meeting criteria for septic shock who were admitted to the ICU. VDBP, 25-hydroxy vitamin D, 1,25-dihydroxy vitamin D, cathelicidin and beta-defensin levels were determined in blood samples obtained on admission to the ICU. RESULTS: Seventy-five patients were studied. The best area under the curve (AUC) for prediction of in-hospital mortality was for VDBP (0.78), with a negative predictive value of 85.45% for the optimal cut-off point. VDBP was also the only variable that had a statistically significant association with a higher risk of in-hospital mortality, regardless of other assessed variables and pre-determined confounders: adjusted odds ratio of 5.20 (95% confidence interval: 1.21-22.36). When restricted to patients with vitamin D insufficiency (n=54), the AUC was 0.77, and the adjusted OR 12.22 (95% CI: 1.46-102.14; p=0.021) for in-hospital mortality. CONCLUSIONS: VDBP levels showed a statistically significant association with in-hospital mortality, supporting the clinical utility of VDBP as a good prognostic marker in septic shock patients. Vitamin D and vitamin D-related peptides are not associated with in-hospital mortality. These results should be confirmed in a multicentre study with a larger sample size.

The Ratio Serum Creatinine/Serum Cystatin C (a Surrogate Marker of Muscle Mass) as a Predictor of Hospitalization in Chronic Obstructive Pulmonary Disease Outpatients.

BACKGROUND: In chronic obstructive pulmonary disease (COPD), low muscle mass has been associated with several clinical outcomes such as low exercise capacity, hospital admission, and mortality. The Sarcopenia Index (SI) is a novel way to estimate muscle mass based on the ratio of serum creatinine (produced exclusively by muscle)/cystatin C (produced by all nucleated body cells). OBJECTIVES: This study aims to assess the SI in stable COPD outpatients, as compared with a healthy control group, to quantify its relationship with several important clinical features in COPD, and to study its potential usefulness to predict COPD exacerbations and hospital admissions. METHODS: The SI was calculated in 18 healthy control subjects and 65 stable COPD outpatients were included in the study. Patients were prospectively followed for 1 year after being enrolled in the study. RESULTS: COPD patients had a lower SI than controls, that is lower muscle mass. Furthermore, patients with a modified Medical Research Council dyspnea score ≥2, patients with a COPD Assessment Test score ≥10, and patients with a high risk of exacerbation had lower levels of SI compared with patients without these characteristics. SI correlated with FEV1 (r = 0.491, p < 0.001), the 6-min walking test (r = 0.560, p = 0.001), and the Fat-Free Mass Index (r = 0.431, p = 0.017). Univariate and multivariate Cox proportional risk analysis showed that a low SI is an independent predictor of hospital admission in COPD outpatients followed for 1 year (HR 5.16, p = 0.025). CONCLUSIONS: The ratio serum creatinine/serum cystatin C correlates with several COPD characteristics, and it can be used to predict COPD hospitalization.