Objective To investigate the relationship of the levels of calcitonin (PCT), brain natriuretic peptide (BNP) and cardiac troponinⅠ(cTnI) with the severity of pneumonia in elderly patients.

Methods A total of 166 patients with pneumonia were included in the study group, and 50 healthy patients who underwent physical examination in the hospital during the same period were included in the control group. The serum levels of PCT, BNP and cTnI were compared between the two groups. According to the pneumonia severity index (PSI), the study group was divided into mild group (88 cases), moderate group (49 cases) and severe group (29 cases). The levels of serum PCT, BNP and cTnI as well as PSI score were compared among the three groups; the correlations of PCT, BNP and cTnI with PSI score were analyzed. The predictive value of PCT, BNP and cTnI levels in severe pneumonia was evaluated by receiver operating characteristic (ROC) curve.

Results The levels of PCT, BNP and cTnI in the study group were significantly higher than those in the control group (P < 0.05). The levels of serum PCT, BNP and cTnI in the mild, moderate and severe groups were significantly increased with the severity of the disease (P < 0.05). Serum PCT, BNP and cTnI levels were positively correlated with PSI scores (r=0.304, 0.297, 0.284; P < 0.05). ROC curve showed that the area under the curve (AUC) of serum PCT, BNP and cTnI in predicting severe pneumonia were 0.627, 0.781 and 0.637, respectively, and the AUC of the combined prediction was 0.830.

Conclusion Serum PCT, BNP and cTnI levels in senile patients with pneumonia are increased abnormally, and are positively correlated with the severity of the patient's disease. The combined prediction value of PCT, BNP and cTnI is better in predicting senile severe pneumonia.