Correlation between inflammatory factors and post-stroke pneumonia in diabetic patients

Pneumonia is the most common cause of mortality in stroke patients and it has been demonstrated to contribute to mortality and poor functional outcome following stroke in the majority of clinical studies. The risk of infection may be attributed to stroke-induced immunodepression syndrome (SIDS). Cytokine production is increased in SIDS. However, the correlation between biomarkers and the risk of post-stroke pneumonia in patients with diabetes mellitus is not clear. The aim of this study was to determine the correlation between pneumonia and the levels of C-reactive protein (CRP) and interleukin-6 (IL-6), as well as to identify early predictors of pneumonia in acute ischemic stroke patients with diabetes mellitus. Additionally, we investigated the impact of pneumonia on functional outcome after 1 month. A total of 106 ischemic stroke patients with diabetes mellitus who were admitted after the onset of symptoms were included in the study. They were divided into two groups, the pneumonia and non-pneumonia groups. CRP, IL-6, white blood cells (WBCs), mean body temperature and National Institutes of Health Stroke Scale (NIHSS) score were measured at the time of admission. The modified Rankin Scale score was assessed at 30 days. The levels of IL-6, CRP and WBCs, as well as mean body temperature were significantly higher in the patients with pneumonia than in the patients without pneumonia. There were also significant differences between the pneumonia and non-pneumonia groups in age, admission NIHSS score, length of hospital stay and dysphagia. Pneumonia patients had worse outcomes compared with patients without pneumonia at 1 month. Age, NIHSS score and dysphagia were significantly associated with pneumonia. WBCs and mean body temperature were not significant predictors of pneumonia. Older patients with more severe ischemic stroke are more susceptible to the development of pneumonia during the stay in hospital. Pneumonia contributes to poor functional outcome. IL-6, CRP, age, NIHSS score and dysphagia may predict the occurrence of pneumonia on the day of stroke symptom onset.