Early glycemic variability ups mortality and ICU stay among patients with pneumonia

The findings imply that patients with high variability in their blood sugar levels, especially those with low HbA1c levels (<7.5%) or diabetes mellitus, should be monitored carefully to reduce mortality. 

Diabetes is a chronic disease characterized by high blood sugar levels due to decreased function or secretion of the insulin hormone. The condition is associated with a high mortality rate due to complications caused by chronic hyperglycemia, including microvascular and macrovascular complications. Also, diabetes has a highly negative effect on the lungs. Some previous studies have shown diabetes patients to be vulnerable to pneumonia, chronic obstructive pulmonary disease, and asthma.

Recent studies have also shown high glycemic variability to be a severe risk factor for high mortality rates in ICU (intensive care unit) patients, similar to chronic hyperglycemia. GV has been suggested as a parameter for predicting prognosis in acute patients since its presence in early hospitalization reflects the physiological stress response. However, there is a lack of evidence on the association between GV and pneumonia mortality.

Against the above background, Seung Min Chung, Yeungnam University College of Medicine, Daegu, Republic of Korea, and colleagues aimed to evaluate the effect of early glycaemic variability on 28-day mortality in critically ill patients with pneumonia.

The study led to the following findings:

• The 28-day mortality rate was 31.6% (n = 89) and was not different according to the presence of diabetes (DM vs. non-DM) or HbA1c levels (≥7.5 vs. <7.5%).
• The mortality rate was remarkably higher in patients with high GV (CV ≥ 36%) than in those with low GV (CV < 36%; 37.5 vs. 25.4%).
• The mortality risk in patients with high GV was prominent in the DM or low HbA1c levels subgroups.
• Among the surviving patients (n = 193), 44 remained in the ICU for more than 14 days.
• Compared to low GV, high GV was associated with a higher rate of prolonged ICU stay, although not statistically significant (27.8 vs. 18.5%).
• After adjusting for the severity of the illness and treatment strategy, CV was an independent risk factor for 28-day mortality (hazard ratio [HR], 1.01) and prolonged ICU stay (odds ratio, 1.02).

"The findings indicate that a high GV can be harmful, especially in patients with low HbA1c levels or diabetes," the researchers wrote in their study. "As pneumonia is one of the most common single diseases resulting in the hospitalization of patients in the ICU, these findings could be usually applied in clinical practice."

They concluded by saying, "there is still no clarity on the association of GV and lung function; therefore, there is a need for further studies to identify GV's effect on various respiratory diseases."

Reference:

Kim, Seong Ho, et al. "Early Glycaemic Variability Increases 28-day Mortality and Prolongs Intensive Care Unit Stay in Critically Ill Patients With Pneumonia." Annals of Medicine, vol. 54, no. 1, 2022, pp. 2736-2743.