Adults with diabetes are more likely to die of infectious diseases, such as sepsis or pneumonia, than patients without diabetes, even after accounting for other comorbidities, according to findings published in Nutrition, Metabolism & Cardiovascular Diseases.
“The excess risk of death from infectious diseases in patients with diabetes may be multifactorial,” Giacomo Zoppini, MD, of University and Hospital Trust of Verona, Italy, and colleagues wrote in the study background. “An important role is played by the presence of microangiopathy and renal failure. The other important factor is hyperglycemia. Hyperglycemia on admission has been shown to increase the risk of pneumonia-related mortality.”
Zoppini and colleagues analyzed electronic health records data from 185,341 adults aged 30 to 89 years from the Veneto region of northern Italy who received a copayment exemption for diabetes in January 2010. Researchers linked the patient data with the archive of causes of death occurring between 2010 and 2015. Researchers assessed the effect of infections on mortality risk in patients with diabetes using the underlying cause of death, as well as multiple causes of death analysis, to estimate the mortality burden from infection-related causes.
At the end of follow-up, 36,382 patients died (24.7%), with the main cause of death attributed to cardiovascular disease.
Researchers observed an increased risk for death from 40 infection-related causes, with a standardized mortality ratio (SMR) of 1.83 (95% CI, 1.71-1.94). When assessing specific infections, the SMR for death from septicemia was 1.91 (95% CI, 1.76-2.06), and the SMR for death from pneumonia was 1.47 (95% CI, 1.36-1.59).
“It is worth noting that the highest SMRs, with a twofold increased risk for mortality with respect to the general population, were observed for sepsis as well as for [a] few already well-known causes of death in diabetic subjects: ischemic heart diseases, liver and pancreatic cancer and chronic liver diseases,” the researchers wrote.
The researchers also noted that infections may largely be underestimated as causes of death. From 2013 to 2015, infectious diseases were selected as the underlying cause of death in 6% of overall deaths, whereas they were mentioned in 20.6% of all death certificates in patients with diabetes. Additionally, risk persisted after adjusting for comorbidities.
“Our study may have important clinical implications, as it suggests that infectious diseases greatly increase the risk of a worse prognosis in patients affected by diabetes,” the researchers wrote. “Even though the absolute risk based on the [underlying cause of death] is quite small, it should be emphasized that the real impact of infectious diseases on mortality may be largely underestimated, as the use of [multiple causes of death analysis] seems to indicate.”