Does Influenza Vaccination Benefit Patients Hospitalized With Diabetes?

In patients hospitalized for diabetes, influenza vaccination lowers the need for intensive care and the risk of death and complications such as pneumonia, septicemia, and urinary tract infection, according to study results published in Diabetes Research and Clinical Practice.

Prior studies have shown that influenza vaccination has a beneficial effect in patients with stroke and chronic obstructive pulmonary disease, but the research on influenza vaccination in those with diabetes was primarily observational. The authors of this study sought to better understand the advantages of influenza vaccination in patients hospitalized with diabetes.

Researchers based in Taipei, Taiwan, conducted a population-based cohort study, using data on eligible participants from the Taiwan National Health Insurance Program database. The researchers identified 167,162 patients aged 20 years and older who were hospitalized in Taiwan because of diabetes between January 1, 2008 and December 31, 2013. Of the total, 45,160 had been inoculated with influenza vaccine in the previous year. The investigators selected 30,501 of the unvaccinated patients as well as 30,501 vaccinated patients (N=61,002) utilizing propensity matching to adjust for baseline demographic differences. The primary outcome of this investigation was 30-day in-hospital mortality.

The data revealed that influenza vaccine cut the risk of 30-day in-hospital mortality, even in diabetes patients with hypertension (odds ratio [OR], 0.72; 95% CI, 0.61-0.85), chronic obstructive pulmonary disease (OR, 0.66; 95% CI, 0.50-0.87), and ischemic heart disease (OR, 0.66; 95% CI, 0.50-0.87). When compared with unvaccinated diabetes patients, vaccinated patients also had lower risks of 30-day in-hospital mortality, even when their data showed a previous diabetes hospitalization (OR, 0.61, 95% CI, 0.48-0.76), poor diabetes control (OR, 0.74; 95% CI, 0.63-0.85), eye involvement (OR, 0.65; 95% CI, 0.53-0.78), ketoacidosis (OR, 0.73; 95% CI, 0.56-0.95), kidney involvement (OR, 0.71; 95% CI, 0.61-0.83), or coma (OR. 0.77; 95% CI, 0.62-0.96).

The advantages of influenza vaccine also extended to fewer complications. “Previous research has made it clear that bacterial coinfection can significantly increase the morbidity and mortality of influenza infection,” the authors noted. “Our study showed that influenza vaccine reduced the risk of infectious complications, including pneumonia, septicemia and urinary tract infection, in hospitalized patients with diabetes,” they added.

Limitations of the study include data deficient in sociodemographic characteristics, lifestyle factors, and laboratory data; the inability to confirm the vaccination status of some participants; and data that may have been skewed because individuals who seek vaccination may also engage in healthier lifestyle practices.

“The findings of our study were consistent with previous reports showing that [influenza vaccination] was associated with a 25% reduced risk of 30-day in-hospital

mortality and an 8% reduced risk of pneumonia in patients with diabetes,” said study authors. They further noted that influenza vaccine “was significantly associated with reduced risks of infectious complications and mortality in patients admitted for diabetes, even in those with poor glycemic control and/or complicated diabetes.” These findings provide support for health authorities to “encourage patients with diabetes to receive complete vaccination against influenza annually, particularly elderly people,” study authors concluded.

Reference

Lin CS, Chang CC, Yeh CC, Chang YC, Chen TL, Liao CC. Outcomes following diabetes admission in patients who had influenza vaccination: A population-based cohort study. Diabetes Res Clin Pract. Published online May 21, 2022. doi:10.1016/j.diabres.2022.109930