Influenza Virus Causes Potential Hospitalizations in Patients with Type 2 Diabetes

Flu season is upon us; what do influenza complications mean for patients with type 2 diabetes?

In the study, there was a higher risk of infections, post-infection complications, and increased risk of mortality in patients with type 2 diabetes. Serious influenza complications can also result in a higher risk of hospitalization, and also mortality, in patients with diabetes. The influenza virus, commonly known as the flu, has the potential of exacerbating chronic health problems that lead to worsening the disease state of diabetes. This negative effect is due to patients with diabetes being susceptible to having weaker immune systems, which makes it harder to fight off diseases. In addition, having certain illnesses can make it harder to control or manage blood glucose levels.

The 2009-2010 influenza A H1N1 virus infection caused a global influenza pandemic; after the pandemic, people with type 2 diabetes were reported to have a higher risk of complications and hospitalizations. Studies after that have assessed diabetes as being a risk for severe outcomes associated with pandemic influenza.  Furthermore, It has been interpreted that patients with diabetes contracting the influenza virus have higher all-cause mortality compared to those without diabetes. However, there has been limited evidence on whether the risk of hospitalization with pandemic influenza is higher in those with type 2 diabetes compared to those without type 2 diabetes.

Paz L.D. Ruiz, from the Norwegian Institute of Public Health in Oslo, and colleagues conducted a study known as the DiaFlu to investigate the pandemic influenza virus and diabetes. individual-level data from several national registers for all Norwegian residents aged 30 years and older January 1st, 2009 (n= 2,992,228) was used to assess influenza-related complications among patients with type 2 diabetes. Norwegian residents were followed to the end of the study, December 31, 2013; death, or emigration. The study’s primary outcome was hospitalization with pandemic influenza exposure with the study variables being type 2 diabetes, pandemic influenza vaccination, hospitalization, and mortality. The covariates included age, sex, education, country of birth, and county of residence.

Vaccination coverage was higher among those with type 2 diabetes, ranging from 65% of people aged under 69 years to 27% over 90 years old, seen more in females than males. In patients with type 2 diabetes, hospitalization with pandemic influenza was twice as common with a hazard ratio of 2.46 (95% Cl 2.04 – 2.98, unadjusted HR 2.10, 95% Cl 1.75- 2.52). Hospitalization with pandemic influenza and mortality in patients with type 2 diabetes was associated with two-fold increased mortality (hazard ratio 1.82, 95% Cl 1.21-2.74), vs. patients without type 2 diabetes; hazard ratio 3.89(95% 3.27 – 4.62). A nearly 4-fold increase and 10- fold increase of all-cause mortality within 90 days of influenza hospitalization appeared in patients with type 2 diabetes and those without, respectively. Amongst those who were vaccinated, hospitalization for pandemic influenza was less common. Mortality during 2009-2013 was slightly lower in those without type 2 diabetes who were vaccinated with a hazard ratio of 0.91 (95% Cl 0.90 – 0.92) compared to those with type 2 diabetes; hazard ratio of 0.75 (95% Cl 0.73 – 0.77).

These findings concluded that hospitalization for pandemic influenza was more likely to occur in patients with type 2 diabetes. Relatively, mortality was lower in this group of patients. This study results highlighted the importance of influenza vaccine amongst patients with diabetes, especially during flu season.

The influenza vaccine is the best protection against the flu. According to the CDC, flu vaccines are updated every year to better match the circulating viruses. Due to the high risk of developing serious flu complications, flu vaccination is essential for patients with diabetes. The flu vaccine has been shown to reduce the risk of hospitalization due to severe flu complications in these patients. This vaccine is recommended in these patients and serves as a safety record. Patients with diabetes or certain underlying medical conditions should take precautions in receiving the nasal spray flu vaccine.

For patients with diabetes, the CDC also recommends they should take preventative actions towards getting the flu. Covering coughs, washing hands often, and avoiding people who are sick are ways patients can protect themselves. Patients should contact their doctor immediately if they notice flu symptoms, including fever, cough, running nose, body aches, chills, and fatigue.

Practice Pearls:

• Patients with type 2 diabetes are more likely to be hospitalized with the influenza virus.
• The influenza virus can exacerbate several chronic conditions.
• Vaccination coverage was higher in those with type 2 diabetes.

Flu and People with Diabetes | CDC. (n.d.). Retrieved from https://www.cdc.gov/flu/highrisk/diabetes.htm.

 Patients With T2DM Who Have Flu More Likely to Be Hospitalized. (2019, October 11). Retrieved from https://www.physiciansbriefing.com/diabetes-endocrinology-4/type-ii-diabetes-news-183/patients-with-t2dm-who-have-flu-more-likely-to-be-hospitalized-751133.html.

Ruiz, Bakken, I. J., Håberg, S. E., Tapia, Hauge, S. H., Birkeland, K. I., … Stene, L. C. (2019, October 6). Higher frequency of hospitalization but lower relative mortality for pandemic influenza in people with type 2 diabetes. Retrieved from https://onlinelibrary.wiley.com/doi/pdf/10.1111/joim.12984#accessDenialLayout.

Taylor-Eugene Simmons, Florida A&M University, College of Pharmacy & Pharmaceutical Sciences, PharmD Candidate

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