Older Adults with Diabetes: Relaxed Glycemic Control Shows Unexpectedly Low Infection Risks, Study Reveals

A study published in Diabetes Care has indicated that older patients who maintain relaxed glycemic control levels, as outlined by clinical guidelines, do not face a significantly increased risk of hospitalization for most infections. However, those with an HbA1c level between 8% and 9% may be at a heightened risk for specific infections, particularly affecting the skin, soft tissue, and bones.

The management of diabetes in older adults often requires a careful balance between controlling blood sugar levels and avoiding the potential complications associated with strict glycemic targets. Relaxed glycemic control, characterized by higher HbA1c levels, can lead to concerns about an increased risk of infections, as hyperglycemia is known to impair the immune response. In light of this, Kasia J. Lipska, Section of Endocrinology, Department of Internal Medicine, Yale School of Medicine, New Haven, CT, and colleagues aimed to compare the risk of hospitalization for infection between patients who maintain intensive glycemic control and those who achieve relaxed glycemic control.

For this purpose, the researchers conducted a retrospective cohort study involving adults aged 65 and older with type 2 diabetes from an integrated healthcare delivery system. They utilized negative binomial models to estimate incidence rates and relative risks (RR) of hospitalization for various infections—including respiratory, genitourinary, skin, soft tissue, bone infections, and sepsis.

The study compared two levels of relaxed glycemic control (hemoglobin A1c [HbA1c] 7% to <8% and 8% to <9%) against intensive control (HbA1c 6% to <7%) over the period from January 1, 2019, to March 1, 2020.

The study revealed the following findings:

• Among 103,242 older patients:

• 48.5% had HbA1c levels between 6% to <7%.

• 35.3% had HbA1c levels between 7% to <8%.

• 16.1% had HbA1c levels between 8% to <9%.

• The overall rate of hospitalization for infections was 51.3 per 1,000 person-years.

• Compared to patients with HbA1c 6% to <7%:

 • The unadjusted risk of hospitalization for infections was significantly higher in those with HbA1c 8% to <9%.

• No significant increase in risk was observed for patients with HbA1c 7% to <8% (RR 0.99), and this difference became nonsignificant after adjustment.

• In terms of specific infection categories:

• The adjusted relative risk of hospitalization was significantly higher for skin, soft tissue, and bone infections in patients with HbA1c 8% to <9% (RR 1.33).

"The findings showed that older patients with type 2 diabetes who maintain relaxed glycemic control levels, as recommended by clinical guidelines, do not face a significantly higher risk of hospitalization for most infections. However, those with HbA1c levels between 8% and <9% are associated with an increased risk of hospitalization specifically for skin, soft tissue, and bone infections," the researchers concluded.

Reference:

Kasia J. Lipska, Lisa K. Gilliam, Catherine Lee, Jennifer Y. Liu, Vincent X. Liu, Howard H. Moffet, Melissa M. Parker, Heidi Zapata, Andrew J. Karter; Risk of Infection in Older Adults With Type 2 Diabetes With Relaxed Glycemic Control. Diabetes Care 2024; dc241612. https://doi.org/10.2337/dc24-1612