Aline Zakhem, MD
Infectious Diseases Specialist
Clinical Associate, AUBMC
Diabetes mellitus (DM) increases the risk of infections, as high blood sugar levels can weaken the patient’s immune system defenses. In addition, some diabetes-related health issues, such as nerve damage and reduced blood flow to the extremities, increase the body’s vulnerability to infection. Any infection, no matter how mild it is, can cause alterations in blood sugar levels. As such, an uncontrolled blood sugar in the setting of adequate medication and controlled diet could be the first sign of infection in diabetic patients. A very important point to keep in mind is that diabetics do not always display all the symptoms of an infection, and therefore an infection can go silent for some time before becoming aware of it. For example, patients can still have an infection even in the absence of fever. Early diagnosis and prompt treatment of infections is important.
The most common sites of infections are mainly in the respiratory tract, the urinary system, and the skin, as well as diabetic foot infections.
The most frequent respiratory infections associated with DM are bacterial pneumonia caused by Streptococcuspneumoniae and viral infections, mainly the influenza virus. Persons with DM are six times more likely to need hospitalization during influenza epidemics than non-diabetic patients. They also have higher risk of complications secondary to pandemic influenza H1N1. Guidelines recommend anti-pneumococcal and influenza vaccination for people with DM, since vaccines were shown to reduce the number of respiratory infections, the number and length of hospitalizations as well as the deaths caused by respiratory tract infections.
Urinary tract infections (UTIs) are more prevalent in individuals with DM and may evolve so the infection extends to the kidneys and even to the blood. As noted earlier, patients don’t necessarily spike a fever and therefore any change in the urine quantity, color and smell should be reported.
Another very common site of infection is the skin. Patients can have a mild infection, like at the base of the hair follicle, or a more serious one like extensive cellulitis (skin redness) or even abscesses under the skin.
Furthermore, foot infections are the most prevalent chronic complications of diabetes. In advanced cases, diabetic neuropathy (nerve damage) causes problems with sensation, particularly in the feet. This lack of sensation sometimes means foot injuries go unnoticed. Untreated injuries can lead to infection. Some types of neuropathy can also lead to dry, cracked skin, which allows a convenient entry point for infection into the body. So it is very important to keep the skin moisturized and to avoid walking barefoot.
In summary, uncontrolled blood sugar levels can predispose diabetic patients to serious infections. However, most of them can be preventable with adequate awareness about the symptoms, vaccinations and with proper skin and foot care. It is very important that patients know to report any of the symptoms above to their primary physician.