The influenza A H3N2 strain has replaced last season's influenza A H1N1, becoming the currently predominant circulating strain.

For patients with diabetes, especially elderly diabetics with reduced physiological function, due to relatively lower immunity, once infected with influenza, not only is the course longer and symptoms more severe, but it is also more likely to trigger dramatic blood glucose fluctuations and even precipitate life-threatening acute complications such as diabetic ketoacidosis.

01 Double threat: diabetics’ influenza predicament

1+1>2

Director Ren Shuhong explained that the coexistence of diabetes and influenza creates a health risk greater than the sum of its parts ("1+1>2"). On one hand, fever and the stress response caused by influenza infection prompt the body to secrete large amounts of hyperglycemic hormones that counteract insulin, leading to marked and difficult-to-control increases in blood glucose.

On the other hand, loss of appetite and medication irregularities during illness can also trigger severe hypoglycemia. These "roller-coaster" fluctuations in blood glucose cause significant damage to blood vessels and organs and are a direct precipitant of acute complications.

Therefore, Director Ren emphasizes that people with diabetes facing influenza must grasp the core response principle of "one must, two don'ts," manage scientifically, and transition smoothly.

02 Core response: Scientific guideline of "one test, two don'ts"

One test: When fever occurs, promptly check blood glucose

。

Body temperature changes are a "weathervane" for blood glucose. Director Ren Shuhong reminds that when fever occurs, basal metabolic rate accelerates; like a machine running at excessive speed, it consumes more energy and can easily cause blood glucose to surge.

When body temperature falls and appetite decreases, blood glucose may drop sharply. Therefore, during infections blood glucose monitoring frequency must be increased; it is recommended to monitor at least four times daily (fasting and after the three main meals), and during fever to monitor every 2–4 hours. Adjust glucose-lowering regimens flexibly and cautiously under physician guidance according to blood glucose values to avoid loss of glycemic control.

Use antibiotics with caution after infection

"This is a very critical misconception," Director Ren Shuhong states clearly. Influenza is caused by a virus; antibiotics are effective only against bacteria. Misuse of antibiotics is not only ineffective but also disrupts the gut microbiota and induces bacterial resistance.

Only when a bacterial co-infection is clearly confirmed (e.g., yellow purulent sputum, laboratory tests showing elevated white blood cell count, etc.) should antibiotics be used under a physician's guidance. The early stage of influenza (within 48 hours) is the golden window for antiviral drugs (such as oseltamivir); timely use can effectively shorten the course of illness and alleviate symptoms.

Be cautious about taking medications after a cold; do not purchase "cold medicines" on your own.

Director Ren issues a special warning that many common cold medications have "contraindications" with glucose-lowering drugs, and the risk of self-mixing them is very high. For example, commonly used acetaminophen (paracetamol) combined with large doses of aspirin may increase the risk of lactic acidosis in patients with diabetes.

In addition, large doses of acetaminophen can also interfere with continuous glucose monitoring device readings, causing them to display falsely elevated values; if insulin is increased based on those readings, it can easily precipitate true hypoglycemia, which is very dangerous.

She recommends that diabetic patients who need medication must inform their doctor or pharmacist of all glucose-lowering drugs they are currently taking, so a professional can recommend safe cold remedies.

03 Strengthen the defense line: prevention strategies tailored for northern diabetic patients

In addition to the above emergency measures, proactive prevention is the best approach. Director Ren Shuhong offers the following enhanced preventive recommendations for diabetic patients, especially those living in the dry, cold northern regions:

Primary shield: receive the influenza vaccine

Director Ren strongly recommends that all eligible diabetic patients receive an influenza vaccination every autumn (preferably the quadrivalent inactivated vaccine); this is the most effective preventive measure. Ensure blood glucose is stably controlled before vaccination, and avoid coadministration with the pneumococcal vaccine—allow at least a 14-day interval.

Daily protection: details determine success or failure

In the North, large indoor-outdoor temperature differences and dry air in winter favor viral transmission and survival. Diabetic patients should:

Wear masks properly: in densely populated public places, on public transportation, and in medical facilities, always wear a protective mask.

Strengthen hand and environmental hygiene: wash hands frequently; daily wipe high-touch items such as doorknobs and mobile phones with a chlorine-containing disinfectant; in northern homes with heating, use a humidifier to maintain appropriate humidity (50%–60%) to reduce the suspension time of viruses in dry air.

Reduce gatherings and keep warm: during peak influenza season, minimize unnecessary gatherings; when going out, keep warm to avoid cold-induced respiratory problems and blood glucose fluctuations.

Address the root: enhance personal immunity

Controlling and stabilizing blood glucose is the cornerstone of immunity. Director Ren noted that efforts should be made to keep blood glucose within the ideal range (for example, fasting 4.4–7.0 mmol/L, postprandial <10.0 mmol/L).

At the same time, ensure adequate nutritional intake (high-quality protein, abundant vitamins and dietary fiber), engage in moderate regular exercise (such as 150 minutes of brisk walking per week), and secure 7–8 hours of quality sleep each night to collectively build a strong immune defense.

For diabetic patients with persistent fever that does not subside, persistently high blood glucose or frequent hypoglycemia, and severe symptoms such as lethargy, dyspnea, or altered consciousness, Director Ren Shuhong emphasized that they must seek medical attention immediately and must not delay.

Influenza is a trial, but for people with diabetes it is more like a mirror reflecting whether daily blood glucose management is solid.