The first thing upon waking in the morning is to measure fasting blood glucose. Unlike usual, today’s glucometer displayed a significantly higher reading than normal. Puzzled, he retested, but the result remained abnormal. “Could the glucometer be broken?” wondered Grandpa Zhang as he went to consult at Lanzhou Ruijing Diabetes Hospital. After some questioning, Li Ruijuan, the head nurse and diabetes educator in the shared care center, discovered that Grandpa Zhang’s glucometer had been left on a cold windowsill overnight, and his hands were not fully warmed when he took the measurement. Winter is a special period for individuals with diabetes. The drop in temperature not only affects blood glucose levels but can also directly impact the accuracy of blood glucose measurements. Diabetes educator Li Ruijuan pointed out, “The significant temperature difference between indoors and outdoors in winter makes glucometers and test strips highly sensitive to environmental temperature. Improper handling can easily lead to measurement errors.” 01 Keep Your Glucometer Warm in Winter When measuring blood glucose in winter, the first step is to ensure that the measuring device is at an appropriate temperature. The normal operating temperature for a glucometer typically ranges between 14-40°C, while the optimal temperature for using blood glucose test strips is between 15-30°C. If the outdoor temperature is too low, the glucometer may “freeze” and fail to function properly or produce inaccurate test results. Diabetes educator Li Ruijuan reminds individuals with diabetes to measure their blood glucose indoors as much as possible during winter. If outdoor measurement is necessary, warm the glucometer in a warm environment, such as a down jacket pocket, before use. Especially when bringing a glucometer from outdoors to indoors, avoid using it immediately. It is best to wait 30-45 minutes for the device to acclimate to room temperature before taking a measurement. 02 Warm Your Hands Before Measuring Blood Glucose in Winter Low winter temperatures can lead to poor blood circulation, making it difficult to draw blood. Diabetes educator Li Ruijuan recommends warming the fingers before measuring blood glucose. You can start by washing your hands with warm water or letting your arms hang naturally while gently rubbing your fingers to improve blood circulation and ensure sufficient blood flow. Another effective method is to soak your hands in warm water at around 40°C until they are warm. Avoid using alcohol or iodine to warm your hands, as this can affect the measurement results. When drawing blood, appropriately increase the depth of the lancet, press it firmly against the skin, and then press the release button. This can improve blood flow. 03 Details Determine Success in Blood Glucose Measurement The correct blood collection method is key to obtaining accurate blood glucose readings. After pricking the fingertip, wipe away the first drop of blood with a cotton swab, then gently squeeze the fingertip and use the test strip to absorb the second drop of blood for testing. Avoid squeezing the finger forcefully, as this may release not only blood but also tissue fluid, which can dilute the blood sample and result in a lower blood glucose reading. When disinfecting, use 75% alcohol to clean the finger. After disinfection, wait until the finger is completely dry before drawing blood, as residual alcohol can dilute the blood and affect the measurement results. It is particularly important to note that iodine or iodine tincture should not be used for disinfection, as they can react with the chemicals on the test strip, leading to falsely elevated results. 04 Calibration and Storage of Glucometers Are Also Important The accuracy of a glucometer requires regular maintenance. Diabetes educator Li Ruijuan emphasizes that glucometers generally need to be calibrated every six months to a year. Proper storage of test strips is equally important. Test strips should be sealed and stored in a dry, cool, and dark place. They should not be stored in a refrigerator or excessively cold environment. After opening a bottle of test strips, they are valid for three months. The discard date should be marked on the bottle after the first use to avoid using expired test strips, which could affect monitoring results. Never reuse lancets. This not only increases the risk of infection but also dulls the needle tip, causing more pain during blood collection and affecting the blood volume and measurement results. 05 Avoid Common Mistakes When Measuring Blood Glucose Many individuals with diabetes fall into common misconceptions when self-monitoring their blood glucose. Diabetes educator Li Ruijuan points out that focusing solely on fasting blood glucose while neglecting postprandial blood glucose is one such misconception. Postprandial blood glucose is crucial for assessing diabetes control. Patients should measure their postprandial blood glucose periodically to understand the impact of diet on blood glucose levels. There is an inherent difference between home self-monitored blood glucose (capillary whole blood glucose) and hospital blood tests (venous plasma glucose). A deviation within 20% is generally acceptable. Additionally, blood glucose values measured at different times are not comparable. Factors such as insomnia and emotional fluctuations can also affect blood glucose measurement results.