FEMH Magazine

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  • 2025-11-03

Continuous Glucose Monitoring: Spotting the Hidden Culprits Behind High Blood Sugar!

Department of Metabolism Diabetes Educator Hung, Ling-Yu

PIC
                 
Diabetes is a long-term metabolic condition marked by persistently high blood sugar levels. This happens because of insufficient insulin secretion, impaired insulin function, or the body’s reduced response to insulin. Poor long-term blood sugar control can easily lead to complications such as cardiovascular disease, kidney damage, retinopathy, and neuropathy, and it may also affect quality of life and life expectancy.

              For people with diabetes, blood sugar control is one of the most important daily challenges. Good control is not just about lowering blood sugar; it’s about keeping blood sugar within a stable and  safe range. In other words, preventing big swings—both highs and lows—is the real key.

              Current diabetes care guidelines, both internationally and in Taiwan, highlight three core strategies:

  • Dietary management: Eat a balanced diet, avoid too much refined sugar and high-calorie foods.
  • Regular exercise: Combine aerobic activities and strength training to improve insulin sensitivity.
  • Medication: Depending on a doctor’s evaluation, take oral medicine, insulin injections, or incretin-based therapies.

                However, no matter how much effort you put into adjusting your lifestyle, without accurate blood sugar data as a guide, it is hard to know if your control is truly effective. This is why blood sugar monitoring is so valuable.

 

Why Blood Sugar Monitoring Matters

              Blood sugar data is like a health dashboard for people with diabetes. It shows whether your lifestyle, eating habits, and treatments are working well.

(1) Traditional Monitoring

                The most common method has been the fingerstick blood glucose meter. You prick your finger, place a drop of blood on a test strip, and get an immediate reading. This method is simple and inexpensive, but it has some limitations:

  • Only snapshots: Testing a few times a day can’t show the full 24-hour picture.
  • Missed fluctuations: Post-meal spikes may be overlooked if you don’t test at the right time.
  • Limited frequency: Since it requires pricking and bleeding, many people find it inconvenient or painful.

(2) Why Monitoring Is So Important

              Blood sugar levels can change due to food, exercise, emotions, stress, and medication. Without monitoring, it’s impossible to know:

  • Which foods cause your blood sugar to rise quickly?
  • Which type of exercise lowers your blood sugar most effectively?
  • Do you experience “hidden hypoglycemia” at night or early morning?
  • Is your medication dosage adequate?

To answer these questions, we need continuous and complete monitoring.

 

What Is Continuous Glucose Monitoring (CGM)?

               Thanks to medical technology, a new method has emerged—Continuous Glucose Monitoring (CGM)—and it’s becoming increasingly popular.

(1) How CGM Works

               A tiny sensor is placed under the skin on the arm or abdomen. Using a fine filament, it measures glucose levels in the interstitial fluid. The sensor continuously records data and sends it via Bluetooth or other methods to a receiver or smartphone app, so users can view their blood sugar trends in real time.

(2) Key Features of CGM

  • 24-hour recording: Not just single numbers, but a full blood sugar curve.
  • Alerts: Warns you immediately if blood sugar is too high or too low.
  • Trend analysis: Shows whether blood sugar is rising or falling.
  • Lifestyle insights: Lets you see the impact of food, exercise, stress, and medication.

              With CGM, it’s like switching on headlights at night—you’re no longer driving in the dark. Instead, they have a real-time navigator showing them the direction of their blood sugar.

 

How to Use CGM to Unlock the Secrets of Blood Sugar

               CGM is not just about “looking at numbers.” It helps us uncover the hidden culprits behind blood sugar changes and make the right adjustments.

(1) Identifying Post-Meal Spikes

               Many people think it’s only about controlling total calories. In fact, different foods affect blood sugar very differently. For example:

  • White rice, white bread: Cause blood sugar to rise quickly.
  • Brown rice, oats: Cause a slower increase.

                  CGM allows you to clearly see post-meal blood sugar curves and identify which foods cause spikes—helping you make better food choices.

(2) Detecting Nighttime or Early Morning Lows

             Some patients may have good control during the day but unknowingly experience hypoglycemia at night or early morning. CGM can reveal these “hidden lows,” so doctors can adjust medication or insulin doses.

(3) Understanding Exercise and Stress Effects

                 Different types of exercise affect blood sugar in different ways. Aerobic exercise usually lowers blood sugar, while high-intensity workouts may temporarily raise it. With CGM data, you can find the activities that work best for you.

             Stress and poor sleep can also raise blood sugar. By linking these lifestyle factors with your glucose trends, you can make more conscious improvements.

(4) Teamwork With Healthcare Providers

               CGM data not only helps patients but also provides valuable information to doctors, dietitians, and nurses. It can be used to:

  • Decide whether medications need to be changed or adjusted.
  • Evaluate the effectiveness of diet and exercise plans.
  • Develop personalized strategies for specific times of high blood sugar.

 

            Diabetes care is no longer just about “taking medicine” or “eating less sugar.” With CGM, it’s like turning on a spotlight—revealing the dynamic changes in blood sugar and exposing the hidden culprits that truly affect control.

         For the general public, this technology makes diabetes care more precise and helps us better understand our own bodies and health. In the future, as devices become more widespread, CGM may become a daily tool not only for people with diabetes but also for those at risk of developing it.

        Managing blood sugar is like running an invisible marathon—only with real-time monitoring and smart adjustments can we keep moving farther and healthier. Only with real-time monitoring and smart adjustments can we go farther and healthier.

        At Far Eastern Memorial Hospital, we also provide CGM services to help you better manage your blood sugar. If you are interested, feel free to contact our medical team to learn more.