Blood Sugar Testing in Type 2 Diabetes

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Blood sugar testing is a standard part of type 1 diabetes treatment. If you have type 2 diabetes, should you also test your blood sugar? Are there benefits? Let’s take a look at the pros and cons.


What is blood sugar?

Blood sugar is another term for blood glucose. In type 2 diabetes, your ability to produce or respond to insulin is impaired. Insulin’s job role is to move glucose out of your bloodstream. When you don’t have enough insulin – or you are insulin resistant – blood sugar become elevated. Type 2 diabetes treatment has two key goals:

  1. Ensure you have sufficient levels of insulin, and
  2. Help your body respond to that insulin.


Measuring blood sugar

There are several ways to measure blood sugar:

  • Laboratory test: Fasting blood sugar, also known as fasting plasma glucose
  • Laboratory test: Hemoglobin A1C (HA1C), which measures your average blood sugar levels over two to three months.
  • Self-testing device: A home glucose meter (glucometer), which measures the blood sugar from a drop of fingertip blood.
  • Wearable device: A continuous glucose meter (CGM), where a sensor below the skin continually track your glucose levels.


Self-testing for type 2 diabetes

Do you take insulin to manage your type 2 diabetes? Your doctor will likely recommend self-testing. There’s no standard on how often and when to test. For example, your doctor may suggest morning, bedtime, before and/or after meals, and after a workout.

If you have type 2 diabetes and don’t take insulin, your doctor may not recommend self-testing.


Target blood sugar levels

High blood sugar levels increase the risk of type 2 diabetes complications. The American Diabetes Association recommends the following target levels:

  • Between 80 and 130 milligrams per deciliter (mg/dL) before meals
  • Less than 180 mg/dL two hours after meals

Lab tests like fasting glucose and HA1C give general information. They don’t show your response to foods or medications, or daily deviations outside the target range.


What makes your blood sugar level fluctuate?

What causes blood sugar to fluctuate in people with type 2 diabetes? There are several reasons:

  • Insulin intake, and the type of insulin (long-, short-, or intermediating-acting).
  • Drugs like sulfonylureas that lower blood sugar levels.
  • The type, quantity, and timing of the food you eat — especially your carbohydrates.
  • Exercise.
  • Sleep.
  • Illness or stress.
  • Other medications you take.


If you aren’t on insulin

It’s controversial to recommend self-testing to people with type 2 diabetes who aren’t on insulin. A 2017 study from the University of North Carolina School of Medicine found that blood sugar monitoring does not improve the health of people with type 2 diabetes not taking insulin. A 2018 study said to “avoid routine multiple daily self-glucose monitoring” with the same group.


Benefits of blood sugar testing

Some doctors say that blood sugar testing helps them carefully manage blood sugar and better treat type 2 diabetes. Blood sugar readings help them finetune drugs and dosages. And their see in real time how different foods, activities, and events affect their blood sugar.


A glucometer or a CGM?

A 2018 study in people with type 2 diabetes found that a CGM was more effective than a glucometer. CGM users saw bigger drops in HA1C levels, body weight, and calorie intake. They also had better blood sugar management.

Similarly, a 2016 study found that CGM’s are valuable because they:

  • identify previously unknown episodes of high and low blood sugar (hyperglycemia and hypoglycemia).
  • provide actionable information to finetune treatment.


Obstacles to self-testing with a glucometer

There are several obstacles glucometer testing:

  • For some people, finger sticks for self-testing are uncomfortable or painful.
  • While glucometers are usually inexpensive, test strips are usually costly. Health insurance often doesn’t cover the cost of a glucometer and strips for people with type 2 diabetes.

Note: There are services, however, such as OneDropDiaThrive, and MySugr that offer low cost subscription programs for test strips.


Obstacles to continuous glucose monitoring

Cost can be a barrier for CGM use. Without insurance coverage, CGMs like the popular Dexcom and Medtronic models can cost more than $4,000 per year. Abbott’s Freestyle Libre is more affordable, but still costs approximately  $1,500 per year. The Freestyle Libre is a “flash” CGM, however, and to obtain a reading, you manually pass the receiver over the sensor patch. Dexcom and Medtronic CGMs are passive. They automatically deliver continuous blood sugar readings to the receiver.


Your next steps?

You may not need blood sugar monitoring if you have type 2 diabetes and:

  • You have no other health problems or complications.
  • You have a good HA1C level.
  • You’re not on insulin or sulfonylurea drugs.
  • You’re not overweight.

Remember, however, that without personal blood sugar monitoring, you have no way to tell each day whether your medications, diet, or exercise are effectively preventing high or low blood sugar episodes during the day.


Going forward

If your type 2 diabetes and related health issues are not well-managed, data from daily blood sugar testing or a CGM could be very valuable. Talk with your doctor about your treatment goals, health coverage, and other relevant factors.