Normal glucose levels in non-diabetic people
Normal glucose levels are between 3.5 and 7.0mmol/L. Typically, glucose levels are between 3.0 and 5.5mmol/L on waking, and range between 3.5 – 6.7mmol/L during the day. They can rise up to a peak of 7.8mmol/L after eating a serve of carbohydrate, but glucose levels return to normal range within 2 hours.
How to test the glucose level
First, set things up:
Method: How to test your glucose
When to check the glucose levels
Checking the glucose levels will give and your patient valuable information about how food affects their glucose levels and whether the medications are working.
If your patient is on tablets only, then glucose strips are not subsidized via the NDSS. Your patient is welcome to buy the strips, but these are expensive.
If your patient is not monitoring their glucose levels, use the 3-monthly HbA1c values to judge whether their glucose control is adequate and whether the medications need to change.
Your patient is not subsidized to receive glucose strips and doesn’t plan to check glucose levels
Your patient wants to learn about how food affects the glucose levels
Your patient wants to understand your diabetes, but is reluctant to check glucose levels frequently
Your patient will follow your instructions
Your patient is not likely to monitor glucose levels very often
Your patient is just starting insulin
You are concerned that your patient may be experiencing hypoglycemic episodes (Eg. night sweats, chest pain or night mares)
How to interpret the glucose levels
When you check glucose levels, you are testing how well the available insulin levels match the carbohydrate that is eaten and how much glucose the liver is making.
To better understand this, it is good to remember the physiological insulin profile:
Normally, the pancreas secretes a background rate of insulin all day long.
When food is eaten, it secretes a quick surge of insulin that is matched to the amount of carbohydrate and protein that was contained in that meal:
In people with type 2 diabetes, the insulin resistance requires much higher rates of insulin secretion to maintain normal glucose levels. If there is a mismatch between the insulin required, and actual amount of insulin secreted, the glucose levels rise. The greater the mismatch, the higher the glucose level.
The pre-meal glucose levels reflect how much glucose the liver is making during fasting and in between meals (hepatic gluconeogenesis). Normally, insulin controls this tightly, but if insulin is deficient, the glucose level will be high before meals. How can this be controlled? Insulin-sensitizing medications do, and any of the lifestyle strategies will help.
The glucose levels after a meal reflects how well the endogenous insulin response matched the food that was just eaten. If the insulin response was sufficient, the glucose level will be similar to the one checked before the meal. High post-meal glucose levels indicate that there is insufficient insulin to meet the required dose for the carbohydrate and, to a lesser extent, the protein in that meal.
High post-meal glucose levels are seen in people with diabetes in response to: