Trend Arrows

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The FreeStyle Libre sensor collects glucose data every minute and automatically stores a reading every 15 minutes. When scanned with the reader or FreeStyle LibreLink app, it provides the user with:

• Current sensor glucose reading,
• A graph of stored glucose readings.
• It also typically displays a glucose Trend Arrow pointing to where glucose levels are heading.1

Depending on the direction of change, you can use the Trend Arrow alongside your current glucose reading to make an informed decision as to whether to take any corrective action.

 
HOW MIGHT TREND ARROWS HELP?

Treatment decisions based on trend arrows may include1:

Adjusting insulin dose

(more than 2 mg/dL per minute)

Eating a snack

(between 1 and 2 mg/dL per minute)

Using fast-acting carbohydrates

(less than 1 mg/dL per minute)

“Watch and wait”
scanning to monitor changes

(less than 1 mg/dL per minute)

 
CALCULATING PROJECTED GLUCOSE

Each Trend Arrow indicates a rate of change of glucose in mg/dL and the speed at which the glucose is either rising or falling, which means you can roughly estimate where they are going to be.

Glucose reading is 117 mg/dL and an upward Trend Arrow [...] is displayed

Lower rate of change:
1 mg/dL x 15 minutes = 15 mg/dL

Higher rate of change:
2 mg/dL x 15 minutes = 30 mg/dL

In this example, the glucose is RISING (with an upward [...] trend arrow), therefore you could ADD those figures onto your current reading to give an estimate of the glucose range you will be in the next 15 minutes:

Current glucose reading + rate of change = estimated glucose in 15 minutes:

Lower rate of change:
117 mg/dL + 15 mg/dL = 132 mg/dL

Higher rate of change:
117 mg/dL + 30 mg/dL = 147 mg/dL

In this example, the estimated glucose in 15 minutes will be between 132 mg/dL and 147 mg/dL.

The same theory can be applied to calculate falling glucose too. In the example above, if the glucose had been FALLING in a downward direction (with a [...] trend arrow), you would SUBTRACT those figures from the current reading of 117 mg/dL to estimate the glucose range in the next 15 minutes.

Understanding Reports and Data

LEARN MORE ABOUT THE FREESTYLE LIBRE SYSTEM

WHY FREESTYLE LIBRE?

GETTING STARTED WITH FREESTYLE LIBRE

UNDERSTANDING REPORTS AND DATA

Want to know more?

Get the answers you're looking for!

1. Ajjan et al Optimising Rate-of -Change Trend Arrows for Insulin Dosing Decisions Using the FreeStyle Libre Flash Glucose Monitoring System Diabetes & Vascular Disease Research 2018 1-10.

– Images are for illustrative purposes only. Not real patient or Health Care Professional.

– Simulated data for illustrative purposes only. Not real patient or data.

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