CGM Reports: Understanding Your Data

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Pattern Recognition with CGM: Senior’s Guide

This article provides general information about CGM reports and data interpretation. Always consult your healthcare provider for personalized medical advice.

About the Author: This article was written by Susie Adriance, founder of Senior CGM Support. With years of experience helping seniors navigate Medicare CGM coverage and diabetes management, Susie combines practical caregiving knowledge with evidence-based health information to support older adults in managing their diabetes effectively.

Understanding your CGM reports and data doesn’t have to be overwhelming. As more Medicare seniors embrace continuous glucose monitoring (CGM) technology, making sense of all those numbers and graphs is becoming an essential skill. Let’s break down CGM reports understanding data into simple, manageable steps that will help you take control of your diabetes management.

What Are CGM Reports?

Think of CGM reports as your diabetes diary, automatically recorded by your device. These reports show patterns in your blood sugar levels throughout the day and night, helping you and your doctor make better decisions about your care.

Your CGM collects data every 5 minutes, creating up to 288 readings per day. That’s much more information than you’d get from finger sticks alone!

Why Reports Matter

Traditional Method:

  • 4-6 finger sticks daily
  • Snapshot moments only
  • Miss overnight patterns
  • Limited trend data

CGM Reports Show:

  • Complete 24-hour picture
  • Trends and patterns
  • Overnight activity
  • Real-time changes

Basic CGM Reports You’ll See

Let’s look at the most common reports you’ll encounter:

1. Daily Overview

  • Shows your glucose levels throughout a single day
  • Looks like a line graph with times along the bottom
  • Highlights when you’re in, above, or below your target range

💡 Tip: Start by looking at just one day at a time until you’re comfortable reading the graphs. Many seniors find it helpful to review their daily report each morning with breakfast.

What to Look For:

  • Morning rise patterns
  • Meal responses
  • Overnight stability
  • Exercise effects

2. Weekly Patterns

  • Combines several days to show regular patterns
  • Helps identify times when your glucose typically goes high or low
  • Often color-coded for easier understanding

Pattern Recognition:

  • Same time daily spikes
  • Weekend vs. weekday differences
  • Medication timing effects
  • Activity impact

3. AGP (Ambulatory Glucose Profile)

The AGP is your most important report – it’s what doctors love to see!

Understanding AGP:

  • Shows your “typical” day
  • Dark line = median glucose
  • Shaded areas = variability
  • Easy pattern spotting

Making Sense of CGM Reports and Understanding Data

Let’s break down what you’re looking at:

Target Range (The Green Zone)

This is your ideal glucose range, usually shown in green. Most CGMs set this between 70-180 mg/dL, but your doctor might customize this for you.

Understanding Your Zones:

  • Green (70-180): Target range
  • Yellow (181-250): High glucose
  • Red (>250): Very high
  • Red (<70): Low glucose

Time in Range

This percentage shows how long your glucose stays in your target range. Think of it like a report card – many doctors aim for 70% or more time in range.

Time in Range Goals:

  • Excellent: 70% or more
  • Good: 50-70%
  • Needs work: Below 50%

Don’t worry about perfection! Even a 5% improvement in your Time in Range can make a difference in how you feel.

Understanding the Numbers

Average Glucose:

  • Your typical blood sugar
  • Compare to A1C
  • Track monthly changes
  • Celebrate improvements

Standard Deviation:

  • How much levels vary
  • Lower = more stable
  • Higher = roller coaster
  • Aim for under 50

GMI (Glucose Management Indicator):

  • Estimated A1C
  • Based on CGM data
  • Updated every 2 weeks
  • Trends matter most

Reading Different Report Types

Line Graphs

How to Read:

  1. Time runs left to right
  2. Glucose levels go up and down
  3. Colors show ranges
  4. Dots mark events

What They Show:

  • Real-time changes
  • Rate of change
  • Pattern development
  • Cause and effect

Bar Charts

Common Uses:

  • Time in each range
  • Daily comparisons
  • Weekly summaries
  • Monthly trends

Reading Tips:

  • Taller = more time
  • Green = good
  • Compare side by side
  • Note improvements

Pie Charts

Shows Percentages:

  • Time in range
  • Time high
  • Time low
  • At a glance view

Quick Assessment:

  • Mostly green = good
  • Too much red = concern
  • Balance is key
  • Easy to understand

Common Questions About CGM Reports

Q: How often should I look at my reports?

Start with a quick daily review and a longer weekly review. Many seniors check their daily report at breakfast and their weekly report every Sunday.

Suggested Schedule:

  • Daily: 5 minutes at breakfast
  • Weekly: 15 minutes Sunday morning
  • Monthly: Share with doctor
  • Quarterly: Deep dive review

Q: What should I do if I see lots of high or low readings?

First, don’t panic. Make notes about what you were doing during those times (eating, exercising, sleeping) and share this information with your healthcare team.

Action Steps:

  1. Note the time patterns
  2. Check for common causes
  3. Document activities
  4. Contact healthcare provider
  5. Adjust as directed

Ask a family member or grandchild to help you set up your CGM app to send automatic reports to your doctor.

Understanding Patterns

Morning Patterns

Dawn Phenomenon:

  • Early morning rise (4-8 AM)
  • Natural hormone release
  • Common in many people
  • May need adjustment

Feet on Floor:

  • Rise when getting up
  • Stress hormone response
  • Usually temporary
  • Monitor trends

Meal Patterns

What to Watch:

  • Pre-meal baseline
  • Peak after eating (1-2 hours)
  • Return to baseline (3-4 hours)
  • Different food effects

Identifying Issues:

  • Spike too high = portion/type
  • Slow return = timing
  • Never returns = basal issue
  • Drops low = too much medication

Exercise Patterns

During Activity:

  • Initial rise possible
  • Gradual decrease common
  • Type matters
  • Duration affects

After Exercise:

  • Continued drop possible
  • May last 24 hours
  • Plan snacks
  • Adjust medications

Sleep Patterns

Overnight Goals:

  • Stable line
  • Minimal variation
  • No severe lows
  • Gradual changes only

Red Flags:

  • Multiple lows
  • Roller coaster pattern
  • Consistent highs
  • Poor sleep correlation

Tips for Success with CGM Data

  • Keep a simple food and activity log to match with your reports
  • Use the larger text settings if available on your device
  • Share reports with family members who help with your care
  • Ask your doctor which patterns they want you to watch for

Creating Your Review Routine

Morning Review (5 minutes):

  1. Check overnight patterns
  2. Note morning glucose
  3. Plan day based on trends
  4. Celebrate successes

Weekly Review (15 minutes):

  1. Look for repeat patterns
  2. Compare to last week
  3. Note improvements
  4. List questions for doctor

Monthly Review (30 minutes):

  1. Download full report
  2. Review with family
  3. Prepare for doctor visit
  4. Set new goals

Using Reports with Your Healthcare Team

Before Your Appointment

Prepare These Reports:

  • AGP (most important)
  • Daily overlay
  • Weekly summary
  • Logbook notes

Highlight Concerns:

  • Circle problem times
  • Note questions
  • Mark improvements
  • Bring medication list

During Your Visit

Discuss:

  • Time in range progress
  • Pattern concerns
  • Medication timing
  • Lifestyle impacts

Ask About:

  • Target adjustments
  • Medication changes
  • Pattern explanations
  • Next steps

After Your Visit

Follow Up:

  • Implement changes
  • Track results
  • Note improvements
  • Schedule next review

Technology Tips

Making Reports Easier to Read

On Your Phone:

  • Rotate to landscape
  • Zoom in on graphs
  • Screenshot important ones
  • Increase brightness

On Computer:

  • Use larger monitor
  • Print key reports
  • Zoom browser to 150%
  • Save as PDFs

Sharing Your Data

With Family:

  • Set up follower apps
  • Email reports
  • Text screenshots
  • Regular updates

With Doctors:

  • Auto-share if available
  • Email before visits
  • Bring printed copies
  • Use patient portals

Common Report Misunderstandings

“My Line Should Be Straight”

Reality:

  • Some variation is normal
  • Food causes rises
  • Activity causes changes
  • Perfection isn’t the goal

“Red Always Means Bad”

Context Matters:

  • Brief highs after meals = normal
  • Persistent highs = concern
  • Exercise lows = expected
  • Random lows = investigate

“I Failed If Not 100% in Range”

Truth:

  • 70% is excellent
  • 50% is good progress
  • Any improvement matters
  • Trends beat perfection

Advanced Features

Predictive Alerts

What They Show:

  • Where glucose is heading
  • Potential highs/lows
  • Time to act
  • Prevention opportunities

Pattern Insights

Automatic Detection:

  • Repeated patterns
  • Weekly trends
  • Problem times
  • Success patterns

Comparison Tools

Compare:

  • Week to week
  • Month to month
  • Before/after changes
  • Medication effects

Creating Action Plans from Reports

For Consistent Highs

If Reports Show High Patterns:

  1. Note timing
  2. Check food diary
  3. Review medications
  4. Discuss with doctor
  5. Make one change at a time

For Frequent Lows

Low Pattern Response:

  1. Identify triggers
  2. Adjust meal timing
  3. Review medication doses
  4. Carry glucose always
  5. Share with family

For High Variability

Stabilization Steps:

  1. Consistent meal times
  2. Similar food choices
  3. Regular activity
  4. Stress management
  5. Sleep hygiene

Success Stories

Margaret, 73: “Once I learned to read the weekly overlay, I spotted my afternoon highs. A simple snack adjustment fixed it!”

Robert, 69: “The AGP report helped my doctor see I needed less dinner insulin. My overnight graphs are so much better now.”

Helen, 71: “I print my favorite report each week and highlight the good days. It keeps me motivated!”

Resources and Support

Free Help Available

Manufacturer Support:

  • Report tutorials
  • Phone assistance
  • Online classes
  • Local workshops

Medicare Resources:

  • Diabetes education
  • Technology training
  • Coverage information
  • Support groups

Medicare covers CGM supplies and equipment for qualifying beneficiaries. Contact us at 727-831-3729 to learn about your coverage options.

Your Report Review Checklist

Daily: â–¡

  • Check time in range
  • Note unusual patterns
  • Celebrate successes
  • Plan tomorrow

Weekly: â–¡

  • Review overlay report
  • Spot repeat patterns
  • Compare to goals
  • Adjust if needed

Monthly: â–¡

  • Download all reports
  • Review with support
  • Share with doctor
  • Set new goals

The Bottom Line

Remember, understanding your CGM reports is a journey, not a race. Take it one step at a time, and don’t hesitate to ask for help when you need it.

Your CGM collects valuable information about your diabetes. Learning to read and understand these reports empowers you to make better decisions about your health. Start simple, be patient with yourself, and celebrate every insight you gain.

The most important thing? You’re already taking a huge step by wanting to understand your data. That’s something to be proud of!

Last updated: January 2025

 

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