← Back to the work-schedule question · Front page

CGMA CGM (continuous glucose monitor) is a small sensor worn on the arm that reads glucose every few minutes, day and night, for about two weeks. More at en.wikipedia.org/wiki/Continuous_glucose_monitor · work schedule

Client name: Ruth

Is a more intense work schedule associated with different glucose levels?

Presenting Question

  • Question: “Is a more intense work schedule associated with different glucose levels?”
  • Interpretation of the Question (an attempt to make the question slightly more precise, computable and scientific):
    • “More intense” we are interpreting as more hours a week. You worked 40 (4d × 10hrs), 30 (3d × 10hrs), 24 (3d × 8hrs) hours a week, in that order.
    • “Glucose levels” we are interpreting as three glucose levels for each day you wore the CGMA CGM (continuous glucose monitor) is a small sensor worn on the arm that reads glucose every few minutes, day and night, for about two weeks. More at en.wikipedia.org/wiki/Continuous_glucose_monitor: its Daily Max, Daily Mean and Daily Low, taken together as one family, decided before any result was seen.
    • So: did any of your Daily Max, Daily Mean or Daily Low differ between your 40-, 30- and 24-hour weeks?

Answer to the Presenting Question: Partly

Partly, based on the analysis below, and within its assumptions and limits.

Glucose LevelStatistical Significance1Re-Test2
Daily MaxSignificant: 40 h higher than 24 h, by 25 mg/dLholds (21 mg/dL, vs 24 h)
Daily MeanSignificant: 40 h higher than 30 h, by 10 mg/dL; 40 h higher than 24 h, by 11 mg/dLborderline (about 5 mg/dL, vs 30 h and 24 h)
Daily LowNot significantNot re-tested: nothing to re-test
  1. Statistical significance, corrected across all 9 comparisons. Each pair of your schedules was compared on each glucose level: 3 levels × 3 pairs = 9 comparisons. Each comparison asks how often shuffling your days between two schedules makes a gap as big as the real one. The more comparisons are made, the likelier one looks real by chance alone, so each result is corrected for all 9 (the Holm method), keeping the chance of even one false alarm among them under 5%. “Significant” means it passed that corrected bar.
  2. Re-test, like for like. Your lighter schedules were all recorded through the Libre appThe Libre app is Abbott's phone app that reads a FreeStyle Libre sensor and uploads its readings. In an export it names the software that uploaded a reading, not the sensor that took it. More at freestyle.abbott, but 79 of the 98 days you worked 40 hours through an earlier device, so a difference could come from the device rather than your hours. The re-test compares again using only the 19 days at 40 hours recorded through the Libre appThe Libre app is Abbott's phone app that reads a FreeStyle Libre sensor and uploads its readings. In an export it names the software that uploaded a reading, not the sensor that took it. More at freestyle.abbott (2025), corrected among the re-tests. “Holds”: still significant. “Borderline”: corrected chance between 5% and 10%. Only significant differences from your 40-hour schedule are re-tested.

Do you have a similar question? Join the waitlist.

How does each glucose level compare across your schedules?

100150mg/dL40 hours a week4d × 10hrs · 98 days30 hours a week3d × 10hrs · 15 days24 hours a week3d × 8hrs · 8 daysDaily Max, 40 hours a week: typical day 165 mg/dL (could be 161–168 with a different set of days; 98 days)165Daily Max, 30 hours a week: typical day 152 mg/dL (could be 141–163 with a different set of days; 15 days)152Daily Max, 24 hours a week: typical day 139 mg/dL (could be 127–152 with a different set of days; 8 days)139Daily Mean, 40 hours a week: typical day 107 mg/dL (could be 105–108 with a different set of days; 98 days)107Daily Mean, 30 hours a week: typical day 96 mg/dL (could be 92–100 with a different set of days; 15 days)96Daily Mean, 24 hours a week: typical day 96 mg/dL (could be 93–99 with a different set of days; 8 days)96Daily Low, 40 hours a week: typical day 76 mg/dL (could be 74–79 with a different set of days; 98 days)76Daily Low, 30 hours a week: typical day 68 mg/dL (could be 64–73 with a different set of days; 15 days)68Daily Low, 24 hours a week: typical day 70 mg/dL (could be 64–76 with a different set of days; 8 days)70Daily MaxDaily MeanDaily Low

Each point is the typical day under that schedule; its bar shows how much it might move with a different set of days. Which differences are statistically significant is in the Answer above; each level's own section below shows every day.

Data Source(s) and Date(s)

  • Data sources:
    • Devices: FreeStyle LibreFreeStyle Libre is a line of CGM sensors made by Abbott; the number after the name is the model. More at freestyle.abbott CGMA CGM (continuous glucose monitor) is a small sensor worn on the arm that reads glucose every few minutes, day and night, for about two weeks. More at en.wikipedia.org/wiki/Continuous_glucose_monitor data, exported September 2026. Your readings came first through the FreeStyle LibreFreeStyle Libre is a line of CGM sensors made by Abbott; the number after the name is the model. More at freestyle.abbott 3 and then the Libre appThe Libre app is Abbott's phone app that reads a FreeStyle Libre sensor and uploads its readings. In an export it names the software that uploaded a reading, not the sensor that took it. More at freestyle.abbott.
    • Textual sources: notes on your work hours (September 2026), and your email confirming when your hours changed (October 2026).
  • Dates: 121 days of readings, February 2023 to July 2026, in 8 stretches of wear.
  • People and Organizations Named or Anonymized:
    • Named (in your template names, your notes, or what you told us): None
    • Anonymized (shown by alias, inside your own notes and quotes too): None

What we compared (: “independent variable”)

Your work schedule:

  • 4d × 10hrs: 4 days a week, 10 hours a day (until December 2025)
  • 3d × 10hrs: 3 days a week, 10 hours a day (January to April 2026)
  • 3d × 8hrs: 3 days a week, 8 hours a day (from May 2026)

What we measured (: “dependent variable”)

Your glucose on each day you wore the sensor:

  • lowest reading
  • average reading
  • highest reading

In each chart below, each dot is one day. The black mark is the typical day for that schedule, with a bar showing how much it might move with a different set of days.

Your lowest reading of the day

The lowest reading did not differ significantly between any of the schedules.

40 60 80 100 76 mg/dL 4d × 10hrs (98 days) n = 98 68 mg/dL 3d × 10hrs (15 days) n = 15 70 mg/dL 3d × 8hrs (8 days) n = 8 lowest reading of the day (mg/dL)
ComparisonDifferenceSignificant?
4d × 10hrs vs 3d × 10hrs8 mg/dL higherNo (about 1 in 7 by chance)
4d × 10hrs vs 3d × 8hrs6 mg/dL higherNo (often, by chance alone)
3d × 8hrs vs 3d × 10hrs2 mg/dL higherNo (often, by chance alone)

Your average reading of the day

The average reading under 4d × 10hrs was significantly higher than under the other schedules.

80 100 120 107 mg/dL 4d × 10hrs (98 days) n = 98 96 mg/dL 3d × 10hrs (15 days) n = 15 96 mg/dL 3d × 8hrs (8 days) n = 8 average reading of the day (mg/dL)
ComparisonDifferenceSignificant?
4d × 10hrs vs 3d × 10hrs10 mg/dL higherYes (about 1 in 1,000 by chance)
4d × 10hrs vs 3d × 8hrs11 mg/dL higherYes (about 1 in 1,000 by chance)
3d × 10hrs vs 3d × 8hrsno differenceNo (often, by chance alone)

Your highest reading of the day

The highest reading under 4d × 10hrs was significantly higher than under 3d × 8hrs.

100 150 200 165 mg/dL 4d × 10hrs (98 days) n = 98 152 mg/dL 3d × 10hrs (15 days) n = 15 139 mg/dL 3d × 8hrs (8 days) n = 8 highest reading of the day (mg/dL)
ComparisonDifferenceSignificant?
4d × 10hrs vs 3d × 10hrs12 mg/dL higherNo (about 1 in 7 by chance)
4d × 10hrs vs 3d × 8hrs25 mg/dL higherYes (about 1 in 140 by chance)
3d × 10hrs vs 3d × 8hrs13 mg/dL higherNo (often, by chance alone)

Caveats

  • Few days: 15 days of 3d × 10hrs and 8 days of 3d × 8hrs, each from a single stretch of wear. More days, spread over more weeks, would make this firmer.
  • Other things changed too: the lighter schedules were all in 2026, measured through a newer app.
  • The drop may have started earlier: in 2025, still on 4d × 10hrs, your daily average was already down to 101, from 108 before.
  • Season looks unlikely to explain it: on 4d × 10hrs, your daily average was 109 in winter and 107 in summer.
  • The odds above are a little too confident: they treat every day as separate, but days in the same two-week stretch tend to run alike. Compared with just your 2025 wear (same app, still 4d × 10hrs), the lower daily high under 3d × 8hrs still holds up, by 21 mg/dL, but the gap in your daily average under both lighter schedules shrinks to about 5 mg/dL and is borderline.

Your glucose over time

The biggest step down in your daily average comes between July 2024 and May 2025: 107 to 101 mg/dL, and your daily low with it, 84 to 68. That is where your readings start coming through the Libre appThe Libre app is Abbott's phone app that reads a FreeStyle Libre sensor and uploads its readings. In an export it names the software that uploaded a reading, not the sensor that took it. More at freestyle.abbott, while you were still working 40 hours a week. Your hours were cut after that, and your average went 101 at 40 hours, then 96 at 30 hours, then 96 at 24 hours. This chart cannot say whether the newer setup reads lower or something else changed then: both happened at once.

100200glucose (mg/dL)Feb ’23109Feb ’23 stretch, day 1: low 85, average 115, high 173Feb ’23 stretch, day 2: low 58, average 106, high 139Feb ’23 stretch, day 3: low 58, average 106, high 186Feb ’23 stretch, day 4: low 76, average 105, high 170Feb ’23 stretch, day 5: low 59, average 104, high 235Feb ’23 stretch, day 6: low 67, average 108, high 162Feb ’23 stretch, day 7: low 75, average 109, high 191Feb ’23 stretch, day 8: low 68, average 115, high 183Feb ’23 stretch, day 9: low 68, average 110, high 165Feb ’23 stretch, day 10: low 73, average 109, high 174Feb ’23 stretch, day 11: low 84, average 109, high 177Feb ’23 stretch, day 12: low 79, average 112, high 198Feb ’23 stretch, day 13: low 84, average 111, high 182Feb ’23 stretch, day 14: low 85, average 114, high 18420 dMar ’23106Mar ’23 stretch, day 1: low 62, average 114, high 196Mar ’23 stretch, day 2: low 76, average 108, high 148Mar ’23 stretch, day 3: low 69, average 104, high 137Mar ’23 stretch, day 4: low 66, average 102, high 147Mar ’23 stretch, day 5: low 75, average 109, high 213Mar ’23 stretch, day 6: low 70, average 101, high 152Mar ’23 stretch, day 7: low 83, average 105, high 138Mar ’23 stretch, day 8: low 66, average 100, high 156Mar ’23 stretch, day 9: low 80, average 103, high 146Mar ’23 stretch, day 10: low 80, average 107, high 155Mar ’23 stretch, day 11: low 80, average 110, high 151Mar ’23 stretch, day 12: low 94, average 110, high 181Mar ’23 stretch, day 13: low 83, average 113, high 165Mar ’23 stretch, day 14: low 86, average 100, high 1299 moJan ’24109Jan ’24 stretch, day 1: low 69, average 104, high 153Jan ’24 stretch, day 2: low 72, average 103, high 166Jan ’24 stretch, day 3: low 72, average 109, high 205Jan ’24 stretch, day 4: low 68, average 99, high 146Jan ’24 stretch, day 5: low 45, average 104, high 142Jan ’24 stretch, day 6: low 85, average 107, high 156Jan ’24 stretch, day 7: low 87, average 107, high 154Jan ’24 stretch, day 8: low 76, average 107, high 176Jan ’24 stretch, day 9: low 82, average 110, high 163Jan ’24 stretch, day 10: low 90, average 111, high 170Jan ’24 stretch, day 11: low 82, average 112, high 171Jan ’24 stretch, day 12: low 92, average 114, high 157Jan ’24 stretch, day 13: low 94, average 120, high 182Jan ’24 stretch, day 14: low 99, average 121, high 1834 moJun ’24108Jun ’24 stretch, day 1: low 86, average 118, high 166Jun ’24 stretch, day 2: low 76, average 114, high 159Jun ’24 stretch, day 3: low 99, average 120, high 179Jun ’24 stretch, day 4: low 85, average 108, high 159Jun ’24 stretch, day 5: low 80, average 105, high 159Jun ’24 stretch, day 6: low 77, average 97, high 138Jun ’24 stretch, day 7: low 82, average 105, high 150Jun ’24 stretch, day 8: low 57, average 93, high 181Jun ’24 stretch, day 9: low 51, average 77, high 129Jun ’24 stretch, day 10: low 97, average 116, high 156Jun ’24 stretch, day 11: low 53, average 108, high 173Jun ’24 stretch, day 12: low 65, average 106, high 178Jun ’24 stretch, day 13: low 83, average 109, high 154Jun ’24 stretch, day 14: low 83, average 120, high 219Jun ’24 stretch, day 15: low 82, average 113, high 158Jun ’24 stretch, day 16: low 78, average 107, high 173Jun ’24 stretch, day 17: low 76, average 105, high 171Jun ’24 stretch, day 18: low 84, average 108, high 163Jun ’24 stretch, day 19: low 83, average 107, high 145Jun ’24 stretch, day 20: low 71, average 106, high 142Jun ’24 stretch, day 21: low 78, average 111, high 190Jun ’24 stretch, day 22: low 89, average 109, high 159Jun ’24 stretch, day 23: low 79, average 114, high 1742 dJul ’24107Jul ’24 stretch, day 1: low 83, average 111, high 170Jul ’24 stretch, day 2: low 65, average 106, high 159Jul ’24 stretch, day 3: low 84, average 98, high 143Jul ’24 stretch, day 4: low 77, average 97, high 143Jul ’24 stretch, day 5: low 82, average 104, high 167Jul ’24 stretch, day 6: low 83, average 107, high 145Jul ’24 stretch, day 7: low 79, average 111, high 181Jul ’24 stretch, day 8: low 89, average 108, high 149Jul ’24 stretch, day 9: low 92, average 111, high 163Jul ’24 stretch, day 10: low 91, average 109, high 167Jul ’24 stretch, day 11: low 85, average 104, high 148Jul ’24 stretch, day 12: low 88, average 110, high 176Jul ’24 stretch, day 13: low 91, average 110, high 149Jul ’24 stretch, day 14: low 81, average 110, high 1909 moreadings via Libre appMay ’25101May ’25 stretch, day 1: low 58, average 104, high 171May ’25 stretch, day 2: low 70, average 98, high 138May ’25 stretch, day 3: low 40, average 92, high 165May ’25 stretch, day 4: low 49, average 91, high 156May ’25 stretch, day 5: low 55, average 91, high 152May ’25 stretch, day 6: low 50, average 94, high 152May ’25 stretch, day 7: low 63, average 91, high 145May ’25 stretch, day 8: low 68, average 99, high 155May ’25 stretch, day 9: low 77, average 107, high 178May ’25 stretch, day 10: low 81, average 102, high 166May ’25 stretch, day 11: low 84, average 106, high 163May ’25 stretch, day 12: low 62, average 107, high 169May ’25 stretch, day 13: low 64, average 102, high 168May ’25 stretch, day 14: low 82, average 107, high 164May ’25 stretch, day 15: low 92, average 109, high 157May ’25 stretch, day 16: low 69, average 108, high 174May ’25 stretch, day 17: low 67, average 106, high 159May ’25 stretch, day 18: low 84, average 105, high 158May ’25 stretch, day 19: low 80, average 107, high 15310 mo30 h a weekApr ’2696Apr ’26 stretch, day 1: low 68, average 95, high 129Apr ’26 stretch, day 2: low 56, average 88, high 127Apr ’26 stretch, day 3: low 46, average 78, high 122Apr ’26 stretch, day 4: low 60, average 89, high 135Apr ’26 stretch, day 5: low 70, average 92, high 157Apr ’26 stretch, day 6: low 73, average 97, high 171Apr ’26 stretch, day 7: low 76, average 96, high 144Apr ’26 stretch, day 8: low 70, average 98, high 174Apr ’26 stretch, day 9: low 72, average 102, high 201Apr ’26 stretch, day 10: low 70, average 92, high 139Apr ’26 stretch, day 11: low 64, average 105, high 180Apr ’26 stretch, day 12: low 70, average 100, high 144Apr ’26 stretch, day 13: low 66, average 105, high 161Apr ’26 stretch, day 14: low 84, average 101, high 160Apr ’26 stretch, day 15: low 82, average 109, high 1392 mo24 h a weekJul ’2696Jul ’26 stretch, day 1: low 69, average 97, high 135Jul ’26 stretch, day 2: low 70, average 99, high 172Jul ’26 stretch, day 3: low 68, average 90, high 138Jul ’26 stretch, day 4: low 53, average 91, high 127Jul ’26 stretch, day 5: low 69, average 100, high 147Jul ’26 stretch, day 6: low 75, average 102, high 143Jul ’26 stretch, day 7: low 81, average 98, high 146Jul ’26 stretch, day 8: low 79, average 93, high 107avghighaveragelow

One line each for your highest, average and lowest reading of every day you wore the sensor. Each stretch of wear is drawn as wide as its number of days; the gaps between them are not to scale, and their real length is printed in each one. The number under each stretch is its average. Hover a day for its values.

Related Pages

What would you like to know next? →

All the numbers on this page
ScheduleDays Typical lowestTypical averageTypical highest
4d × 10hrs9876107165
3d × 10hrs156896152
3d × 8hrs87096139

How sure: each gap was tested by shuffling the days between the two schedules 10,000 times and counting how often chance alone made a gap as big. That share is the p-value. Nine comparisons were made, so each p-value is also shown corrected for that (Holm); "significant" means corrected p under 0.05.

ReadingComparison Gap mg/dLpcorrected p
lowest3d × 10hrs vs 4d × 10hrs-80.0230.137
lowest3d × 8hrs vs 4d × 10hrs-60.2050.737
lowest3d × 8hrs vs 3d × 10hrs+20.6251.000
average3d × 10hrs vs 4d × 10hrs-100.0000.000
average3d × 8hrs vs 4d × 10hrs-110.0000.001
average3d × 8hrs vs 3d × 10hrs-00.9591.000
highest3d × 10hrs vs 4d × 10hrs-120.0230.137
highest3d × 8hrs vs 4d × 10hrs-250.0010.007
highest3d × 8hrs vs 3d × 10hrs-130.1840.737

If you have a health-related question about your own data, join the waitlist for your own custom analysis.

Act soon: it is free while we stand this service up and refine it. All we ask in return is permission to publish a results page like the ones we have made for our other clients. We never publish your surname or your date of birth. The page shows a first name or a pseudonym, whichever you prefer, and your age in years and your sex.

Made by PerSci from your CGMA CGM (continuous glucose monitor) is a small sensor worn on the arm that reads glucose every few minutes, day and night, for about two weeks. More at en.wikipedia.org/wiki/Continuous_glucose_monitor export. It describes a pattern in your readings; it is not medical advice.