Glucose Variability Assessed with Continuous Glucose Monitoring: Reliability, Reference Values, and Correlations with...

Area of Science:

• Endocrinology
• Metabolic Health
• Diabetes Management

Background:

• Glucose variability (GV) is a key glycemic control marker, but its measurement needs methodological refinement.
• Continuous glucose monitoring (CGM) offers insights into GV, yet optimal assessment duration and reference values require clarification.

Purpose of the Study:

• To determine the minimum number of monitoring days for reliable GV assessment using CGM.
• To establish reference values for CGM-derived GV indices.
• To correlate GV metrics with established glycemic control indicators like HbA1c and oral glucose tolerance test (OGTT) results.

Main Methods:

• Analysis of cross-sectional data from The Maastricht Study (n=851) with over 48 hours of CGM data.
• Calculation of reliability using the Spearman-Brown prophecy formula.
• Determination of reference ranges (2.5th-97.5th percentiles) and correlations (Spearman's rho) for CGM indices (mean sensor glucose, standard deviation, coefficient of variation).

Main Results:

• Reliable GV measurement was achieved with two monitoring days for mean sensor glucose (MSG) and standard deviation (SD), and three days for coefficient of variation (CV).
• Reference ranges in individuals with normal glucose metabolism were established: MSG (90.5-120.6 mg/dL), SD (7.9-24.8 mg/dL), and CV (7.74%-22.45%).
• MSG correlated strongest with fasting plasma glucose; SD and CV showed significant correlations with 1-hour OGTT values and incremental glucose peak (IGP).

Conclusions:

• The findings provide essential reliability data and reference values for CGM-based GV studies.
• One-hour OGTT and IGP values serve as viable surrogate markers for GV when CGM data is inaccessible.