Glucose Measurement

Ascencia’s Contour® Next Gen may be the most accurate over-the-counter product for measuring capillary blood glucose. The company cites “an error margin of only ± 5.3%.” The study, published in a peer-reviewed journal, described two laboratory-quality comparators: a Roche COBAS and a YSI 2300.

Measurement accuracy is essential when making therapy decisions. The HbA1c measurement is superior for diagnosing pre-diabetes and Type 2 diabetes. According to the Mayo Clinic, fasting glucose values less than 100 mg/dL (5.6 mmol/L) are Normal. Fasting glucose of 100-125 mg/dL (5.6—6.9 mmol/L) is the range for pre-diabetes. Fasting glucose of 126 mg/dL (7.0 mmol/L) is the threshold for diagnosing Type 2 diabetes. At the edges of the reference ranges, measurement accuracy is useful. People making lifestyle choices to transition from a diagnosis of Type 2 diabetes to pre-diabetes may leverage measurement accuracy.

Glucose Monitoring

The FDA established a regulation for continuous glucose monitors (CGM) for therapy decisions without requiring an adjunctive capillary glucose measurement: 21 CFR 862.1355 Integrated continuous glucose monitoring system (iCGM). Special controls define performance standards for iCGMs. Sponsors: Abbott, Dexcom, and Ascencia market iCGMs.

The FDA warned: “Do Not Use Smartwatches or Smart Rings to Measure Blood Glucose Levels: FDA Safety Communication” – FDA, February 21, 2024.

Pure Research

Research in statistically predicting (guessing) glucose using multivariate noninvasive data is ongoing within several venture-funded adventures. Some stories target wellness applications, evading the high bar of accuracy. Among the noninvasive sponsors, promises of pending submissions are popular. Such research has been underway for decades. None of the efforts have achieved FDA clearance as a medical device. Electrochemistry continues to reign as the state-of-the-art method in glucose measurement and monitoring.