The Association for Diagnostics and Laboratory Medicine (previously the AACC)—in collaboration with the American Diabetes Association (ADA)—released evidence-based guidelines to help diagnose and manage patients with diabetes using the latest laboratory-analysis tools. 

The new guidelines replace previous versions published in 2002 and 2011. The  document features extensive updates on continuous glucose monitoring and more precise recommendations for measuring glucose and hemoglobin A1c, a marker of average blood glucose. Written by a cross-disciplinary team of medical experts, the guidelines provide specific, actionable advice that will enhance collaboration among healthcare professionals and improve care for millions of people.   

Diabetes affects approximately 37.3 million people in the United States and 537 million worldwide. It is a disorder in which glucose (or sugar) from food builds up in the blood because insulin—a hormone produced by the pancreas that signals the body to metabolize glucose—is underproduced or underutilized. Diabetes increases people’s risk of heart attacks, stroke, vision loss, kidney disease, and other conditions. These new guidelines are based on a thorough assessment of the quality and strength of research on state-of-the-art diabetes lab tests.

Continuous Glucose Monitoring Recommendations

Among the most significant additions to the 2023 document is its detailed recommendations around continuous glucose monitoring (CGM). In this technology, a device measures patients’ blood glucose every 5-15 minutes. 

“The field has really advanced dramatically,” says David Sacks, MD, the guidelines’ primary author. “The goal is to develop what people have termed the artificial pancreas,” he said, “where basically you have a sensor under your skin that measures your glucose every few minutes—and that information is fed to your computer or phone.” A pump is then used to automatically deliver insulin when people need it most.   

The expert team strongly recommends using real-time CGM in conjunction with insulin as a tool in certain teens and adults with type 1 diabetes—a form of the disease in which the body doesn’t produce insulin. 

This recommendation applies to patients with type 1 diabetes who are not meeting their blood sugar (glycemic) targets, are unaware of when their blood sugar is low, and/or are prone to low blood sugar. CGM is not used frequently for patients with type 2 diabetes, the more common form of diabetes in which the body doesn’t use insulin well. However, the guidelines suggest that providers consider CGM for type 2 patients using insulin and not meeting glycemic targets.

Additional Diabetes Diagnostics Updates

The new document also recommends that healthcare workers use blood-collection tubes that contain a citrate buffer to minimize the breakdown of glucose after blood samples are taken. This is important because such glucose breakdown compromises the accuracy of measurements. 

“We’re trying to encourage manufacturers of blood-collection tubes to make these available in the U.S.,” says Sacks. When the tubes aren’t an option, the team recommends an alternate technique that uses an ice-water bath and other steps.

“We’ve also recommended improving the accuracy of both glucose and hemoglobin A1c measurements and have come up with tighter analytic (measurement) criteria … again to improve patient care,” said Sacks. The guidelines state that fasting glucose values of more than 7.0 mmol/L (>126 mg/dL), and hemoglobin A1c measures of at least 6.5% (>48 mmol/mol), should be considered diagnostic of diabetes.

In addition, the team provides new guidance for standardizing measurements of insulin and C-peptide, a marker that helps distinguish between type 1 and type 2 diabetes. Further updates cover autoimmune and genetic markers for type 1 diabetes, including a promising analysis of gene mutations that can detect rare forms of neonatal diabetes.

The new guidelines are intended to help the full healthcare team make the best possible clinical decisions. This requires cultivating a sophisticated understanding of lab tests’ strengths and limitations. 

“It’s important to measure accurately—but it’s also very important to communicate the relevance to clinicians and to listen to them and share information,” says Sacks. “Patient care is a team effort.”