Continuous glucose monitoring and 1-h plasma glucose identifies glycemic variability and dysglycemia in high-risk individuals with HbA1c < 5.7%: a pilot study

Excerpt

The global incidence and prevalence of diabetes continue to rise [1]. Hence, identifying individuals at high risk for prediabetes and type 2 diabetes (T2D) is paramount. As glucose levels increase insidiously in the progression from normal glucose tolerance to prediabetes and T2D, early identification of high-risk individuals could result in the prescription of lifestyle interventions to decrease progression to T2D. HbA1c is widely used to screen for prediabetes (5.7–6.4% [39–46 mmol/mol]) and T2D (≥6.5% [48 mmol/mol]) [2]. However, HbA1c has poor sensitivity in identifying early pancreatic β-cell dysfunction [3]. Individuals with prediabetes, already on the accelerated slope of the glucose trajectory, are diagnosed too late in the progression to T2D when significant β-cell dysfunction has already occurred. Increased 1-hour plasma glucose (1-h PG) ≥ 155 mg/dL (8.6 mmol/L) during a 75-g oral glucose tolerance test (OGTT) is more predictive than HbA1c or 2-h PG for future development of diabetes, complications, and mortality [4‐6]. However, measurement of the 1-h PG during the OGTT requires fasting. In addition, plasma glucose (PG) levels can become unstable if specimens are not properly handled [7]. A potential alternative approach for detecting early pancreatic β-cell dysfunction is implementation of continuous glucose monitoring (CGM) during an OGTT. CGM can identify increased glycemic variability (GV), an index of glucose fluctuation, in patients with T2D [8]. However, it is unclear if CGM can detect GV in high-risk subjects without diabetes or with HbA1c < 5.7% (39 mmol/mol). …