Objective: Glycemic variability (GV) and 1 hour plasma glucose (1-h PG) ≥ 8.6 mmol/L during a 75-gram oral glucose tolerance test (OGTT) are associated with increased risk for type 2 diabetes (T2D). GV may be overlooked in high-risk individuals. The objectives of this study are: (1) to determine if continuous glucose monitoring (CGM) using the Abbott Freestyle Libre Pro can replace the OGTT in high-risk subjects with HbA1c < 5.7%; and (2) to determine if GV indices correlate with the OGTT-derived 1-h PG ≥ 8.6 mmol/L.
Methods: Subjects were recruited with a HbA1c < 5.7% and at least one other risk factor including: overweight or obesity, PCOS, fatty liver, hypertension, family history of T2D, or history of gestational diabetes. The CGM, placed days prior to the OGTT, was worn up to 14 days. Anthropometric and vital signs were measured. HbA1c, fasting, 1-h and 2-h PG levels during an OGTT were obtained.
Results: The 1-h PG correlated significantly with CGM glucose levels (r=0.883, p<0.001) and GV indices: mean amplitude of glucose excursions (MAGE) (r=0.665,p=0.006), lability index (LI) (r=0.601, p=0.014), and high blood glucose index (HBGI) (r=0.743, p=0.001) (Table 1).
Conclusions: The 1-h CGM glucose and elevated GV indices significantly correlate with 1-h PG (> 8.6 mmol/L) in high-risk subjects with HbA1c < 5.7%. CGM could potentially replace the OGTT for detecting early dysglycemia in those with HbA1c < 5.7%.
B. Dorcely: None. E. Sifonte: None. A. Divakaran: None. K. Katz: None. R. Jagannathan: None. I.J. Goldberg: None. M. Bergman: None.
Abbott Diabetes Care; New York University Clinical and Translational Science Award (UL1 TR001445)