Residual dysglycemia when at target HbA1c of 7% (53 mmol/mol) in persons with type 2 diabetes

AimsTo understand the composition of the residual dysglycemia when HbA1c is between 6.5% (48 mmol/mol) and 7% (53 mmol/mol), representing the definition of diabetes and the recommended treatment goal, respectively.MethodsOne hundred persons with type 2 diabetes and a HbA1c < 7% (53 mmol/mol), treated with diet alone and/or oral hypoglycemic agents underwent continuous glucose monitoring (CGM) and were further divided into two subgroups 1 (n = 50) and 2 (n = 50) according to whether the HbA1c was <6.5% (48 mmol/mol) or 6.5–6.9% (48–52 mmol/mol), respectively. A similar analysis was performed in those on diet alone: subgroups A (n = 34, HbA1c < 6.5%, 48 mmol/mol) and B (n = 10, HbA1c 6.5–6.9%, 48–52 mmol/mol). The residual dysglycemia determined from the CGM was assessed using glucose exposures defined as areas under curves (AUCs) and mean glucose values.ResultsAveraged 2-h postprandial glucose value (averaged PPG, mmol/L, mean ± SD) and postprandial glucose exposure (AUCpp, mean ± SD, mmol·L−1·h) were significantly higher in subgroup 2 (mean HbA1c = 6.7%, 50 mmol/mol) than in subgroup 1 (mean HbA1c = 6.0%, 42 mmol/mol): averaged PPG = 8.1 ± 1.3 versus 7.3 ± 1.3 mmol/L (p < 0.002); AUCpp = 23.5 ± 8.6 versus 16.2 ± 8.6 (p < 0.0001). The percentages of persons with averaged PPG ≥ 7.8 mmol/L were 52% and 24% (p < 0.01) in subgroups 2 and 1, respectively. Similar results were observed in those (subgroups A and B) who were on diet alone.ConclusionsThe residual dysglycemia in type 2 diabetes with HbA1c between 6.5 and 6.9% (48–52 mmol/mol) inclusive is mainly due to remnant abnormal postprandial glucose excursions. Consequently, HbA1c < 6.5% (48 mmol/mol) is an achievable goal with therapeutic measures aimed at reducing postmeal glucose when the HbA1c is at 7% (53 mmol/mol).