Sevil IsmayilovaAzerbaijan State Advanced Training Institute for Doctors, Azerbaijan
Title: Oral glucose tolerance test 90-minutes values in prediabetes detection
Prediabetes (PD) is a serious health condition where blood sugar levels are higher than normal, but not enough yet to be diagnosed as diabetes mellitus type 2 (DM). PD is necessary stage before DM. Macro- and microvascular complications of DM, neuropathy have their start already at PD.
However, the diagnosis of PD has not yet been clarified. Glycohemoglobin (A1C), fasting glucose (FG), and oral glucose tolerance test (OGTT) are used for PD diagnostics.
The aim of our study was to determine the diagnostic value of 90 minutes post-load plasma glucose (PG90) and reveal the optimal cut-off point for separation of normal and impaired glucose metabolism.
At first, we analyzed the relationship between PG90 and FG (r=+0.53 [95%CI +0.397; +0.641]),
PG90 and A1C (r=+0.71 [95%CI +0.615; +0.785]),
PG90 and PG120 (r=+0.85 [95%CI +0.796; +0.891]).
The multiple regression analysis was used to reveal the optimal cut off point. Based on result of regression analysis, multiple regression equations were received.
By this equation if FG is equal to 109 mg/dL (in accordance with International Diabetes Federation, Canadian Diabetes Association, Australian Diabetes Association, Azerbaijan Association Endocrinology, Diabetology and Therapeutic Education), and A1C is equal to 38mmol/mol (as recommended by the American Diabetes Association, Azerbaijan Association
Endocrinology, Diabetology and Therapeutic Education) and PG120 is equal to 139 mg/dL (according to all recommendations) the maximal
normal value for PG90 should be 168 mg/dL.
Cut-off point “?168 mg/dL” for PD diagnostics had 55.3% Sensitivity, 97.7% Specificity, 92.9% Positive Predictive Value, 80.2% Negative Predictive Value, 82.8% Overall Diagnostic Accuracy and 53.0 % Youden Index. Qualitative characteristics of PG90 were assessed. Cut-off point “?168 mg/dL” provided possibility to recognize 66.7% cases of DM, 53.7% cases of PD and falsely recognize as pathological 2.3% of normal glucose metabolism.
Sevil Ismayilova is a senior laboratory assistant at the department of Therapy at the Azerbaijan State Advanced Training Institute for Doctors. She has been working on her PHD since 2021. She has over 20 publications. Sevil Ismayilova attended numerous congresses, and presented poster abstract at AACE 2021 and oral presentation at Endocrine Society 2021.