Use of First-phase Insulin Secretion in Early Diagnosis of Thyroid Diabetes and Type 2 Diabetes Mellitus

Abstract

Background:A relationship between hyperthyroidism and insulin secretion in type 2 diabetes mellitus (T2DM) has been reported. Therefore, this study explored the use of first-phase insulin secretion in the differential diagnosis of thyroid diabetes (TDM) and T2DM.Methods:In total, 101 patients with hyperthyroidism were divided into hyperthyroidism with normal glucose tolerance (TNGT), hyperthyroidism with impaired glucose regulation (TIGR), and diabetes (TDM) groups. Furthermore, 96 patients without hyperthyroidism were recruited as control groups (normal glucose tolerance [NGT], impaired glucose regulation [IGR], and T2DM). The following parameters were evaluated: homeostasis model assessment (HOMA)-IR, HOMA-β, modified β-cell function index (MBCI), peak insulin/fasting insulin (IP/I0), AUCins-OGTT, and AUCins-OGTT/AUCglu-OGTT from the oral glucose tolerance test (OGTT) insulin release test were utilized to assess the second-phase insulin secretion, while the IP/I0, AIR0′~10′, and AUCins-IVGTT from the intravenous glucose tolerance test (IVGTT) insulin release test were used to assess the first-phase insulin secretion.Results:In the OGTT, the HOMA-β values of the TNGT and TDM groups were higher than those of the NGT and T2DM groups (all P < 0.05). In the hyperthyroidism groups, the MBCI of the TDM group was lower than that of the TNGT and TIGR groups (all P < 0.05). Among the control groups, the MBCI values of the IGR and T2DM groups were lower than that of the normal glucose tolerance (NGT) group (all P < 0.05). In the IVGTT, insulin secretion peaked for all groups at 2–4 min, except for the T2DM group, which showed a low plateau and no secretion peak. The IP values of the TNGT, TIGR, and TDM groups were higher than those of the NGT, IGR, and T2DM groups (all P < 0.05). The Ip/I0, AIR0′~10′, and AUCins-IVGTT values of the TDM group were higher than those of the T2DM group but were lower than those of the TNGT, TIGR, NGR, and IGR groups (all P < 0.05). Compared with the other five groups, the Ip/I0, AIR0′~10′, and AUCins-IVGTT values of the T2DM group were significantly decreased (all P < 0.05). The Ip/I0 and AUCins-IVGTT values of the TNGT group were higher than those of the NGT group (all P < 0.05).Conclusions:β-cell function in TDM patients is superior to that in T2DM patients. First-phase insulin secretion could be used as an early diagnostic marker to differentiate TDM and T2DM.

Pancreatic Fat is not significantly correlated with β-cell Dysfunction in Patients with new-onset Type 2 Diabetes Mellitus using quantitative Computed Tomography

“…The areas under the curves (AUC), which were calculated using the trapezoid rule, for glucose and insulin were used to represent the total secretory response over the entire OGTT period. The modified β-cell function index (MBCI) was calculated as follows: (Fasting insulin (Fins)×fasting plasma glucose (FPG))/(120 min plasma glucose (Glucose 120min )+60 min plasma glucose (Glucose 60min )-2FPG) 23 . IR was assessed by the Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) (HOMA-IR=(Fins×FPG)/22.5).…”

Preoperative Fasting C-Peptide Acts as a Promising Predictor of Improved Glucose Tolerance in Patients With Acromegaly After Transsphenoidal Surgery: A Retrospective Study of 64 Cases From a Large Pituitary Center in China

“…PG, CP and INS levels were evaluated at 0, 30, 60, 120, and 180 min after the 75-g OGTT. Pancreatic islet β-cell functioning was evaluated from the INS; CP; the homeostasis assessment models of β-cell function (HOMA1-%β [INS]) (13, 14), HOMA2-%β (INS) (15), and HOMA2-%β (CP) (15); the areas under the curve for INS (AUC INS ) (16), AUC CP , AUC INS /AUC PG (17), and AUC CP /AUC PG ; the insulinogenic index (IGI) (18); IGI/IR; the disposition index (DI) (19); the OGTT insulin secretion sensitivity index 2 (ISSI2) (20); the modified β-cell function index (MBCI) (21); estimated first-phase insulin release (eFPIS) and estimated second-phase insulin release (eSPIS) (22). Insulin sensitivity was evaluated using the homeostasis assessment models of insulin sensitivity (HOMA1-%S [INS]) (13, 14), HOMA2-%S (INS) (15), HOMA2-%S (CP) (15); the quantitative insulin sensitivity check index (QUICKI) (23); the Matsuda index (whole-body insulin sensitivity index, WBISI) (24, 25) and the estimated metabolic clearance rate of glucose (eMCR) (22).…”