[The relation between fasting plasma glucose concentrations and insulin resistance]

Area of Science:

• Endocrinology and Metabolism
• Diabetes Research
• Human Physiology

Background:

• Impaired glucose regulation (IGR) is a precursor to type 2 diabetes mellitus (T2DM).
• Accurate identification of insulin resistance in IGR is crucial for early intervention.
• The American Diabetes Association (ADA) criteria for impaired fasting glucose (IFG) have been revised.

Purpose of the Study:

• To investigate the presence of insulin resistance in Chinese individuals with IGR.
• To assess IGR using the modified 2003 ADA criteria for IFG.
• To evaluate beta-cell function in different glucose regulation categories.

Main Methods:

• Participant groups included normal glucose regulation (NGR), isolated IFG (n-i-IFG), combined IGT (n-c-IGT and o-c-IGT), and T2DM.
• Insulin resistance was quantified using the hyperinsulinemic-euglycemic clamp (glucose infusion rate [GIR]).
• Beta-cell function was assessed via intravenous glucose tolerance tests (IVGTT).

Main Results:

• Significantly lower GIR (indicating insulin resistance) was observed in n-i-IFG and n-c-IGT groups compared to NGR.
• The lowest GIR was found in the old criteria combined IGT (o-c-IGT) and T2DM groups.
• Fasting insulin levels increased across IGR groups, while insulin secretion deficits worsened with IGR progression.

Conclusions:

• IGR individuals, defined by the revised ADA criteria, demonstrate insulin resistance.
• A progressive decline in insulin secretion capacity correlates with the severity of IGR.
• Early detection and management of insulin resistance in IGR are vital.