Insulin sensitivity (Si) assessment in lean and overweight subjects using two different protocols and updated...

Area of Science:

• Metabolic research
• Endocrinology
• Physiology

Background:

• The frequently-sampled intravenous glucose tolerance test (FSIVGTT) is a key method for estimating insulin sensitivity (Si).
• Comparing FSIVGTT protocols and software is crucial for accurate Si assessment.
• Understanding Si differences between lean and overweight individuals is important for metabolic health.

Purpose of the Study:

• To compare insulin sensitivity (Si) in lean versus overweight individuals using FSIVGTT.
• To evaluate the intra-individual reproducibility of two FSIVGTT protocols (full and short).
• To assess the impact of different software (COMAL and Minmod Millennium) on Si measurements.

Main Methods:

• FSIVGTT was performed on 14 lean and 14 overweight subjects using full (29 samples) and short (12 samples) protocols.
• Intra-individual reproducibility was assessed in four normal subjects over 1-week intervals.
• Data were analyzed using COMAL and Minmod Millennium software.

Main Results:

• Mean Si values were significantly lower in overweight subjects compared to lean subjects (p < 0.001).
• No significant differences in Si were found between the full and short protocols for either software.
• High correlation (r > 0.85) between protocols was observed for both lean and overweight individuals, with slightly better agreement in lean subjects.

Conclusions:

• A short protocol FSIVGTT provides accurate insulin sensitivity (Si) assessment in normal individuals.
• The short FSIVGTT protocol may yield less reliable results for insulin sensitivity in individuals with normal glucose tolerance but high BMI.
• Both COMAL and Minmod Millennium software demonstrate good reproducibility for Si measurements across protocols.