Role of Matsuda Index in Identifying Patients at Risk for Cystic Fibrosis-Related Diabetes Development

Area of Science:

• Endocrinology
• Pediatrics
• Metabolic Disorders

Background:

• Cystic fibrosis-related diabetes (CFRD) is a common complication in cystic fibrosis (CF) patients.
• Insulin secretion defects are primary drivers of CFRD, but insulin resistance may also contribute.
• Early identification of insulin resistance can help predict CFRD risk in pediatric CF patients.

Purpose of the Study:

• To assess the Matsuda Index's effectiveness in identifying insulin resistance in pediatric CF patients.
• To compare the Matsuda Index with HOMA-IR for evaluating glucose metabolism.
• To explore the utility of the Matsuda Index for early risk stratification of CFRD.

Main Methods:

• A cross-sectional study included 50 pediatric CF patients (aged 6-16).
• Measurements included anthropometrics, fasting glucose/insulin, HbA1c, C-peptide, and an oral glucose tolerance test (OGTT).
• The Matsuda Index was calculated, with a threshold of ≤4.5 indicating insulin resistance.

Main Results:

• The average Matsuda Index was 17.08 (SD 11.16).
• 22% (11/50) of patients showed insulin resistance (Matsuda Index ≤ 4.5).
• Insulin resistance group had significantly higher insulin levels at 60 and 120 min during OGTT (p=0.008, p=0.002).

Conclusions:

• The Matsuda Index shows promise as an adjunctive tool for detecting insulin resistance in pediatric CF patients, particularly during puberty.
• Early detection via the Matsuda Index could enable timely interventions to delay CFRD onset or progression.
• The study acknowledges a limitation: the ≤4.5 cut-off was derived from adult studies and its validity in pediatric CF populations requires further establishment.