Body Composition Changes Impact Islet β-Cell Function in Patients With Type 2 Diabetes Mellitus.

Area of Science:

• Endocrinology
• Metabolic Diseases
• Body Composition Analysis

Background:

• Dysregulation of pancreatic beta cells is central to type 2 diabetes mellitus (T2DM).
• Weight fluctuations are common in T2DM management, yet the link between body composition shifts and beta-cell function is understudied.
• Understanding these relationships is vital for effective T2DM treatment strategies.

Purpose of the Study:

• To investigate the association between longitudinal changes in body composition and islet beta-cell function in T2DM patients.
• To determine how metrics like fat mass index and muscle mass index correlate with insulin resistance, sensitivity, and secretion.
• To identify key body composition parameters that predict the progression of insulin resistance in T2DM.

Main Methods:

• Retrospective longitudinal study of 775 T2DM patients with a median follow-up of 2.29 years.
• Body composition assessed using dual-energy X-ray absorptiometry (DEXA), measuring BMI, FMI, TFMI, MMI, ASMI, M/F ratio, and A/T ratio.
• Beta-cell function evaluated via HOMA-IR, Matsuda index (MI), HOMA-β, and C-peptidogenic index (CGI) through glucose load tests.

Main Results:

• Despite stable BMI, patients showed increased fat mass index (FMI), trunk fat mass index (TFMI), and appendicular skeletal muscle mass index (ASMI) at readmission.
• Elevated insulin resistance (HOMA-IR) and improved insulin secretion (CGI) were observed alongside increased FMI.
• Increased ASMI correlated positively with insulin sensitivity (MI) and secretion (CGI), while increased FMI was linked to progressive insulin resistance.

Conclusions:

• Increased fat mass (FMI) contributes to worsening insulin resistance in T2DM.
• Enhanced muscle mass (ASMI) is associated with better insulin sensitivity and secretion.
• Maintaining optimal BMI and muscle-to-fat ratio is crucial for preventing insulin resistance progression in T2DM.