Spontaneous baroreflex sensitivity is attenuated in male UCD-type 2 diabetes mellitus rats: A link between metabolic...

Area of Science:

• Cardiovascular Physiology
• Metabolic Syndrome
• Autonomic Nervous System Function

Background:

• Patients with type 2 diabetes mellitus (T2DM) exhibit impaired arterial baroreflex function, potentially linked to obesity.
• The specific impact of obesity and associated metabolic disturbances on baroreflex dysfunction in T2DM remains unclear.

Purpose of the Study:

• To investigate the influence of visceral fat and adiponectin on baroreflex dysfunction in a rat model of T2DM.
• To explore the relationship between obesity-related metabolic factors and autonomic dysfunction in T2DM.

Main Methods:

• Adult male UCD-T2DM rats and age-matched controls were used, with groups assessed at prediabetic, diabetes-onset, and 4 and 12 weeks post-onset.
• Spontaneous baroreflex sensitivity (BRS) was measured using beat-to-beat blood pressure recordings and the sequence technique.
• Body composition, visceral fat mass, adiponectin, and insulin concentrations were assessed using Dual-energy X-ray absorptiometry (DEXA) and biochemical assays.

Main Results:

• BRS was significantly lower in T2DM rats at diabetes onset compared to controls (3.7 ± 3.2 vs. 16.1 ± 8.4 ms/mmHg, P = 0.01).
• T2DM rats exhibited increased visceral fat mass, adiponectin, and insulin concentrations compared to controls (P < 0.01).
• Changes in adiponectin and insulin levels over time were inversely related to BRS in T2DM rats.

Conclusions:

• Obesity-related metabolic impairments, including elevated visceral fat and adiponectin, contribute to attenuated spontaneous BRS in T2DM.
• These findings suggest a significant link between metabolic dysregulation and autonomic dysfunction in type 2 diabetes mellitus.
• Targeting visceral fat and adiponectin may offer therapeutic potential for improving baroreflex function in T2DM patients.