Compromised cardiac autonomic function in non-diabetic subjects with 1 h post-load hyperglycemia: a cross-sectional...

Area of Science:

• Cardiology
• Endocrinology
• Metabolic Syndrome

Background:

• Cardiac autonomic dysfunction is linked to insulin resistance disorders like obesity, impaired glucose tolerance (IGT), and type 2 diabetes.
• High 1-hour plasma glucose (1hPG) levels (≥155 mg/dl) during an oral glucose tolerance test (OGTT) identify a prediabetes category (NGT 1h-high) with increased cardiovascular risk.

Purpose of the Study:

• To investigate the association between 1-hour post-load hyperglycemia and cardiac autonomic dysfunction.
• To determine if 1hPG is an independent predictor of cardiac autonomic neuropathy (CAN) and heart rate variability (HRV) reduction.

Main Methods:

• Evaluated cardiac autonomic neuropathy (CAN) using cardiovascular autonomic reflex tests (CARTs) and heart rate variability (HRV) via 24-h electrocardiography.
• Assessed 88 non-diabetic subjects, categorized by OGTT results: normal glucose tolerance (NGT) with low 1hPG (NGT 1h-low), NGT with high 1hPG (NGT 1h-high), and IGT.

Main Results:

• Subjects with NGT 1h-high and IGT exhibited higher rates of CAN and reduced HRV parameters compared to NGT 1h-low.
• 1hPG, not fasting or 2-hour PG, was significantly associated with CAN and HRV.
• Multivariate analysis confirmed 1hPG as an independent predictor of HRV and CAN presence.

Conclusions:

• Individuals with 1hPG ≥155 mg/dl demonstrate impaired cardiac autonomic function.
• This 1hPG threshold identifies a prediabetic state associated with autonomic dysfunction and potential cardiovascular risk.