Aortic-to-brachial stiffness gradient and kidney function in type 2 diabetes

Area of Science:

• Cardiovascular Physiology
• Nephrology
• Diabetes Mellitus Research

Background:

• A reversed aortic-to-brachial stiffness gradient (ab-SG), where aortic pulse wave velocity (aPWV) exceeds brachial PWV (bPWV), predicts mortality in dialysis patients.
• Type 2 diabetes mellitus (T2DM) is associated with renal damage and hemodynamic alterations, potentially impacting ab-SG.

Purpose of the Study:

• To investigate the ab-SG in patients with T2DM compared to non-diabetic controls during rest and exercise.
• To determine the association between ab-SG, aPWV, and kidney function (eGFR) in T2DM.

Main Methods:

• Sixty patients with T2DM and 60 matched non-diabetic controls were studied.
• ab-SG was calculated as the ratio of bPWV (carotid-to-radial) to aPWV (carotid-to-femoral) using applanation tonometry.
• Kidney function assessed by estimated glomerular filtration rate (eGFR); exercise substudy conducted in subsets of participants.

Main Results:

• Patients with T2DM had a significantly lower resting ab-SG (0.99 vs. 1.2, P<0.001) and higher aPWV (P<0.001).
• A reversed ab-SG (aPWV ≥ bPWV) was more prevalent in T2DM patients (58% vs. 27%, P<0.001).
• Resting ab-SG independently predicted eGFR (β=13.2, P=0.024), while aPWV did not (β=-0.88, P=0.30). Exercise ab-SG was also lower in T2DM but did not predict eGFR.

Conclusions:

• Patients with T2DM exhibit a reversed ab-SG during both rest and exercise.
• The resting ab-SG is a significant independent predictor of kidney function in T2DM, suggesting a pathophysiological role beyond arterial stiffness alone.