Carotid arterial stiffness is associated with selective glomerular hypofiltration of middle-sized molecules in type 2 diabetes

BackgroundType 2 diabetes (T2D) is a major driver of premature vascular aging. We investigated whether Selective Glomerular Hypofiltration Syndromes (SGHS), expressed as ratios of cystatin C- or β2-microglobulin-based estimated glomerular filtration rate to creatinine-based eGFR (eGFRcys/eGFRcr and eGFRb2M/eGFRcr), are associated with carotid, femoral, or aortic stiffness.MethodsWe studied 144 individuals with T2D recruited from the University Diabetology Unit of Pisa, Italy. Local arterial stiffness was assessed at the carotid and femoral arteries using β stiffness index, Peterson's elastic modulus (Ep), and local wave speed (WS). Systemic stiffness was evaluated by carotid-femoral pulse wave velocity (cfPWV) and augmentation index (AIx). Kidney function was assessed using eGFRcr, eGFRcys, eGFRb2M, mean eGFR, urinary albumin-to-creatinine ratio (UACR), and eGFR ratios.ResultsA 0.1-unit decrease in eGFRcys/eGFRcr showed a borderline association with higher cfPWV (p=0.087), while age, diabetes duration, UACR, and central pulse pressure were stronger predictors. Lower eGFR ratios were associated with higher carotid WS in unadjusted analyses; after adjustment, eGFRcys/eGFRcr showed a nonsignificant trend (p=0.074). No associations were found with femoral stiffness indices.ConclusionsSGHS was inversely associated with carotid WS in T2D but not with aortic or femoral stiffness.