Carotid intima media thickness and glomerular filtration rate: a baseline analysis of the PolyIran-L trial.

Background: The relationship between kidney and vascular health is acknowledged, but detailed information is still missing. This study examines the relationship of estimated glomerular filtration rate (eGFR) and carotid intima media thickness, providing insights into the association between atherosclerosis and kidney function.

Methods: Participants older than 50 years of age who were part of the PolyIran-L study, a trial nested in the Golestan Cohort Study, were included. The maximal intima media thickness of both common carotid arteries was evaluated using B-mode ultrasonography. Four different cut-off values for abnormal carotid intima media thickness were considered. Correlation of carotid intima media thickness and eGFR was assessed with linear correlation and multivariable binary logistic regression models after adjusting for several confounders.

Results: In total, 1562 participants (750 females, 48%) were included in this population-based study. Assuming the eGFR < 45 [mL/min/1.73 m²] group as reference in the crude analysis, those with eGFR ≥ 45 and < 60 [mL/min/1.73 m²] showed an association of being less likely to have carotid intima media thickness above the 0.8 cutoff. However, the fully adjusted analysis showed no significant statistical association between carotid intima media thickness and eGFR.

Conclusion: This study did not support the independent association of eGFR and different carotid intima media thickness cutoffs. This pattern may be different in patients with severely decreased eGFR, a subset of cases in which it should be further investigated.