Relation between physiological variation of renal function and carotid intima media thickness in non-diabetic individuals

Abstract

Aim: Moderate to severe renal insufficiency and albuminuria have been shown to be independent risk factors for atherosclerosis. However, the association between renal function and intima media thickness (IMT) in non-diabetic individuals is less clear. We therefore investigated the relation between renal function, established cardiovascular risk factors and carotid intima media thickness in non-diabetic individuals. Methods: 853 non-diabetic participants were included in this project. Renal function was estimated using the simplified Modification of Diet in Renal Disease (MDRD) formulae, a refit MDRD equation for healthy persons (MDRD-1) or the Jellife 2 formula, an age independent estimate of glomerular filtration rate (GFR). Carotid arterial intima-media thickness was measured at the posterior wall of the common carotid artery and the bulbus (IMTACC, IMTBulbus). Results: Weak correlations between IMTACC or IMTBulbus and MDRD were found (r =-0.105, p=0.002; r =-0.127, p<0.001). and similiar results were found for MDRD-1. However, adjustment of that relation for age modified the picture. While age was an independent predictor, MDRD or MDRD-1 were not further informative. Further adjustment for cardiovascular risk factors confirmed that relation. Correspondingly, GFR estimated by the age-independent formula Jellife 2 was not correlated with IMT. Conclusions: The results of this study indicate that variation of renal function within the normal range is not independently associated with carotid intima media thickness in non-diabetic individuals. Crude correlations between MDRD and IMT appear to reflect the inter-relation among age, eGFR and IMT.