Is Carotid Intima-Media Thickness Useful in Predicting Renal Insufficiency in Asymptomatic Hypertensive Patients Attending a Tertiary Hospital in Nigeria?

Intima-media thickness of the carotid artery wall (CIMT) is a strong predictor of cardiovascular disease (CVD). The aim of this study was to investigate the association between CIMT and renal insufficiency as determined by the estimated glomerular filtration rate (eGFR), as well as determine the ability of CIMT to predict the presence of covert renal insufficiency in hypertensive Nigerian adults. Two hundred and sixteen participants took part in the study, comprising of 72 hypertensive patients on antihypertensive medication (treated), 72 newly-diagnosed patients, and 72 apparently healthy, normotensive subjects.  The eGFR was determined from serum creatinine using the Cockroft-Gault formula, while the CIMT was determined by carotid ultrasonography. There was no significant difference in the mean age of the study population (p=0.073). CKD was found more in patients with increased CIMT (33.5%), than in those with normal CIMT (6.5%) (x 2 =12.170, p<0.0001). CKD was also most prevalent in the untreated hypertensive patients than in any of the other groups (x 2 =15.022, p=0.011). Patients with increased CIMT suffered from a lower glomerular filtration rate (p<0.0001). The decline in eGFR with increasing CIMT had a significant inverse correlation in the untreated group (r=-0.391, p=0.013). The predictability of renal insufficiency by CIMT determined using the Receiver Operating Characteristics (ROC) curve, showed an area under the curve (AUC) of 0.807 (95% CI: 0.708-0.907) (p<0.0001). CIMT is a strong and independent predictor of renal insufficiency in the untreated hypertensive adult Nigerian patients and should be considered a valuable tool for cardiovascular risk stratification in this population group.