Homa-IR: A Marker of Vascular Dysfunction in Nondiabetic Hemodialysis Patients?

to the study and the institute’s ethics committee approved the study protocol. Predialysis blood samples were taken on a midweek session to assess biochemical parameters, including glucose, insulin, CRP, total and HDL cholesterol, triglycerides, and apolipoproteins A and B. We estimated HOMA-IR (Homeostasis Model Assessment for Insulin Resistance) according to the formula: fasting glucose (mmol/l) ! fasting insulin (IU/ml)/22.5 [2] . All patients underwent B-mode ultrasonography of common carotid arteries (bilaterally) to obtain measures of arterial stiffness (including distensibility, compliance and carotid incremental elastic modulus; Einc index), and central (aortic) blood pressure was estimated using SphygmoCor, as we have previously described [3, 4] . Einc is an index of the elastic properties of vessels, which is inversely correlated to distensibility. Einc is calculated by the following mathematic formula: Einc = 3(1 + LCSA/WCSA)/distensibility. LCSA (lumen cross-sectional area) is estimated by the internal common carotid artery diameter (CCI) as: LCSA =  (CCI/2) 2 , where = 3.14 and WCSA (wall cross-sectional area) is estimated by the external comWe found the paper of Zhou et al. [1] , recently published in your journal, of special interest. We would like to report that we observed similar findings in a group of 63 (27 female and 36 male) nondiabetic chronic hemodialysis patients. Our patients, aged 60.5 8 12.1 years, were on chronic hemodialysis for at least 6 months (median 38 months). Causes of renal disease were chronic glomerulonephritis (34.3%), primary hypertension (27.1%), polycystic kidney disease (7.1%), chronic interstitial nephritis (7.2%) and unknown (24.3%). None of the patients was diagnosed to suffer from diabetes mellitus (based on medical history, or abnormal blood glucose). All patients were dialyzed on a 4-hour, thrice weekly schedule with a bicarbonate-buffered dialysate. All patients had a functioning vascular access (arteriovenous fistula or graft) and were clinically stable (no acute inflammatory event or cardiovascular event for the last 3 months, no malignant or severe hepatic disease). Twenty patients had a history of smoking, but none was a current smoker. Seventeen patients had a medical history remarkable for cardiovascular disease. All participants gave their informed consent Published online: February 24, 2010