LETTER TO THE EDITOR: The Effects of Nutraceuticals in Patients with or without Chronic Kidney Disease: Classification Matters

Abstract

DEAR EDITOR We have read with great interest the study by Cicero and colleagues [1], reporting the long-term effects of lipidlowering nutraceuticals on Low Density Lipoprotein - Cholesterol (LDL-C) levels and arterial stiffness. The impressive reduction of LDL-C combined with the excellent safety profile points towards further research in this field and calls for a wider use of nutraceuticals in everyday clinical practice. Furthermore, the beneficial effects of nutraceuticals in patients with chronic kidney disease (CKD) are of clinical importance, since this group of patients is highly susceptible to atherosclerosis and cardiovascular disease is their primary cause of death [2-4]. However, a closer look at the demographic data of participating patients in the Cicero et al. study [1] raises a question: whether patients included in the non-CKD group were actually free of renal disease. As depicted in Table 1 [1], the mean estimated glomerular filtration rate (eGFR) levels in the non-CKD group were 67.7 ml/min/1.73m2. According to the 2002 K/DOQI clinical practice guidelines [5] that were recently updated by the KDIGO 2012 clinical practice guidelines [6], stage I and II CKD have eGFR levels over 60 ml/min/1.73m2, when other indices of renal damage are present. Therefore, we would be really grateful to the authors if they could clarify this issue. In addition, it would be interesting to know how many patients had stage I, II, IIIa and IIIb CKD. Moreover, it would be important to know whether nutraceuticals were equally effective in all stages of CKD, although we acknowledge that the small number of study participants would probably not allow for statistical comparisons. In conclusion, we would like to congratulate the authors for their interesting study with significant findings, and thank them in advance for their clarifications.