Compliance, Adherence and Concordance Differently Predict the Improvement of Uremic and Microbial Toxins in Chronic Kidney Disease on Low Protein Diet.

Background: In medicine, "compliance" indicates that the patient complies with the prescriber's recommendations, "adherence" means that "the patient matches the recommendations" and "concordance" means "therapeutic alliance" between patient and clinician. While a low protein diet (LPD) is a cornerstone treatment of chronic kidney disease (CKD), monitoring the actual performance of LPD is a challenge.
Patients: Fifty-seven advanced CKD adult patients were enrolled and LPD prescribed. Compliance was evaluated through the normalized protein catabolic rate (nPCR), adherence by the dietitian by means of a 24-h dietary recall and concordance by the nephrologist during consultations. Traditional parameters as well as total p-Cresyl Sulphate (t-PCS), total Indoxyl Sulphate (t-IS) and Lipoprotein-associated phspholipase A ₂ (Lp-PLA ₂ ) were compared between adherent/not adherent and concordant/not concordant subjects at enrolment and after two months.
Results: nPCR, blood urea nitrogen, cholesterol and triglycerides significantly decreased in all patients. t-PCS and t-IS decreased among adherent subjects. Lp-PLA ₂ , t-PCS, free-PCS and t-IS decreased among concordant subjects, while these increased in non-concordant ones.
Conclusion: This study demonstrates that LPD may improve the control of traditional uremic toxins and atherogenic toxins in "adherent" and "concordant" patients. A comprehensive and multidisciplinary approach is needed to evaluate the compliance/adherence/concordance to LPD for optimizing nutritional interventions.