Timing of Onset of CKD-Related Metabolic Complications

Abstract

Chronic kidney disease (CKD) guidelines recommend evaluating patients with GFR Ͻ60 ml/min per 1.73 m 2 for complications, but little evidence supports the use of a single GFR threshold for all metabolic disorders. We used data from the NephroTest cohort, including 1038 adult patients who had stages 2 through 5 CKD and were not on dialysis, to study the occurrence of metabolic complications. GFR was measured using renal clearance of 51 Cr-EDTA (mGFR) and estimated using two equations derived from the Modification of Diet in Renal Disease study. As mGFR decreased from 60 to 90 to Ͻ20 ml/min per 1.73 m 2 , the prevalence of hyperparathyroidism increased from 17 to 85%, anemia from 8 to 41%, hyperphosphatemia from 1 to 30%, metabolic acidosis from 2 to 39%, and hyperkalemia from 2 to 42%. Factors most strongly associated with metabolic complications, independent of mGFR, were younger age for acidosis and hyperphosphatemia, presence of diabetes for acidosis, diabetic kidney disease for anemia, and both male gender and the use of inhibitors of the renin-angiotensin system for hyperkalemia. mGFR thresholds for detecting complications with 90% sensitivity were 50, 44, 40, 39, and 37 ml/min per 1.73 m 2 for hyperparathyroidism, anemia, acidosis, hyperkalemia, and hyperphosphatemia, respectively. Analysis using estimated GFR produced similar results. In summary, this study describes the onset of CKD-related complications at different levels of GFR; anemia and hyperparathyroidism occur earlier than acidosis, hyperkalemia, and hyperphosphatemia.

Fibroblast Growth Factor-23 in Early Chronic Kidney Disease

“…The prevalence of hyperparathyroidism observed in the present cohort is substantially lower than that reported previously in patients with comparable kidney function (4,21). This discrepancy may be explained by differences in case mix (e.g., race) and PTH assay (22,23).…”

Risk of ESRD and Death in Patients with CKD Not Referred to a Nephrologist

“…The clinical characteristics of our patients with CKD stage 3a, in fact, show low prevalence for the main cardiorenal risk factors (i.e., albuminuria, anemia, diabetes, and CAD) with respect to more advanced stages of CKD (3b-5), and therefore, their profile is compatible with nonprogressive CKD (26)(27)(28)(29)(30). However, the suggestion of referring patients with CKD when eGFR is ,45 ml/min per 1.73m 2 is in agreement with the timing of onset of CKD-related metabolic complications (31). Obviously, because of the observational nature of this study and the sole inclusion of patients who were not referred to a nephrologist, the indication of starting referral of patients with CKD stage 3b remains a suggestion, because no formal comparison between patients who were and were not referred to a nephrologist could be made in this work.…”

Dietary Approach to Stop Hypertension (DASH) diet and risk of renal function decline and all-cause mortality in renal transplant recipients

“…It is known that a decline in kidney function is associated with a progressive increase in cardiovascular risk 38. In addition, in patients with impaired renal function, cardiovascular risk factors, including hypertension, diabetes, albuminuria, anemia, vascular stiffness, metabolic acidosis, and dyslipidemia are common 38, 39. Moreover, these patients often deal with multimorbidity40; hence, they may not be able to benefit enough from only high adherence to the DASH diet.…”