Association of plasma des-acyl ghrelin levels with CKD.

Background and objectives There are no effective therapies for malnutrition in CKD/ESRD patients. This study hypothesized that ghrelin, an endogenous orexigenic hormone, would correlate with renal function and might suggest therapeutic interventions for CKD/ESRD malnutrition. Design, setting, participants, & measurements Fifty-one CKD and 15 hemodialysis patients were enrolled. Acyl ghrelin (AG) and des-acyl ghrelin (DG) were determined using separate two-site specific assays. Leptin, insulin, growth hormone, insulin-link growth factor-1, C-reactive protein, INF-alpha, and IL-6 were also measured. Results Univariate correlation analyses showed that CKD stage was highly, positively correlated with the levels of preprandial and postprandial DG and positively correlated with INF-a, IL-6, leptin, and age. Multivariate partial-correlation analyses showed that CKD was independently associated with the proportion of preprandial and postprandial DG, whereas TNF-alpha, IL-6, leptin, insulin, and age were not independently associated with either. Geometric mean (GM) preprandial and postprandial AG were comparable between CKD stages <= 2 and >2, whereas GM preprandial DG and postprandial DG were 1.95-fold and 2.17-fold greater, respectively, for CKD stage >2 versus stage DG was the dominant form of ghrelin preprandially and postprandially for both CKD stages <= 2 and >2. Dialysis had no effect on AG, but reduced DG by 73% to levels even lower (GM 48.7 pg/ml) than those seen postprandially in CKD stage <= 2 patients (GM 77.0 pg/ml). Conclusions This study shows a strong and independent correlation of DG with CKD stage. Postprandial suppression of ghrelin is impaired with reduced renal function. Hemodialysis selectively removes DG but not AG.