Arch Hellen Med, 22(4), July-August 2005, 348-357
Increased plasma total ghrelin levels in patients with chronic renal failure:
D. DOULGERAKIS,1 Ν. TENTOLOURIS,1 K. MAKRILAKIS,1 I. MOYSSAKIS,2
OBJECTIVE Ghrelin is an orexigenic peptide identified in the stomach as a ligand for the growth hormone secretagogue-receptor. The effect of renal function on plasma ghrelin levels is little known. Recent studies have shown that ghrelin has important hemodynamic effects. The aim of this cross-sectional study was to investigate differences in plasma ghrelin levels between patients with chronic renal failure (CRF) and healthy subjects and explore the relationship between plasma ghrelin levels and indices of left ventricular function.
METHOD Fasting plasma total ghrelin levels in 122 patients with CRF (57 on hemodialysis and 65 not on hemodialysis) were compared with those of 57 control subjects. Indices of left ventricular systolic and diastolic function, left ventricular mass and myocardial performance index were measured using M-mode and Doppler echocardiography.
RESULTS Mean (95% CI) plasma total ghrelin levels were higher in patients with CRF than in controls: 4,620.4 (4,305.2-4,935.8) vs 1,998.6 (1,674.6-2,322.6) pg/mL (age-adjusted P<0.001). Plasma ghrelin levels were no different in patients on or not on hemodialysis: 4,742.6 (4,305.8-5,170.5) vs 4,520.1 (4,055.3- 4,948.3) pg/mL (P=0.85). In a multivariate linear regression analysis model, the presence of kidney dysfunction explained 41% of the variability in ghrelin values, while sex and body mass index accounted for another 5%. The etiology of renal failure (diabetic nephropathy or nephropathy from other causes) had no influence on ghrelin levels in the renal failure patients. Plasma ghrelin levels were associated with the early diastolic to atrial peak velocity ratio (P=0.003), but not with indices of systolic function of the left ventricle, left ventricular mass, myocardial performance index, or with blood pressure in the CRF patients.
CONCLUSIONS Fasting plasma total ghrelin concentrations are higher in patients with renal failure, regardless of their need for hemodialysis, compared to control subjects. The etiology of renal failure (diabetic nephropathy or nephropathy from other causes) has no effect on ghrelin levels. In addition, plasma ghrelin levels are not associated with hemodynamic parameters in patients with CRF.
Key words: Chronic renal failure, Ejection fraction, Left ventricular mass, Myocardial performance index, Plasma ghrelin.