Are ghrelin and leptin involved in food intake and body mass index in maintenance hemodialysis?

Abstract

Objectives: Both leptin and ghrelin (in the forms of acyl ghrelin and des-acyl ghrelin) are involved in food intake, and appear to be dysregulated in chronic kidney disease. This study describes plasma leptin, acyl, and des-acyl ghrelin concentrations in relation to protein intake and body mass index (BMI) in hemodialysis (HD) patients.

Design: This was a cross-sectional study.

Setting: This study was conducted during the baseline phase of the French multicenter Influence of a High-Flux Dialyzer on Long-Term Leptin Levels Study.

Patients: We studied 125 HD patients (aged 72.5+/-11.7 years; 59% males).

Main outcome measure: Blood samples were collected during fasting, and before a regular HD session. Plasma ghrelin and leptin were evaluated. The protein equivalents of total nitrogen appearance and BMI were calculated.

Results: Patients demonstrated elevated serum leptin (48.0+/-49.0 ng/mL) and des-acyl ghrelin (646.6+/-489.5 pg/mL) levels, and low acyl ghrelin levels (29.8+/-58.5 pg/mL), according to normal values. Acyl ghrelin was negatively correlated with C-reactive protein (r=-0.34, P < .001). The des-acyl to acyl ghrelin ratio was negatively correlated with protein intake, as estimated by normalized Protein Nitrogen Appearance (r=-0.22, P=.01). Serum leptin exhibited its well-described positive correlation with BMI and waist circumference, but the other hormones did not.

Conclusions: This study reports high des-acyl ghrelin and leptin levels and low acyl ghrelin levels in HD patients, a finding potentially associated with inflammation and food intake.