Malnutrition is prevalent in patients with
end-stage renal disease (
ESRD). Elevated serum
leptin levels were thought to contribute to the
anorexia and poor nutrition in
renal failure. However, studies of the relationship between nutritional status and
leptin concentration in
chronic renal failure have yielded conflicting results. Plasma
insulin-like growth factor I (
IGF-I) level has been used as an
indicator of nutritional status in patients with
renal failure. The relationship between
leptin and
IGF-I is controversial. The present study was conducted with the aim of assessing the relationship between nutritional status, hyperleptinemia, and serum
IGF-I. Seventeen
ESRD patients (8 male, 9 female), aged 8-18 years (mean 15.3+/-3.3 years) and undergoing standard
hemodialysis for 58.8+/-23.1 months were enrolled. Nine age-matched healthy children served as controls. In all patients, energy and
protein intakes were 40-70 kcal/kg per day and 1-1.54 g/kg per day, respectively. Predialysis serum
leptin and
IGF-I levels were measured by radioimmunoassay. Body mass index was decreased in 13 (76%) patients. Triceps skinfold thickness (TST) was reduced (below the 5th percentile) in 7 (41%), whereas mid arm circumference and mid arm muscle circumference were reduced in 14 (82.5%) and 13 (76.5%), respectively. The median serum
leptin level was significantly higher in patients than in controls [13.7 interquartile range (IQR) 30.50 pg/ml vs. 6.50 IQR 8.65 pg/ml, P=0.01]. The median serum
IGF-I level was lower in the patients (205.1 ng/ml IQR 194.4 ng/l) than controls (418.0 ng/l IQR 310.5 ng/ml) ( P=0.01).
IGF-I levels were more decreased in patients with severe
malnutrition, defined according to TST (145.0 ng/ml IQR 125.5 ng/l) than patients without
malnutrition (301.2 ng/l IQR 218.8 ng/ml) ( P=0.03) and healthy children ( P=0.002). Although statistically not significant,
IGF-I levels tended to be decreased, while
leptin levels were increased. The median plasma
insulin concentration was 15 microU/ml (1.63-45.80) and did not correlate with
leptin and
IGF-I levels. In conclusion, the results of this study confirm the presence of high circulating plasma
leptin levels, which may be one of the many factors involved in the pathogenesis of the
malnutrition in children on
hemodialysis.