Recombinant human insulin-like growth factor-I (IGF-I) therapy decreases plasma leptin concentration in patients with chronic renal insufficiency.
OBJECTIVE
To determine the relationship between plasma leptin and insulin-like growth factor-I (IGF-I) levels in healthy subjects and patients with chronic renal insufficiency at baseline, and during administration of recombinant human IGF-I in the renal impaired patients.


METHODS
20 healthy subjects (six men, 14 women, age: 42.7 +/- 3.2 y) and nine subjects with chronic renal insufficiency (five men, four women, age: 53.6 +/- 3.7 y).


METHODS
Daily s.c. injection of recombinant human IGF-I (50 micrograms/kg) for 24 d.


METHODS
Fasting plasma levels of leptin, IGF-I, growth hormone, C-peptide, glucagon and IGF binding proteins by specific radioimmunoassays at baseline in all subjects and serially during IGF-I therapy in the renal impaired subjects.


RESULTS
Baseline leptin levels were correlated with body mass index (BMI, R = 0.72, P = 0.0001) but not IGF-I levels (R = 0.02). During IGF-I therapy, plasma IGF-I levels increased from 128 +/- 17.4 ng/ml at baseline to 250 +/- 36.8 ng/ml on day 3 (P = 0.003) and 323 +/- 61.6 ng/ml on day 24 (P = 0.01), whereas leptin levels declined: 24.4 +/- 10.3 ng/ml (baseline), 19.5 +/- 6.2 ng/ml (day 3, P = 0.028), and 17.2 +/- 4.9 ng/ml (day 24, P = 0.05).


CONCLUSIONS
Basal plasma leptin and IGF-I levels are not correlated; however, chronic administration of recombinant IGF-I is associated with an early and sustained decrease in plasma leptin levels. IGF-I may have an inhibitory effect on leptin secretion in humans.
Dagogo-Jack
S
S
Department of Medicine, Washington University School of Medicine, St Louis, MO 63110, USA.
Franklin
S C
SC
Vijayan
A
A
Liu
J
J
Askari
H
H
Miller
S B
SB
D000328:Adult; D001665:Binding Sites; D015992:Body Mass Index; D002096:C-Peptide / Q000097:blood; D005260:Female; D005934:Glucagon / Q000097:blood; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins / Q000097:blood; D007334:Insulin-Like Growth Factor I / Q000627:therapeutic use*; D007676:Kidney Failure, Chronic / Q000188:drug therapy*; D020738:Leptin; D008297:Male; D008875:Middle Aged; D011506:Proteins / Q000378:metabolism*; D011863:Radioimmunoassay; D017526:Receptor, IGF Type 1 / Q000378:metabolism; D054411:Receptors, Leptin; D011994:Recombinant Proteins / Q000627:therapeutic use
D002096:C-Peptide; D018969:Insulin-Like Growth Factor Binding Proteins; C515448:LEPR protein, human; D020738:Leptin; D011506:Proteins; D054411:Receptors, Leptin; D011994:Recombinant Proteins; D007334:Insulin-Like Growth Factor I; D005934:Glucagon; D017526:Receptor, IGF Type 1