Effects of short-term recombinant human growth hormone therapy on plasma leptin concentrations in dialysis patients.
BACKGROUND
Hyperleptinaemia is a well-known biochemical feature found in uraemic patients. However, little is known about the hormonal regulation of leptin in chronic renal disease. Recent studies have shown that circulating leptin levels are modified by treatment with recombinant human growth hormone (rhGH), by recombinant insulin-like growth factor I (rhIGF I), or by a combination of rhIGF I plus rhGH in patients with chronic renal failure. We performed a prospective study to assess plasma leptin concentrations in a group of dialysis patients both before and during short-term rhGH therapy.


METHODS
We studied eight dialysis patients (four haemodialysis (HD) and four on continuous ambulatory peritoneal dialysis (CAPD); three female, five male; mean age 63.9 +/- 3.1 years). All patients were instructed to maintain a stable diet (35 kcal/kg/day and 1 g protein/kg/day ideal body weight) and were treated with rhGH (0.2 IU/kg/day s.c.) for 4 weeks. Blood samples were taken at 0, 2, 4, and 8 weeks for determination of leptin, GH, and IGF I. Serum insulin concentrations were assessed at 0 and 4 weeks.


RESULTS
Mean plasma leptin concentrations were elevated (36.2 +/- 12.8 ng/ml) at study outset and increased progressively throughout the 4 weeks of rhGH therapy (43.7 +/- 13.5 ng/ml (2 weeks, NS) and 70.6 +/- 18.4 ng/ml (4 weeks, P<0.0001)). These values returned to baseline levels (38.0 +/- 12.0 ng/ml, NS) at 1 month after rhGH withdrawal. rhGH therapy was accompanied by the development of direct correlations between leptin and IGF I concentrations at 2 weeks (r=0.86, P<0.01), and with correlations between leptin and IGF I (r=0.84, P<0.01) and between leptin and insulin (r=0.88, P<0.01) after 4 weeks of rhGH administration.


CONCLUSIONS
These results confirm the presence of high circulating plasma leptin in dialysis patients and show that these levels are further increased by exogenous rhGH administration. The increase in plasma leptin after rhGH therapy may be related to the rhGH-induced changes in insulin in these patients.
Iglesias
Pedro
P
Department of Endocrinology, Hospital General de Segovia, C/Maria Sevilla Diago, 9, 3o dcha, E-28022 Madrid, Spain. piglesias@mi.madritel.es
Díez
Juan José
JJ
Fernández-Reyes
Ma José
MJ
Bajo
Mc Auxiliadore
MA
Aguilera
Abelardo
A
Méndez
Javier
J
Codoceo
Rosa
R
Selgas
Rafael
R
D000368:Aged; D018592:Cross-Over Studies; D004334:Drug Administration Schedule; D005260:Female; D013006:Growth Hormone / Q000008:administration & dosage* / Q000627:therapeutic use; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000628:therapy*; D020738:Leptin / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009994:Osmolar Concentration; D010531:Peritoneal Dialysis, Continuous Ambulatory; D011446:Prospective Studies; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000627:therapeutic use; D006435:Renal Dialysis
D020738:Leptin; D011994:Recombinant Proteins; D013006:Growth Hormone