Cholesterol absorption and synthesis in pediatric kidney, liver, and heart transplant recipients.
BACKGROUND
Hypercholesterolemia after organ transplantation is common. Previously, we observed higher serum total cholesterol (TC) concentrations in our pediatric kidney than liver or heart transplant recipients. To find an explanation to the observed difference, our kidney recipients' cholesterol synthesis and absorption efficiency was compared to those of liver and heart recipients.


METHODS
Serum noncholesterol sterol ratios (10 x mmol to the mol of TC, surrogate estimates of hepatic cholesterol synthesis and intestinal absorption) were studied in 50 pediatric kidney, 25 liver and 12 heart transplant recipients without diabetes or cholestasis, and in 29 controls.


RESULTS
The kidney recipients had lower Delta-cholesterol (P=0.031), similar lathosterol and higher desmosterol ratios (markers of cholesterol synthesis) (P=0.020), and similar campesterol and sitosterol ratios (markers of cholesterol absorption) when compared to the controls. The liver recipients had lower campesterol ratios than the kidney recipients and controls (P=0.002). Glomerular filtration rates were not associated with the ratios of noncholesterol sterols. Multivariate analysis showed markers of cholesterol synthesis to be lower and absorption to be higher in the kidney than the liver or the heart transplant recipients. Weight-adjusted dosages of immunosuppressive agents were associated with some ratios of noncholesterol sterols and cholestanol though these varied between the transplant recipient groups.


CONCLUSIONS
Serum TC concentration in kidney recipients was not significantly associated with absorption efficiency or synthesis of cholesterol, though kidney transplantation was associated with low synthesis and high absorption efficiency of cholesterol. Immunosuppressive therapy with cyclosporine and methylprednisolone may modulate absorption efficiency and synthesis of cholesterol.
Siirtola
Arja
A
Pediatric Research Center, University of Tampere, Tampere, Finland. arja.siirtola@uta.fi
Ketomäki
Anna
A
Miettinen
Tatu A
TA
Gylling
Helena
H
Lehtimäki
Terho
T
Holmberg
Christer
C
Salo
Matti K
MK
Antikainen
Marjatta
M
D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D002784:Cholesterol / Q000096:biosynthesis / Q000097:blood*; D004041:Dietary Fats / Q000008:administration & dosage; D005260:Female; D016027:Heart Transplantation; D006801:Humans; D016030:Kidney Transplantation; D016031:Liver Transplantation; D008297:Male; D013185:Squalene / Q000097:blood; D013261:Sterols / Q000097:blood
D004041:Dietary Fats; D013261:Sterols; D013185:Squalene; D002784:Cholesterol