Hyperleptinemia is not responsible for decreased paraoxonase activity in hemodialysis patients.
BACKGROUND
Exogenous leptin markedly decreased plasma paraoxonase (PON1) activity in rats. Hyperleptinemia and decreased PON1 activity have previously been demonstrated in uremia. Therefore, we investigated the relationship between leptin level and PON1 activity in hemodialysis (HD) patients.


METHODS
Leptin and PON1 were determined in 40 HD patients and 40 age-matched controls with similar body mass index (BMI).


RESULTS
Leptin was higher (p < 0.001) and PON1 activity was lower (p < 0.001) in HD patients than in controls. PON1 and PON1/HDL ratio was higher in HD patients with BMI >25 kg/m2 than in HD patients with BMI <25 kg/m2. It was not due to a difference in frequency of high activity phenotype of PON1 among subgroups of HD patients. There was no similar difference in controls. Spearman analysis showed a significant correlation between leptin and PON1 activity (p < 0.02), BMI (p < 0.001), triglyceride (TG) (p < 0.03), and Kt/V (-0.323, p < 0.03), but multiparametric regression analysis did not reveal it. PON1 activity depended on BMI in both models. In controls, leptin correlated with BMI (p < 0.001) and TG (p < 0.002) but not PON1 activity. A slight decrease in leptin concentration and PON1 activity during HD was observed.


CONCLUSIONS
Our results suggest the role of other pathophysiological conditions besides hyperleptinemia resulting in decreased PON1 activity in HD patients.
Varga
Zsuzsa
Z
Division of Nephrology, 1st Department of Medicine, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary. vargazs@internal.med.unideb.hu
Paragh
Gyorgy
G
Seres
Ildiko
I
Kakuk
Gyorgy
G
Karanyi
Zsolt
Z
Karpati
Istvan
I
Matyus
Janos
J
Csongradi
Eva
E
Juhasz
Attila
A
Balla
Jozsef
J
Bajnok
Laszlo
L
D000328:Adult; D000368:Aged; D043303:Aryldialkylphosphatase / Q000097:blood*; D015992:Body Mass Index; D016022:Case-Control Studies; D006801:Humans; D020738:Leptin / Q000097:blood*; D008075:Lipoproteins, HDL / Q000097:blood; D008875:Middle Aged; D009994:Osmolar Concentration; D006435:Renal Dialysis; D013997:Time Factors; D014280:Triglycerides / Q000097:blood
D020738:Leptin; D008075:Lipoproteins, HDL; D014280:Triglycerides; D043303:Aryldialkylphosphatase; C468406:PON1 protein, human