Free carnitine levels in children with steroid-sensitive nephrotic syndrome.

Abstract

Carnitine transports long-chain fatty acids across the inner mitochondrial membrane. Carnitine metabolism is disturbed in some renal diseases, such as chronic renal failure. Previous studies have shown that children had normal serum free carnitine (FC) and total carnitine levels in idiopathic nephrotic syndrome, IgA nephropathy, non-IgA nephropathy and focal segmental glomerulosclerosis. The aim of the present study was to determine FC concentrations in plasma and urine during acute and remission periods of steroid-sensitive nephrotic syndrome (SSNS) and its association with hyperlipidemia. Plasma and urinary FC concentrations were assayed in 15 children with SSNS in acute and in 16 children in remission period. Six of them were followed-up longitudinally in both periods. Plasma FC concentrations were significantly higher in the acute period of the disease than in the remission period and of the controls. The patients had lower FC levels in the remission period as compared to the controls. Urinary FC concentration was decreased in acute disease period when compared to the remission period and the controls. The FC concentrations in plasma and urine did not correlate with each other. Plasma FC exhibited significant positive correlation with low-density lipoprotein cholesterol, total cholesterol and trygliceride, but negative correlation with high-density lipoprotein cholesterol. The present study showed disturbed FC concentration in SSNS. Increased plasma and decreased urinary FC levels in acute disease might be associated with its altered renal handling or some extrarenal factors such as hyperlipidemia.