Hypercholesterolemia in children with cystinosis.

Ten children with cystinosis had their diet, serum creatinine, and total cholesterol (averaged in 6-month blocks and normalized by calculating a z score (TCz)] monitored for a mean of 5 years. The TCz scores were elevated in boys (P < 0.01) but not girls (P = 0.67). The boys had elevated TCz scores for 58% of their 29 pre-transplantation years of follow-up, rising as early as 1 year of age at a mean rate of 0.67 standard deviations per year. Cystinotic boys had higher TCz scores than children with other tubular disorders (P < 0.025). All 4 cystinotic boys who developed renal insufficiency had a rise in TCz scores at a rate greater than control children with comparable renal impairment. Two cystinotic boys received a renal transplant; subsequent TCz scores were markedly lower, but remained elevated. The nutritional status of cystinotic children deteriorates after 3 years of age: they have decreased fat stores, elevated TCz scores and consume high fat diets insufficient in total calories. In summary, cystinotic boys have marked, progressive hypercholesterolemia which improves after renal transplantation.