Hypertriglyceridemia is associated with increased risk for stone recurrence in patients with urolithiasis.

OBJECTIVE

To assess the influence of dyslipidemia on urinary lithogenic metabolites and stone recurrence in stone formers.

MATERIALS AND METHODS

We retrospectively selected 321 patients with urolithiasis who had been followed up for >24 months between 2004 and 2009. Fasting blood samples were taken, and serum lipid profiles were measured. All subjects also underwent 24-hour urinary metabolic evaluation and stone analysis. The radiographic appearance of new stones was defined as stone recurrence.

RESULTS

There was no significant correlation between lipid profiles and 24-hour urine metabolites (all P >.05). Stone formers with hypertriglyceridemia had significantly higher urinary calcium, sodium, uric acid, magnesium, and potassium excretions. Only in a subgroup of uric acid stone, hypertriglyceridemia was significantly associated with decreased urinary pH. Those with low high-density lipoprotein (HDL) cholesterolemia had higher urinary sodium, magnesium, and potassium excretions, whereas those with high low-density lipoprotein (LDL) cholesterolemia had lower urinary sodium excretion. Stone analysis revealed that uric acid stones were more commonly found in patients with hypertriglyceridemia and low-HDL cholesterolemia. After a median follow-up of 35.0 months, 109 patients (34% of cohort) had stone recurrence. Stone recurrence was more common in the hypertriglyceridemia group compared with the normal triglyceridemia group (45.9% vs 29.7%; P = .005). The multivariate Cox regression model revealed that hypertriglyceridemia is associated independently with stone recurrence (hazard ratio, 1.857; 95% confidence interval, 1.211-2.847; P = .005). Kaplan-Meier curves showed similar results.

CONCLUSION

Our study showed that serum lipid profile is associated with urine metabolic alterations. More importantly, hypertriglyceridemia is independently associated with increased risk for stone recurrence in patients with urolithiasis.