Does fluid amount and choice influence urinary stone formation in persons with spinal cord injury?

OBJECTIVE

To examine the effects of fluid intake and beverage type on stone formation in persons with spinal cord injury (SCI).

DESIGN

A matched case-control study.

SETTING

A rehabilitation center within a university hospital.

PATIENTS: Forty-one patients with SCI who were diagnosed with urinary stones between 1992 and 1998 (stone cases) and 171 age- and duration-matched controls were interviewed by telephone.

INTERVENTIONS: Not applicable.

MAIN OUTCOME MEASURES: Urinary stones.

RESULTS

Stone cases were more likely than controls to be white, to be current smokers, to be users of indwelling catheterization, and to have a lower body mass index (kg/m(2)), worse renal function, and higher urine specific gravity (P<.10). In a multivariable model that adjusted simultaneously for other possible risk factors, the greater consumption of juice (>207mL/d) was associated with a 70% decreased risk (odds ratio=0.3; 90% confidence interval, 0.1-1.0). An interesting, but not significant (P=.15), increased risk for coffee consumption was observed. There was no association for total fluid intake.

CONCLUSION

Total fluid intake does not appear to determine stone occurrence; however, fluid type may influence stone formation in persons with SCI. Further study is required to verify these findings, thus possibly leading to an effective fluid regimen for stone prophylaxis.