Increasing BMI Linked to Several Nephrolithiasis Risk Factors
Researchers suggest weight reduction be included in counseling of stone-formers
FRIDAY, June 11 (HealthDay News) -- Increasing body mass index (BMI) is associated with the presence of several urinary stone risk factors in the urine chemistry, suggesting that weight loss should be part of a urinary stone prevention regimen, according to a study in the June issue of Urology.
Brian H. Eisner, M.D., of the Massachusetts General Hospital in Boston, and colleagues analyzed 880 individuals evaluated at a metabolic stone clinic. The subjects were placed in quartiles by BMI, and bivariate and multivariate linear regression were used to identify associations between BMI and urine chemistry.
The analyses revealed that increasing BMI was associated with several known risk factors for urinary stone disease. In bivariate analysis in men, increased BMI was associated with increases in urinary levels of sodium, calcium, citrate, calcium oxalate, uric acid and magnesium, along with a decrease in pH. In multivariate analysis, however, it was linked only to increases in calcium oxalate and sodium and decreases in pH. In bivariate analysis in women, increased BMI was associated with significant increases in sodium, uric acid and oxalate, and decreased pH; however, in multivariate analysis, the researchers found a positive association between BMI and urine sodium, creatinine and phosphate, as well as a negative association with sulfate and citrate.
"Just as general recommendations for patients with nephrolithiasis include high voided volumes, low dietary sodium, and low animal protein intake, perhaps weight reduction should be included as part of the counseling of stone-formers to optimize 24-hour urine parameters," the authors write.