Dietary and behavioral risk factors for urolithiasis: potential implications for prevention

Few studies have examined urolithiasis in primary care populations, and limited data are available on non-drug interventions to reduce the risk for urinary calculi. Therefore, we conducted a case control study of patients enrolled in a large prepaid health maintenance organization. The 240 study cases were men experiencing initial episodes of urolithiasis, ascertained by reviewing radiology procedure logs and medical records. The 392 controls were age-matched men with no history of urolithiasis chosen from a list of randomly selected men. Data were collected using standardized telephone interviews. Odds ratios were calculated for potential risk factors. In logistic regression analyses the risk for urinary tract calculi was related to both consumption variables, such as a low-fat or weight reduction diet (adjusted odds ratio, 0.41; P < 0.0005) and beer drinking (adjusted odds ratio, 0.41; P < 0.0001), and to demographic variables, such as African-American ethnicity (adjusted odds ratio, 0.29; P = 0.03) and a positive family history (adjusted odds ratio, 2.22; P < 0.001). These findings suggest the need to evaluate appropriate behavioral interventions to reduce the morbidity associated with urolithiasis. Prospective studies should evaluate the possibilities that beer drinking, even in modest amounts, and a low-fat or weight reduction diet are associated with substantial reductions in risk.