The Effect of the Amount and Type of Liquid Intake on Kidney Calculi: A Case-Control Study

Urinary calculi are a common problem worldwide. The pattern of fluid consumption in healthy people and patients with renal calculi is not totally clear. The aim of this study was to determine the association between the amount of fluids intake and urinary calculi. In this case-control study, cases were the patients with urinary calculi admitted to Emam-Hossein Hospital, Shahroud, Iran. The controls were selected among the patients admitted to other wards of the hospital except for dialysis and ICU wards. The association between independent variables and urinary calculi was investigated using logistic regression analysis. A total of 127 people (60 cases and 67 controls) participated in this study. The mean age of the participants was 44.6 years (SD = 1.7). The mean intake of tea, natural juice, alcohol free beer, and total fluid intake were higher in cases compare to controls. In participants with a negative history of urinary calculi, the total intake of fluid (P=0.021) and natural juice (P=0.006) was higher in cases. The male gender (OR=3.2), higher BMI (OR=1.2), and a positive family history of urinary calculi (OR=3.5) were associated with renal calculi in a multivariate logistic regression model, while the milk intake (OR=0.995) was a protective factor in this model. Milk intake is a protective factor and the male gender, higher BMI and a positive family history are the risk factors for urinary calculi.