Fluid Intake and Dietary Factors and the Risk of Incident Kidney Stones in UK Biobank: A Population-based Prospective Cohort Study.

BACKGROUND: Fluid intake and diet are thought to influence kidney stone risk. However, prospective studies have been limited to small samples sizes and/or restricted measures. OBJECTIVE: To investigate whether fluid intake and dietary factors are associated with the risk of developing a first kidney stone. DESIGN, SETTING, AND PARTICIPANTS: Participants were selected from UK Biobank, a population-based prospective cohort study. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Cox proportional hazards models were used to investigate the association between fluid intake and dietary factors and the risk of a first incident kidney stone, ascertained from hospital inpatient records. RESULTS AND LIMITATIONS: After exclusion, 439 072 participants were available for the analysis, of whom 2057 had hospital admission with an incident kidney stone over a mean of 6.1 yr of follow-up. For every additional drink (200 ml) consumed per day of total fluid, the risk of kidney stones declined by 13% (hazard ratio [HR] = 0.87, 95% confidence interval [CI] 0.85-0.89). Similar patterns of associations were observed for tea, coffee, and alcohol, although no association was observed for water intake. Fruit and fibre intake was also associated with a lower risk (HR per 100 g increase of fruits per day = 0.88, 95% CI 0.83-0.93, and HR per 10 g fibre per day = 0.82, 95% CI 0.77-0.87), whereas meat and salt intake was associated with a higher risk (HR per 50 g increase in meat per week = 1.17, 95% CI 1.05-1.29, and HR for always vs never/rarely added salt to food = 1.33, 95% CI 1.12-1.58). Vegetable, fish, and cheese intake was not associated with kidney stone risk. CONCLUSIONS: The finding that high intake of total fluid, fruit, and fibre was associated with a lower risk of hospitalisation for a first kidney stone suggests that modifiable dietary factors could be targeted to prevent kidney stone development. PATIENT SUMMARY: We found that higher intake of total fluid, specifically tea, coffee, and alcohol (but not water), and consumption of fruit and foods high in fibre are linked with a reduced likelihood of developing kidney stones.

A clinical evaluation of the new digital single-use flexible ureteroscope (UscopePU3022): an international prospective multicentered study.

INTRODUCTION: We assessed the clinical performance of a new digital single-use flexible ureteroscope (UscopePU3022). MATERIAL AND METHODS: A prospective cohort study was carried out across 11 centers (July-Oct. 2017). The UscopePU3022 was assessed regarding ease of insertion; deflection, image quality, maneuverability and overall performance using either a visual analog* or Likert scale. RESULTS: A total of 56 procedures were performed in 11 centers (16 surgeons) with the indication being renal stones in 83%. The median score for ease of scope insertion was 10 (3-10). Intraoperative maneuverability was rated as 'good' in 38% and 'very good' in 52%. Visual quality was rated as 'poor or bad' in 18%, 'fair' in 37% and 'good or very good' in 43%. Two scopes failed intraoperatively (4%). Preoperative and postoperative median upward and downward deflection was 270 degrees. Compared to standard flexible ureteroscopy (f-URS) maneuverability was rated as 'equivalent' in 30% and 'better' in 60%; visual quality was 'worse' in 38% and 'equivalent or better' in 62%; limb fatigue scores were 'better' in 86%; and overall performance was 'worse' in 55% and 'equivalent or better' in 45%. CONCLUSIONS: UscopeTM3022 performed well with regards to maneuverability, deflection and limb fatigue and appears to be at least non-inferior to standard f-URS with regards to these parameters. Poor image quality is a concern for UscopePU3022 with it receiving a low overall performance rating when compared to standard f-URS. Despite this it scored highly when investigators were asked if they would use it in their practice if it was cost-effective to do so.