A nationwide cross-sectional survey was conducted among individuals aged ≥18 years across China, from May 2013 to July 2014. Participants underwent urinary tract ultrasonographic examinations, completed pre-designed and standardised questionnaires, and provided blood and urine samples for analysis. Kidney stones were defined as particles of ≥4 mm. Prevalence was defined as the proportion of participants with kidney stones and binary logistic regression was used to estimate the associated factors. ResultsA total of 12 570 individuals (45.2% men) with a mean (sd, range) age of 48.8 (15.3, 18-96) years were selected and invited to participate in the study. In all, 9310 (40.7% men) participants completed the investigation, with a response rate of 74.1%. The prevalence of kidney stones was 6.4% [95% confidence interval (CI) 5.9, 6.9], and the age-and sex-adjusted prevalence was 5.8% (95% CI 5.3, 6.3; 6.5% in men and 5.1% in women). Binary logistic regression analysis showed that male gender, rural residency, age, family history of urinary stones, concurrent diabetes mellitus and hyperuricaemia, increased consumption of meat, and excessive sweating were all statistically significantly associated with a greater risk of kidney stones. By contrast, consumption of more tea, legumes, and fermented vinegar was statistically significantly associated with a lesser risk of kidney stone formation. ConclusionKidney stones are common among Chinese adults, with about one in 17 adults affected currently. Some Chinese dietary habits may lower the risk of kidney stone formation.

The objective of the study was to analyze the treatment outcomes for staghorn stones in patients with solitary kidney using either the single-tract or the multi-tract minimally invasive percutaneous nephrolithotomy (MPCNL). We retrospectively reviewed 105 patients who underwent MPCNL for staghorn calculi in solitary kidney from 2012 to 2014. The patients who underwent the single-tract approach (71 patients) were assigned to Group 1. The 34 patients who underwent the multi-tract approach (34 patients) were assigned to Group 2. We recorded and compared the patient's demographics, intraoperative parameters, and post-operative outcomes. We also analyzed any complications as a result of the particular procedure, as well as any resulting stone-free rates (SFRs). The mean number of access tracts was 2.38 ± 0.70 (range 2-4) for Group 2. The mean operative time was longer for Group 2, p = 0.01. The initial SFR was 52.1% for Group 1 and 47.1% for Group 2 after the one-session procedure, p = 0.63.The final SFR improved to 83.1 and 79.4% for both groups following auxiliary treatment, p = 0.65. The mean hemoglobin drop was higher in Group 2 as compared to Group 1, p < 0.01. There was no significant difference in the change of mean serum creatinine in either group. There were fewer overall complications in Group 1 than in Group 2 (23.9 vs. 44.1%). Almost half of the patients who underwent multi-tract MPCNL required an additional procedure to achieve satisfactory stone clearance. The results showed that single-tract MPCNL might be a better treatment option for staghorn stones in a solitary kidney with the same therapeutic outcome, but with less complications.

The present study revealed the normal metabolic status for stone risk factors of the Chinese Han population. It is therefore necessary for each country or region to define their own reference intervals for comparison of stone risk factors between patients and healthy subjects.