Diet can be a helpful tool to enhance the quality of urine and lower the likelihood and recurrence of kidney stones. This study set out to identify the foods and nutrients that are associated with each type of calcium oxalate kidney stone formation. A single-center, cross-sectional study was conducted. Between 2018 and 2021, a sample of 90 cases (13 cases with papillary COM, 27 with non-papillary COM, and 50 with COD kidney stones), as well as a control group of 50 people, were chosen. A food intake frequency questionnaire was completed by the study’s participants, and the results were compared between groups. Additionally, a comparison of the 24 h urine analysis between stone groups was made. Processed food and meat derivatives were linked to COM papillary calculi (OR = 1.051, p = 0.032 and OR = 1.013, p = 0.012, respectively). Consuming enough calcium may offer protection against non-papillary COM stones (OR = 0.997; p = 0.002). Similarly, dairy product consumption was linked to COD calculi (OR = 1.005, p = 0.001). In conclusion, a diet high in animal items may increase the risk of developing papillary COM stones. Consuming calcium may be preventive against non-papillary COM calculi, and dairy product consumption may be a risk factor for COD stones.

(1) Background: This study aimed to determine the relationship between metabolic urine conditions and the formation, severity, and composition of encrustations in ureteral stents. (2) Methods: Ninety stone-former patients requiring a double-J stent were prospectively enrolled. We collected 24 h metabolic urine samples and demographic data, including indwelling time and previous stone composition. The total deposit weight was obtained, and a macroscopic classification according to the degree of encrustation (null, low, moderate, and high) was created, allowing for intergroup comparisons. Stereoscopic and scanning electron microscopy were performed to identify the type of embedded deposits (calcium oxalate, uric acid, and infectious and non-infectious phosphates). (3) Results: In total, 70% of stents were encrusted; thereof, 42% had a moderate degree of encrustation. The most common encrustation type was calcium oxalate, but infectious phosphates were predominant in the high-encrustation group (p < 0.05). A direct correlation was observed between the purpose-built macroscopic classification and the encrustation weights (p < 0.001). Greater calciuria, uricosuria, indwelling time, and decreased diuresis were observed in stents with a higher degree of encrustation (p < 0.05). The urinary pH values were lower in patients with uric acid encrustations and higher in those with infectious phosphate encrustations (p < 0.05). When compared to non-encrusted stents, patients with calcium-oxalate-encrusted stent showed greater calciuria, phosphaturia, indwelling time, and reduced diuresis; patients with uric-acid-encrusted stent showed greater uricosuria; and patients with infectious and non-infectious phosphate encrustation showed greater urinary pH (p < 0.05). (4) Conclusions: Metabolic urine conditions play a critical role in the formation, composition, and severity of double-J stent encrustation.

Background: Our purpose was to study the relationship of the 3 different types of endoscopic calcifications of the renal papilla (Randall’s plaque, intratubular calcification, papillary crater) with the type of stone and urine analysis. Methods: This prospective study examined 41 patients (age range: 18 to 80 years) who received retrograde intrarenal surgery (RIRS) for renal lithiasis (mean stone size: 15.3 ± 7.2 mm). The renal papilla injuries were endoscopically classified as Randall’s plaque, intratubular calcification, or papillary crater. Calculi were classified as uric acid, calcium oxalate monohydrate (COM; papillary and cavity), calcium oxalate dihydrate (COD), or calcium phosphate (CP). A 24 h urine analysis of calcium, oxalate, citrate, phosphate, and pH was performed in all patients. The relationship of each type of papillary injury with type of stone and urine chemistry was determined. Fisher’s exact test and Student’s t-test were used to determine the significance of relationships, and a p value below 0.05 was considered significant. Results: The most common injury was tubular calcification (78%), followed by Randall’s plaque (58%), and papillary crater (39%). There was no significant relationship of Randall’s plaque with type of stone. However, endoscopic intratubular calcification (p = 0.025) and papillary crater (p = 0.041) were more common in patients with COD and CP stones. There were also significant relationships of papillary crater with hypercalciuria (p = 0.036) and hyperoxaluria (p = 0.024), and of Randall’s plaque with hypocitraturia (p = 0.005). Conclusions: There are certain specific relationships between the different types of papillary calcifications that were endoscopically detected with stone chemistry and urine analysis. COD and CP stones were associated with endoscopic tubular calcifications and papillary craters. Hypercalciuria was associated with tubular calcification, and hypocitraturia was associated with Randall’s plaque.

Background: Idiopathic hypercalciuria (IH) is the most common genetic metabolic disorder in patients with urinary stones and is usually treated with thiazide-type diuretics. However, direct evidence comparing low-dose indapamide and hydrochlorothiazide is scarce. This study aimed to compare their safety, efficacy and adherence in patients with IH. Methods: In this randomized prospective trial, a total of 101 patients with IH were recruited at Son Espases University Hospital (2020–2023), assigned to receive indapamide 1.5 mg/day (n = 53) or hydrochlorothiazide 25 mg/day (n = 48), and followed for 18 months. Adverse events, biochemical parameters and therapeutic adherence were evaluated. Results: A total of 90.24% patients on indapamide and 85.71% on hydrochlorothiazide showed normal calciuria (p = 0.53). Both treatments increased serum urate (p = 0.62). Indapamide significantly reduced β-crosslaps (p < 0.05), suggesting bone protection. No significant differences were found in citraturia, uricosuria, phosphaturia, magnesiuria, magnesemia, natremia, or kalemia. Indapamide caused more mild adverse events, lowering adherence, while hydrochlorothiazide caused the only severe adverse effect—moderate hypokalemia. No differences in kidney stone recurrence were observed (p = 0.82). Conclusions: This is the first paper elucidating low-dose indapamide and hydrochlorothiazide efficacy and safety for the treatment of IH. No significant differences were observed between the two drugs in terms of adverse events or treatment adherence. A longer follow-up is needed to assess kidney stone recurrence.

Background: Adults who have incomplete distal renal tubular acidosis (dRTA) may present with recurrent urolithiasis due to metabolic acidosis, leading to bone resorption, which in turn causes hypercalciuria and urine alkalinization (pH > 6.0). Oral potassium citrate is the most commonly used treatment for dRTA, but some patients cannot tolerate this treatment. The objective of this single-arm study was to evaluate the effect of phytate, an inhibitor of bone resorption, on calciuria of patients with incomplete dRTA. Methods: The calciuria levels of 16 patients who had incomplete dRTA with urolithiasis and could not tolerate potassium citrate treatment were recorded before (baseline) and after 6 months of treatment with oral calcium magnesium phytate (380 mg every 12 h). There were no dietary modifications or other treatments. Results: The baseline calciuria was 317 ± 81 mg/24 h and the level after 6 months was 221 ± 38 mg/24 h (p < 0.005). Conclusions: Our results suggest that calcium magnesium phytate should be considered as an alternative or adjunctive treatment for hypercalciuria in patients with incomplete dRTA.