Eating Habits among Lithiasic Patients in Kinshasa, the Democratic Republic of Congo

Introduction: Worldwide, the incidence of kidney stones has been progressively increasing. Various factors can influence the risk of stone formation, including lifestyle and eating habits. The dietary investigation is a standard of care in patients with urolithiasis. The objectives of this study were to determine the dietary habits of lithiasis patients in the city of Kinshasa and to investigate the association between dietary habits and the composition of the stones. Material and Methods: From January 2017 to September 2019, 85 patients attending 8 hospitals participated in the nutrition survey. Various foods commonly consumed in the Democratic Republic of Congo were categorized based on their composition: foods rich in animal proteins, foods rich in calcium, foods high in sugar, foods high in oxalate, and various vegetables and fruits. We also investigated daily water intake. The composition of the collected stones was analyzed by infrared spectrophotometry. Results: The mean (SD) age of patients was 47.1 (14.0) years, 63.5% of patients were males, 75.3% of the patients had stones located in the upper urinary tract, and 7.1% were undernourished. Most of patients consumed vegetables (77.6%), animal proteins (62.4%), and foods rich in oxalate (58.8%). The daily water intake was less than 1500 mL in more than half of the patients (68.2%). Major anhydrous uric acid stones were associated with a high body mass index (p = 0.025). Male patients with a high oxalate diet had more calcium oxalate stones (64.3%) compared to other types of stones (p = 0.041). Conclusion: High consumptions of vegetables and low water intake were linked to the formation of calcium oxalate monohydrate stones. More data are needed to confirm these findings.

Adenine phosphoribosyltransferase deficiency: Leave no stone unturned

Adenine phosphoribosyltransferase(APRT)deficiency is a rare autosomal recessive disease leading to generation of large amounts of 2,8-dihydroxyadenine(DHA).DHA is excreted in urine,where it precipitates into crystals due to its low solubility.DHA crystals can aggregate into stones or cause injury to the renal parenchyma(DHA nephropathy).Recurrent urolithiasis and DHA nephropathy are the two clinical manifestations of APRT deficiency.Diagnosis of APRT deficiency can be made during childhood as well as adulthood.Diagnosis mainly relies on the recognition of DHA in stones or urine crystals.Measurement of APRT activity and genetic testing are useful for confirmation of diagnosis,for family screening and should be considered in difficult cases of urolithiasis or crystalline nephropathy.Allopurinol therapy is the cornerstone of treatment and is highly effective in preventing recurrence of stones and kidney disease.High fluid intake and dietary modifications are also recommended.Early diagnosis and treatment are of paramount importance to prevent renal damage.Unfortunately,diagnosis of APRT deficiency is often overlooked and irreversible renal failure still occurs in a substantial proportion of patients.Clinicians must be alert to the possibility of APRT deficiency and consider the appropriate diagnostic tests in certain cases.This review discusses the genetic and biochemical mechanisms of APRT deficiency,and the issues of diagnosis and management.