Role of Citrus Fruit Juices in Prevention of Kidney Stone Disease (KSD): A Narrative Review

To explore the relationship between citrus fruit juices (oranges, grapefruits, and lemonades) and kidney stone disease (KSD). Methods: A systematic review was performed using the Medline, EMBASE, and Scopus databases, in concordance with the PRISMA checklist for all English, French, and Spanish language studies regarding the consumption of citrus fruit juices and the relationship to urinary stone disease. The main outcome of interest was the association of citrus fruit juices with KSD. Results: Thirteen articles met the criteria for inclusion in the final review. Three large epidemiological studies found that grapefruit juice was a risk factor for stone formation, while orange juice did not increase the risk for KSD. Ten small prospective clinical studies found that orange, grapefruit, and lemon juices all increased urinary citrate levels. Only orange and grapefruit juices had an alkalinizing effect and while lemon juice has a protective effect by raising urinary citrate levels, it lacked a significant alkalinizing effect on urine pH. Orange juice and grapefruit juices significantly increased urinary oxalate levels, while orange juice also had a high carbohydrate content. Conclusion: While orange juice seems to play a protective role against stone formation, grapefruit was found to raise the risk of KSD in epidemiological studies but had a protective role in smaller clinical studies. Lemon juice had a smaller protective role than orange juice. Larger amounts of, as well as more accurate, data is needed before recommendations can be made and a high carbohydrate content in these juices needs to be taken into consideration.

Urinary risk factors for calcium oxalate urolithiasis in children with monosymptomatic enuresis

Introduction: A disturbed calcium-phosphate balance is an important issue for kidney stone formation in nephrolithiasis. Hypercalciuria (HC) has been proposed as an essential etiology of monosymptomatic nocturnal enuresis (MNE). Objectives: We may suspect that patients with MNE may be at risk of stone formation hence the objective of this paper was to assess the risk in MNE children using Bonn Risk Index (BRI). Patients and Methods: The urinary work-up of 204 children (83 with MNE and 121 controls) included urinary calcium (Ca), magnesium (Mg) and sodium (Na) excretion, Ca/creatinine ratio, BRI, ionized calcium (Ca2+), Mg/creatinine and Ca/citrate ratios, urinary citrates and oxalates (Ox). Results: Ca/creatinine and Mg/creat ratios were higher in the MNE group. There were no differences in Mg and Ca amount in urine and Mg/Ca ratio between MNE and the reference group. Both groups differed in Mg and Ca excretion per kg of body mass. MNE children differed from controls regarding BRI, Ox and urinary Ca2+. No differences in urinary citrate excretion nor Ca/citrate ratio between MNE and the controls were found. Correlations between factors important in the crystallization process in MNE children were recorded. Conclusion: MNE patients may be at risk of oxalate nephrolithiasis. Further studies to assess the role of the BRI and Ca/citrate ratio in predicting stone formation in MNE children are needed.

Association of urinary sex steroid hormones with urinary calcium, oxalate and citrate excretion in kidney stone formers

Background Sex-specific differences in nephrolithiasis with respect to both distribution of prevalence and stone composition are widely described and may be influenced by sex hormones. Methods We conducted a cross-sectional analysis of the relationship between 24-hour urinary sex hormone metabolites measured by gas chromatography–mass spectrometry with urinary calcium, oxalate and citrate excretion in a cohort of 628 kidney stone formers from a tertiary care hospital in Switzerland, taking demographic characteristics, kidney function and dietary factors into account. Results We observed a positive association of urinary calcium with urinary testosterone and 17β-estradiol. Positive associations of urinary calcium with dehydroepiandrosterone, 5α-DH-testosterone, etiocholanolone, androsterone, and estriol were modified by net gastrointestinal alkali absorption or urinary sulfate excretion. As the only sex hormone, dehydroepiandrosterone was inversely associated with urinary oxalate excretion in adjusted analyses. Urinary citrate correlated positively with urinary testosterone. Associations of urinary citrate with urinary androsterone, 17β-estradiol and estriol were modified by urinary sulfate or sodium, or by sex. Conclusions Urinary androgens and estrogens are significantly associated with urinary calcium and citrate excretion, and associations are in part modified by diet. Our data furthermore reveal dehydroepiandrosterone as a novel factor associated with urinary oxalate excretion in humans.

The association of dietary inflammatory index with urinary risk factors of kidney stones formation in men with nephrolithiasis

Objective: Inflammation plays a leading role in the pathogenesis of nephrolithiasis. The association of the dietary inflammatory index (DII) with urinary lithogenic factors is unclear. This study aimed to evaluate the relation of DII to urinary risk factors of kidney stones formation.Results: Of 264 participants, 61.4% (n= 162), 72% (n=190), 74.6% (n=197), 68.6% (n=181), and 80.3% (n=212) had hyperoxaluria, hypercreatininuria, hypercalciuria, hyperuricosuria, hypocitraturia, respectively. There was a significant increasing trajectory in urinary calcium, uric acid, and creatinine as well as a decreasing trend in urinary citrate across tertiles of DII score (all P=≤0.001). After multivariate adjustment for energy intake, age, physical activity and body mass index, high DII scores were associated with elevated odds of having hypercreatininuria (OR=2.80, 95%CI: 1.10-7.12, Ptrend=0.04), hypercalciuria (OR=7.44, 95%CI: 2.62-21.14, Ptrend≤0.001), hyperuricosuria (OR=2.22, 95%CI: 1.001-4.95, Ptrend=0.05), and hypocitraturia (OR=5.84, 95%CI: 2.14-15.91, Ptrend≤0.001). No association was identified between DII and hyperoxaluria.

The association of dietary inflammatory index with urinary risk factors of kidney stones formation in men with nephrolithiasis

Objective: Inflammation plays a leading role in the pathogenesis of nephrolithiasis. The association of the dietary inflammatory index (DII) with urinary lithogenic factors is unclear. This study aimed to evaluate the relation of DII to urinary risk factors of kidney stones formation.Results: Of 264 participants, 61.4% (n= 162), 72% (n=190), 74.6% (n=197), 68.6% (n=181), and 80.3% (n=212) had hyperoxaluria, hypercreatininuria, hypercalciuria, hyperuricosuria, hypocitraturia, respectively. There was a significant increasing trajectory in urinary calcium, uric acid, and creatinine as well as a decreasing trend in urinary citrate across tertiles of DII score (all P=≤0.001). After multivariate adjustment for energy intake, age, physical activity and body mass index, high DII scores were associated with elevated odds of having hypercreatininuria (OR=2.80, 95%CI: 1.10-7.12, Ptrend=0.04), hypercalciuria (OR=7.44, 95%CI: 2.62-21.14, Ptrend≤0.001), hyperuricosuria (OR=2.22, 95%CI: 1.001-4.95, Ptrend=0.05), and hypocitraturia (OR=5.84, 95%CI: 2.14-15.91, Ptrend≤0.001). No association was identified between DII and hyperoxaluria.

The association of dietary inflammatory index with urinary risk factors of kidney stones formation in men with nephrolithiasis

Objective Inflammation plays a leading role in the pathogenesis of nephrolithiasis. The association of the dietary inflammatory index (DII) with urinary lithogenic factors is unclear. This study aimed to evaluate the relation of DII to urinary risk factors of kidney stones formation. Results Of 264 participants, 61.4% (n= 162), 72% (n=190), 74.6% (n=197), 68.6% (n=181), and 80.3% (n=212) had hyperoxaluria, hypercreatininuria, hypercalciuria, hyperuricosuria, hypocitraturia, respectively. There was a significant increasing trajectory in urinary calcium, uric acid, and creatinine as well as a decreasing trend in urinary citrate across tertiles of DII score (all P=≤0.001). After multivariate adjustment for energy intake, age, physical activity and body mass index, high DII scores were associated with elevated odds of having hypercreatininuria (OR=2.80, 95%CI: 1.10-7.12, P trend =0.04), hypercalciuria (OR=7.44, 95%CI: 2.62-21.14, P trend ≤0.001), hyperuricosuria (OR=2.22, 95%CI: 1.001-4.95, P trend =0.05), and hypocitraturia (OR=5.84, 95%CI: 2.14-15.91, P trend ≤0.001). No association was identified between DII and hyperoxaluria.