Dietary treatment of urinary risk factors for renal stone formation. A review of CLU Working Group.

OBJECTIVE: Diet interventions may reduce the risk of urinary stone formation and its recurrence, but there is no conclusive consensus in the literature regarding the effectiveness of dietary interventions and recommendations about specific diets for patients with urinary calculi. The aim of this study was to review the studies reporting the effects of different dietary interventions for the modification of urinary risk factors in patients with urinary stone disease. MATERIALS AND METHODS: A systematic search of the Pubmed database literature up to July 1, 2014 for studies on dietary treatment of urinary risk factors for urinary stone formation was conducted according to a methodology developed a priori. Studies were screened by titles and abstracts for eligibility. Data were extracted using a standardized form and the quality of evidence was assessed. RESULTS: Evidence from the selected studies were used to form evidence-based guideline statements. In the absence of sufficient evidence, additional statements were developed as expert opinions. CONCLUSIONS: General measures: Each patient with nephrolithiasis should undertake appropriate evaluation according to the knowledge of the calculus composition. Regardless of the underlying cause of the stone disease, a mainstay of conservative management is the forced increase in fluid intake to achieve a daily urine output of 2 liters. HYPERCALCIURIA: Dietary calcium restriction is not recommended for stone formers with nephrolithiasis. Diets with a calcium content ≥ 1 g/day (and low protein-low sodium) could be protective against the risk of stone formation in hypercalciuric stone forming adults. Moderate dietary salt restriction is useful in limiting urinary calcium excretion and thus may be helpful for primary and secondary prevention of nephrolithiasis. A low-normal protein intake decrease calciuria and could be useful in stone prevention and preservation of bone mass. Omega-3 fatty acids and bran of different origin decreases calciuria, but their impact on the urinary stone risk profile is uncertain. Sports beverage do not affect the urinary stone risk profile. HYPEROXALURIA: A diet low in oxalate and/or a calcium intake normal to high (800-1200 mg/day for adults) reduce the urinary excretion of oxalate, conversely a diet rich in oxalates and/or a diet low in calcium increase urinary oxalate. A restriction in protein intake may reduce the urinary excretion of oxalate although a vegetarian diet may lead to an increase in urinary oxalate. Adding bran to a diet low in oxalate cancels its effect of reducing urinary oxalate. Conversely, the addition of supplements of fruit and vegetables to a mixed diet does not involve an increased excretion of oxalate in the urine. The intake of pyridoxine reduces the excretion of oxalate. HYPERURICOSURIA: In patients with renal calcium stones the decrease of the urinary excretion of uric acid after restriction of dietary protein and purine is suggested although not clearly demonstrated. HYPOCITRATURIA: The administration of alkaline-citrates salts is recommended for the medical treatment of renal stone-formers with hypocitraturia, although compliance to this treatment is limited by gastrointestinal side effects and costs. Increased intake of fruit and vegetables (excluding those with high oxalate content) increases citrate excretion and involves a significant protection against the risk of stone formation. Citrus (lemons, oranges, grapefruit, and lime) and non citrus fruits (melon) are natural sources of dietary citrate, and several studies have shown the potential of these fruits and/or their juices in raising urine citrate levels. CHILDREN: There are enought basis to advice an adequate fluid intake also in children. Moderate dietary salt restriction and implementation of potassium intake are useful in limiting urinary calcium excretion whereas dietary calcium restriction is not recommended for children with nephrolithiasis. It seems reasonable to advice a balanced consumption of fruit and vegetables and a low consumption of chocolate and cola according to general nutritional guidelines, although no studies have assessed in pediatric stone formers the effect of fruit and vegetables supplementation on urinary citrate and the effects of chocolate and cola restriction on urinary oxalate in pediatric stone formers. Despite the low level of scientific evidence, a low-protein (< 20 g/day) low-salt (< 2 g/day) diet with high hydration (> 3 liters/day) is strongly advised in children with cystinuria. ELDERLY: In older patients dietary counseling for renal stone prevention has to consider some particular aspects of aging. A restriction of sodium intake in association with a higher intake of potassium, magnesium and citrate is advisable in order to reduce urinary risk factors for stone formation but also to prevent the loss of bone mass and the incidence of hypertension, although more hemodynamic sensitivity to sodium intake and decreased renal function of the elderly have to be considered. A diet rich in calcium (1200 mg/day) is useful to maintain skeletal wellness and to prevent kidney stones although an higher supplementation could involve an increase of risk for both the formation of kidney stones and cardiovascular diseases. A lower content of animal protein in association to an higher intake of plant products decrease the acid load and the excretion of uric acid has no particular contraindications in the elderly patients, although overall nutritional status has to be preserved.

The burden of vitamin D deficiency in a mediterranean country without a policy of food fortification.

BACKGROUND: Vitamin D deficiency is a public healthcare issue and its correction is increasingly regarded as a cornerstone of preventive medicine. METHODS: We designed a retrospective observational study to clearly define the burden of total vitamin D (25-hydroxyvitamin D) deficiency in a supposedly healthy population of outpatients residing in two regions (Emilia Romagna and Veneto) of Northern Italy. RESULTS: 25-hydroxyvitamin D results were available for a total number of 5,096 outpatients in the two centers. The median value of 25-hydroxyvitamin D was 60 nmol/L, and was higher in women than in men (62 nmol/L versus 56 nmol/L; p<0.001). The rate of 25-hydroxyvitamin D deficiency was 36%, and was marginally but significantly higher in men than in women (40% versus 35%; p=0.003). A significant variation in the rate of 25-hydroxyvitamin D deficiency was found throughout different age ranges, exhibiting a significant increase in the elderly. CONCLUSIONS: The results of this large observational study show that the burden of 25-hydroxyvitamin D deficiency in two regions of a Mediterranean country without a policy of food fortification is as high as 36%, and this evidence represents a background for healthcare preventive measures aimed at reducing the prevalence of this condition in the general population. (www.actabiomedica.it).

Hippuric acid in 24 h urine collections as a biomarker of fruits and vegetables intake in kidney stone formers.

This work aimed to underline the prospects of hippuric acid, a product of the metabolism of polyphenols, as a new biomarker of fruits and vegetables intake associated with lithogenic risk. Biochemical parameters of lithogenic risk and hippuric acid were measured in the 24 h urine collections of a cohort of 696 Italian kidney stone formers divided into two subgroups according to their different dietary habits. The link between lithogenic risk parameters and hippuric acid was assessed and this compound was revealed as a valuable biomarker of fruits and vegetables intake in kidney stone formers. A cut-off value of urinary excretion of hippuric acid, 300 mg/24 h, was set as the threshold of discrimination between low and high intake of fruits and vegetables for these patients. These results highlight the importance of monitoring of the excretion hippuric acid in urine to address proper dietary guidelines for the management of stone former patients.

IGF-1, the cross road of the nutritional, inflammatory and hormonal pathways to frailty.

The decline in functional capacity is a heterogeneous phenomenon in the elderly. An accelerated ageing determines a frail status. It results in an increased vulnerability to stressors for decreased physiological reserves. The early identification of a frail status is essential for preventing loss of functional capacity, and its clinical consequences. Frailty and mobility limitation result from an interplay of different pathways including multiple anabolic deficiency, inflammation, oxidative stress, and a poor nutritional status. However, the age-related decline in insulin-like growth factor 1 (IGF-1) bioactivity deserves special attention as it could represent the ideal crossroad of endocrine, inflammatory, and nutritional pathways to frailty. Several minerals, namely magnesium, selenium, and zinc, appear to be important determinants of IGF-1 bioactivity. This review aims to provide an overview of the potential usefulness of nutrients modulating IGF-1 as potential therapeutic targets in the prevention of mobility limitation occurring in frail older subjects.

Association of plasma selenium concentrations with total IGF-1 among older community-dwelling adults: the InCHIANTI study.

BACKGROUND & AIMS: Insulin-like growth factor (IGF-1) stimulates cell proliferation and inhibits cell apoptosis. Recent studies underline its importance as anabolic hormone and nutritional marker in older individuals. IGF-1 synthesis and bioactivity are modulated by nutritional factors including selenium intake. However, whether circulating IGF-1 levels are positively influenced by plasma selenium, one of the most important human antioxidants, is still unknown. METHODS: Selenium and total IGF-1 were measured in 951 men and women ≥ 65 years from the InCHIANTI study, Tuscany, Italy. RESULTS: Means (SD) of plasma selenium and total IGF-1 were 0.95 (0.15) µmol/L and 113.4 (31.2)ng/mL, respectively. After adjustment for age and sex, selenium levels were positively associated with total IGF-1 (ß±SE: 43.76±11.2, p=0.0001). After further adjustment for total energy and alcohol intake, serum alanine aminotransferase (ALT), congestive heart failure, selenium remained significantly associated with IGF-1 (ß±SE: 36.7±12.2, p=0.003). The association was still significant when IL-6 was introduced in the model (ß±SE: 40.1±12.0, p=0.0008). CONCLUSIONS: We found an independent, positive and significant association between selenium and IGF-1 serum levels in community dwelling older adults.

Dietary treatment of nephrolithiasis.

The prevalence of idiopathic nephrolithiasis is increasing in rich countries. Dietary manipulation could contribute to the prevention of both its first appearance and the recurrence of the disease. The target of dietary treatment is to decrease the "urinary lithogenic risk factors" such as low urine volume, hypercalciuria, hyperoxaluria, hyperuricosuria, hyperphosphaturia, hypocitraturia, hypomagnesuria and excessively alkaline or acid urinary pH. Due to the lack of randomized controlled trials focused on this problem, there is not ample evidence to confidently recommend dietary changes. Despite this, numerous recent and past experiences support modification of diet as having a primary role in the prevention of nephrolithiasis. In particular, it is recommended to limit animal protein and salt intake, to consume milk and derivatives in amounts corresponding to calcium intake of about 1200 mg/day and to assume fiber (40 g/day), vegetables and fruit daily avoiding foods with high oxalate content. Furthermore, vitamin C intake not exceeding 1500 mg/day plays a protective role as well as avoiding vitamin B6 deficiency and abstaining, if possible, from vitamin D supplements. Lastly, it is recommended to drink enough water to bring the urinary volume up to at least 2 L/day and, as much as possible, to use fresh or frozen products rather than prepacked or precooked foods which are often too rich in sodium chloride.

A curcumin-based 1-week triple therapy for eradication of Helicobacter pylori infection: something to learn from failure?

BACKGROUND: Curcumin is the principal element of turmeric powder extracted from the root of Curcuma longa. Studies on curcumin have demonstrated some anti-Helicobacter pylori activity as well as immunomodulating properties. N-acetylcysteine and lactoferrin with their respective mucolytic and antibacterial activities might also be effective in H. pylori eradication therapy. AIM: To determine if a 7-day non-antibiotic therapy comprised of curcumin, lactoferrin, N-acetylcysteine, and pantoprazole was effective for eradication of H. pylori infection and reduction of gastric inflammation, assessed by serum pepsinogens and relief of symptoms. SUBJECTS AND METHODS: Twenty-five consecutive H. pylori-positive patients (12 males, mean age 50 +/- 12 years, range 31-76) with functional dyspepsia were enrolled. Patients were administered for 7 days curcumin 30 mg b.i.d., bovine lactoferrin 100 mg b.i.d., N-acetylcysteine 600 mg b.i.d., and pantoprazole 20 mg b.i.d. H. pylori status and upper gastrointestinal symptoms were assessed by (13)C-urea breath test and a scale of upper gastrointestinal symptoms intensity (absent, mild, moderate, and severe), as well as a blood test for serum pepsinogens (sPGI, sPGII), gastrin-17 (G-17), and anti-H. pylori IgG (IgG-Hp) at baseline (T0) and after 2 months (T1). RESULTS: Three of 25 patients (12%) were cured of H. pylori infection. A significant decrease in the overall severity of symptoms (T0: 6, interquartile range [IQR]: 4.5-8; T1: 2, IQR: 2-3; p < or = .001), and sPGII (T0: 16 microg/L, IQR: 13-22; T1: 10 microg/L, IQR: 8-16; p < or = .001) and sPGI (T0: 82 microg/L, IQR: 67-97; T1: 74 microg/L, IQR: 62-94; p = .02) levels were observed after 2 months of the treatment. IgG and G-17 values did not significantly decrease after 2 months. CONCLUSIONS: This novel therapy was not effective for H. pylori eradication. However, despite the bacterium persistence, significant improvement of dyspeptic symptoms and reduction of serologic signs of gastric inflammation were observed after 2 months at the end of the 7-day treatment schedule.

Concentrated urine and diluted urine: the effects of citrate and magnesium on the crystallization of calcium oxalate induced in vitro by an oxalate load.

Supplementation of certain calcium crystallization inhibitors, such as citrate and magnesium, and the dilution of urine with water are now considered consolidated practice for the prevention of calcium kidney stones. The aim of this study is to verify, using tried and true in vitro methods, whether the effect of these inhibitors can manifest itself in different ways depending on whether the urine is concentrated or diluted. Calcium oxalate crystallization was studied on 4-h urine of 20 male idiopathic calcium oxalate stone formers, first under low hydration conditions (non-diluted urine) and then under high hydration conditions (diluted urine). Both the diluted and the non-diluted urine samples were subjected to three types of load: (a) an oxalate concentration increment of 1.3 mmol/l only; (b) an oxalate concentration increment of 1.3 mmol/l with a citrate concentration increment of 1.56 mmol/l; (c) an oxalate concentration increment of 1.3 mmol/l with a magnesium concentration increment of 2.08 mmol/l. In non-diluted urine, the addition of the citrate and magnesium did not modify the crystallization parameters under study. In contrast, in the diluted urine the addition of the citrate and magnesium led to a reduction in the total quantity of crystals (equivalent to 35-45%) and their aggregates (equivalent to 30-40%); at the same time, there was an increase in the diameter of the monohydrate calcium oxalate crystals, which also underwent a morphological change. In conclusion, the inhibitory effects of citrate and magnesium on the crystallization of calcium oxalate do not manifest themselves in highly concentrated urine.