Beatrice Prati

Effects of a low-salt diet on idiopathic hypercalciuria in calcium-oxalate stone formers: a 3-mo randomized controlled trial

BACKGROUND A direct relation exists between sodium and calcium excretion, but randomized studies evaluating the sustained effect of a low-salt diet on idiopathic hypercalciuria, one of the main risk factors for calcium-oxalate stone formation, are still lacking. OBJECTIVE Our goal was to evaluate the effect of a low-salt diet on urinary calcium excretion in patients affected by idiopathic calcium nephrolithiasis. DESIGN Patients affected by idiopathic calcium stone disease and hypercalciuria (>300 mg Ca/d in men and >250 mg Ca/d in women) were randomly assigned to receive either water therapy alone (control diet) or water therapy and a low-salt diet (low-sodium diet) for 3 mo. Twenty-four-hour urine samples were obtained twice from all patients: one sample at baseline on a free diet and one sample after 3 mo of treatment. RESULTS A total of 210 patients were randomly assigned to receive a control diet (n = 102) or a low-sodium diet (n = 108); 13 patients (2 on the control diet, 11 on the low-sodium diet) withdrew from the trial. At the follow-up visit, patients on the low-sodium diet had lower urinary sodium (mean +/- SD: 68 +/- 43 mmol/d at 3 mo compared with 228 +/- 57 mmol/d at baseline; P < 0.001). Concomitant with this change, they showed lower urinary calcium (271 +/- 86 mg/d at 3 mo compared with 361 +/- 129 mg/d on the control diet, P < 0.001) and lower oxalate excretion (28 +/- 8 mg/d at 3 mo compared with 32 +/- 10 mg/d on the control diet, P = 0.001). Urinary calcium was within the normal range in 61.9% of the patients on the low-salt diet and in 34.0% of those on the control diet (difference: +27.9%; 95% CI: +14.4%, +41.3%; P < 0.001). CONCLUSION A low-salt diet can reduce calcium excretion in hypercalciuric stone formers. This trial was registered at clinicaltrials.gov as NCT01005082.

Diet to Reduce Mild Hyperoxaluria in Patients With Idiopathic Calcium Oxalate Stone Formation: A Pilot Study

OBJECTIVES To assess whether a normal-calcium, low-animal protein, low-salt diet is effective in reducing hyperoxaluria in idiopathic calcium oxalate nephrolithiasis compared with a traditional low-oxalate diet, routinely recommended by clinicians METHODS We treated 56 patients with idiopathic calcium oxalate stone formation who presented with mild hyperoxaluria (>40 mg/d) while consuming a free diet with a normal-calcium, low-animal protein, low-salt diet for a 3-month period. We compared the results obtained with this diet with those of a historical control group of 20 hyperoxaluric patients treated in the traditional way with a low-oxalate diet RESULTS After 3 months of therapy, the mean oxaluria level had decreased from 50.2 to 35.5 mg/d with the normal-calcium, low-animal protein, low-salt diet and from 45.9 to 40.2 mg/d with the traditional diet (adjusted difference between post-treatment mean value -7.3 mg/d, 95% confidence interval -12.3 to -2.2, P = .005) CONCLUSIONS The results suggest that a normal-calcium, low-animal protein, low-salt diet can reduce oxalate excretion in hyperoxaluric patients. This should encourage the undertaking of a randomized-control study to confer more solid evidence in support of our findings.

Reducing unnecessary hospital days to improve quality of care through physician accountability: a cluster randomised trial

BackgroundOver 20% of hospital bed use is inappropriate, implying a waste of resources and the increase of patient iatrogenic risk.MethodsThis is a cluster, pragmatic, randomised controlled trial, carried out in a large University Hospital of Northern Italy, aiming to evaluate the effect of a strategy to reduce unnecessary hospital days. The primary outcome was the percentage of patient-days compatible with discharge. Among secondary objectives, to describe the strategy’s effect in the long-term, as well as on hospital readmissions, considered to be a marker of the quality of hospital care. The 12 medical wards with the longest length of stay participated. Effectiveness was measured at the individual level on 3498 eligible patients during monthly index days. Patients admitted or discharged on index days, or with stay >90 days, were excluded. All ward staff was blinded to the index days, while staff in the control arm and data analysts were blinded to the trial’s objectives and interventions. The strategy comprised the distribution to physicians of the list of their patients whose hospital stay was compatible with discharge according to a validated Delay Tool, and of physician length of stay profiles, followed by audits managed autonomously by the physicians of the ward.ResultsDuring the 12 months of data collection, over 50% of patient-days were judged to be compatible with discharge. Delays were mainly due to problems with activities under medical staff control. Multivariate analysis considering clustering showed that the strategy reduced patient-days compatible with discharge by 16% in the intervention vs control group, (OR=0.841; 95% CI, 0.735 to 0.963; P=0.012). Follow-up at 1 year did not yield a statistically significant difference between the percentages of patient-days judged to be compatible with discharge between the two arms (OR=0.818; 95% CI, 0.476 to 1.405; P=0.47). There was no significant difference in 30-day readmission and mortality rates for all eligible patients (N=3498) between the two arms.ConclusionsResults indicate that a strategy, involving physician direct accountability, can reduce unnecessary hospital days. Relatively simple interventions, like the one assessed in this study, should be implemented in all hospitals with excessive lengths of stay, since unnecessary prolongation may be harmful to patients.Trial registrationClinicalTrials.gov, identifier NCT01422811.

Dietary habits in women with recurrent idiopathic calcium nephrolithiasis.

BackgroundNutrition has been widely recognized to influence the risk of kidney stone formation. Therefore the aim of our study was to assess: a) whether usual diet of women with idiopathic calcium nephrolithiasis (ICN) living in Parma (Northern-Italy) is different compared to healthy controls, b) how their diet differs from Italian National guidelines and c) whether it is related to nephrolithiasis clinical course.Methods143 women with recurrent ICN (mean age 43 ± 13 ys) and 170 healthy women (mean age 42 ± 11 ys) were enrolled. All women completed a food frequency questionnaire for the last 60-days and a 3-day dietary diary analysed with a dedicated software.ResultsStone formers showed a higher consumption of sausages, ham, meat and sweets than healthy controls (43.1% vs 11.1%, 29.4% vs 13.9%, 21.6% vs 4.2%, 66.7% vs 18.1%, p < 0.001). The 3-day diary analysis showed an intake of calories, carbohydrates, lipids and non-discretionary sodium about 10% higher than healthy controls (p < 0.001). Finally, after dividing the population into 3 age groups (≤30, 31-40, > 40 years), the differences described above were amplified in the class ≤30 years, where nephrolithiasis presented a more serious course (shorter recurrence interval, greater stone-rate). In this age group the intake of fruit and vegetables was notably lower than guideline recommendations.ConclusionsWe conclude that the usual diet of women with recurrent ICN is different from controls and characterized by low intake of fruits and vegetables and higher consumption of simple sugars and foods with high protein and salt content. This dietary imbalance could play a role in the ICN pathogenesis, especially in younger women.This work was financed by grants from Italian Ministry of University and Research as part of a larger project about the prevention of kidney stones (PRIN 2005063822) and by Fondazione per la Ricerca Scientifica Termale (FoRST). No potential conflict of interest relevant to this paper was reported.

Effects of urine dilution on quantity, size and aggregation of calcium oxalate crystals induced in vitro by an oxalate load.

Abstract Increasing urinary volume is an important tool in the prevention of calcium renal stones. However, the mechanism of how it actually works is only partially understood. This study aimed at assessing how urine dilution affects urinary calcium oxalate crystallization. A total of 16 male idiopathic calcium oxalate (CaOx) stone-formers and 12 normal male subjects were studied and 4 h urine samples were taken twice, under low (undiluted urine) and high hydration conditions (diluted urine). An equal oxalate load (1.3mmol/L) was added to both types of urine and the crystallization parameters were assessed. In both stone-formers and normal subjects, the crystallization processes were significantly (p<0.05 or less) more marked in the undiluted urine than in the diluted urine in terms of: a) total quantity of calcium oxalate dihydrate (COD) and calcium oxalate monohydrate (COM) crystals; b) total quantity of crystalline aggregates; and c) aggregation index (i.e., ratio between the area occupied by crystalline aggregates and the area occupied by all the crystals present). The comparison between stone-formers and normal subjects showed that the greatest difference was for the size of COD crystals, which were larger in the urine of the stone-formers. A further important finding was an inverse relationship between changes in urinary volume and in the aggregation index (r=–0.53, p=0.004). In conclusion, urine dilution considerably reduces crystallization phenomena induced in vitro by an oxalate load in both calcium stone-formers and normal subjects.

Multimorbidity in elderly hospitalised patients and risk of Clostridium difficile infection: a retrospective study with the Cumulative Illness Rating Scale (CIRS)

Objectives To identify the role of chronic comorbidities, considered together in a literature-validated index (Cumulative Illness Rating Scale, CIRS), and antibiotic or proton-pump inhibitor (PPI) treatments as risk factors for hospital-acquired Clostridium difficile infection (CDI) in elderly multimorbid hospitalised patients. Design Retrospective cohort study. Setting Subacute hospital geriatric care ward in Italy. Participants 505 (238 male (M), 268 female (F)) elderly (age ≥65) multimorbid patients. Main outcome measures The relationship between CDI and CIRS Comorbidity Score, number of comorbidities, antibiotic, antifungal and PPI treatments, and length of hospital stay was assessed through age-adjusted and sex-adjusted and multivariate logistic regression models. The CIRS Comorbidity Score was handled after categorisation in quartiles. Results Mean age was 80.7±11.3 years. 43 patients (22 M, 21 F) developed CDI. The prevalence of CDI increased among quartiles of CIRS Comorbidity Score (3.9% first quartile vs 11.1% fourth quartile, age-adjusted and sex-adjusted p=0.03). In the multivariate logistic regression analysis, patients in the highest quartile of CIRS Comorbidity Score (≥17) carried a significantly higher risk of CDI (OR 5.07, 95% CI 1.28 to 20.14, p=0.02) than patients in the lowest quartile (<9). The only other variable significantly associated with CDI was antibiotic therapy (OR 2.62, 95% CI 1.21 to 5.66, p=0.01). PPI treatment was not associated with CDI. Conclusions Multimorbidity, measured through CIRS Comorbidity Score, is independently associated with the risk of CDI in a population of elderly patients with prolonged hospital stay.

The Prognostic Value of High-sensitivity C-reactive Protein and Prealbumin for Short-term Mortality in Acutely Hospitalized Multimorbid Elderly Patients: A Prospective Cohort Study.

ObjectivesTo establish the predictive value on mortality after 2 months from hospital admission of two laboratory markers of nutritional and inflammatory status, high-sensitivity C-reactive protein (hs-CRP) and prealbumin, in a cohort of frail multimorbid elderly without terminal illness.DesignProspective cohort study.SettingInternal medicine ward of a large teaching hospital in Italy.Participants544 Caucasian patients with acute disease consecutively admitted from January to June 2013. 102 were excluded for being younger than 65 years old, having life expectancy <30 days or not having frailty syndrome. Further 42 patients were excluded for missing data or withdrawn at follow-up. Final analysis was performed on 400 subjects (179 M, 221 F, mean age 79±10).MeasurementsSerum prealbumin and hs-CRP were measured at admission. Death within 2 months from hospital admission was assessed through a telephonic interview with the caregiver for each patient discharged alive. Inhospital mortality was also recorded. Survival was calculated from date of admission to our unit.ResultsMean prealbumin at admission was 17.3±7.7 mg/dl, while hs-CRP median was 24.2 mg/L (IQR 8.7 to 51.8). 108 patients (27%) died within two months from admission. In an age- and sexadjusted analysis, log(hs-CRP) levels at admission, but not prealbumin, were independently associated with an increased risk for mortality (HR 1.40, 95% CI 1.18 to 1.66, p<0.001). After multiple adjustments for covariates, including comorbidity burden measured through Charlson score, log(hs-CRP) remained significantly associated with mortality (HR 1.38, 95% CI 1.08 to 1.76, p=0.01). A Receiver Operating Characteristic (ROC) curve was performed to test the predictive value of hs-CRP at admission on two-month mortality (AUC 0.68, 95% CI 0.63 to 0.72, p<0.001). Cut-off value was set at 38.4 mg/L. After dichotomization of hs-CRP values according to this cut-off, hs-CRP=38.4 mg/L at admission proved to be a significant risk factor for mortality (HR 2.10, 95% CI 1.23 to 3.58, p=0.006).ConclusionSerum hs-CRP, but not prealbumin, values at admission are predictors of short-term mortality at hospital admission in elderly multimorbid patients. Inflammation seems to affect prognosis more than malnutrition in this setting and may therefore guide clinicians’ attitude towards therapeutic choices.

An investigation of multimorbidity measures as risk factors for pneumonia in elderly frail patients admitted to hospital

OBJECTIVES To investigate the association of different chronic comorbidities, considered singularly and together in Cumulative Illness Rating Scale (CIRS) indexes, with pneumonia diagnosis in a group of elderly frail hospitalized patients. DESIGN AND METHODS With a retrospective cohort design, all clinical records of frail (Rockwood ≥ 5) nonterminal patients ≥ 65 years old acutely admitted over a 8-month span in an internal medicine ward were evaluated. Pneumonia status and its categorization (community-acquired, CAP, vs healthcare-associated, HCAP) were defined according to chest radiology findings and validated criteria. Chronic comorbidities, CIRS Comorbidity Score and CIRS Severity Index were collected for each participant through a standardized methodology. Multivariate logistic regression models were applied to assess the association of each comorbid condition or scores with pneumonia. RESULTS 1199 patients (546 M, median age 81.9, IQR 72.8-87.9 years), of whom 239 with pneumonia (180 CAP, 59 HCAP) were evaluated. CIRS Comorbidity Score was significantly associated with pneumonia, both at an age- and sex-adjusted model and at a multivariate model (OR for each unitary increase 1.03, 95% CI 1.001-1.062, p=0.04), together with provenience from nursing home (OR 1.96, 95% CI 1.41-2.73, p<0.001). Among single comorbidities, only COPD (OR 2.7, 95% CI 1.9-3.6, p<0.001) and dementia (OR 2.3, 95% CI 1.7-3.3, p<0.001) were associated with pneumonia, while stroke, cancer, cardiovascular, chronic liver and kidney disease were not. CONCLUSIONS In a small cohort of elderly frail hospitalized patients, measures of multimorbidity, like CIRS, are significantly associated with the risk of pneumonia. COPD and dementia are the main conditions concurring to define this risk.

Molecular and Clinical Issues about the Risk of Venous Thromboembolism in Older Patients: A Focus on Parkinson’s Disease and Parkinsonism

Venous thromboembolism (VTE) is a common and potentially life-threatening condition which includes both deep-vein thrombosis (DVT) and pulmonary embolism (PE). VTE has a significant clinical and epidemiological impact in the elderly, and its incidence increases to more than 1% per year in older patients, suggesting the presence of specific age-related risk factors in this population. Immobilization seems to predominate as the main cause in patients admitted for medical acute illness in medicine wards, and there is evidence of a high risk in older patients with immobilization resulting from advanced forms of Parkinson’s disease (PD), regardless of the presence of an acute medical condition. In this review, we would to discuss the recent evidence on clinical, molecular and epidemiological features of VTE in older frail subjects focusing on patients with PD and parkinsonism. We also discuss some therapeutic issues about the risk prevention and we suggest a thorough comprehensive geriatric assessment that can represent an optimal strategy to identify and prevent the VTE risk in these patients.

Insights about urinary hippuric and citric acid as biomarkers of fruit and vegetable intake in patients with kidney stones: the role of age and gender

OBJECTIVES Urinary hippuric acid (HA) and citrate can represent useful biomarkers of fruit and vegetable (FAV) intake in nephrolithiasis. However, their clinical significance across the life span has been poorly investigated. The aim of this study was to investigate the association between the two biomarkers with FAV intake across different age groups and sexes in a large group of stone formers (SFs). METHODS SFs undergoing baseline 24-h urinary collection for metabolic profile of lithogenic risk at our institution were consecutively enrolled for a 6-y time span (N = 1185; 625 men). HA and citrate excretions were determined by ion chromatography and ultraviolet method, respectively. SFs completed a food frequency questionnaire on the intake of FAV. Stepwise logistic regression was applied to investigate factors associated with very low FAV (≤1 servings/d) and analysis of covariance to compare citrate and HA excretion across age groups and sexes. RESULTS Very low FAV intake prevalence declined with age (Ptrend < 0.001), and was inversely associated with HA and citrate excretion (P < 0.001) in a stepwise logistic regression model. A significant increasing trend was verified for both biomarkers across age groups until the age of 65 for HA (P < 0.001) and 55 for citrate (P < 0.001). Citrate excretion significantly declined after the age of 65, and was higher in women than men in adult age groups, regardless of FAV intake. CONCLUSIONS Both urinary citrate and HA were positively associated with FAV intake in SFs. However, unlike HA, citrate excretion was significantly influenced by the female sex and by older age.