Giovanni Gambaro

Oral Sulodexide Reduces Albuminuria in Microalbuminuric and Macroalbuminuric Type 1 and Type 2 Diabetic Patients: The Di.N.A.S. Randomized Trial

Diabetic nephropathy may be effectively prevented and treated by controlling glycemia and administering angiotensin-converting enzyme (ACE) inhibitors. However, strict metabolic control can be difficult, and ACE inhibitors may be poorly tolerated and only partially effective, particularly in diabetes mellitus type 2 (DM2), warranting the search for ancillary treatment. Sulodexide is a glycosaminoglycan, a new class of drug that has demonstrated nephroprotective activity in experimental investigations. The Di.N.A.S. study was a randomized, double-blind, placebo-controlled, multicenter, dose-range finding trial to evaluate the extent and duration of the hypoalbuminuric effect of oral sulodexide in diabetic patients. A total of 223 microalbuminuric and macroalbuminuric DM1 and DM2 patients with serum creatinine < or =150 micromol/L and stable BP and metabolic control were recruited. They were randomly allocated to one of four groups: 50 mg/d, 100 mg/d, or 200 mg/d sulodexide daily or placebo for 4 mo (T0 to T4), with 4 mo of follow-up after drug suspension (T4 to T8). Treatment with 200 mg/d sulodexide for 4 mo significantly reduced log albumin excretion rate (logAER) from 5.25 +/- 0.18 at T0 to 3.98 +/- 0.11 at T4 (P < 0.05), which was maintained till T8 (4.11 +/- 0.13; P < 0.05 versus T0). Moreover, the sulodexide-induced percent reductions in AER at T4 were significantly different from the placebo value at T4 and approximately linear to dose increments (30% [confidence limits, 4 to 49%], P = 0.03; 49% [30 to 63%], P = 0.0001; and 74% [64 to 81%], P = 0.0001 in the sulodexide 50, 100, and 200 mg/d groups, respectively. At T8, the sulodexide 200 mg/d group maintained a 62% (45 to 73%) AER significant reduction versus placebo (P = 0.0001). Subanalysis by type of diabetes (DM1 versus DM2, microalbuminuric versus macroalbuminuric, or on concomitant ACE inhibitors versus not on ACE inhibitors) demonstrated similar findings. These effects were obtained without any significant variation in metabolic control and BP or serum creatinine. Very few adverse events were reported; none were serious. In conclusion, a 4-mo course of high doses of sulodexide significantly and dose-dependently improves albuminuria in DM1 and DM2 patients and micro- or macroalbuminuric patients with or without concomitant ACE inhibition. The effect on albuminuria is long-lasting and seemingly additive to the ACE inhibitory effect.

A genome-wide association study of anorexia nervosa

Anorexia nervosa (AN) is a complex and heritable eating disorder characterized by dangerously low body weight. Neither candidate gene studies nor an initial genome-wide association study (GWAS) have yielded significant and replicated results. We performed a GWAS in 2907 cases with AN from 14 countries (15 sites) and 14 860 ancestrally matched controls as part of the Genetic Consortium for AN (GCAN) and the Wellcome Trust Case Control Consortium 3 (WTCCC3). Individual association analyses were conducted in each stratum and meta-analyzed across all 15 discovery data sets. Seventy-six (72 independent) single nucleotide polymorphisms were taken forward for in silico (two data sets) or de novo (13 data sets) replication genotyping in 2677 independent AN cases and 8629 European ancestry controls along with 458 AN cases and 421 controls from Japan. The final global meta-analysis across discovery and replication data sets comprised 5551 AN cases and 21 080 controls. AN subtype analyses (1606 AN restricting; 1445 AN binge–purge) were performed. No findings reached genome-wide significance. Two intronic variants were suggestively associated: rs9839776 (P=3.01 × 10−7) in SOX2OT and rs17030795 (P=5.84 × 10−6) in PPP3CA. Two additional signals were specific to Europeans: rs1523921 (P=5.76 × 10−6) between CUL3 and FAM124B and rs1886797 (P=8.05 × 10−6) near SPATA13. Comparing discovery with replication results, 76% of the effects were in the same direction, an observation highly unlikely to be due to chance (P=4 × 10−6), strongly suggesting that true findings exist but our sample, the largest yet reported, was underpowered for their detection. The accrual of large genotyped AN case-control samples should be an immediate priority for the field.

CKD Prevalence Varies across the European General Population

CKD prevalence estimation is central to CKD management and prevention planning at the population level. This study estimated CKD prevalence in the European adult general population and investigated international variation in CKD prevalence by age, sex, and presence of diabetes, hypertension, and obesity. We collected data from 19 general-population studies from 13 European countries. CKD stages 1-5 was defined as eGFR<60 ml/min per 1.73 m(2), as calculated by the CKD-Epidemiology Collaboration equation, or albuminuria >30 mg/g, and CKD stages 3-5 was defined as eGFR<60 ml/min per 1.73 m(2) CKD prevalence was age- and sex-standardized to the population of the 27 Member States of the European Union (EU27). We found considerable differences in both CKD stages 1-5 and CKD stages 3-5 prevalence across European study populations. The adjusted CKD stages 1-5 prevalence varied between 3.31% (95% confidence interval [95% CI], 3.30% to 3.33%) in Norway and 17.3% (95% CI, 16.5% to 18.1%) in northeast Germany. The adjusted CKD stages 3-5 prevalence varied between 1.0% (95% CI, 0.7% to 1.3%) in central Italy and 5.9% (95% CI, 5.2% to 6.6%) in northeast Germany. The variation in CKD prevalence stratified by diabetes, hypertension, and obesity status followed the same pattern as the overall prevalence. In conclusion, this large-scale attempt to carefully characterize CKD prevalence in Europe identified substantial variation in CKD prevalence that appears to be due to factors other than the prevalence of diabetes, hypertension, and obesity.

Low level exposure to cadmium increases the risk of chronic kidney disease: analysis of the NHANES 1999-2006

BackgroundEnvironmental factors have been associated with the outbreak of chronic kidney disease (CKD). We evaluated the association of Cadmium (Cd) exposure with the risk of CKD in U.S. adults who participated in the 1999-2006 National Health and Nutrition Examination Surveys (NHANES).Methods5426 subjects ≥ 20 years were stratified for values of urinary and blood Cd and a multivariate logistic regression was performed to test the association between blood and urinary Cd, CKD and albuminuria (ALB) after adjustment for age, gender, race/ethnicity, body mass index and smoking habits.ResultsSubjects with urinary Cd > 1 mcg/g and subjects with blood Cd > 1 mcg/L showed a higher association with ALB (OR 1.63, 95% CI 1.23, 2.16; P = 0.001). Subjects with blood Cd > 1 mcg/L showed a higher association with both CKD (OR 1.48, 95% CI 1.01, 2.17; P = 0.046) and ALB (OR 1.41, 95% CI 1.10, 1.82; P = 0.007). An interaction effect on ALB was found for high levels of urinary and blood Cd (P = 0.014).ConclusionsModerately high levels of urinary and blood Cd are associated with a higher proportion of CKD and ALB in the United States population.

Improved imputation of low-frequency and rare variants using the UK10K haplotype reference panel

Imputing genotypes from reference panels created by whole-genome sequencing (WGS) provides a cost-effective strategy for augmenting the single-nucleotide polymorphism (SNP) content of genome-wide arrays. The UK10K Cohorts project has generated a data set of 3,781 whole genomes sequenced at low depth (average 7x), aiming to exhaustively characterize genetic variation down to 0.1% minor allele frequency in the British population. Here we demonstrate the value of this resource for improving imputation accuracy at rare and low-frequency variants in both a UK and an Italian population. We show that large increases in imputation accuracy can be achieved by re-phasing WGS reference panels after initial genotype calling. We also present a method for combining WGS panels to improve variant coverage and downstream imputation accuracy, which we illustrate by integrating 7,562 WGS haplotypes from the UK10K project with 2,184 haplotypes from the 1000 Genomes Project. Finally, we introduce a novel approximation that maintains speed without sacrificing imputation accuracy for rare variants.

Soda and Other Beverages and the Risk of Kidney Stones

BACKGROUND AND OBJECTIVES Not all fluids may be equally beneficial for reducing the risk of kidney stones. In particular, it is not clear whether sugar and artificially sweetened soda increase the risk. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS We prospectively analyzed the association between intake of several types of beverages and incidence of kidney stones in three large ongoing cohort studies. Information on consumption of beverages and development of kidney stones was collected by validated questionnaires. RESULTS The analysis involved 194,095 participants; over a median follow-up of more than 8 years, 4462 incident cases occurred. There was a 23% higher risk of developing kidney stones in the highest category of consumption of sugar-sweetened cola compared with the lowest category (P for trend=0.02) and a 33% higher risk of developing kidney stones for sugar-sweetened noncola (P for trend=0.003); there was a marginally significant higher risk of developing kidney stones for artificially sweetened noncola (P for trend=0.05). Also, there was an 18% higher risk for punch (P for trend=0.04) and lower risks of 26% for caffeinated coffee (P for trend<0.001), 16% for decaffeinated coffee (P for trend=0.01), 11% for tea (P for trend=0.02), 31%-33% for wine (P for trend<0.005), 41% for beer (P for trend<0.001), and 12% for orange juice (P for trend=0.004). CONCLUSIONS Consumption of sugar-sweetened soda and punch is associated with a higher risk of stone formation, whereas consumption of coffee, tea, beer, wine, and orange juice is associated with a lower risk.

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.

Combined treatment with renin–angiotensin system blockers and polyunsaturated fatty acids in proteinuric IgA nephropathy: a randomized controlled trial

BACKGROUND Currently, several therapeutic protocols exist for IgA nephropathy (IgAN); results in slowing the progression to end-stage renal disease (ESRD) are variable, but approximately 30-40% of patients require replacement therapy (dialysis or renal transplantation) by 20 years from the onset. The adverse effects brought by the chronic assumption of drugs can be a potential limit. Actually, the most used therapies for IgAN are renin-angiotensin system blockers (RASB), glucocorticoids and immunosuppressive agents. Trials with polyunsaturated fatty acids (PUFA) in IgAN have been done since the first successful attempt by Hamazaki in 1984, resulting in alternate answers, but no trials have ever been done testing the efficacy of combined therapy with RASB and PUFA. METHODS We tested the effect of a 6-month course of PUFA (3 grams/day) in a group of 30 patients with biopsy-proven IgAN and proteinuria already treated with RASB randomized to receive PUFA supplementation or to continue their standard therapy. The primary end-point was the percent reduction of proteinuria from the baseline. Secondary end-points were modifications in glomerular filtration rate (GFR), blood pressure, serum triglycerides and erythrocyturia. RESULTS At the end of the 6-month trial, the percent reduction of proteinuria was 72.9% in the PUFA group and 11.3% in the RASB group (P < 0.001). A reduction of >or=50% of baseline proteinuria was achieved in 80.0% of PUFA patients and 20.0% of RASB patients (P = 0.002). Erythrocyturia was significantly lower in the PUFA group (P = 0.031). No significant changes in renal function, blood pressure and triglycerides were observed. CONCLUSIONS PUFA associated with RASB reduced proteinuria in patients with IgAN more than RASB alone.

Prevalence of CKD in Northeastern Italy: Results of the INCIPE Study and Comparison with NHANES

BACKGROUND AND OBJECTIVES Sufficiently powered studies to investigate the CKD prevalence are few and do not cover southern Europe. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS For the INCIPE study, 6200 Caucasian patients ≥40 years old were randomly selected in northeastern Italy in 2006. Laboratory determinations were centralized. The albumin to creatinine ratio in urine and estimated GFR from calibrated creatinine (SCr) were determined. A comparison with 2001 through 2006 NHANES surveys was performed. RESULTS Prevalence of CKD was 13.2% in northeastern (NE) Italy (age and gender standardized to the U.S. 2007 Caucasian population). Prevalence of CKD in U.S. Caucasians is higher (20.3%), the major difference being in CKD 3. Risk factors for CKD are more prevalent in the United States than in Italy. With use of CKD 3a and 3b stages, CKD prevalence decreased in NE Italy (8.5%) and in the United States (12.8%). CONCLUSIONS The prevalence of CKD is high in NE Italy, but lower than that in the United States. A large part of the difference in CKD prevalence in NE Italy versus that in the United States is due to the different prevalence of CKD 3. The higher prevalence of a number of renal risk factors in persons from the United States explains in part the different dimensions of the CKD problem in the two populations.

Heparanase and Syndecan-1 Interplay Orchestrates Fibroblast Growth Factor-2-induced Epithelial-Mesenchymal Transition in Renal Tubular Cells

Background: FGF-2 induces EMT in PTECs, and HPSE regulates HS/syndecans. Results: The lack of HPSE prevents FGF-2-induced EMT; FGF-2 induces EMT through PI3K/AKT and produces an autocrine loop. Conclusion: HPSE is necessary for FGF-2 to produce EMT, to activate FGF-2 intracellular signaling, and to regulate its autocrine loop. Significance: HPSE is an interesting pharmacological target for the prevention of renal fibrosis. The epithelial-mesenchymal transition (EMT) of proximal tubular epithelial cells (PTECs) into myofibroblasts contributes to the establishment of fibrosis that leads to end stage renal disease. FGF-2 induces EMT in PTECs. Because the interaction between FGF-2 and its receptor is mediated by heparan sulfate (HS) and syndecans, we speculated that a deranged HS/syndecans regulation impairs FGF-2 activity. Heparanase is crucial for the correct turnover of HS/syndecans. The aim of the present study was to assess the role of heparanase on epithelial-mesenchymal transition induced by FGF-2 in renal tubular cells. In human kidney 2 (HK2) PTEC cultures, although FGF-2 induces EMT in the wild-type clone, it is ineffective in heparanase-silenced cells. The FGF-2 induced EMT is through a stable activation of PI3K/AKT which is only transient in heparanase-silenced cells. In PTECs, FGF-2 induces an autocrine loop which sustains its signal through multiple mechanisms (reduction in syndecan-1, increase in heparanase, and matrix metalloproteinase 9). Thus, heparanase is necessary for FGF-2 to produce EMT in PTECs and to sustain FGF-2 intracellular signaling. Heparanase contributes to a synergistic loop for handling syndecan-1, facilitating FGF-2 induced-EMT. In conclusion, heparanase plays a role in the tubular-interstitial compartment favoring the FGF-2-dependent EMT of tubular cells. Hence, heparanase is an interesting pharmacological target for the prevention of renal fibrosis.