Association between Sodium Intake and Urinary Fractional Albumin and Immunoglobulin G Excretion in Chronic Nondialytic Renal Disease: A Prospective Longitudinal Study.

BACKGROUND/AIMS: Previous studies reported that fractional clearance of urinary proteins is better than total proteinuria in predicting chronic kidney disease (CKD) progression. However, the role of sodium in the fractional excretion of proteins has not been established. We aimed to evaluate the association between sodium intake and fractional albumin and immunoglobulin G (IgG) excretion in nondialytic CKD. METHODS: We did a longitudinal, observational, and prospective study that included CKD patients aged 18-80. Included patients performed basal routine laboratory evaluations, urinary sodium excretion, and fractional albumin and IgG excretion that were repeated after 6-month of follow-up. RESULTS: We evaluated 84 patients, mean age 55 ± 15.6 years, 40 women, and 74 whites. The change of estimated sodium intake had an association with the change of fractional albumin (R = 0.54; p < 0.001) and IgG (R = 0.56; p < 0.001) excretion in univariate analysis (increases in sodium intake were paralleled by increases in albumin and IgG excretion fractions). This association was maintained in a multiple generalized linear model even after adjusting for age and for changes in blood pressure, urinary potassium, protein intake, and blood glucose. CONCLUSION: In CKD patients, changes in estimated sodium intake were associated with changes in the fractional albumin and IgG excretion regardless of confounding factors. Findings of this study support the idea that reducing salt intake, and consequently, albumin and IgG fractional excretions could help to slow CKD progression. This hypothesis must be tested in long-term interventional studies.

Attenuation of Renal Functional Decline Following Angioplasty and Stenting in Atherosclerotic Renovascular Disease.

BACKGROUND: To date, renal revascularization has not been shown to be advantageous when compared to optimized medical treatment in patients with atheromatous renovascular disease (ARVD). This study aims to investigate the effect of revascularization in patients with pre-intervention worsening renal function and in those with stable renal function. PATIENTS AND METHODS: In this single-centre observational study, patients who were diagnosed with at least 60% angiographic stenosis unilaterally or bilaterally between January 1996 and October 2008 and who were followed-up until February 2011 were retrospectively analysed. Evolution of renal function was determined from the slope of reciprocal of serum creatinine (RCr-slope) before and after diagnostic angiography or revascularization; this required 5 or more creatinine measurements before and at least another 5 measurements post-procedure. Patients were divided into 2 groups: one comprising patients with negative RCr-slope before the procedure and a second group of patients with prior positive RCr-slope. A stepwise, adjusted logistic regression was used to determine the OR of revascularization on attenuation of RCr-slope. RESULTS: Data for 52 patients were analysed. Median age was 64 (58-72) and median follow-up was 15 (8-34) months. Only patients with a negative RCr-slope (-0.0078 (95% CI -0.0174, -0.0033) dl/mg/month) who underwent revascularization manifested an improved RCr-slope during follow-up (+0.0013 (95% CI -0.0002, 0.0039) dl/mg/month, p < 0.001). This finding remained statistically significant even after the adjustment for proteinuria and bilateral arterial disease. CONCLUSION: Revascularization may be indicated for patients with ARVD and progressively worsening renal function. This patient subgroup should ideally be evaluated in future randomized controlled trials.