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.

The Correlation Between Students' Progress Testing Scores and Their Performance in a Residency Selection Process.

Brazil is currently seeing an increased number of medical schools, leading to high competition for medical residency vacancies. Public managers have thus considered Progress Testing scores potentially useful as part of the final decision in the medical residency selection process. We analyzed whether there is a correlation between students' Progress Testing scores and their performances in medical residency selection. We examined four subsequent cohorts of students who attempted Progress Testing yearly and compared their accumulated scores with their medical residency selection scores from Botucatu Medical School, Universidade Estadual Paulista. We included 212 students who finished the 6-year medical course in 2013, 2014, 2015, and 2016. The comparison between the area under the Progress Testing curve and the medical residency selection score was performed using a Pearson correlation, with a p value set at < 0.05. We found a positive association between the two scores (p < 0.05 for the 4 years). Next, the students were grouped according to their performance in Progress Testing: above one, within one, and below one standard deviation. A chi-square test was used to compare the rates of approval with the second step of the medical residency selection process. Approval rates were 91.7%, 69.2%, and 42.1%, respectively (p < 0.05). We conclude that, in fact, there is a correlation between students' performance on these measures. This is partially explained by the fact that both instruments measure cognitive competencies and knowledge. These data may support national policy changes for medical residency selection.