Smoking amplifies the risk of albuminuria in individuals with high sodium intake: the Korea National Health and Nutrition Examination Survey (KNHANES) 2008-2011 and 2014-2018.

Background: Smoking and sodium intake (SI) have been evaluated as risk factors for kidney disease; however, the data are inconsistent. We assessed the association between SI and cotinine-verified smoking status and the risk of albuminuria. Methods: An observational study using the Korea National Health and Nutrition Examination Survey (2008-2011 and 2014-2018) was performed. We included 37,410 adults with an estimated glomerular filtration rate of ≥60 mL/min/1.73 m2 . The smoking status was assumed based on the urine cotinine/creatinine ratio (Ucot/Ucrea). SI was estimated from spot urine sodium using the Kawasaki formula. Results: Ucot/Ucrea levels were significantly higher in current smokers (920.22 ± 9.00 ng/mg) than in ex-smokers and nonsmokers (48.31 ± 2.47 and 23.84 ± 1.30 ng/mg) (p < 0.001). Ucot/Ucrea levels were significantly higher in second-hand smokers than in participants without a history of smoking (p < 0.001). Ucot/ Ucrea levels were positively associated with SI (p for trend < 0.001). Smoking status was not associated with albuminuria. SI had a linear relationship with albuminuria (p < 0.001). In groups with the highest Ucot/Ucrea levels, the highest SI quartile indicated a significantly higher risk of albuminuria than that in the lowest quartile (risk ratio, 2.22; 95% confidence interval, 1.26-3.92; p = 0.006). The risk of albuminuria was not significant in groups with the lowest and middle tertile adjusted for multiple risk factors. Conclusion: Smokers consume higher dietary sodium and dietary SI was positively related to the risk of albuminuria. Smoking is not associated with albuminuria as a single factor. The risk of albuminuria is the higher in participants with smoking and high SI.

Impact of acute kidney injury on long-term adverse outcomes in obstructive uropathy.

Obstructive uropathy is known to be associated with acute kidney injury (AKI). This study aimed to investigate the etiologies, clinical characteristics, consequences and also assess the impact of AKI on long-term outcomes. This multicenter, retrospective study of 1683 patients with obstructive uropathy who underwent percutaneous nephrostomy (PCN) analyzed clinical characteristics, outcomes including progression to end-stage kidney disease (ESKD), overall mortality, and the impact of AKI on long-term outcomes. Obstructive uropathy in adults was most commonly caused by malignancy, urolithiasis, and other causes. AKI was present in 78% of the patients and was independently associated with preexisting chronic kidney disease (CKD). Short-term recovery was achieved in 56.78% after the relief of obstruction. ESKD progression rate was 4.4% in urolithiasis and 6.8% in other causes and older age, preexisting CKD, and stage 3 AKI were independent factors of progression. The mortality rate (34%) was highly attributed to malignant obstruction (52%) stage 3 AKI was also an independent predictor of mortality in non-malignant obstruction. AKI is a frequent complication of adult obstructive uropathy. AKI negatively affects long-term kidney outcomes and survival in non-malignant obstructions. A better understanding of the epidemiology and prognostic factors is needed for adult obstructive uropathy.