Current practice guidelines recommend alkali therapy in patients with chronic kidney disease (CKD) and metabolic acidosis to prevent complications. This study aims to investigate the effect of oral sodium bicarbonate supplementation on the progression of renal function and nutritional indices in patients with predialysis advanced CKD. Forty patients with predialysis stage 5 CKD(estimated glomerular filtration rate, eGFR <15mL/min per 1.73m(2)) and 40 patients with stage 4 CKD (eGFR 15 to 30mL/min per 1.73m(2)) who had a total CO2 less than 22mEq/L were assigned into the bicarbonate treatment group or control group for 12 months. In stage 4 CKD, there were significant differences in the changes of eGFR during the study between the treatment group and the control group (-2.30±4.49 versus -6.58±6.32mL/min/1.73m(2), p<0.05). However, in stage 5 CKD, there were no significant differences in the change of eGFR during the study between the two groups (-2.10±2.06 versus -3.23±1.95mL/min/1.73 m(2)).There were no significant differences in the changes of nutritional indices such as albumin, prealbumin, transferrin, total lymphocyte count (TLC), and Ondodera's prognostic nutritional index (OPNI) during the study between the two groups. In stage 5 CKD, there were significant differences in the changes of TLC and OPNI between the two groups. In conclusion, our results demonstrate that bicarbonate supplementation slows the rate of decline of renal function in stage 4 CKD and improves nutritional indices in stage 5 CKD. Alkali therapy in advanced CKD may have beneficial effect on renal function and malnutrition.

Kim KB, et al. J Korean Med Sci. 2012 Sep;27(9):1120-1123. http://dx.doi.org/10.3346/jkms.2012.27.9.1120

(1) Background: Oxidative stress and inflammation are associated with higher risk of chronic kidney disease (CKD). Serum ferritin concentrations correlate with total iron levels and systemic inflammation. (2) Methods: This study was cross-sectionally designed, based on the 2010–2012 Korean National Health and Nutrition Examination Survey (KNHANES). According to ferritin values, 13,462 participants (6082 men and 7380 women) were categorized into the normal- and high-ferritin groups (cut-off points: 200 ng/mL in men, 150 ng/mL in women). (3) Results: The mean ages of men and women were 44.5 and 48.4 years, respectively. The percentage of participants categorized into the high-ferritin group was 15.1% for men and 3.6% for women. The estimated glomerular filtration rate levels in the normal- and high-ferritin groups were 93.2 and 93.8 mL/min/1.73 m² for men and 97.1 and 87.7 mL/min/1.73 m² for women, respectively. The prevalence of CKD in the normal- and high-ferritin groups was 2.6% and 3.9% for men and 3.2% and 8.1% for women, respectively. Compared with the normal-ferritin group, the odds ratios (95% confidence intervals) for CKD of the high-ferritin group were 1.573 (1.014–2.441) in men and 1.061 (0.381–2.955) in women, after adjustments for age and other covariates. (4) Conclusions: High ferritin levels were associated with a higher risk of CKD in men but not in women.

Min J, et al. J Korean Med Sci. 2018 Dec;33(53):e341. https://doi.org/10.3346/jkms.2018.33.e341

Podocytes play an important role in maintaining the glomerular filtration barrier and in formation of the slit diaphragm. Podocyte loss is associated with chronic kidney disease progression, but it is not clear whether urinary podocyte proteins in urine reflect the clinical extent of glomerular damage. We investigated the correlation between the amounts of urinary podocyte proteins and renal function and albuminuria. The study enrolled 33 patients with diabetic kidney disease or glomerular disease and measured urinary podocytes proteins using Western blotting. Urinary podocyte proteins were measured according to the density of the bands on Western blotting. We measured serum creatinine and the spot urine albumin/creatinine ratio as markers of renal damage, and compared the correlation of urinary podocyte protein in the glomerular disease patients. The mean patient age was 49.3 ± 16.5 years, the mean serum creatinine level was 2.30 ± 1.76 mg/dL, and the mean albumin/creatinine ratio was 4.85 ± 3.52. Among the podocyte proteins, urine synaptopodin showed strong correlation with serum creatinine by multivariate regression analysis (p < 0.001) and showed linear correlation (r = 0.429, p < 0.01). Urine podocyte proteins were increased in patients with diabetes, and synaptopodin showed the greatest significant difference (7.68 ± 5.61 vs. 2.56 ± 3.11, p < 0.001), but this might be associated with renal impairment. The urine albumin excretion did not differ between the diabetics and non-diabetics (p = 0.73). Urine synaptopodin is associated with serum creatinine elevation in the patients with glomerulonephritis including diabetic kidney disease regardless of urine albumin excretion. We suggest that the urine synaptopodin level can predict glomerular damage independently of the urine albumin excretion.

Kwon SK, et al. J Korean Med Sci. 2019 Jun;34(25):e176. https://doi.org/10.3346/jkms.2019.34.e176