Chronic kidney disease (CKD) associates with complex lipoprotein disturbances resulting in high cardiovascular risk. Apolipoprotein E (APOE) is a polymorphic protein with three common isoforms (E2; E3; E4) that plays a crucial role in lipoprotein metabolism, including hepatic clearance of chylomicrons and very low-density lipoprotein (VLDL) remnants, and reverse cholesterol transport. It demonstrates anti-atherogenic properties but data concerning the link between polymorphism and level of APOE in CKD patients are inconclusive. The aim of our research was to assess the relationship between APOE gene polymorphism and APOE concentration and its redistribution among lipoproteins along with CKD progression. 90 non-dialysed CKD patients were included into the study. Real time PCR was used for APOE genotyping. APOE level was measured in serum and in isolated lipoprotein fractions (VLDL; IDL + HDL; HDL). Kidney function was assessed using eGFR CKD-EPI formula. The population was divided into three APOE genotype subgroups: E2(ε2ε3), E3(ε3ε3) and E4(ε3ε4). The highest APOE level was observed for the E2 subgroup (p < 0.001). APOE concentration positively correlated with eGFR value in the E2 subgroup (r = 0.7, p < 0.001) but inversely in the E3 subgroup (r = − 0.29, p = 0.02).). A lower concentration of APOE in the E2 subgroup was associated with its diminished contents in HDL and IDL + LDL particles. In the E3 subgroup, the higher concentration of APOE was related to the increased number of non-HDL lipoproteins. In patients with CKD, APOE genotype as well as renal function are associated with the concentration of APOE and its redistribution among lipoprotein classes.

Background and Objectives: Kidney transplant recipients (KTRs) are at a higher risk of severe COVID-19 development. The course of the infection may vary. Long-term consequences for graft function are still being studied. We investigate whether the clinical course of SARS-CoV-2 infection among KTRs had a long-term effect on graft function. Patients and method: 128 KTRs with confirmed SARS-CoV-2 infection were included in the study. They were divided into two groups: mild (without the need for oxygen therapy; n = 91) and severe (with the need for oxygen therapy; n = 21). Baseline characteristics and medical data, especially creatinine level, estimated glomerular filtration rate (eGFR) CKD-EPI, and proteinuria, were analyzed. The main outcomes were the absolute and relative change in eGFR during the one-year follow-up after COVID-19. In the final models, sex, age, smoking, presence of diabetes mellitus (DM), and cardiovascular disease (CVD) were included. Results: KTRs with severe COVID-19 were older, more likely to smoke, and had DM and CVD more frequently. Our analysis reveals that COVID-19 severity was associated with a significantly more pronounced relative eGFR decline one year after recovery only in males [−13.94 (95% CI: −25.13 to −2.76, p = 0.015) percentage points]. One year after the disease onset, males with a severe course of the infection had a higher eGFR decline than those with a mild one. The COVID-19 severity did not affect eGFR loss in females. Conclusions: In KTRs suffering from COVID-19, deterioration of graft function was noticed. The eGFR decline was associated with disease severity and sex. It indicates a need for further research, observation, and preventive actions for KTRs, especially males.

Background: Chronic kidney disease (CKD) is widespread in the general population. It is generally accepted that worsening renal function is common with aging. However, the question still remains whether it is caused by the natural process of aging or whether coexisting chronic diseases and comorbid conditions contribute to deteriorating renal function. Methods: The frequency of albuminuria—the marker of early kidney damage—was evaluated according to different coexisting conditions in younger (18–64 years old, n=2074) and elderly (≥65 years old, n=395) participants of the Polish study PolNef on early detection of CKD. Multivariate logistic regression was performed to identify associations between elevated levels of albuminuria, age and coexisting conditions. Results: 12% of the younger group demonstrated albuminuria compared to 18% of the elderly. Independent predictors of detecting an elevated level of albuminuria for the whole examined population were male gender (2.48, 1.59-3.88), hypertension ineffectively treated (1.8, 1.34-2.4), diabetes (1.67, 1.11-2.49), and age (1.56, 0.97-2.52) at border levels of significance. Moreover, elevated levels of albuminuria occurred more frequently in the obese elderly group (1.89, 0.98-3.63, p=0.058). The following predictors were found based on gender: for men, hypertension regardless of efficacy of treatment, diabetes, smoking, and age at border level of significance, in contrast to women who had the sole predictor of ineffectively treated hypertension. Conclusions: The influence of aging alone on kidney damage is not evident. Moreover, it is different in males and females. Hypertension is the only coexisting comorbid condition contributing to kidney damage in both males and females. Advanced age together with comorbid conditions is more harmful to the kidney in males.