Association of the Intensive Blood Pressure Target and Cardiovascular Outcomes in the Population With Chronic Kidney Disease: A Retrospective Study in Korea.

BACKGROUND: Recently, the target systolic blood pressure (BP) <120 mm Hg was suggested in the population with chronic kidney disease. We aimed to determine the applicability of intensified BP and to assess the incidence of cardiovascular disease (CVD) in the population with chronic kidney disease. METHODS AND RESULTS: Participants who were >20 years old and had estimated glomerular filtration rate 15 to 60 mL/min per 1.73 m2 during 2009 to 2011 were included from the database of Korean National Health Insurance Service and were followed up to 2018. Participants were categorized by BP as <120/80 mm Hg; 120 to 129/<80 mm Hg; 130 to 139/80 to 89 mm Hg; ≥140/90 mm Hg. The primary outcome was CVD risk and the secondary outcomes were all-cause mortality and progression to end-stage renal disease followed by subgroup analysis. Among the 45 263 adults with chronic kidney disease, 5196 CVD events were noted. In Cox regression analysis, higher BP was associated with a higher risk for CVD (hazard ratio [HR], 1.15 [95% CI, 1.12-1.19]; P for trend <0.001), end-stage renal disease (HR, 1.29 [95% CI, 1.22-1.37]; P for trend <0.001), and all-cause mortality (HR, 1.09 [95% CI, 1.06-1.13]; P for trend <0.001) than BP <120/80 mm Hg. In subgroup analysis, the association between BP and CVD showed a different trend in participants taking antihypertensives compared with those not using antihypertensive drugs. When comparing BP-treated individuals to untreated individuals, a significant interaction in the association between BP categories and end-stage renal disease was observed. CONCLUSIONS: The new intensive BP target proposed by 2021 Kidney Disease: Improving Global Outcomes should be applied to patients with chronic kidney disease in a personalized and advisory manner.

Clinical Relevance of Serum Galactose Deficient IgA1 in Patients with IgA Nephropathy.

New biomarkers of IgA nephropathy (IgAN) are needed for non-invasive diagnosis and appropriate treatment. There is emerging evidence that galactose deficient IgA1 (Gd-IgA1) is a pivotal molecule in the pathogenesis of IgAN. However, few studies have investigated the role of Gd-IgA1 as a biomarker in IgAN. In this study, we investigated the clinical relevance of serum Gd-IgA1 levels in patients with IgAN. Two hundred and thirty biopsy-proven IgAN patients, 74 disease controls (patients with non-IgAN nephropathy), and 15 healthy controls were enrolled in this study. Levels of serum Gd-IgA1 were measured using an ELISA kit in serum samples obtained the day of renal biopsy. We compared levels of serum Gd-IgA1 according to the type of glomerular disease and analyzed the association between Gd-IgA1 levels and clinical and pathological parameters in patients with IgAN. We then divided IgAN patients into two groups according to Gd-IgA1 level and investigated the predictive value of Gd-IgA1 for progression of chronic kidney disease (CKD). Serum Gd-IgA1 levels were significantly higher in IgAN patients than disease controls and healthy controls. In patients with IgAN, serum Gd-IA1 levels were significantly correlated with estimated glomerular filtration rate, serum IgA level, and tubular atrophy/interstitial fibrosis. CKD progression was more frequent in IgAN patients with higher serum Gd-IgA1 levels than in those with lower serum Gd-IgA1 levels. Cox proportional hazard models showed that high GdIgA1 level was an independent risk factor for CKD progression after adjusting for several confounders. Our results suggest that serum Gd-IgA1 level is a useful diagnostic and prognostic marker in IgAN patients. Further studies with a larger sample size and longer follow-up duration are needed.

Renal dysfunction is associated with decline of cognitive function in community-dwelling older adults: Korean frailty and aging cohort study.

BACKGROUND: Cognitive decline is common in older adults. Similarly, the prevalence of renal dysfunction is also increased in the elderly population. We conducted this study to clarify the relationship between renal dysfunction and decline of cognitive function in community-dwelling elderly population. METHODS: A cross-sectional analysis was performed using data from the Korean Frailty and Aging Cohort Study, a nationwide cohort study. Total 2847 (1333 men, 1514 women) eligible participants were enrolled for this study. The estimated glomerular filtration rate (eGFR, mL/min/1.73m2) was calculated using the Chronic Kidney Disease Epidemiology Collaboration equation. Global cognitive function was assessed with the Mini-mental State Examination-Korean version. Other domains of cognitive function were tested with the Consortium to Establish a Registry for Alzheimer's disease and the Frontal Assessment Battery. RESULTS: The mean age of all participants was 76.0 ± 3.9 years and eGFR (all in mL/min/1.73 m2) was 77.5 ± 14.3. And the mean eGFR was 91.7 ± 3.2 in quartile 1, 84.9 ± 1.8 in quartile 2, 76.1 ± 3.7 in quartile 3, and 57.2 ± 10.8 in quartile 4. In baseline characteristics, participants with lower eGFR tend to have lower cognitive function scores than participant with higher eGFR. In linear regression analysis, eGFR was correlated with the word list memory (ß = 0.53, P = 0.005), word list recall (ß = 0.86, P < 0.001), and word list recognition (ß = 0.43, P = 0.030) after adjustment of confounding variables. Moreover, after multivariate adjustment the association with cognitive impairment in quartile 2 was stronger (adjusted OR: 1.535, 95% CI: 1.111-2.120, P = 0.009), and the ORs of cognitive impairment were 1.501 (95% CI: 1.084-2.079, P = 0.014) in quartile 3 and 1.423 (95% CI: 1.022-1.983, P = 0.037) in quartile 4. CONCLUSION: In older adults, the immediate, recent memory, and recognition domains were significantly related to renal function. Also, the mild renal dysfunction was independently associated with impairment of global cognitive function. These results suggest that the early stages of renal dysfunction could be an effective target to prevent worsening of cognitive impairment. Therefore, regular monitoring and early detection of mild renal dysfunction in elderly population might be needed.

Defining the role of Parasutterella, a previously uncharacterized member of the core gut microbiota.

The genus of Parasutterella has been defined as a core component of the human and mouse gut microbiota, and has been correlated with various health outcomes. However, like most core microbes in the gastrointestinal tract (GIT), very little is known about the biology of Parasutterella and its role in intestinal ecology. In this study, Parasutterella was isolated from the mouse GIT and characterized in vitro and in vivo. Mouse, rat, and human Parasutterella isolates were all asaccharolytic and producers of succinate. The murine isolate stably colonized the mouse GIT without shifting bacterial composition. Notable changes in microbial-derived metabolites were aromatic amino acid, bilirubin, purine, and bile acid derivatives. The impacted bile acid profile was consistent with altered expression of ileal bile acid transporter genes and hepatic bile acid synthesis genes, supporting the potential role of Parasutterella in bile acid maintenance and cholesterol metabolism. The successful colonization of Parasutterella with a single environmental exposure to conventional adult mice demonstrates that it fills the ecological niche in the GIT and contributes to metabolic functionalities. This experiment provides the first indication of the role of Parasutterella in the GIT, beyond correlation, and provides insight into how it may contribute to host health.