Prognosis of microscopic polyangiitis is well predictable in the first 2 weeks of treatment.

BACKGROUND: Kidney and life outcomes remain unsatisfactory in patients with microscopic polyangiitis (MPA). Appropriate treatment intensity must be provided to the appropriate patients. To identify severe cases early, we investigated the factors related to kidney and life outcomes. METHODS: We included patients diagnosed with MPA based on myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) positivity and kidney histopathology results after kidney biopsies between January 1, 2021, and May 11, 2023, at 10 affiliated centers, including our hospital. Death, maintenance dialysis, and estimated glomerular filtration rate (eGFR) < 15 after 6 months of treatment were defined as poor prognosis groups, and factors associated with these conditions were investigated. RESULTS: We included 84 (36 men and 48 women) patients in this study. Median age was 73.8 (interquartile range: 71-81) years. After 6 months of treatment, the proportion of patients in the poor prognosis group was 16.7 %, with a mortality of 7.1 % and a poor kidney prognosis rate of 9.5 %. Area under the receiver operating characteristic curve showed that eGFR at 2 weeks had a comparable prognostic performance equal as eGFR at 4 weeks (area under the curve: 0.875 and 0.896, respectively). After adjustment by various factors, eGFR at 2 weeks was related with prognosis significantly (p = 0.031). CONCLUSION: Kidney function 2 weeks after the start of treatment for MPA can predict prognosis.

Menthol alleviates post-race elevations in muscle soreness and metabolic and respiratory stress during running.

PURPOSE: We evaluated (1) whether participating in middle- and long-distance running races augments muscle soreness, oxygen cost, respiration, and exercise exertion during subsequent running, and (2) if post-race menthol application alleviates these responses in long-distance runners. METHODS: Eleven long-distance runners completed a 1500-m race on day 1 and a 3000-m race on day 2. On day 3 (post-race day), either a 4% menthol solution (Post-race menthol) or a placebo solution (Post-race placebo) serving as a vehicle control, was applied to their lower leg skin, and their perceptual and physiological responses were evaluated. The identical assessment with the placebo solution was also conducted without race participation (No-race placebo). RESULTS: The integrated muscle soreness index increased in the Post-race placebo compared to the No-race placebo (P < 0.001), but this response was absent in the Post-race menthol (P = 0.058). Oxygen uptake during treadmill running tended to be higher (4.3%) in the Post-race placebo vs. No-race placebo (P = 0.074). Oxygen uptake was 5.4% lower in the Post-race menthol compared to the Post-race placebo (P = 0.018). Minute ventilation during treadmill running was 6.7-7.6% higher in the Post-race placebo compared to No-race placebo, whereas it was 6.6-9.0% lower in the Post-race menthol vs. Post-race placebo (all P ≤ 0.001). The rate of perceived exertion was 7.0% lower in the Post-race menthol vs. Post-race placebo (P = 0.007). CONCLUSIONS: Middle- and long-distance races can subsequently elevate muscle soreness and induce respiratory and metabolic stress, but post-race menthol application to the lower legs can mitigate these responses and reduce exercise exertion in long-distance runners.

Low energy availability reduces bone mass and gonadal function in male mice.

INTRODUCTION: In women, the female athlete triad, marked by low energy availability, functional hypothalamic amenorrhea and osteoporosis, is a recognized risk for stress fractures. Stress injuries also occur in men, but by contrast risks and mechanisms underlying them are less characterized. MATERIALS AND METHODS: 5 week-old wild-type male mice were fed ad libitum (ad) or subjected to 60% food restriction (FR) for five weeks. In both groups, some mice were allowed access to an exercise wheel in cages to allow voluntary wheel running (ex) and/or treated with active vitamin D analogues. Mice were sacrificed and analyzed at 10 weeks of age. RESULT: Male FR mice exhibited significantly reduced testicle weight, serum testosterone levels and bone mass. Such bone losses in FR male mice were enhanced by exercise. Histological analysis revealed that both bone-resorbing and -forming activities were significantly reduced in FR or FR plus exercise (FR + ex) mice, mimicking a state of low bone turnover. Significantly reduced bone mass in FR or FR + ex male mice was significantly rescued by treatment with active vitamin D analogues, with significant restoration of osteoblastic activities. Serum levels of insulin-like growth factor I (IGF-I), which is critical for bone remodeling, were significantly lower in FR versus control male mice. CONCLUSIONS: Low energy availability puts men at risk for stress injuries as well, and low energy availability is upstream of gonadal dysfunction and osteoporosis in males. Active vitamin D analogues could serve as therapeutic or preventive options for stress injuries in men.

Treatment with an active vitamin D analogue blocks hypothalamic dysfunction-induced bone loss in mice.

Estrogen deficiency can be caused by ovarian dysfunction in females. Mechanisms underlying osteoporosis in this condition have been characterized in animal models, such as ovariectomized mice and rats, although it remains unclear how hypothalamic dysfunction promotes osteoporosis. Here, we show that administration of a gonadotropin-releasing hormone antagonist (GnRHa) significantly decreases uterine weight, a manifestation of hypothalamic dysfunction, and promotes both cortical and trabecular bone loss in female mice in vivo. We also report that osteoclast number significantly increased in mice administered GnRHa, and that the transcription factor hypoxia inducible factor 1 alpha (HIF1α) accumulated in those osteoclasts. We previously reported that treatment of mice with the active vitamin D analogue ED71, also known as eldecalcitol, inhibited HIF1α accumulation in osteoclasts. We show here that in mice, co-administration of ED71 with GnRHa significantly rescued the reduced cortical and trabecular bone mass promoted by GnRHa administration alone. GnRHa-dependent HIF1α accumulation in osteoclasts was also blocked by co-administration of ED71. We conclude that hypothalamic dysfunction promotes HIF1α accumulation in osteoclasts and likely results in reduced bone mass. We conclude that treatment with ED71 could serve as a therapeutic option to counter osteoporotic conditions in humans.

Smad2 and Smad3 expressed in skeletal muscle promote immobilization-induced bone atrophy in mice.

Skeletal muscle is known to regulate bone homeostasis through muscle-bone interaction, although factors that control this activity remain unclear. Here, we newly established Smad3-flox mice, and then generated skeletal muscle-specific Smad2/Smad3 double conditional knockout mice (DcKO) by crossing Smad3-flox with skeletal muscle-specific Ckmm Cre and Smad2-flox mice. We show that immobilization-induced gastrocnemius muscle atrophy occurring due to sciatic nerve denervation was partially but significantly inhibited in DcKO mice, suggesting that skeletal muscle cell-intrinsic Smad2/3 is required for immobilization-induced muscle atrophy. Also, tibial bone atrophy seen after sciatic nerve denervation was partially but significantly inhibited in DcKO mice. Bone formation rate in wild-type mouse tibia was significantly inhibited by immobilization, but inhibition was abrogated in DcKO mice. We propose that skeletal muscle regulates immobilization-induced bone atrophy via Smad2/3, and Smad2/3 represent potential therapeutic targets to prevent both immobilization-induced bone and muscle atrophy.

Synoviolin is not a pathogenic factor for auto-inflammatory diseases.

Auto-inflammatory syndromes are rare diseases characterized by arthritis and joint destruction, symptoms similar to but distinct from rheumatoid arthritis (RA). Therapeutic targets have not been well characterized for auto-inflammatory syndromes, although the E3 ligase Synoviolin was previously shown to be a novel therapeutic target for RA. Here, we show that Synoviolin loss has little impact on a model of auto-inflammatory diseases. We previously established such a model, the hIL-1 cTg mouse, in which IL-1 signaling was constitutively activated, and animals exhibit symptoms recapitulating auto-inflammatory syndromes such as major joint dominant arthritis. Here, we crossed hIL-1 cTg with Synoviolin flox'd mice to yield hIL-1 cTg/Synoviolin cKO mice. Synoviolin gene expression was ablated in adult hIL-1 cTg/Synoviolin cKO mice by injection of pIpC to activate Mx1 promoter-driven Cre recombinase. However, symptoms seen in hIL-1 cTg mice such as arthritis and joint destruction were not alleviated by targeting Synoviolin, ruling out Synoviolin as a therapeutic target for auto-inflammatory disease. Our results indicate that although similar, RA and auto-inflammatory diseases are different diseases, and treatment strategies should differ accordingly.

Food restriction reduces cortical bone mass and serum insulin-like growth factor-1 levels and promotes uterine atrophy in mice.

Low energy availability in female athletes often causes hypothalamic amenorrhea and osteoporosis, in turn promoting stress fractures. Mechanisms underlying these conditions remain unclear. Here we show that model mice subjected to food restriction (FR) or FR-plus-voluntary running exercise exhibit significantly reduced bone mineral density, cortical bone parameters and uterine weight than do control mice, and that these parameters worsen in the FR-plus-exercise group. Relative to controls, FR and FR-plus-exercise groups showed significantly lower mineral apposition rate and osteoclast number and significantly reduced serum insulin-like growth factor-1 (IGF1) levels. Outcomes were rescued by ED71 or 1.25(OH)2D3 treatment. Thus, we conclude that administration of active vitamin D analogues represents a possible treatment to prevent these conditions.

Tooth extraction in mice administered zoledronate increases inflammatory cytokine levels and promotes osteonecrosis of the jaw.

INTRODUCTION: Osteonecrosis of the jaw (ONJ) occurring after invasive dental treatment often adversely affects patients' activities of daily living. Long-term administration of strong anti-bone resorptive agents such as bisphosphonates prior to invasive dental treatment is considered an ONJ risk factor; however, pathological mechanisms underlying ONJ development remain unclear. MATERIALS AND METHODS: We developed an ONJ mouse model in which a tooth is extracted during treatment with the bisphosphonate zoledronate. RESULTS: We observed induction of apoptosis in osteocytes, resulting in formation of empty lacunae in jaw bones at sites of tooth extraction but not in other bones of the same mice. We also observed elevated levels of inflammatory cytokines such as TNFα, IL-6 and IL-1 in jaw bone at the extraction site relative to other sites in zoledronate-treated mice. We also report that treatment in vitro with either zoledronate or an extract from Porphyromonas gingivalis, an oral bacteria, promotes expression of inflammatory cytokines in osteoclast progenitor cells. We demonstrate that gene-targeting of either TNFα, IL-6 or IL-1 or treatment with etanercept, a TNFα inhibitor, or a neutralizing antibody against IL-6 can antagonize ONJ development caused by combined tooth extraction and zoledronate treatment. CONCLUSIONS: Taken together, the cytokine storm induced by invasive dental treatment under bisphosphonate treatment promotes ONJ development due to elevated levels of inflammatory cytokine-producing cells. Our work identifies novel targets potentially useful to prevent ONJ.

Relationship between selection of dosage forms of vitamin D receptor activators and short-term survival of patients on hemodialysis.

BACKGROUND: The benefits of vitamin D receptor activators (VDRAs) for patients with chronic kidney disease are well recognized. However, the optimal criteria for patient selection, dosage forms, and duration providing the highest benefit and the least potential risk remain to be confirmed. MATERIALS AND METHODS: The study population was derived from the Aichi Cohort Study of Prognosis in Patients Newly Initiated into Dialysis, a multicenter prospective cohort study of 1520 incident dialysis patients. According to the VDRA usage status in March 2015 (interim report), the 967 patients surviving after March 2015 were classified into three groups: without VDRA (NV, n = 177), oral VDRA (OV, n = 447), and intravenous VDRA (IV, n = 343). Mortality rates were compared using the log-rank test, and factors contributing to all-cause mortality were examined using both univariate and multivariate Cox proportional hazard regression analyses. RESULTS: There were 104 deaths (NV, n = 27; OV, n = 53; IV, n = 24) during the follow-up period (1360 days, median), and significant differences in cumulative survival rates were observed between the three groups (p = 0.010). Moreover, lower all-cause mortality was associated with IV versus NV (hazard ratio, 0.46 [95% confidence interval 0.24-0.89]; p = 0.020). CONCLUSION: This study demonstrated the impact of the VDRA dosage form on the short-term survival of incident hemodialysis patients during the introduction period. Our results suggest that relatively early initiation of intravenous VDRA in patients beginning hemodialysis may have some clinical potential.

Extreme hyperuricemia is a risk factor for infection-related deaths in incident dialysis patients: a multicenter prospective cohort study.

INTRODUCTION: There are few studies on the association between serum uric acid (UA) level and mortality in incident dialysis patients. We aimed to clarify whether the serum UA level at dialysis initiation is associated with mortality during maintenance dialysis. METHODS: We enrolled 1486 incident dialysis patients who participated in a previous multicenter prospective cohort study in Japan. We classified the patients into the following five groups according to their serum UA levels at dialysis initiation: G1 with a serum UA level <6 mg/dL; G2, 6.0-8.0 mg/dL; G3, 8.0-10.0 mg/dL; G4, 10.0-12.0 mg/dL; and G5, ≥12.0 mg/dL. We created three models (Model 1: adjusted for age and sex, Model 2: adjusted for Model 1 + 12 variables, and Model 3: stepwise regression adjusted for Model 2 + 13 variables) and performed a multivariate Cox proportional hazard regression analysis to examine the association between the serum UA level and outcomes, including infection-related mortality. RESULTS: Hazard ratios (HRs) were calculated relative to the G2, because the all-cause mortality rate was the lowest in G2. For Models 1 and 2, the all-cause mortality rate was significantly higher in G5 than in G2 (HR: 1.63, 95% confidence interval [CI]: 1.14-2.33 and HR: 1.78, 95% CI: 1.19-2.68, respectively). For Models 1, 2, and 3, the infection-related mortality rate was significantly higher in G5 than in G2 (HR: 2.75, 95% CI: 1.37-5.54, HR: 3.09, 95% CI: 1.45-6.59, HR: 3.37, and 95% CI: 1.24-9.15, respectively). CONCLUSIONS: Extreme hyperuricemia (serum UA level ≥12.0 mg/dL) at dialysis initiation is a risk factor for infection-related deaths.

Oral ferrous citrate or ferrous sulfate use during predialysis may reduce serum phosphate level at dialysis initiation
.

AIM: Some reports claim that intravenous iron supplements reduce serum phosphate levels in patients with chronic kidney disease (CKD), including those on dialysis. However, whether divalent oral iron supplements influence serum phosphate levels in patients with CKD remains unclear; thus, this study aimed to address this topic. MATERIALS AND METHODS: The study database was derived from the Aichi Cohort Study of Prognosis in Patients Newly Initiated into Dialysis (AICOPP), which is a multicenter, prospective, cohort study. Patients were classified into two groups: those who received iron orally (iron group, n = 255) from pre-dialysis to dialysis initiation and those who did not receive iron supplements (no-iron group, n = 1,261). Moreover, patients were classified into two groups (255 patients in each) by propensity score (PS) matching. We compared serum phosphate level at dialysis initiation and all-cause mortality. Multivariate regression analysis was used to extract factors contributing to serum phosphate level at dialysis initiation through a stepwise method. RESULTS: Serum phosphate levels at dialysis initiation were significantly lower in the iron group (all cohort, 6.0 ± 1.6 vs. 6.4 ± 1.9 mg/dL, p = 0.001; PS-matched cohort, 6.0 ± 1.6 vs. 6.5 ± 1.7 mg/dL, p = 0.001). Multivariate regression analysis revealed that oral iron supplementation was significantly correlated to serum phosphate level (p = 0.023). There were no significant differences in all-cause mortality after dialysis initiation. CONCLUSION: This study showed that oral ferrous citrate or ferrous sulfate use during predialysis was associated with differences in serum phosphate level at dialysis initiation.

Late-Stage Functionalization of Arylacetic Acids by Photoredox-Catalyzed Decarboxylative Carbon-Heteroatom Bond Formation.

The rapid transformation of pharmaceuticals and agrochemicals enables access to unexplored chemical space and thus has accelerated the discovery of novel bioactive molecules. Because arylacetic acids are regarded as key structures in bioactive compounds, new transformations of these structures could contribute to drug/agrochemical discovery and chemical biology. This work reports carbon-nitrogen and carbon-oxygen bond formation through the photoredox-catalyzed decarboxylation of arylacetic acids. The reaction shows good functional group compatibility without pre-activation of the nitrogen- or oxygen-based coupling partners. Under similar reaction conditions, carbon-chlorine bond formation was also feasible. This efficient derivatization of arylacetic acids makes it possible to synthesize pharmaceutical analogues and bioconjugates of pharmaceuticals and natural products.

Ratio of blood urea nitrogen to serum creatinine at initiation of dialysis is associated with mortality: a multicenter prospective cohort study.

BACKGROUND: Some studies have shown that the estimated glomerular filtration rate (eGFR) at the time of initiating dialysis was associated with mortality. However, the relationship between ratio of blood urea nitrogen to serum creatinine (BUN/Cr) and mortality is unknown. METHODS: The study was a multicenter, prospective cohort analysis including 1520 patients. Patients were classified into four quartiles based on the BUN/Cr ratio at the dialysis initiation, with Q1 having the lowest ratio and Q4 the highest. All-cause mortality after initiating dialysis was compared using the log-rank test. All-cause mortality of Q1, Q2, and Q3 was compared with that of Q4 using multivariate Cox proportional hazard regression analysis. Moreover, we compared the renal parameters including BUN/Cr ratio, eGFR, and creatinine clearance for sensitivity and specificity using receiver operative characteristic (ROC) curve. RESULTS: Significant differences were observed in all-cause mortality among the four groups (p < 0.001). Multivariate analysis revealed that all-cause mortality was significantly higher in Q4 than in Q1 [hazard ratio (HR) = 1.82, 95% confidence interval (CI) 1.24-2.67, p = 0.002]. The increase in BUN/Cr ratio was positively associated with mortality (HR 1.04, 95% CI 1.02-1.06, p = 0.002). The sensitivity and specificity of BUN/Cr ratio for 180, 365, 730, and 1095 days mortality ranged between 0.60-0.72 and 0.59-0.71, respectively. The area under the curve of BUN/Cr for all-cause mortality was the highest among the renal parameters. CONCLUSION: The BUN/Cr ratio at the time of initiation of dialysis was associated with all-cause mortality.

Impact of high mortality in incident dialysis patients due to hypertensive nephrosclerosis: a multicenter prospective cohort study in Aichi, Japan.

INTRODUCTION: An increasing number of patients worldwide require dialysis as a result of hypertensive nephrosclerosis (HTN). However, in Japan, mortality in patients with end-stage renal disease (ESRD) has not been well by primary kidney disease including HTN and diabetic nephropathy (DN). Hence, we examined the differences in mortality among the primary kidney diseases of incident dialysis patients. METHODS: The study was a multicenter prospective cohort analysis including 1520 incident dialysis patients in Aichi prefecture, Japan. We classified patients into three groups according to the primary kidney disease [i.e., a HTN group, n = 384, a DN group n = 658, and a chronic glomerulonephritis (CGN) group, n = 224]. In addition, we classified patients into the HTN group and the DN group using propensity score matching. We compared outcomes including all-cause and infection-related mortality. RESULTS: The mortality rates of the HTN, the DN, and the CGN group, were 135.9, 64.2, and 34.8 per 1000 patient years, respectively. All-cause mortality and infection-related mortality rates in the HTN group were as high as those in the DN group after adjustment for age, gender, history of cardiovascular disease, and estimated glomerular filtration rate. No significant difference of all-cause mortality was observed after propensity score matching between the two groups (Logrank test: p = 0.523). CONCLUSIONS: The present study was Japan's first large-scale prospective cohort to demonstrate that HTN is the second most common cause of ESRD. In addition, the prognosis of patients with HTN was as poor as that of patients with DN.

Effect of combined vitamin D receptor activator and lanthanum carbonate on serum fibroblast growth factor 23 level in predialysis patients (CVD-LAF study): design and method.

BACKGROUND: Whether vitamin D receptor activator (VDRA) use is beneficial in chronic kidney disease (CKD) is unclear, because it is possible that VDRA increases serum fibroblast growth factor 23 (FGF23) levels. We will conduct a randomized controlled trial in predialysis patients to determine the effect of VDRA alone or in combination with lanthanum carbonate (LC) on serum FGF23 levels. METHODS: This is a single-center, open-label, randomized controlled trial. Enrollment will commence February 1, 2018, using the following inclusion criteria: (1) age ≥ 20 years, (2) CKD with an estimated glomerular filtration rate of 10-45 mL/min/1.73 m2, (3) serum adjusted calcium level < 9.5 mg/dL, (4) serum phosphate level 4.0-6.0 mg/dL, and (5) serum intact parathyroid hormone (PTH) level ≥ 60 pg/mL. Study patients will be randomized 1:1 to receive alfacalcidol alone or in combination with LC. The initial dose of alfacalcidol will be 0.25-0.5 µg once a day according to serum adjusted calcium level. The initial dose of LC will be 250 mg once a day. We will measure serum intact and C-terminal FGF23 at 0, 4, 8, 12, 24, and 52 weeks. The primary outcome will be serum FGF23 level at 24 weeks compared with baseline. DISCUSSION: This study aims to determine whether low-dose oral VDRA increases serum FGF23 level and whether the combination of VDRA and LC inhibits this increase. The results will be useful in the management of CKD-mineral and bone disorder in predialysis patients. TRIAL REGISTRATION: UMIN000030503. Registered 20 January 2018.

Aortic stenosis is a risk factor for all-cause mortality in patients on dialysis: a multicenter prospective cohort analysis.

BACKGROUND: Aortic stenosis (AS) is common in patients on dialysis as well as in the general population. AS leads to difficulty with dialysis therapy because of unstable conditions such as intradialytic hypotension due to low cardiac output. However, the precise morbidity rates and risk factors of AS in patients on dialysis are unknown. Moreover, there are no large-scale observational studies regarding the association between AS in patients on dialysis and mortality. Therefore, we will investigate whether morbidity of AS in patients on dialysis is associated with mortality. METHODS: This is a multicenter prospective cohort analysis in the Tokai region of Japan. The 75 participating centers in this study will enroll approximately 2400 patients during 12 months, with or without AS. We started enrollment in July 2017 and will follow patents until June 2023. Transthoracic echocardiography will be performed to evaluate aortic valve. Parameters used for evaluation of aortic valve are mean pressure gradient between left ventricle and ascending aorta, aortic valve area, and maximum aortic jet velocity. We will diagnose AS using the criteria based on the 2014 American Heart Association/ American College of Cardiology Guideline. We will also perform transthoracic echocardiography at 12, 24, 36, 48, and 60 months. Survival prognosis and CV events will be determined at the end of June 2019, 2020, 2021, 2022, and 2023. Development of AS will be also evaluated as new onset or annual change in AS parameters. We will classify patients based on the presence or absence of AS and the stages of AS and will compare outcomes. Study outcomes will include the following: 1) all-cause mortality rates; 2) incidence of cardiovascular (CV) events; 3) CV-related mortality rates; 4) infection-related mortality rates; 5) new onset or development of AS. DISCUSSION: We will consider the following hypotheses in this study, among others: The prevalence of AS is higher in dialysis patients; new onset and development of AS are associated with factors that are specific for dialysis, such as hyperphosphatemia, hyperparathyroidism, and medication; and outcomes in AS patients are poorer than in patients without AS at baseline. TRIAL REGISTRATION: UMIN000026756 , Registered March 29 2017.

Serum phosphate level at initiation of dialysis is associated with all-cause mortality: a multicenter prospective cohort study.

INTRODUCTION: As glomerular filtration rate (GFR) decreases, serum phosphate level increases. Previous reports indicated that serum phosphate level was associated with mortality in patients on dialysis. However, few reports have examined the association using dialysis initiation as the baseline period. METHODS: This was a multicenter prospective cohort analysis including 1492 patients. Patients were classified into four quartiles based on the serum phosphate level at dialysis initiation, with Q1 being the lowest and Q4 the highest. All-cause mortality after dialysis initiation was compared using the log-rank test. The propensity score represented the probability of being assigned to group Q1 or Q2-4. All-cause mortality was compared in propensity score-matched patients by using the log-rank test for Kaplan-Meier curves. All-cause mortality of Q1 was compared with that for Q2-4 using multivariate Cox proportional hazard regression analysis. All-cause mortality was also determined among stratified groups with or without use of phosphate binders. RESULTS: Significant differences in cumulative survival rates were observed between the four groups (p < .001). After propensity score-matching, mortality was significantly higher in the Q1 group than the Q2-4 group (p = .046). All-cause mortality was significantly higher in the Q1 group after adjustment for history of CAD (hazard ratio [HR] = 0.76, 95% confidence interval [CI]: 0.58 - 1.00, p = .048). However, there was no significant difference between the two groups after adjustment for estimated GFR. CONCLUSION: The serum phosphate level at the time of dialysis initiation was associated with all-cause mortality. However, the serum phosphate level was dependent on the renal function.

Ferrokinetics is associated with the left ventricular mass index in patients with chronic kidney disease.

Background Patients with chronic kidney disease (CKD) often have the complication of anaemia. Usage of an erythropoietin-stimulating agent accelerates iron deficiency because it promotes iron utilization. Recently, iron administration was reported to be effective for patients with cardiac failure. We examined the association between ferrokinetics and cardiac function in patients with CKD. Methods In this cross-sectional study, we examined 558 patients (424 men and 134 women; mean age, 68.9 ± 13.1 years) with CKD who were admitted to our hospital. We assessed cardiac function by ultrasonography and ferrokinetics through transferrin saturation (TSAT) and ferritin levels. Results The primary diseases of CKD were nephrosclerosis (n = 247), diabetic nephropathy (n = 154), chronic glomerulonephritis (n = 73), and others. The mean estimated glomerular filtration rate was 16.9 ± 9.3 mL/min/1.7 m2, and the haemoglobin (Hb) level was 11.0 ± 1.7 g/dL. The median of TSAT was 28.05%, and patients were divided into two groups: below (L-Ts) and above (H-Ts) the median. The median of ferritin was 122 ng/mL, and patients were divided into two groups: below (L-f) and above (H-f) the median. We categorized four groups as H-Ts + H-F, H-Ts + L-F, L-Ts + H-F, and L-Ts + L-F. The Hb levels were 11.1 ± 1.8, 11.3 ± 1.4, 10.9 ± 1.6, and 10.8 ± 1.5 g/dL, respectively, and there was no difference between groups. However, the left ventricular mass indices (LVMIs) were 122.6 ± 46.6, 110.8 ± 32.0, 118.3 ± 36.0, 126.7 ± 46.9, respectively (P = 0.0291). This tendency was stronger in patients without cardiovascular events. Conclusion In patients with CKD, there is an association between ferrokinetics and LVMI. We have to be mindful not only of anaemia but also of ferrokinetics.

Factors associated with severity of sleep apnoea syndrome in patients with chronic kidney disease.

Background In patients with chronic kidney disease (CKD), prevalence of sleep apnoea syndrome (SAS) is reported to be markedly high. However, the factors associated with severity of SAS in such patients rarely have been reported. Methods This was a cross-sectional study of 100 stable non-dialysis patients with CKD who attended a CKD educational programme from April 2014 to August 2015. Diagnosis of SAS and its severity were assessed using a type-3 portable monitor. Results Eighty-six men and 14 women with a mean age of 71.6 ± 9.7 years were included. Mean apnoea-hypopnoea index (AHI) was 26.0 ± 13.8. Severe SAS was seen in 39 patients. Significant differences in brain natriuretic peptide (BNP) level (213.6 ± 329.6 pg/mL vs 107.8 ± 141.3 pg/mL, P < 0.05) and cardiothoracic ratio (CTR, 52.4% ± 6.3% vs 49.6% ± 5.7%, P < 0.05) were seen between patients with and without severe SAS. After adjusting for various parameters, BNP level, CTR, and diameter of the inferior vena cava at the end of inhalation were found to correlate with AHI. Conclusions In patients with CKD, prevalence of severe SAS is extremely high. In these patients, fluid retention, rather than systolic or diastolic function, correlates with severity of SAS.

Association between 1,25-dihydroxyvitamin D and left atrial diameter in pre-dialysis chronic kidney disease patients
.

OBJECTIVE: To investigate the correlation between serum 1,25-dihydroxyvitamin D (1,25D) levels and left atrial diameter (LAD) using echocardiography in pre-dialysis chronic kidney disease (CKD). SUBJECTS AND METHODS: From an initial population of 487 patients (109 met the exclusion criteria), a total of 378 patients with CKD stage 3a - 5 who had not undergone dialysis or kidney transplantation were included in the study. The relationship between serum 1,25D levels and LAD was examined. Moreover, factors that impacted LAD were extracted through stepwise multiple regression analyses. RESULTS: Serum 1,25D levels correlated negatively with LAD, left ventricular end-diastolic diameter, interventricular septum thickness, end-diastolic volume, stroke volume, left ventricular mass index (LVMI), and E/e'. Stepwise multiple regression analyses revealed there was a significant relationship between serum 1,25D levels and LAD (regression coefficient = -0.070, p = 0.001). In the stratified analysis, serum 1,25D levels were associated with LAD in the LVMI < 125 g/m2 (regression coefficient = -0.067, p = 0.038) and ejection fraction (EF) ≥ 60% groups (regression coefficient = -0.080, p = 0.004). CONCLUSION: Serum 1,25D levels were independently associated with LAD in CKD patients; however, the association was not significant in patients with an EF < 60% and LVMI > 125 g/m2.