Patient-reported difficulty in activities of daily living and corresponding muscle weakness in elderly patients undergoing haemodialysis

AIM

Patients undergoing haemodialysis have reduced muscle strength and impaired activities of daily living (ADL). We examined possible relationship between difficult ADL and corresponding muscle weakness in elderly haemodialysis patients.

METHODS

This was a single-centre, cross-sectional study. Patient-reported ADL difficulty was examined using a questionnaire in six ADL using upper limbs (eating, grooming and dressing) and lower limbs (bathing, toileting and locomotion). We measured six muscle strengths by dynamometers of shoulder flexion, shoulder abduction, elbow flexion, handgrip, hip abduction and knee extension. The muscle strength with the lowest Z-score was considered as the weakest muscle strength for the patient.

RESULTS

The six scores of ADL difficulty were all inversely associated with the six muscle strengths in the 81 total participants of whom 71 individuals (87.7%) had any ADL difficulty. Among the six measurements of muscle strength, handgrip strength showed the highest associations with all ADL difficulties. In 25 patients who perceived that the most difficult ADL was an activity using upper limbs, the common weakest muscle strengths were the hip abduction, handgrip and elbow flexion. In 44 patients who perceived that the most difficult ADL was an activity using lower limbs, knee extension was the most prevalent weakest muscle strength.

CONCLUSION

This study suggested preferential relationship between the most difficult ADL and corresponding muscle weakness in elderly haemodialysis patients. This finding may be useful in prevention and treatment.

Differential associations of fetuin-A and calcification propensity with cardiovascular events and subsequent mortality in patients undergoing hemodialysis

Background

Fetuin-A inhibits precipitation of calcium-phosphate crystals by forming calciprotein particles (CPP). A novel T50 test, which measures transformation time from primary to secondary CPP, is an index for calcification propensity. Both lower fetuin-A and shorter T50 levels were associated with cardiovascular disease (CVD) risk in patients with chronic kidney disease (CKD). Extremely high risk for CVD death in advanced CKD patients consists of high-incidental CVD event and high mortality after CVD event. To date, it is unclear whether fetuin-A and/or T50 can equally predict each CVD outcome.

Methods

This prospective cohort study examined patients undergoing maintenance hemodialysis. The exposures were fetuin-A and T50. The outcomes of interests were new CVD events and subsequent deaths. The patients were categorized into tertiles of fetuin-A or T50 (T1 to T3).

Results

We identified 190 new CVD events during the 5-year follow-up of the 513 patients and 59 deaths subsequent to the CVD events during 2.5-year follow-up. A lower fetuin-A but not T50 was significantly associated with new CVD events [subdistribution hazard ratio (HR) 1.73, 95% confidence interval (CI) 1.15-2.61, P = .009 for T1 vs T3]. In contrast, a shorter T50 but not fetuin-A was a significant predictor of deaths after CVD events (HR 3.31, 95% CI 1.42-7.74, P = .006 for T1 + T2 vs T3). A lower fetuin-A was predictive of new CVD events, whereas a shorter T50 was more preferentially associated with subsequent death.

Conclusion

These results indicate that fetuin-A and T50 are involved in cardiovascular risk in different manners.

Patients with infusion-related reactions on fixed-dose rituximab treatment have higher body surface area than those without infusion-related reactions in adults with frequently relapsing minimal change nephrotic syndrome: a retrospective study

BACKGROUND

Infusion-related reactions (IRRs) are major side effects of rituximab administration. Male sex, high body weight, body surface area (BSA), and body mass index are predictive markers of rituximab-induced IRRs. However, as rituximab was not administered at a fixed dosage in a previous study, whether a higher dosage or factors associated with a larger physique are more strongly associated with rituximab-induced IRRs is unknown.

MAIN BODY

Thirteen adults with frequently relapsing minimal change nephrotic syndrome (MCNS) who received an initial rituximab dose of 500 mg between September 2015 and November 2022 were retrospectively evaluated. Data on IRRs were collected from medical records. The incidence of rituximab-induced IRRs was 38.5% (5/13). The IRR group had a significantly higher BSA than the non-IRR group (median, 1.86 vs. 1.48 m2; p = 0.045). Additionally, rituximab dosage normalized by BSA in the IRR group was significantly lower than that in the non-IRR group (median, 268.8 vs. 337.9 mg/m2; p = 0.045).

CONCLUSIONS

Our study revealed that adults with frequently relapsing MCNS who experienced IRRs tend to have a higher BSA, even with fixed-dose rituximab treatment. Therefore, when patients with higher BSA receive rituximab treatment, clinicians should be careful about monitoring patient condition whether the dosage is fixed or not.

Seasonal variations for newly prescribed urate-lowering drugs for asymptomatic hyperuricemia and gout in Japan

Background: Urate-lowering drugs (ULDs) have been approved for treatment of asymptomatic hyperuricemia and gout in Japan. Although serum urate levels and rates of gout onset are known to have seasonal variations, no survey results regarding the seasonality of ULD prescriptions for asymptomatic hyperuricemia and gout have been reported. Methods: A large-scale database of medical claims in Japan filed between January 2019 and December 2022 was accessed. In addition to total size of the recorded population for each month examined, the numbers of patients every month with newly prescribed ULDs for asymptomatic hyperuricemia and gout were noted, based on the International Classification of Diseases, 10th Revision, codes E79.0 and M10. Results: The results identified 201,008 patients with newly prescribed ULDs (median age 49.0 years, male 95.6%). Of those, 64.0% were prescribed ULDs for asymptomatic hyperuricemia and 36.0% for gout. The proportion of new ULD prescriptions was seasonal, with that significantly (p < 0.001) higher in summer (June-August) [risk ratio (RR) 1.322, 95% CI 1.218 to 1.436] and autumn (September-November) (RR 1.227, 95% CI 1.129-1.335) than in winter (December-February), whereas the proportion in spring (March-May) was not significantly different from winter. There was no significant difference after stratification by drug type (uric acid production inhibitor/uricosuric agent) or size of the medical institution, nor subgrouping by age or sex (p for interaction = 0.739, 0.727, 0.886, and 0.978, respectively). On the other hand, the proportions of new ULD prescriptions for asymptomatic hyperuricemia were significantly lower and for gout significantly higher in spring than winter, while those were similar in summer and autumn for both groups (p for interaction<0.001). Conclusion: The present findings indicate that new prescriptions for ULDs to treat asymptomatic hyperuricemia or gout in Japan show seasonal differences, with higher rates noted in summer and autumn as compared to winter.

Novel Digenic Variants in COL4A4 and COL4A5 Causing X-Linked Alport Syndrome: A Case Report

Introduction

Alport syndrome (AS) is a hereditary, progressive kidney disease characterized by structural abnormalities and dysfunction of the glomerular basement membrane (GBM). AS is classified as X-linked, autosomal, and digenic. The number of cases of digenic AS has increased, but the genotype-phenotype correlation of patient with digenic AS is still unclear. Here, we present a case of digenic AS with novel digenic missense variants in COL4A4 (c.827G>C, p.Gly276Ala) and COL4A5 (c.4369G>C, p.Gly1457Arg).

Case Presentation

The patient was a 29-year-old Japanese man suffering from persistent microscopic hematuria and proteinuria without kidney function impairment. Kidney biopsy showed focal interstitial foam cell infiltration, global and segmental glomerulosclerosis. Immunofluorescence staining for collagen IV α5 was almost negative in the GBM and Bowman's capsule. Electron microscopy revealed irregular thickening with lamellation and segmental thinning of the GBM. Clinical and pathological findings were consistent with AS. Comprehensive next-generation sequencing revealed a heterozygous missense variant in COL4A4 (c.827G>C, p.Gly276Ala) in exon 1 and a hemizygous missense variant in COL4A5 (c.4369G>C, p.Gly1457Arg) in exon 49 on the patient's paternal and maternal alleles, respectively. The same digenic variants were detected in his sister, and she also showed a similar phenotype. After treatment with angiotensin-converting enzyme inhibitors, proteinuria decreased from 2.3 to 1.1 g/g creatinine, but occult blood persisted. During follow-up, kidney function has been preserved.

Conclusion

The novel genotype of our case provides more information on the genotype-phenotype correlation of digenic XLAS, although long-term follow-up is required. The findings in the present case also indicate the importance of genetic tests for family members of a patient diagnosed with digenic AS.

Dapagliflozin administration for 1 year promoted kidney enlargement in patient with ADPKD

To date, there is insufficient evidence regarding use of sodium-glucose cotransporter-2 (SGLT2) inhibitors for patients with autosomal-dominant polycystic kidney disease (ADPKD), as such cases have been excluded from previous clinical trials exploring the kidney protection effects of such medications. Here, findings of an ADPKD patient who received dapagliflozin, a selective SGLT2 inhibitor, for 1 year are presented. A 38-year-old woman with a family history of ADPKD wished for treatment with dapagliflozin. After starting administration at 10 mg/day, total kidney volume (TKV) continued to increase, from 1641 to 1764 mL after 84 days and then to 2297 mL after 340 days. The estimated glomerular filtration rate (eGFR) was also decreased from 67.3 to 56.2 mL/min/1.73 m2, and then to 51.4 mL/min/1.73 m2 at those times. Immediately after discontinuation of dapagliflozin, TKV and eGFR were slightly improved to 2263 mL and 55.1 mL/min/1.73 m2, respectively. Following a review of basic research studies, we consider that increased intratubular urinary osmotic pressure, compensatory glucose reabsorption by sodium-glucose cotransporter-1 in the late proximal tubule, and hypertrophy shown in collected cells caused by increased vasopressin may be associated with ADPKD disease progression. Caution may be needed when administering dapagliflozin to patients with ADPKD.

Serum Fibroblast Growth Factor 23 Levels are Associated with Vascular Smooth Muscle Dysfunction in Type 2 Diabetes

AIM

Increased level of serum fibroblast growth factor 23 (FGF23) is a hallmark of abnormal phosphate metabolism in patients with chronic kidney disease (CKD) and is recently shown to be associated with the risk of cardiovascular disease even in those without CKD. This study investigated the association between serum FGF23 levels and vascular function in patients with type 2 diabetes.

METHODS

This was a cross-sectional study involving 283 Japanese patients with type 2 diabetes. Flow-mediated dilatation (FMD) and nitroglycerin-mediated dilatation (NMD) of the brachial artery were measured via ultrasonography to evaluate vascular endothelial and smooth muscle functions, respectively. Serum intact FGF23 levels were determined via a sandwich enzyme-linked immunosorbent assay.

RESULTS

The median values of FMD, NMD, and serum FGF23 were 6.0%, 14.0%, and 27.3 pg/mL, respectively. The serum FGF23 levels were inversely associated with NMD but not with FMD, and the association was independent of atherosclerotic risk factors, estimated glomerular filtration rate (eGFR), and serum phosphate levels. Furthermore, the relationship between serum FGF23 levels and NMD was modified by kidney function, which was pronounced in subjects with normal kidney function (eGFR ≥ 60 mL/min/1.73 m2).

CONCLUSION

Serum FGF23 levels are independently and inversely associated with NMD in patients with type 2 diabetes, particularly in those with normal kidney function. Our results indicate that FGF23 is involved in vascular smooth muscle dysfunction and that increased serum levels of FGF23 may serve as a novel biomarker for vascular smooth muscle dysfunction in patients with type 2 diabetes.

Short-Term Dapagliflozin Administration in Autosomal Dominant Polycystic Kidney Disease-A Retrospective Single-Arm Case Series Study

Treatment with sodium-glucose cotransporter-2 (SGLT2) inhibitors may have pleiotropic and beneficial effects in terms of ameliorating of risk factors for the progression of autosomal dominant polycystic kidney disease (ADPKD). However, there is insufficient evidence regarding the use of these drugs in patients with ADPKD, as they were excluded from several clinical trials conducted to explore kidney protection provided by SGLT2 inhibitors. This retrospective single-arm case series study was performed to investigate the effects of dapagliflozin, a selective SGLT2 inhibitor administered at 10 mg/day, on changes in height-adjusted kidney volume (htTKV) and estimated glomerular filtration rate (eGFR) in ADPKD patients. During a period of 102 ± 20 days (range 70-156 days), eGFR was decreased from 47.9 (39.7-56.9) to 40.8 (33.7-44.5) mL/min/1.73 m2 (p < 0.001), while htTKV was increased from 599 (423-707) to 617 (446-827) mL/m (p = 0.002) (n = 20). The annual increase in htTKV rate was significantly promoted, and urinary phosphate change was found to be correlated with the change in htTKV (rs = 0.575, p = 0.020). In the examined patients, eGFR was decreased and htTKV increased during short-term administration of dapagliflozin. To confirm the possibility of the effects of dapagliflozin on ADPKD, additional interventional studies are required.

Association of plasma xanthine oxidoreductase activity with vascular endothelial function independent of serum uric acid level: MedCity21 health examination registry

Background

Xanthine oxidoreductase (XOR) inhibitor administration, known to reduce uric acid and reactive oxygen species (ROS) production, also improves vascular endothelial function (VEF). This cross-sectional study examined our hypothesis that XOR contributes to impaired VEF through ROS but not uric acid production.

Methods

In 395 subjects (196 males, 199 females) without urate-lowering agent administration who underwent a health examination, plasma XOR activity was determined using our highly sensitive assay based on [13C2,15N2] xanthine and liquid chromatography/triple quadrupole mass spectrometry. For VEF evaluation, flow-mediated dilatation (FMD) in the brachial artery was determined by ultrasound, with physical and laboratory measurements also obtained.

Results

The median values for plasma XOR activity, serum uric acid, and FMD were 26.6 pmol/h/mL, 5.4 mg/dL, and 6.2%, respectively. Simple regression analysis showed weak correlations of both log plasma XOR activity and serum uric acid level with FMD (r = -0.213, p < 0.001 and r = -0.139, p = 0.006, respectively). However, multivariable linear regression analyses revealed that log plasma XOR activity but not serum uric acid level remained associated with FMD (β = -0.116, p = 0.037 and β = 0.041, p = 0.549, respectively) after adjustments for various clinical parameters, with no remarkable inconsistencies for the association observed in subgroups divided based on sex or uric acid level. Finally, a series of mediation analyses showed that serum uric acid level did not meet the criteria for mediator of the association of plasma XOR activity with FMD (p = 0.538).

Conclusions

These findings suggest the possibility that XOR contributes to the pathophysiology of impaired VEF through ROS but not uric acid production.

Differential effects on renal function and glucose metabolism of renal dependent bezafibrate and non-renal dependent pemafibrate in patients with hypertriglyceridemia

OBJECTIVE

Among fibrates as triglyceride-lowering agents, bezafibrate and fenofibrate are predominantly renally excreted, while pemafibrate is mainly hepatically metabolized and biliary excreted. To elucidate possible different properties among fibrates, this retrospective observational study examined the changes in clinical laboratory parameters, including indices of renal function and glucose metabolism, in cases of switching from bezafibrate to pemafibrate.

MATERIALS AND METHODS

In 93 patients with hypertriglyceridemia, the average values of laboratory parameters including serum creatinine, estimated glomerular filtration rate (eGFR), plasma glucose, and hemoglobin A1c on respective two occasions before and after switching from bezafibrate to pemafibrate were evaluated.

RESULTS

Triglycerides, low-density and high-density lipoprotein cholesterol, creatine kinase, and uric acid did not change before and after switching from bezafibrate to pemafibrate. Serum creatinine significantly decreased and eGFR significantly increased after switching from bezafibrate to pemafibrate (p < 0.001, respectively). Plasma glucose tended to increase (p = 0.070) and hemoglobin A1c significantly increased (p < 0.001) after switching to pemafibrate. The degrees of changes in creatinine, eGFR, glucose, and hemoglobin A1c before and after drug switching were not affected by the presence or absence of coexisting disease, and with or without drug treatment including statin and renin-angiotensin system inhibitor.

CONCLUSION

Our findings indicate that switching from bezafibrate to pemafibrate produces a significant decrease in serum creatinine and increases in eGFR and hemoglobin A1c in patients with hypertriglyceridemia, suggesting that the effects on renal function and glucose metabolism differ among fibrates.

Elevated free thyroxine and free triiodothyronine probably caused by high-dose biotin intake in a patient with Graves' disease: a case report

Biotin is a water-soluble vitamin that acts as a cofactor for carboxylase, and is often used as a component in several immunoassays. We present a case of a 46-year-old male with Graves' disease (GD) who revealed elevated free thyroxine (FT4) and free triiodothyronine (FT3) levels after high-dose biotin intake. Levels of these hormones had been within the reference range when he was on thiamazole 5 mg/day for 7 years; however, the levels increased from 1.04 to 2.20 ng/dL and from 3.05 to 9.84 pg/mL for FT4 and FT3, respectively, after he started taking biotin 72 mg/day. Despite these high levels, his symptoms and the other laboratory results, including the thyroid-stimulating hormone level, did not suggest GD relapse. His thyroid hormone data was decreased and returned within the reference range immediately after the laboratory assays for FT3 and FT4 had been coincidentally changed from those containing streptavidin-biotin complexes to biotin-free ones. Biotin interference, which is caused by high-dose biotin intake and immunoassays using some form of streptavidin-biotin complex, is sometimes clinically problematic, giving high or low results. To our knowledge, this is the first case report of a patient with GD on high-dose biotin receiving high thyroid hormone level results that were initially misunderstood as an aggravation of the disease; there are some reports of misdiagnosis of hyperthyroidism due to biotin administration. Unexpected fluctuations in thyroid function test results in patients with GD should be checked for biotin intake, immunoassays and the limiting concentration of biotin to avoid misdiagnosis of relapse.

Inflammation Related to Association of Low Uric Acid and Progression to Severe Disease in Patients Hospitalized for Non-Severe Coronavirus Disease 2019

Uric acid has antioxidant properties. To examine whether a low uric acid level is associated with severe coronavirus disease 2019 (COVID-19) progression via inflammation, alveolar damage, and/or coagulation abnormality, a retrospective observational study of 488 patients with non-severe COVID-19 and serum uric acid level ≤7 mg/dL at admission was conducted. Serum C-reactive protein (CRP), serum Krebs von den Lungen 6 (KL-6), and plasma D-dimer levels were also measured as markers of inflammation, alveolar damage, and coagulation abnormality, respectively. Median values for uric acid, CRP, KL-6, and D-dimer at admission were 4.4 mg/dL, 3.33 mg/dL, 252.0 U/mL, and 0.8 µg/mL, respectively. Among the total cohort, 95 (19.5%) progressed to severe COVID-19 with a median (interquartile range) time of 7 (4–14) days. Multivariable Cox proportional hazards regression analysis showed that low uric acid level was associated with a higher rate of severe COVID-19 progression. However, uric acid level was inversely associated with CRP level, and the association between the level of uric acid and severe COVID-19 progression was significantly different with and without CRP level inclusion. In contrast, no such association was found for KL-6 or D-dimer level. Low uric acid may contribute to severe COVID-19 progression via increased inflammation in subjects without hyperuricemia.

Improvement in the mobility of a patient with fibroblast growth factor 23-related hypophosphatemic osteomalacia and decompensated liver cirrhosis in response to burosumab: a case report

Acquired fibroblast growth factor (FGF) 23-related hypophosphatemic osteomalacia is characterized clinically by muscle weakness, bone pain, and fractures. Its biochemical features include hypophosphatemia, caused by renal phosphate wasting, and inappropriately normal or low 1,25-dihydroxy-vitamin D levels. Recently, burosumab, a fully human monoclonal antibody targeting FGF23, was approved for the treatment of FGF23-related hypophosphatemic rickets and osteomalacia. We report the case of a 75-year-old Japanese woman with decompensated liver cirrhosis and hepatic encephalopathy, caused by primary biliary cholangitis, who complained of back pain and limited mobility resulting from multiple vertebral fractures. She was not receiving iron infusion therapy and denied alcohol consumption. The patient exhibited hypophosphatemia with a low tubular maximum reabsorption of phosphate per unit glomerular filtration rate (TmP/GFR) and a high circulating concentration of FGF23. Conventional therapy with alfacalcidol and oral phosphate slightly improved her serum phosphate concentration and back pain, but she experienced a hip fracture, causing her to become wheelchair-dependent. Burosumab was initiated 8 weeks after the hip fracture, which increased her serum phosphate concentration and TmP/GFR. Her mobility gradually improved, such that she could walk without a cane after 16 weeks of treatment. Her lumbar bone mineral density increased after 48 weeks. Hepatic encephalopathy developed once before the initiation of treatment and twice after the initiation of the therapy, but her liver function was preserved. This is the first study to report the efficacy and safety of burosumab treatment for FGF23-related hypophosphatemic osteomalacia with decompensated liver cirrhosis.

Seronegative Full-house Nephropathy with Crohn's Disease

Systemic lupus erythematosus (SLE) is a chronic autoimmune inflammatory disease. Lupus nephritis (LN) is a major risk factor for mortality in SLE, and glomerular "full-house" immunofluorescence staining is a well-known characteristic of LN. However, some cases of non-lupus glomerulonephritis can also present with a "full-house" immunofluorescence pattern. We recently encountered a patient with full-house nephropathy (FHN) during adalimumab administration for Crohn's disease. IgA nephropathy or idiopathic FHN was diagnosed, and treatment with steroids was started, after which there was improvement in proteinuria. The prognosis of FHN has been reported to be poor; therefore, aggressive treatment is required for such patients.

Receiver circuit improvement of dual frequency-comb ka-band Doppler backscattering system in the large helical device (LHD)

Doppler-backscattering (DBS) has been used in several fusion plasma devices because it can measure the perpendicular velocity of electron density perturbation v_⊥, the radial electric field E_r, and the perpendicular wavenumber spectrum S(k_⊥) with high wavenumber and spatial resolution. In particular, recently constructed frequency comb DBS systems enable observation of turbulent phenomena at multiple observation points in the radial direction. A dual-comb microwave DBS system has been developed for the large helical device plasma measurement. Since it is desirable to control the gain of each frequency-comb separately, a frequency-comb DBS system was developed with a function to adjust the gain of the scattered signal intensity of each channel separately. A correction processing method was also developed to correct the amplitude ratio and the phase difference between the in-phase and quadrature-phase signals of the scattered signals. As a result, the error in Doppler-shift estimation required to observe vertical velocity and the radial electric field was reduced, which enables more precise measurements.

Reduced Risk of Progression from Non-Severe to Severe COVID-19 in Hospitalized Dialysis Patients by Full COVID-19 Vaccination

Coronavirus disease 2019 (COVID-19) vaccination reduces the risk of progression to severe COVID-19 in the general population. To examine that preventive effect in dialysis patients, the association of vaccination status with severe COVID-19 progression was investigated in this retrospective observational study conducted from December 2020 to May 2022 of 100 such patients hospitalized for non-severe COVID-19 at Inoue Hospital (Suita, Japan). Fifty-seven were fully vaccinated, defined as receiving a COVID-19 vaccine second dose at least 14 days prior to the onset of COVID-19, while 43 were not. Among all patients, 13 (13.0%) progressed to severe COVID-19 with a median (interquartile range) time of 6 (2.5-9.5) days, while 87 (87.0%) were discharged after 11 (8-16) days. Kaplan-Meier analysis showed that fully vaccinated patients had a significantly lower rate of progression to severe COVID-19 (p = 0.001, log-rank test). Cox proportional hazard analysis also indicated that full COVID-19 vaccination was significantly associated with reduced instances of progression to severe COVID-19 (hazard ratio 0.104, 95% confidence interval 0.022 to 0.483; p = 0.004) after balancing patient background characteristics using an inverse probability of treatment weight method. These results suggest that full vaccination status contributes to reducing the risk of progression from non-severe to severe COVID-19 in dialysis patients.

Effects of alfacalcidol on cardiovascular outcomes according to alkaline phosphatase levels in the J-DAVID trial

In the Japan Dialysis Active Vitamin D (J-DAVID) trial, oral alfacalcidol numerically, but not significantly, increased the risk of cardiovascular events among patients undergoing hemodialysis. Because the cardiovascular effect of alfacalcidol could be modulated by bone turnover status, this post-hoc analysis of the J-DAVID examined how alkaline phosphatase (ALP), a more precise marker of bone turnover than parathyroid hormone (PTH), modifies the impact of alfacalcidol. The J-DAVID was a 48-month, open-label, randomized controlled trial comparing oral alfacalcidol with no vitamin D receptor activators use in terms of cardiovascular events among 976 hemodialysis patients without secondary hyperparathyroidism. This post-hoc analysis included 959 patients with available data on baseline ALP. The median [25–75th percentile] baseline ALP level was 234 [183–296] U/L. In a Cox proportional hazards model, ALP did not significantly modify the effect of alfacalcidol on the rate of cardiovascular events or all-cause death (P for effect modification = 0.54 and 0.74, respectively). The effect of alfacalcidol on time-series changes in calcium, phosphate, and intact PTH were similar across ALP subgroups. In conclusion, oral alfacalcidol did not significantly affect cardiovascular outcomes irrespective of bone turnover status.

Dialysate calcium, alfacalcidol, and clinical outcomes: A post-hoc analysis of the J-DAVID trial

The selection of dialysate calcium concentration (D-Ca) is still controversial among chronic hemodialysis (HD) regimens. We examined the trajectories of CKD MBD parameters among the J-DAVID trial participants to see the effect of D-Ca and alfacalcidol. The trial was an open-label randomized clinical trial including 976 HD patients with intact PTH of 180 pg/mL or lower which compared the users of vitamin D receptor activator (oral alfacalcidol) and non-users over a median of 4 years. The main D-Ca used at baseline were 3.0 mEq/L in 70% and 2.5 mEq/L in 25%, respectively. The primary endpoint was the composite of fatal and non-fatal cardiovascular events and the secondary endpoint was all-cause mortality. Multivariable Cox proportional hazard regression analyses in which D-Ca was included as a possible effect modifier and serum laboratory data as time-varying covariates showed no significant effect modification for composite cardiovascular events or all-cause mortality. This post hoc analysis showed that the effects of alfacalcidol on cardiovascular outcomes were not significantly modified by D-Ca.

Associations of time-dependent changes in phosphorus levels with cardiovascular diseases in patients undergoing hemodialysis: Results from the Japan Dialysis Active Vitamin D (J-DAVID) randomized clinical trial

Background

While the risk of exceeding the standard range of phosphorus levels has been investigated, the impact of the degree of fluctuations has not been investigated.

Methods

Data were derived from the Japan Dialysis Active Vitamin D trial, a 4-year prospective, randomized study involving 976 patients without secondary hyperparathyroidism undergoing hemodialysis in Japan. Laboratory data were collected every six months, and the primary outcome was the time to the occurrence of cardiovascular events. The effect of time-dependent changes in phosphorus levels was assessed using a time-varying Cox proportional hazard regression model.

Results

The median serum phosphorus levels at baseline and at the final observation were 4.70 [3.90–5.30] and 5.00 [4.20–5.80] mg/dL, respectively. Over each six-month period, phosphorus changes ranged from -7.1 to +6.7 mg/dL, with a median value of -0.1 to +0.3 mg/dL. During follow-up, composite cardiovascular events occurred in 103 of 964 patients. Although the p-value for the interaction between serum phosphorus level fluctuations and baseline phosphorus levels was insignificant, the following trends were observed. First, patients with relatively high initial phosphorus levels over a six-month period showed a trend towards a higher hazard with greater changes in the phosphorus level over the six-month period. Second, it was suggested that oral VDRAs could contribute to the relationship between fluctuating phosphorus levels and cardiovascular events.

Conclusions

Our results suggest the importance of maintaining stable phosphorus levels, not only in the normal range but also without fluctuations in the risk of cardiovascular events, among patients without secondary hyperparathyroidism undergoing maintenance hemodialysis.

Serum phosphate as an independent factor associated with cholesterol metabolism in patients undergoing hemodialysis: a cross-sectional analysis of the DREAM cohort

Background

Hyperphosphatemia is a risk factor for cardiovascular outcomes in patients with chronic kidney disease. In an experimental model, hyperphosphatemia promotes atherosclerosis by activating sterol regulatory element-binding protein 2 which controls cholesterol homeostasis. In the present study, we hypothesized that serum phosphate level is associated with cholesterol metabolism in patients with kidney failure.

Methods

We conducted a single center cross-sectional study including 492 patients undergoing hemodialysis and 100 healthy controls not on statin or ezetimibe treatment. Serum lathosterol and campesterol levels were measured as a marker of cholesterol synthesis and absorption, respectively. As compared to the control group, the hemodialysis patients had higher median (interquartile range) phosphate [5.8 (5.0 to 6.6) vs. 3.3 (3.0 to 3.6) mg/dL, P &lt; 0.001], lower lathosterol [1.2 (0.8 to 1.7) vs. 2.6 (1.9 to 3.4) µg/mL, P &lt; 0.001] and higher campesterol levels [4.5 (3.6 to 6.0) vs. 4.1 (3.2 to 5.4) µg/mL, P = 0.02]. Serum phosphate correlated positively to campesterol in the control group (Spearman's r = 0.21, P = 0.03) and in the hemodialysis patients (Spearman's r = 0.19, P &lt; 0.001). The positive association between phosphate and campesterol levels in the hemodialysis group remained significant in multivariable-adjusted linear regression analysis. There was no significant association between phosphate and lathosterol in either group.

Conclusions

An independent association was found between phosphate and campesterol levels in patients with kidney failure. This study suggests a novel relationship between phosphate and cholesterol metabolism, both of which could affect cardiovascular outcomes in this population.

Glycated hemoglobin level on admission associated with progression to severe disease in hospitalized patients with non-severe coronavirus disease 2019

Aims/Introduction

Poor glycemic control is known to be associated with severe infection development. This retrospective observational study examined whether glycemic control before coronavirus disease 2019 (COVID‐19) onset contributes to progression from non‐severe to severe COVID‐19.

Materials and Methods

Glycated hemoglobin (HbA1c) was measured on hospital admission in 415 patients with non‐severe COVID‐19. The outcome was determined from time of hospital admission to severe progression, based on clinical practice guidelines for COVID‐19 in Japan.

Results

The median value for HbA1c on admission was 6.1%, with diabetes present in 138 patients (33.3%). Among the total cohort, 93 (22.4%) progressed to severe COVID‐19 with a median (interquartile range) time of 4 days (3–7 days), whereas 322 (77.6%) were discharged after 13 days (10–17 days). A multivariable Cox proportional hazards regression model showed that HbA1c level on admission was independently associated with progression to severe COVID‐19 (hazard ratio for 1% increase 1.237, 95% confidence interval 1.037–1.475; P = 0.018), with findings consistent among several sensitivity analyses. In subgroup analyses, such an association was significant in patients with diabetes, as well as older age, current smoking habit, lower estimated glomerular filtration rate, higher C‐reactive protein level, moderate II COVID‐19, dyslipidemia and chronic respiratory disease, with no remarkable inconsistency among the subgroups. Finally, higher HbA1c level (≥7%) was more strongly associated with severe COVID‐19 progression than diabetes.

Conclusions

The results suggest that poor glycemic control before COVID‐19 onset contributes to progression from non‐severe to severe COVID‐19, even in patients with severe COVID‐19 risk factors regardless of the presence of diabetes.

Clinical and histopathological features related to time to complete remission in adult-onset minimal change nephrotic syndrome patients with corticosteroid treatment

BACKGROUND

Minimal change nephrotic syndrome (MCNS) is a common type of nephrotic syndrome in adults, though evidence regarding its clinical and histopathological features related to time to complete remission (CR) is limited.

METHODS

This was a retrospective study of biopsy-proven, first-onset, adult MCNS patients who achieved CR after undergoing corticosteroid treatment. Body weight (BW) change rate was calculated as follows: (BW at admission - BW at discharge)/BW at discharge × 100. Histopathological examinations were performed, with particular attention given to tubulointerstitial lesions.

RESULTS

Fifty-seven patients (median 41 years old, range 22-63 years; 37 males) were diagnosed with MCNS from 2007 to 2020. Time to CR was a median 11 (8-21) days. In addition to serum creatinine and urinary protein, BW change rate also showed a positive correlation with time to CR (r_s = 0.438, p < 0.001; r_s = 0.280, p = 0.035; r_s = 0.544, p < 0.001; respectively), while multivariate Cox proportional hazards models also revealed those factors as significant predictors for longer time to CR. In MCNS patients with a higher BW change rate (n = 28), serum creatinine, urinary protein, histopathological score, and time to CR were significantly greater as compared to those with a lower BW change rate (n =29). Also, in those patients, histopathological interstitial edema was significantly associated with longer time to CR after adjustments for serum creatinine and urinary protein.

CONCLUSION

The present results indicate that BW change rate can predict time to CR in adult-onset MCNS patients. Histopathologically, interstitial edema is also an important factor for time to CR in MCNS patients with greater BW increase.

Nutritional Status Association With Sarcopenia in Patients Undergoing Maintenance Hemodialysis Assessed by Nutritional Risk Index

Background

Malnutrition and sarcopenia are frequently observed in patients undergoing maintenance hemodialysis (MHD). To elucidate whether malnutrition is associated with sarcopenia in those cases, the relationship of nutritional status with sarcopenia was investigated.

Methods

Nutritional status was assessed using a nutritional risk index (NRI) developed for patients undergoing MHD. This retrospective cross-sectional study included 315 MHD patients (199 males, 116 females), who were divided into low-risk (score 0–7) and medium-/high-risk (score 8–13) groups. Sarcopenia and severe sarcopenia, along with low muscle mass, low muscle strength, and low physical performance were defined using the Asian Working Group for Sarcopenia 2019 criteria.

Results

The median NRI score was 5.0, while the prevalence of medium-/high-risk cases among the patients was 31.1%. Additionally, the rates of those with low muscle mass, low muscle strength, and low physical performance were 55.9, 60.6, and 31.4%, respectively, while those of sarcopenia and severe sarcopenia were 44.1 and 20.0%, respectively. Multivariable logistic regression analyses revealed a significant (P < 0.001) association of NRI score with sarcopenia [odds ratio (OR) 1.255, 95% confidence interval (CI) 1.143–1.377] and severe sarcopenia (OR 1.257, 95% CI 1.122–1.407), as well as low muscle mass (OR 1.260, 95% CI 1.157–1.374), low muscle strength (OR 1.310, 95% CI 1.178–1.457), and low physical performance (OR 1.216, 95% CI 1.104–1.339). Furthermore, medium-/high-risk status showed a significant (P < 0.05) association with sarcopenia (OR 2.960, 95% CI 1.623–5.401) and severe sarcopenia (OR 2.241, 95% CI 1.151–4.362), as well as low muscle mass (OR 2.141, 95% CI 1.219–3.760), low muscle strength (OR 7.665, 95% CI 3.438–17.091), and low physical performance (OR 2.570, 95% CI 1.401–4.716).

Conclusions

These results suggest that malnutrition contributes to sarcopenia/severe sarcopenia in MHD patients by reducing muscle mass and strength, and physical performance.

New-onset Type 1 Diabetes after COVID-19 mRNA Vaccination

During the ongoing coronavirus disease 2019 (COVID-19) pandemic, it is critical to ensure the safety of COVID-19 vaccines. We herein report a 51-year-old Japanese woman who developed acute-onset type 1 diabetes with diabetic ketoacidosis six weeks after receiving the first dose of a COVID-19 messenger ribonucleic acid (mRNA) vaccine. Laboratory tests indicated exhaustion of endogenous insulin secretion, a positive result for insulin autoantibody, and latent thyroid autoimmunity. Human leukocyte antigen typing was homozygous for DRB1*09:01-DQB1*03:03 haplotypes. This case suggests that COVID-19 vaccination can induce type 1 diabetes in some individuals with a genetic predisposition.

Role of adiponectin in the relationship between visceral adiposity and fibroblast growth factor 23 in non-diabetic men with normal kidney function

Fibroblast growth factor 23 (FGF23) is a key regulator of phosphate metabolism. Circulating FGF23 levels are associated with obesity, metabolic syndrome, and cardiovascular disease in the general population, but the underlying mechanism remains unclear. Therefore, we aimed to determine the associations between serum FGF23 levels and visceral adiposity as well as serum adiponectin levels in 189 adults without diabetes and with normal kidney function who were selected from the MedCity21 health examination registry. The exclusion criteria included diabetes mellitus or impaired kidney function (estimated glomerular filtration rate [eGFR] <60 mL/min/1.73 m²). Levels of serum FGF23 and total adiponectin, and visceral fat area (VFA) on computed tomography images were measured. Serum FGF23 levels were higher and VFA was greater, whereas serum adiponectin levels were lower in men than in women. Serum FGF23 levels positively correlated with VFA in men; they remained marginally significant after adjusting for age, eGFR, and serum levels of calcium, phosphate, intact parathyroid hormone, and 1,25-dihydroxyvitamin D. Importantly, when serum adiponectin levels were included as a covariate, serum adiponectin levels comprised an independent determinant of serum FGF23 levels in men, whereas VFA did not. In conclusion, lower serum adiponectin, rather than a greater VFA, was associated with higher serum FGF23 levels in non-diabetic men with normal kidney function. These findings suggest that adiponectin plays a role in the relationship between visceral adiposity and FGF23 in men.

Xanthine Oxidoreductase Inhibitor Use Associated With Reduced Risk of Sarcopenia and Severe Sarcopenia in Patients Undergoing Hemodialysis

Background

Xanthine oxidoreductase (XOR) inhibition reduces reactive oxygen species (ROS) production and enhances adenosine triphosphate (ATP) synthesis. We investigated the protective effects of XOR inhibitor treatment on sarcopenia, frequently observed in patients undergoing hemodialysis (HD), in which increased ROS and ATP shortage are known to be involved.

Methods

This retrospective cross-sectional study included 296 HD patient (203 males, 93 females). Muscle mass, physical performance, and muscle strength were assessed using dual-energy X-ray absorptiometry, five-time chair stand testing, and handgrip strength, respectively. The Asian Working Group for Sarcopenia 2019 criteria were used to define low muscle mass, low physical performance, and low muscle strength, as well as sarcopenia and severe sarcopenia.

Results

Sarcopenia and severe sarcopenia prevalence rates were 42.2 and 20.9%, respectively. XOR inhibitor users (n = 119) showed a significantly (p < 0.05) lower prevalence of sarcopenia and severe sarcopenia, as well as reduced muscle mass, physical performance, and muscle strength than non-users (n = 177). Multivariate logistic regression analyses also revealed XOR inhibitor use to be significantly associated with low muscle mass [odds ratio (OR), 0.384; 95% confidence interval (CI), 0.183–0.806; p = 0.011] and low physical performance (OR, 0.286; 95% CI, 0.142–0.578; p < 0.001), while significance with low muscle strength was borderline. Furthermore, XOR inhibitor use was significantly associated with sarcopenia (OR, 0.462; 95% CI, 0.226–0.947; p = 0.035) and severe sarcopenia (OR, 0.236; 95% CI, 0.091–0.614; p = 0.003).

Conclusions

XOR inhibitor use was significantly associated with reduced risk of sarcopenia/severe sarcopenia in HD patients, suggesting that XOR inhibitor treatment has protective effects on sarcopenia in HD patients.

Parathyroid Hormone Regulates Circulating Levels of Sclerostin and FGF23 in a Primary Hyperparathyroidism Model

Parathyroid hormone (PTH) increases fibroblast growth factor 23 (FGF23), mediated both by protein kinase A (PKA) and Wnt signaling, and decreases expression of sclerostin, a Wnt antagonist derived from osteocytes. Patients with primary hyperparathyroidism (PHPT) have lower serum sclerostin levels than healthy controls, consistent with the idea of SOST downregulation by PTH. Nevertheless, the relationship between FGF23 and sclerostin in PHPT is still unclear. We examined this issue in a mouse model of PHPT. PHPT mice had increased FGF23 and decreased sclerostin expression in calvaria and in their serum concentrations compared with wild-type (WT) mice. In UMR106 osteoblasts, PTH increased Fgf23 expression and decreased Sost expression, as well as forskolin, a PKA agonist, whereas inhibition of PKA reversed the changes in Fgf23 and Sost expression, stimulated by PTH. Sclerostin treatment had no effect on Fgf23 expression, but when it was added together with PTH, it statistically significantly abrogated the increase in Fgf23 expression. By contrast, there was no statistically significant correlation between serum FGF23 and sclerostin, whereas PTH was positively and negatively correlated with serum FGF23 and sclerostin, respectively. These results indicate that the high level of PTH in PHPT mice leads to increased FGF23 and decreased sclerostin expression in serum and calvaria. A decrease of sclerostin may further augment FGF23 in vitro; however, there was no statistically significant association between circulating FGF23 and sclerostin. It is suggested that the pathogenesis of increased FGF23 expression in PHPT mice may be modified by not only sclerostin, but also other regulatory factors modulated by PTH.

New-onset fulminant type 1 diabetes following SARS-CoV-2 vaccination: A case report

Fulminant type 1 diabetes is characterized by a rapid progression of insulin deficiency triggered by viral infection. Here, we report a case of a 45‐year‐old Japanese woman with fulminant type 1 diabetes that developed 8 days after receiving messenger ribonucleic acid vaccine against severe acute respiratory syndrome coronavirus 2. She had been healthy and had no symptoms suggestive of viral infection before the vaccination. Laboratory tests showed exhaustion of insulin secretion and negative results for islet autoantibodies. Human leukocyte antigen genotype analysis showed the DRB1*04:05 and DQB1*04:01 alleles. This is the first case report of new‐onset fulminant type 1 diabetes after severe acute respiratory syndrome coronavirus 2 vaccination, and suggests that a severe acute respiratory syndrome coronavirus 2 vaccine might trigger the onset of fulminant type 1 diabetes in susceptible individuals. However, a causal relationship remains to be identified, and further studies are required to determine the incidence of such cases.

Nutritional disorder evaluated by geriatric nutritional risk index predicts death after hospitalization for infection in patients undergoing maintenance hemodialysis

OBJECTIVE

Infection is related to higher rate of hospitalization and subsequent death in patients undergoing hemodialysis. Limited data are available about factors associated with death after hospitalization for infection. Nutritional disorder also known as protein-energy wasting is profoundly associated with poor consequences. Geriatric nutritional risk index (GNRI) is a simple but useful nutritional screening tool to predict mortality. We examined whether GNRI could predict hospitalization for infection and subsequent death.

DESIGN AND METHODS

This was a prospective cohort study in hemodialysis patients. The predictor was GNRI. The patients were divided into tertiles of GNRI (T1 to T3), with the highest tertile of T3 as referent. The outcomes of interest were all-cause mortality, hospitalization for infection and subsequent death.

RESULTS

Of 518 patients, 107 patients died (median follow-up period, 5.0 years; interquartile range 3.6-5.0) and 169 patients experienced new hospitalization for infection (median follow-up period, 4.5 years; interquartile range 3.4-5.0) during the follow-up period from December 2004 to December 2009. A lower GNRI was a significant predictor for all-cause mortality in multivariable Cox models (hazard ratio [HR] 2.9, 95% confidential interval [CI] 1.5-5.5, p < 0.001 for T1 vs. T3). However, GNRI was not associated with hospitalization for infection in multivariable Fine-Gray models with death as a competing risk (subdistributional HR 1.5, 95% CI 1.0-2.3, p = 0.056 for T1 vs. T3). After hospitalization for infection, 38 patients died during subsequent 2.5-year follow-up period. GNRI was a significant predictor of death after hospitalization for infection in multivariable Cox models (HR 2.7, 95% CI 1.3-5.6, p = 0.006 for T1 vs. T2+T3).

CONCLUSIONS

A lower GNRI predicted a higher risk of all-cause mortality but not hospitalization for infection. However, a lower GNRI was significantly associated with a higher risk of mortality after hospitalization for infection. These findings suggest that long-term mortality after hospitalization for infection was predicted by nutritional disorder evaluated by GNRI.

Bexarotene-induced central hypothyroidism assessed by TRH stimulation test in cutaneous T-cell lymphoma patients

Bexarotene-induced central hypothyroidism (CH), for which levothyroxine (LT4) replacement is recommended, has been shown to be caused by pituitary but not hypothalamic disorder experimentally, though the underlying mechanism in humans remains unclear. Here, the pathophysiology of bexarotene-induced CH was examined using a TRH stimulation test in cutaneous T-cell lymphoma (CTCL) patients. In this retrospective longitudinal observational study, serum TSH and free T4 (F-T4) levels were measured in 10 euthyroid patients with CTCL during 24 weeks of bexarotene treatment. TRH stimulation testing was performed following CH diagnosis, with LT4 replacement dosage adjusted to maintain F-T4 at the pre-treatment level. After one week of bexarotene administration, all 10 patients developed CH, based on combined findings of low or low-normal F-T4 with low or normal TSH levels. TSH peak response after a stimulation test at one week was reached at 30 minutes. However, that was <4 μIU/mL in all patients, indicating a blunted though not exaggerated and delayed TSH response. In eight who continued bexarotene for 24 weeks, median LT4 replacement dosage was 125 (range, 75-150) μg/day. TSH level at 30 as well as 15, 60, 90, and 120 minutes after TRH stimulation was significantly correlated with LT4 replacement dosage (ρ = -0.913, p = 0.002), whereas TSH and F-T4 basal levels at one week were not. These results suggest that pituitary hypothyroidism is responsible for bexarotene-induced CH, while TSH levels after TRH stimulation precisely reflect residual pituitary-thyroid function in patients receiving bexarotene.

Factors associated with atrial fibrillation in Japanese patients with type 2 diabetes mellitus: a cross-sectional study

Aims

Atrial fibrillation (AF) increases cardiovascular complications and mortality in patients with diabetes. Diabetes is a risk factor for AF; however, risk factors for AF among patients with type 2 diabetes (T2D) remain unknown, especially among Asian people. We clarified the prevalence of AF, regardless of type (i.e., paroxysmal, persistent, or permanent) in Japanese patients with T2D and clarified factors associated with AF.

Methods

This cross-sectional study was conducted at Fujiidera Municipal Hospital (Osaka, Japan). Patients with T2D (n = 899: 518 men and 381 women with a mean age ± SD of 69.0 ± 12.1 years) were included. Their electrocardiographs were checked during routine examinations between January 2017 and January 2018. A diagnosis of AF was determined from single time-point standard 12-lead electrocardiographic findings. We analyzed clinical parameters (e.g., age, sex, diabetes duration, glycated hemoglobin, body mass index, estimated glomerular filtration rate, albuminuria or proteinuria, use of biguanide, and presence of hypertension) between patients with and without AF.

Results

The prevalence of AF among patients with T2D was 5.9%; it became higher as age increased and tended to be higher in men than in women. The prevalence became higher as albuminuria or proteinuria progressed and as the eGFR decreased. Multiple logistic regression analyses revealed that older age, male sex, and reduced eGFR were independently and significantly associated with the coexistence of AF. However, multiple logistic regression analysis revealed no significant relationships between AF and the presence of albuminuria or proteinuria.

Conclusions

Older age, male sex, and reduced eGFR were associated with AF in Japanese patients with T2D.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13340-021-00563-w.

Association of Reduced Free T3 to Free T4 Ratio with Lower Serum Creatinine in Japanese Hemodialysis Patients

PURPOSE

Low T3 syndrome is defined by a fall in free triiodothyronine (FT3) in spite of normal serum thyroid-stimulating hormone (TSH) and often normal free thyroxin (FT4). A low FT3/FT4 ratio, a relevant marker for low T3 syndrome, is known as a risk of mortality in hemodialysis (HD) patients, as well as low muscle mass in the general population. Because of the local activation of T4 to FT3 in muscle tissue, we examined the association of FT3/FT4 ratio with serum creatinine, a marker of muscle mass and strength in HD patients to investigate the significance of muscle tissue in the development of low T3 syndrome in HD patients.

METHODS

This was a cross-sectional study derived from our prospective cohort study, named DREAM, of Japanese HD patients. After the exclusion of patients with treated and untreated thyroid dysfunction, 332 patients were analyzed in the study.

RESULTS

The serum FT4 and TSH of HD patients (n = 332) were 0.9 ± 0.1 ng/dL. and 2.0 ± 0.9 μIU/mL, which were within the respective normal range, while serum FT3 was 2.2 ± 0.3 pg/mL. As many as 101 out of 332 (30.4%) HD patients exhibited a serum FT3 less than the normal lower limit of 2.2 pg/mL. The serum FT3/FT4 ratio correlated significantly positively with serum creatinine, and inversely with serum log CRP and total cholesterol, while it exhibited a tendency towards positive correlation with serum albumin. Multiple regression analysis, which included serum creatinine, albumin, and log CRP, simultaneously, in addition to sex, age, diabetic kidney disease or not, log HD duration, body mass index, systolic blood pressure, and Kt/V, as independent variables, revealed an independent and significant positive association of serum creatinine, but not serum albumin or CRP, with the serum FT3/FT4 ratio.

CONCLUSIONS

The present study demonstrated an independent and positive correlation of serum creatinine with the serum FT3/FT4 ratio in HD patients. The lack of association of the serum FT3/FT4 ratio with serum albumin and CRP suggested the presence of a creatinine-specific mechanism to associate with serum FT3/FT4 ratio. Because of the local activation of T4 to T3 at muscle tissue, a lower muscle mass may be causatively associated with low T3 syndrome.

Efficacy of romosozumab in patients with osteoporosis on maintenance hemodialysis in Japan; an observational study

INTRODUCTION

Romosozumab reportedly increases bone mineral density (BMD) potently but might adversely affect cardiovascular disease (CVD). We evaluated the efficacy of romosozumab in osteoporotic HD patients with a high risk of fracture.

MATERIALS AND METHODS

This was a single-center 1-year study in Japanese HD patients. Among 96 HD romosozumab-treated HD patients with high risk of fracture, 76 HD patients completed 1 year of subcutaneous administration of romosozumab (210 mg/4 weeks) for 1 year. Romosozumab-untreated HD patients (n = 55) were also included. Changes in BMD and serum markers, together with fracture occurrence, and CVD events, were monitored.

RESULTS

During romosozumab treatment of 76 HD patients, BMD time-dependently increased significantly by 15.3% ± 12.9% at the lumbar spine (L1-4), and 7.2% ± 8.3% at the femoral neck at 1 year. Serum BAP and total P1NP increased significantly and serum TRACP-5b decreased at 4 weeks. Fragility fractures occurred in three (3.8%) patients. Hypocalcemia occurred at 4-48 weeks despite the increased dosing of active vitamin-D derivatives, but without any symptom. New CVD events occurred in 5.2% of romosozumab-treated HD patients and10.9% in romosozumab-untreated HD patients.

CONCLUSIONS

BMD was increased significantly during romosozumab treatment at the lumbar spine, and the femoral neck, respectively, at 1 year in HD patients. Hypocalcemia occurred but without any intolerable event. There was no apparent increase in CVD events during 1 year of study, suggesting romosozumab as a promising agent for HD patients with severe osteoporosis.

Associations of Serum Insulin-Like Growth Factor 1 with New Cardiovascular Events and Subsequent Death in Hemodialysis Patients: The DREAM Cohort

Aim: Patients with chronic kidney disease (CKD) have elevated risk of death from cardiovascular disease (CVD). A low serum insulin-like growth factor 1 (IGF-1) level is known to predict higher risk for all-cause mortality in incident dialysis patients, although it is unknown whether IGF-1 predicts cardiovascular outcomes.

Methods: This was a prospective cohort study of maintenance hemodialysis patients followed up for 5 years. Serum IGF-1 levels were measured at baseline, and patients were divided into IGF-1 tertiles. The key outcomes were all-cause mortality, a composite of new CVD, and death after new CVD events. Additional outcomes were hospitalization for infection and subsequent death. Association was analyzed using Cox proportional hazards models.

Results: In the 516 patients that were analyzed, we identified 106 all-cause deaths, 190 new CVD events, and 61 subsequent deaths. In addition, there were 169 hospitalizations for infection and 47 subsequent deaths. The risk of all-cause death was the highest in the lowest IGF-1 tertile, and this association remained significant in multivariable-adjusted models. Regarding CVD outcomes, IGF-1 was not associated with new CVD events but significantly associated with subsequent death in adjusted models. Similarly, IGF-1 was not an independent predictor of hospitalization for infection, but it predicted subsequent death.

Conclusions: A low IGF-1 level was not a significant predictor of new CVD events but an independent predictor of subsequent death in hemodialysis patients. Since similar associations with infection outcomes were observed, IGF-1 may be a biomarker of fragility or frailty in this population.

Associations of cardiovascular disease and blood pressure with cognition in hemodialysis patients: The Osaka Dialysis Complication Study

BACKGROUND

Previous studies reported mixed results regarding the contributions of cardiovascular disease (CVD) and blood pressure to cognitive impairment in chronic kidney disease.

METHODS

This was a cross-sectional study in 1213 patients on maintenance hemodialysis from 17 dialysis units in Japan. The main exposures were prior CVD and blood pressure components including systolic (SBP) and diastolic pressure (DBP). The outcome was low cognitive function evaluated with the Modified Mini-Mental State examination (3MS) with a cut-off level of 3MS < 80.

RESULTS

The median age was 67 years, median duration of dialysis was 71 months, 37% were women, 39% had diabetic kidney disease, and 36% had any pre-existing CVD. Median (interquartile range) of 3MS score was 91 (82 to 97), and 240 patients (20%) had 3MS < 80. Logistic regression analysis showed that 3MS < 80 was associated with the presence of any prior CVD, particularly prior stroke. 3MS < 80 was associated with lower DBP but not with SBP. When patients were stratified by the presence of prior stroke, lower DBP, higher age, and lower education level were factors associated with 3MS < 80 in both subgroups. In the subgroup of patients without prior stroke, diabetic kidney disease was an additional factor associated with 3MS < 80. CVDs other than stroke were not associated with 3MS in either subgroup.

CONCLUSIONS

Prior stroke and lower DBP were associated with 3MS < 80 in hemodialysis patients. These findings support the hypothesis that these vascular factors contribute to low cognitive performance in patients undergoing hemodialysis.

Significant Association of Diabetes With Mortality of Chronic Hemodialysis Patients, Independent of the Presence of Obesity, Sarcopenia, and Sarcopenic Obesity

OBJECTIVES

This retrospective cohort study investigated the association of diabetes with mortality in hemodialysis patients with regard to obesity, sarcopenia, and sarcopenic obesity, along with examining the prevalence of each group and diabetes.

METHODS

Muscle strength, muscle mass, and fat mass were evaluated using a hand dynamometer and dual-energy X-ray absorptiometry, respectively, in 308 chronic hemodialysis patients (age 58.0 ± 11.9 years, hemodialysis duration 6.5 ± 6.0 years, males 60.1%, diabetes 32.8%). Sarcopenia was defined according to the new criteria established by the Asian Working Group on Sarcopenia 2019. Obesity was defined by percent body fat mass (males ≥25%, females ≥35%).

RESULTS

The enrolled patients were divided into the normal (38.7%), obesity (18.8%), sarcopenia (26.9%), and sarcopenic obesity (15.6%) groups. The prevalence of diabetes was significantly skewed among the 4 groups (χ² test, P = .0057), being higher in the sarcopenic obesity group (54.2%) compared to the others (25.9-33.7%). Multivariate regression analysis revealed that diabetes was significantly and independently associated with sarcopenic obesity (odds ratio 3.495, 95% confidence interval 1.683-7.255, P = .0008) after adjustments for several cofounders, but not significantly associated with sarcopenia. During the follow-up period of 76 ± 35 months, 100 patients died. Those in the sarcopenia and sarcopenic obesity groups had significantly higher rates of all-cause mortality compared to patients in the normal and obesity groups (P = .0004, log-rank test). Furthermore, multivariate Cox proportional hazards analysis revealed that presence of diabetes was significantly associated with higher all-cause mortality in all 308 patients, after adjustments for several factors, including the presence of each group in 4 models.

CONCLUSION

Sarcopenic obesity is highly prevalent in chronic hemodialysis patients. Diabetes was found to be a significant and independent contributor to the presence of sarcopenic obesity. Diabetes was shown to be a significant predictor of all-cause mortality, independent of the present normal, obesity, sarcopenia, and sarcopenic obesity groups.

Plasma Xanthine Oxidoreductase Activity Associated with Glycemic Control in Patients with Pre-Dialysis Chronic Kidney Disease

INTRODUCTION

Xanthine oxidoreductase (XOR) activity plays an important role as a pivotal source of reactive oxygen species, which is associated with cardiovascular disease (CVD) events. Patients with CKD have increased risk of CVD events. In the present study, factors associated with plasma XOR activity in pre-dialysis CKD patients were investigated.

METHODS

In this cross-sectional study, plasma XOR activity in 118 pre-dialysis CKD patients (age 68 [57-75] years; 64 males, 26 with diabetes mellitus [DM]) was determined using a newly established highly sensitive assay based on (13C2,15N2) xanthine and liquid chromatography/triple quadrupole mass spectrometry.

RESULTS

Plasma glucose, hemoglobin A1c, and estimated glomerular filtration (eGFR) were significantly and positively correlated with plasma logarithmically transformed XOR (ln-XOR) activity. In multiple regression analyses, eGFR and hemoglobin A1c or plasma glucose were significantly, independently, and positively associated with plasma ln-XOR activity after adjusting for several confounders. Plasma XOR activity was significantly higher in CKD patients with (n = 26) than in those without (n = 92) DM (62.7 [32.3-122] vs. 25.7 [13.4-45.8] pmol/h/mL, p < 0.001). A total of 38 patients were taking uric acid-lowering drugs. Multiple regression analysis of CKD patients not administered uric acid-lowering drugs (n = 80) showed no significant association between eGFR and plasma ln-XOR activity. In contrast, association between glycemic control and plasma ln-XOR activity was significant even in CKD patients without uric acid-lowering drug treatment.

CONCLUSIONS

These results indicate the importance of glycemic control in CKD patients in regard to decreased XOR, possibly leading to a decrease in CVD events.

Analysis of the Motional Stark Effect (MSE) diagnostic to measure the rotational transform and current profile in the Large Helical Device

The analysis method of the Motional Stark Effect (MSE) diagnostic to measure the rotational transform and current profiles in the Large Helical Device has been improved. This was done by using the Variational Moments Equilibrium Code to calculate an equilibrium database for various pressure profiles and current profiles. This method looks for the radial profile of the rotational transform in the equilibrium database that gives the best fit to the polarization angle profiles measured with the MSE diagnostic. This analysis improves the measurements of rotational transform, especially near the magnetic axis, where the sensitivity of the polarization angle measurements becomes low and the uncertainty due to error in the estimation of the Pfirsch-Schlüter current becomes large. The radial profiles of the rotational transform and current profiles for Electron Cyclotron Current Drive and Neutral Beam Current Drive are obtained in the new analysis method with a sufficiently high accuracy to discuss the discrepancy of the current density profiles between the measurements and the calculations.

Effect of etelcalcetide on parathyroid hormone secretion by primary hyperparathyroidism patient-derived primary parathyroid cells

INTRODUCTION

Etelcalcetide (Parsabiv^®, AMG 416/ONO-5163) is a novel allosteric modulator for the calcium-sensing receptor approved for hemodialysis patients with secondary hyperparathyroidism of uremia. Etelcalcetide reduced parathyroid hormone levels in hemodialysis patients with secondary hyperparathyroidism of uremia in clinical studies. However, its direct effect on parathyroid hormone secretion in human parathyroid cells remains unknown. This study aimed to determine if etelcalcetide suppresses parathyroid hormone secretion by human parathyroid cells in vitro.

MATERIALS AND METHODS

We prepared primary cell cultures from human parathyroid tissue and determined calcium-sensing receptor expression levels by immunohistochemistry. Pathyroid tumors were removed from fourteen patients with primary hyperparathyrodism. Parathyroid tissue was dispersed with collagenase, resuspended in culture medium, incubated for 2 h with etelcalcetide and Ca²⁺, and the medium was then collected. Final etelcalcetide concentrations in the medium were 0.005-50 µmol/L. Levels of human parathyroid hormone in the medium were determined by enzyme-linked immunosorbent assay.

RESULTS

In eight of the fourteen parathyroid cell cultures, extracellular Ca²⁺ reduced parathyroid hormone levels. In four of the eight parathyroid cell cultures which responded extracellular Ca²⁺, etelcalcetide reduced hormone secretion with the 50% effective concentrations of 0.57, 20.8, 0.42, and 0.57 µmol/L. Expression levels of the calcium-sensing receptor were significantly lower in primary hyperparathyroidism patient-derived parathyroid tissues compared with controls.

CONCLUSION

This is the first report that etelcalcetide directly reduced parathyroid hormone secretion from the primary cultured human parathyroid cells from patients with primary hyperparathyroidism. To verify this conclusion, further studies are needed using secondary hyperparathyroidism patient-derived parathyroid cells.

Etelcalcetide decreases the PTH-calcium setpoint without changing maximum and minimum PTH secretion in mice with primary hyperparathyroidism

INTRODUCTION

Etelcalcetide binds to the extracellular domain of the calcium-sensing receptor (CaSR), while cinacalcet binds to the 7-transmembrane domain of the CaSR; however, it is unknown, whether etelcalcetide has similar effects to cinacalcet on parathyroid hormone (PTH) secretion.

MATERIALS AND METHODS

The PTH-calcium setpoint and maximum and minimum PTH secretion were determined using an 'in vivo setpoint analyses.' The PTH-calcium setpoint was obtained in a mouse model of primary hyperparathyroidism (PC) and wild-type (WT) mice, with PC mice divided into two groups. The setpoint was obtained after 7 days of etelcalcetide (3.0 mg/kg BW/day) or vehicle administration via anosmotic pump. After 7 days of crossover administration, the setpoint was obtained again. Parathyroid glands were obtained after crossover administration, and CaSR expression was analyzed by immunohistochemistry.

RESULTS

Etelcalcetide administration significantly decreased the setpoint from 9.03 ± 0.56 mg/dL to 6.80 ± 0.28 mg/dL, which was restored to 8.81 ± 0.38 mg/dL after vehicle administration. In the second group of mice, vehicle administration did not alter the setpoint (8.84 ± 0.69 mg/dL to 8.98 ± 0.63 mg/dL), but subsequent etelcalcetide administration significantly decreased it to 7.10 ± 0.72 mg/dL. There was no significant change in maximum and minimum PTH secretion. Expression levels of parathyroid CaSR were lower in PC mice than in WT mice; however, no significant differences were observed between the two mouse groups.

CONCLUSION

Etelcalcetide decreased the PTH-calcium setpoint without changing maximum and minimum PTH secretion in PC mice, suggesting that like cinacalcet, etelcalcetide has calcimimetic potency.

Comparative Effects of Etelcalcetide and Maxacalcitol on Serum Calcification Propensity in Secondary Hyperparathyroidism: A Randomized Clinical Trial

BACKGROUND AND OBJECTIVES

Vitamin D receptor activators and calcimimetics (calcium-sensing receptor agonists) are two major options for medical treatment of secondary hyperparathyroidism. A higher serum calcification propensity (a shorter T₅₀ value) is a novel surrogate marker of calcification stress and mortality in patients with CKD. We tested a hypothesis that a calcimimetic agent etelcalcetide is more effective in increasing T₅₀ value than a vitamin D receptor activator maxacalcitol.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A randomized, multicenter, open-label, blinded end point trial with active control was conducted in patients with secondary hyperparathyroidism undergoing hemodialysis in Japan. Patients were randomly assigned to receive intravenous etelcalcetide 5 mg thrice weekly (etelcalcetide group) or intravenous maxacalcitol 5 or 10 µg thrice weekly (maxacalcitol group). The primary, secondary, and tertiary outcomes were changes in T₅₀ value, handgrip strength, and score of the Dementia Assessment Sheet for Community-Based Integrated Care System from baseline to 12 months, respectively.

RESULTS

In total, 425 patients from 23 dialysis centers were screened for eligibility, 326 patients were randomized (etelcalcetide, n=167; control, n=159), and 321 were included in the intention-to-treat analysis (median age, 66 years; 113 women [35%]). The median (interquartile range) of T₅₀ value was changed from 116 minutes (interquartile range, 90-151) to 131 minutes (interquartile range, 102-176) in the maxacalcitol group, whereas it was changed from 123 minutes (interquartile range, 98-174) to 166 minutes (interquartile range, 127-218) in the etelcalcetide group. The increase in T₅₀ value was significantly greater in the etelcalcetide group (difference in change, 20 minutes; 95% confidence interval, 7 to 34 minutes; P=0.004). No significant between-group difference was found in the change in handgrip strength or in the Dementia Assessment Sheet for Community-Based Integrated Care System score.

CONCLUSIONS

Etelcalcetide was more effective in increasing T₅₀ value than maxacalcitol among patients on hemodialysis with secondary hyperparathyroidism. There was no difference in handgrip strength or cognition between the two drugs.

CLINICAL TRIAL REGISTRY NAME AND REGISTRATION NUMBER

VICTORY; UMIN000030636 and jRCTs051180156.

Effects of fetuin-A-containing calciprotein particles on posttranslational modifications of fetuin-A in HepG2 cells

Fetuin-A is an inhibitor of ectopic calcification that is expressed mainly in hepatocytes and is secreted into the circulation after posttranslational processing, including glycosylation and phosphorylation. The molecular weight (MW) of fully modified fetuin-A (FM-fetuin-A) is approximately 60 kDa in an immunoblot, which is much higher than the estimated MW by amino acid sequence. Under conditions of calcification stress such as advanced stage chronic kidney disease, fetuin-A prevents calcification by forming colloidal complexes, which are referred to as calciprotein particles (CPP). Since the significance of CPP in this process is unclear, we investigated the effect of synthetic secondary CPP on the level of FM-fetuin-A in HepG2 cells. Secondary CPP increased the level of FM-fetuin-A in dose- and time-dependent manners, but did not affect expression of mRNA for fetuin-A. Treatment with O- and/or N-glycosidase caused a shift of the 60 kDa band of FM-fetuin-A to a lower MW. Preincubation with brefeldin A, an inhibitor of transport of newly synthesized proteins from the endoplasmic reticulum to the Golgi apparatus, completely blocked the secondary CPP-induced increase in FM-fetuin-A. Treatment with BAPTA-AM, an intracellular calcium chelating agent, also inhibited the CPP-induced increase in the FM-fetuin-A level. Secondary CPP accelerate posttranslational processing of fetuin-A in HepG2 cells.

W-band millimeter-wave back-scattering system for high wavenumber turbulence measurements in LHD

A 90 GHz W-band millimeter-wave back-scattering system is designed and installed for measuring electron scale turbulence (k_⊥ρ_s ∼ 40). A metal lens relay antenna is used for in-vessel beam focusing, and a beam diameter of less than 40 mm is achieved in the plasma core region. This antenna can be steered at an angle of 159° ± 6°, which almost covers the plasma radius. The estimated size of the scattering volume is ∼105 mm at the edge and 135 mm at the core, respectively. A 60 m corrugated waveguide is used to achieve a low transmission loss of ∼8 dB. A heterodyne detection system for millimeter-wave circuits with probing power modulation can distinguish the scattered signal from background noise.

Uric acid shown to contribute to increased oxidative stress level independent of xanthine oxidoreductase activity in MedCity21 health examination registry

Uric acid has both antioxidant and pro-oxidant properties in vitro by scavenging and production of reactive oxygen species (ROS). This cross-sectional study examined whether uric acid possesses effects on oxidative stress under physiological conditions independent of xanthine oxidoreductase (XOR), which is involved in uric acid and ROS production. Serum uric acid level was measured, while plasma XOR activity was determined using our high-sensitive assay in 192 participants (91 males, 101 females) who underwent health examinations and were not taking an antihyperuricemic agent. For antioxidant potential and oxidative stress level, biological antioxidant potential (BAP) and derivative of reactive oxygen metabolites (d-ROMs) in serum, respectively, were measured. Median uric acid level and plasma XOR activity were 5.6 mg/dL and 26.1 pmol/h/mL, respectively, and BAP and d-ROMs levels were 2112.8 μmol/L and 305.5 Carr U, respectively. Multivariable regression analyses revealed no significant association of serum uric acid level with BAP level, whereas serum uric acid level showed a significant association with d-ROMs level independent of plasma XOR activity (p = 0.045), which was prominent in females (p = 0.036; p for interaction = 0.148). Uric acid might contribute to increased oxidative stress independent of XOR activity by increasing ROS production, without affecting ROS scavenging, especially in females.

Difficulty in activities of daily living and falls in patients undergoing hemodialysis: A cross-sectional study with nondialysis controls

INTRODUCTION

Impaired activities of daily living (ADL) and falls are important issues in hemodialysis patients. So far, information is limited regarding self-reported difficulty with ADL (ADL difficulty) in hemodialysis patients. Then, we compared the degree of ADL difficulty and the prevalence of fallers between hemodialysis patients and a nondialyzed control group. Also, the possible association between ADL difficulty and falls was examined.

METHODS

This was a single center, cross-sectional study including two groups of outpatients aged 50 years or older; 209 prevalent hemodialysis patients, and 139 nonrenal patients with diabetes mellitus, hypertension, and/or dyslipidemia (control group). ADL difficulty score was evaluated by a 48-item questionnaire including six subscales of ADLs namely locomotion, eating, toileting, dressing, bathing, and grooming. Experience of falls in the previous year period was examined by a questionnaire.

FINDINGS

The two groups did not differ significantly in age or sex. The hemodialysis group had a higher median (interquartile range) total score of ADL difficulty than the control group [10 (2-39) vs. 2 (0-10); p < 0.001] and a higher prevalence of fallers (73/209, 34.9% vs. 16/139, 11.5%; p < 0.001). In multivariable-adjusted linear regression analyses, history of falls was independently associated with a higher score of ADL difficulty for total or each of the six subscales.

DISCUSSION

The hemodialysis patients had a significantly higher ADL difficulty and a higher prevalence of fallers than the control group. Self-reported ADL difficulty and falls were closely linked regardless of the patient group.

Is Stiffness Parameter β Useful for the Evaluation of Atherosclerosis?~ Its Clinical Implications, Limitations, and Future Perspectives ~

Atherosclerosis comprises two components, atherosis and sclerosis, characterized by morphological wall thickening and functional stiffening, respectively, of the arterial wall. In recent years, much interest has been directed to the role of functional changes in large arteries, i.e., increased stiffness or decreased elasticity, on the development of cardiovascular diseases. In fact, the clinical evaluation of arterial stiffness is increasingly performed in patients with cardiovascular risk factors. Local arterial stiffness is measured using an ultrasound technique implemented with an echo-tracking system at the common carotid and femoral arteries. Several indices of local arterial stiffness are obtained by ultrasound, among which stiffness parameter β is unique because it is the least affected by blood pressure at the time of measurement. Evidence from cross-sectional studies indicates that increased stiffness parameter β is associated with a number of cardiovascular risk factors, such as older age, smoking, insufficient physical activity, hypertension, obesity, metabolic syndrome, insulin resistance, type 2 diabetes, chronic kidney disease, and comorbid cardiovascular disease. Results from several prospective observational studies also suggest that carotid stiffness parameter β is a useful surrogate marker of cardiovascular events and/or mortality, although the results differ depending on the characteristics of the study subjects. Furthermore, several interventional studies have shown that carotid stiffness parameter β improved after lifestyle modification or drug treatment. In this review, we summarize the current evidence of stiffness parameter β of the carotid artery and discuss its clinical implications as a marker of vascular health or as a predictor of cardiovascular outcomes.