Search

Objective: There is now growing evidence that magnesium (Mg) deficiency is implicated in type 2 diabetes and its complications. However, it has not been fully elucidated whether hypomagnesemia is a predictor of end-stage renal disease (ESRD) in type 2 diabetic nephropathy.Research Design and Methods: This retrospective cohort study included 455 chronic kidney disease (CKD) patients (144 with type 2 diabetic nephropathy and 311 with nondiabetic CKD) who were hospitalized at Osaka General Medical Center for a CKD educational program between April 2001 and December 2007. The primary outcome was progression to renal replacement therapy. Participants were categorized based on serum Mg level into Low-Mg (serum Mg level ≤1.8 mg/dL) and High-Mg (serum Mg level >1.8 mg/dL) groups with the previously published normal lower limit chosen as the cutoff point.Results: Of the subjects with type 2 diabetic nephropathy, 102 progressed to ESRD during follow-up (median, 23 months). A multivariate Cox proportional hazards model showed that after adjustment for various demographic factors and laboratory data, the Low-Mg group had a 2.12-fold higher risk of ESRD than the High-Mg group (95% CI 1.28-3.51; P = 0.004). In contrast, 135 of the nondiabetic CKD subjects progressed to ESRD during follow-up (median, 44 months). No significant difference in outcome was found between the Low- and High-Mg groups of this population (adjusted hazard ratio, 1.15; 95% CI 0.70-1.90; P = 0.57).Conclusions: Hypomagnesemia is a novel predictor of ESRD in patients with type 2 diabetic nephropathy. [ABSTRACT FROM AUTHOR]

Rationale & Objective: Prolonged end-stage kidney disease (ESKD) is a risk factor for frailty, and the number of patients in Japan receiving maintenance dialysis for more than 20 years is large and growing. This study characterized the association of dialysis vintage and frailty among patients receiving dialysis in Japan., Study Design: Cross-sectional study., Setting & Participants: Patients with ESKD aged over 50 years who received maintenance dialysis in 2018 as represented in the JSDT Renal Data Registry database (n = 227,136)., Exposure: Dialysis vintage categorized as: 0-<5 years, 5-<10 years, 10-<20 years, 20-<30 years, and over 30 years., Outcome: Frailty and bedridden status were defined as graded≥2 and graded 4, respectively, according to the Eastern Cooperative Oncology Group Performance Status scale., Analytical Approach: Poisson regression models with robust error variance adjusted for potential covariates were used to estimate the adjusted prevalence ratios (APRs) for frailty and bedridden status. Clinical characteristics of patients undergoing dialysis for≥30 years were also described., Results: Among the study cohort, 5,510 patients (2.4%) had been undergoing dialysis for 30 years or more. The prevalence of frailty in the group with over 30 years of dialysis history was 36.2%, and the rate of being bedridden was 6.4%. Compared with<5 years, dialysis vintages of 5-<10 years, 10-<20 years, 20-<30 years, and over 30 years were associated with frailty (APR, 1.06 [95% CI, 1.05-1.08], 1.10 [95% CI, 1.08-1.11], 1.14 [95% CI, 1.10-1.17], and 1.67 [95% CI, 1.60-1.73]), respectively. Compared with<5 years, dialysis vintages of 5-<10 years, 10-<20 years, 20-<30 years, and over 30 years were associated with being bedridden (APR, 1.17 [95% CI, 1.13-1.22], 1.26 [95% CI, 1.20-1.31], 1.17 [95% CI, 1.08-1.26], and 1.66 [95% CI, 1.49-1.86], respectively., Limitations: Patients receiving short-term dialysis may have more unmeasured comorbidities compared with patients receiving long-term dialysis., Conclusions: Long-term dialysis therapy, particularly exceeding 30 years, is associated with deterioration of physical function and frailty., Plain-Language Summary: End-stage kidney disease increases the risk of frailty. Understanding how long-term dialysis affects physical function may help patients and caregivers plan their lives better. Our research explores the relationship between duration of maintenance dialysis and frailty. We found that longer durations of maintenance dialysis, especially longer than 30 years, were associated with a higher risk of frailty and being bedridden among Japanese patients. The factors responsible for these associations should be the focus of future research., (Copyright © 2024 National Kidney Foundation, Inc. Published by Elsevier Inc. All rights reserved.)

Aims: The aim of this cohort study was to evaluate the association between urinary levels of C-megalin, a full-length form of megalin, and kidney dysfunction progression and its dependence on the urinary albumin-creatinine ratio (UACR) in individuals with diabetes., Methods: We enrolled 1,547 individuals with diabetes who visited the ambulatory clinic at Tenri Hospital, a regional tertiary-care hospital in Tenri City, Nara Prefecture, Japan, with an estimated glomerular filtration (eGFR) of ≥ 30 mL/min/1.73 m 2 . The hazard ratio (HR) and 95% confidence interval (CI) were estimated using Cox proportional hazard models to examine the association between urinary C-megalin levels and eGFR decline by ≥ 40% from baseline., Results: Urinary C-megalin level was not associated with ≥ 40% eGFR decline in an age-, sex-, eGFR-, systolic blood pressure-, hemoglobin-, and UACR-adjusted model in the 1,547 patients enrolled in the study. However, urinary C-megalin levels were associated with a ≥ 40% decline in eGFR when accounting for the relationship between urinary C-megalin levels and UACR in the model. This association was UACR-dependent., Conclusions: High urinary C-megalin levels were associated with progressive kidney dysfunction in individuals with diabetes, and this association was attenuated by high UACRs., (© 2023. Springer-Verlag Italia S.r.l., part of Springer Nature.)

Background: Evidence on renin-angiotensin system inhibitors (RASis) effect in reducing urinary protein levels in patients with nephrotic syndrome is insufficient. We determined whether RASis can induce complete remission (CR) in patients on immunosuppressive therapy., Methods: This cohort study included 84 adults (median age, 65 years; males, 57%) with primary nephrotic syndrome (excluding minimal change disease) not receiving RASis during enrollment in the Japanese Nephrotic Syndrome Cohort Study from January 2009 to December 2010, and were followed up for 5 years. Exposure and outcome were RASi initiation and first CR, respectively. Marginal structural models and Poisson regression were used to account for time-varying covariates and estimate causal effects of RASis on CR., Results: Overall, 51 (61%), 73 (87%), and 55 (66%) patients had membranous nephropathy, were prescribed immunosuppressive agents at baseline (1-month post-renal biopsy and/or at start of immunosuppressive therapy), and were prescribed RASis during the study period, respectively. Sixty-five patients experienced first CR (incidence rate, 5.05/100 person-months). RASi use was associated with a higher (adjusted incidence rate ratio [aIRR] 2.27, 95% confidence interval [CI] 1.06-4.84), and lower (aIRR: 0.17, 95% CI 0.04-0.68) first CR in patients with membranous nephropathy and other pathologies, respectively., Conclusion: RASis are beneficial as adjuvant therapy for inducing remission in patients with membranous nephropathy., (© 2023. The Author(s), under exclusive licence to The Japanese Society of Nephrology.)

Aims: Megalin is a multiligand receptor expressed in proximal tubular cells that reabsorbs filtered albumin and correlates cross-sectionally with albuminuria. We investigated the association between urinary C-megalin levels and the incidence of microalbuminuria in patients with diabetes mellitus., Methods: This cohort study included 752 patients with type 1 or 2 diabetes mellitus and a urinary albumin-to-creatinine (Cr) ratio (UACR) within the normoalbuminuric range (<30 mg/g Cr). The association between urinary C-megalin and persistent microalbuminuria, accounting for the possible interaction between baseline UACR and urinary C-megalin, was estimated using a Cox proportional hazards model., Results: During a median follow-up period of 1.99 years, 179 cases of persistent microalbuminuria were observed. The association between urinary C-megalin and persistent microalbuminuria was UACR-dependent (P for interaction < 0.001), with the highest association observed in the absence of UACR (per 100 fM/gCr of urinary C-megalin: adjusted hazard ratio, 1.13; 95% CI 1.07-1.19), gradually decreasing as UACR increased to 30 mg/g Cr. UACR dependence was confirmed by sensitivity analyses according to low-normal (<10 mg/gCr) or high-normal (10-<30 mg/gCr) UACR., Conclusions: Urinary C-megalin is associated with progression to microalbuminuria, especially in those with low-normal UACR levels, and its usefulness to identify high risk patients requires further investigation., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are prescribed as conservative or adjunctive therapies for adult idiopathic nephrotic syndrome. However, studies on real-world practice patterns are scarce. This study aimed to examine the prevalence and incidence of ACEI/ARB prescription and their associated factors. This nationwide cohort study included adult Japanese patients with idiopathic nephrotic syndrome including minimal change disease (MCD), membranous nephropathy (MN), focal segmental glomerulosclerosis (FSGS), and others. The outcomes were the prevalence of ACEI/ARB prescription at baseline (date of renal biopsy or date of immunosuppressant initiation) and at 2 months after baseline. Of the 326 eligible patients, 122 (37.4%) had already been prescribed ACEIs/ARBs. Of the remaining 204 patients, 67 (32.7%) were newly prescribed within the 2-month period. MN/FSGS (vs. MCD, adjusted odds ratio [AOR]: 4.96 [95% confidence interval {CI} 2.53-9.72] and 3.95 [95% CI 1.61-9.66], respectively), higher age (per 1-yr increase, AOR: 1.02 [95% CI 1.00-1.04]), other hypertensive agents (AOR: 2.18 [95% CI 1.21-3.92]), antidiabetic drug (AOR: 6.57 [95% CI 1.77-24.4]) were associated with a higher prevalence of ACEI/ARB prescription. MN (vs. MCD, AOR: 6.00 [95% CI 2.57-14.0]) and higher baseline systolic blood pressure (SBP) (per 10-mmHg increase, AOR: 1.36 [95% CI 1.09-1.70]) were associated with a higher incidence of ACEI/ARB prescription. On average, incidence of ACEI/ARB prescription increased from 19.2% to 40.8% as baseline SBP increased from 100 to 140 mmHg. Thus, Japanese nephrologists are likely to prescribe ACEIs/ARBs for nephrotic patients with MN or high baseline SBP, even below the hypertensive range., (© 2021 The Authors. The Journal of Clinical Hypertension published by Wiley Periodicals LLC.)

Objective: Quality indicators (QIs) are tools that standardize evaluations in terms of the minimum acceptable quality of care, presumably contributing for the better management of patients with systemic lupus erythematosus (SLE). This study aimed to develop QIs for SLE using electronic health data. Methods: The modified RAND/UCLA Appropriateness Method was used to develop the QIs. First, a literature review was conducted. Second, the candidate QI items that were available to be evaluated using the electronic health data were extracted. Third, the appropriateness of the items was assessed via rating rounds and panelists' discussions. Results: We found 3621 articles in the initial search. Finally, 34 studies were reviewed, from which 17 potential indicators were extracted as candidate QIs. Twelve indicators were selected as the final QI set through the process of appropriateness. The median appropriateness of these 12 indicators was at least 7.5, and all of them were without disagreement. The QI included assessment of disease activity, treatment of SLE, drug toxicity monitoring, treatment of glucocorticoid complications, and assessment of SLE complications. Conclusion: We formulated 12 QIs for the assessment of patients with SLE based on electronic medical data. Our QI set would be a practical tool as a quality measure.

Background: Few good-quality clinical trials on adults with nephrotic syndrome exist. Thus, there are discrepancies between real-world practice and clinical practice guidelines. We conducted a questionnaire-based survey to investigate potential discrepancies and the factors associated with variations in clinical practice., Methods: A questionnaire was administered electronically to all board-certified nephrologists in Japan. To examine clinical practice variations in relation to physician characteristics, we estimated the ratio of the mean duration of steroid therapy using a generalized linear model, and the odds ratio of higher level ordinal variables using an ordered logistic regression model., Results: Responses of the 116 participants showed some variation for the majority of questions. Most participants (94.8%) indicated that screening for malignant tumors was "Conducted for almost all patients". The duration of steroid therapy was found to be longer among physicians seeing ≥ 30 patients with nephrotic syndrome per month, both for minimal-change disease (ratio of mean 1.69; 95% CI 1.07-2.66) and membranous nephropathy (ratio of mean 1.71; 95% CI 1.09-2.69)., Conclusions: We identified practice patterns for nephrotic syndrome and discrepancies between clinical practice guidelines and actual practice. Defining the standard therapy for nephrotic syndrome may be necessary to generate high-quality evidence and develop clinical guidelines.

Aims: Several quality indicators (QIs) to improve the quality of practice for hemodialysis patients have been implemented. However, the variations and characteristics of these indicators in terms of their use and feasibility have not been investigated. We conducted a systematic review to evaluate the variations and characteristics of existing QIs for maintenance hemodialysis patients., Methods: We conducted a systematic literature search of MEDLINE via PubMed, Scopus, the Cochrane Library, and CINAHL, without date limits, on February 26, 2016. We selected the English-written articles regarding QIs for patients aged ≥18 years who were on maintenance hemodialysis therapy ≥3 months, and extracted the definition and development process of the reported QIs. We categorized each indicator into one of four types, namely, structure, process, surrogate outcome, and outcome, and assessed the data sources that were necessary to measure it., Results: We included 70 articles and identified 101 indicators, and found that most of the consensus processes for selecting indicators were unclear. We also found that most indicators were not process indicators and that the measurement of some indicators required a chart review, which limits their use and feasibility., Conclusions: Development of QIs for hemodialysis patients in the future should use a definitive consensus process and consider process-centered indicators that can be measured automatically using claims data and test results contained in electronic medical records, to improve usability and feasibility.

Background: Falls and fall-related fractures are a major public health problem among the older adults. Although objective measures of poor vision have been reported to be associated with falls, the association of self-reported visual function and vision-specific quality of life (QOL) with falls has been inconsistent across several studies. We investigated the association of self-reported visual function and vision specific QOL with falls in community-dwelling older adults., Methods: We conducted a cross-sectional analysis using the baseline data from participants of the Locomotive Syndrome and Health Outcome in Aizu Cohort Study (LOHAS), which is an ongoing population-based cohort study to evaluate the association of physical dysfunction with the clinical outcomes in community-dwelling people. In the present study, the participants aged over 65 years in 2010 were eligible. The exposure variable was the composite score of the VFQ-J11, which was newly developed using item response theory to evaluate vision specific QOL, and the self-reported outcomes were any fall and frequent falls (≥2) over a 1-month period. We estimated odds ratios using separate logistic regression models adjusted for relevant confounding factors., Results: Among 1624 participants, the median (interquartile range) composite score of VFQ-J11 was 86.8 (76.0-95.9). Any fall and frequent falls were reported by 13.9% and 5.4% of participants, respectively. The composite score of the VFQ-J11 was significantly associated with both frequent falls (adjusted ORs per 10 points, 0.80; 95% CI, 0.68-0.93) and any fall (adjusted ORs per 10 points, 0.84; 95% CI, 0.76-0.94)., Conclusions: We found that the composite score of the VFQ-J11 was associated with falls in community-dwelling older adults. Detecting individuals with visual impairments associated with falls using the VFQ-J11 and improvement in the score by interventions could prevent falls. We may consider adding self-reported visual function and vision-specific QOL to conventional risk factors for fall among older adults.

Objectives: The experimental studies suggested the hypothesis that the accumulation of advanced glycation end-products (AGEs) could induce hearing impairment. The purpose of this study is to examine the hypothesis among elderly people using an epidemiologic approach., Design: Cross-sectional study., Setting: Sukagawa City, Fukushima, Japan., Participants: A total of 270 residents aged 75 years or over without dementia, who participated in a health check-up conducted in 2015., Measurements: The exposure variable was AGEs, which was assessed using skin autofluorescence (AF) as a proxy measure. The primary outcome was moderate hearing impairment or worse, which was defined as a pure tone average of thresholds ≥41 decibel hearing level at 0.5, 1, 2, and 4 kHz in the better-hearing ear. The secondary outcome was the pure tone average of thresholds as a continuous variable. We estimated the odds ratio using a logistic regression model for the primary outcome and a general linear model for the mean difference in the pure tone average of thresholds for the secondary outcome. Both models were adjusted for relevant confounding factors: age, sex, smoking, diabetes, hypertension, and history of cerebrovascular diseases., Results: The median (interquartile range) AF was 2.2 (2.0, 2.5) arbitrary units (AU). Moderate hearing impairment was reported in 88 participants (32.6%). For the primary outcome, we found significant associations between moderate hearing impairment and AF (adjusted odds ratio per 1 AU, 2.60; 95% confidence interval 1.26-5.35). For the secondary outcome, we also found a significant association between a 1-AU increase in AF and increased pure tone average, with a difference (6.52 dB per 1 AU; 95% confidence interval 2.18-10.86) comparable in magnitude to the increase in pure tone average observed for a 6-year increase in age in our population., Conclusions: Our study indicated that high levels of AGEs were independently associated with hearing impairment. Modifying levels of AGEs may prevent hearing impairment., (Copyright © 2017 AMDA – The Society for Post-Acute and Long-Term Care Medicine. Published by Elsevier Inc. All rights reserved.)

Background: Serum ferritin concentration >100 ng/mL was associated with a higher risk of death in hemodialysis patients in Japan, whereas such an association was less clear in hemodialysis patients in Western countries. Since Japanese dialysis patients are generally less inflamed than those in Western countries, inflammation may modify the association between serum ferritin and the adverse outcomes., Methods: We performed an observational cohort study using data from 2606 Japanese hemodialysis patients who participated in the Dialysis Outcomes and Practice Patterns Study (DOPPS) III (2005-2008) or DOPPS IV (2009-2012). The predictor was serum ferritin category (<50, 50-99.9, 100-199.9, and ≥200 ng/mL), and the primary and secondary outcomes were all-cause mortality and cardiovascular hospitalization, respectively. C-reactive protein (CRP, cut-off by 0.3 mg/dL) and serum albumin (cut-off by 3.8 g/dL) were stratification factors related to systemic inflammation., Results: After adjustment for relevant confounding factors, a U-shaped association was observed between serum ferritin and all-cause mortality in the group with low CRP levels, whereas such relationship was not significant in the high CRP counterparts. In contrast, we found a linear association between serum ferritin and cardiovascular hospitalization in the low CRP and high CRP groups commonly. Similar results were obtained when the total cohort was stratified by serum albumin., Conclusions: Serum ferritin showed different patterns of association with all-cause mortality in hemodialysis patients with versus without inflammation, whereas its association with cardiovascular hospitalization was similar regardless of inflammatory conditions.

Background: Hemodialysis patients are exposed to disease- and treatment-related stresses, and use various coping strategies to deal with these stresses. Although some studies have reported the association of coping strategies with mortality or health-related quality of life (QOL) in some populations, the effect of coping strategies on clinical outcomes in hemodialysis patients remains unclear. We investigated the association in a longitudinal design among Japanese hemodialysis patients., Methods: We examined Japanese hemodialysis patients who participated in the Dialysis Outcomes and Practice Patterns Study (DOPPS) IV, which was conducted between 2009 and 2012. The exposure variable was stress coping strategy, as assessed using subscales in Coping Strategies Inventory Short Form: problem-focused engagement, problem-focused disengagement, emotion-focused engagement, and emotion-focused disengagement. Hazard ratios were estimated using Cox proportional hazard model for all-cause mortality and mean differences for change in health-related QOL in 1 year were estimated using a regression model., Results: Among 1,354 patients, only problem-focused engagement was significantly associated with longer survival; other subscales were not associated with all-cause mortality after adjustment for potential confounding factors. In terms of health-related QOL, the subscale of problem-focused engagement was also associated with improvement in physical functioning and mental health among 1,045 patients. Emotion-focused disengagement was associated with deterioration in mental health, but not with change in physical functioning. The other subscales were not associated with change in physical functioning or mental health., Conclusions: Among hemodialysis patients, "problem-focused engagement" coping strategies were associated with longer survival and also with improvement in physical functioning and mental health. To achieve greater longevity and improve QOL in hemodialysis patients under ongoing stresses, problem-focused engagement should be encouraged.

Background: The prevalence of chronic kidney disease (CKD) has recently increased, and maintaining high quality of CKD care is a major factor in preventing end-stage renal disease. Here, we developed novel quality indicators for CKD care based on existing electronic health data., Methods: We used a modified RAND appropriateness method to develop quality indicators for the care of non-dialysis CKD patients, by combining expert opinion and scientific evidence. A multidisciplinary expert panel comprising six nephrologists, two primary care physicians, one diabetes specialist, and one rheumatologist assessed the appropriateness of potential indicators extracted from evidence-based clinical guidelines, in accordance with predetermined criteria. We developed novel quality indicators through a four-step process: selection of potential indicators, first questionnaire round, face-to-face meeting, and second questionnaire round., Results: Ten expert panel members evaluated 19 potential indicators in the first questionnaire round, of which 7 were modified, 12 deleted, and 4 newly added during subsequent face-to-face meetings, giving a final total of 11 indicators. Median rate of these 11 indicators in the final set was at least 7, and percentages of agreement exceeded 80 % for all but one indicator. All indicators in the final set can be measured using only existing electronic health data, without medical record review, and 9 of 11 are process indicators., Conclusion: We developed 11 quality indicators to assess quality of care for non-dialysis CKD patients. Strengths of the developed indicators are their applicability in a primary care setting, availability in daily practice, and emphasis on modifiable processes.

Background and Objectives: Obstructive sleep apnea (OSA) affects one of five adults in the general population. Although a high prevalence of OSA has been reported among dialysis patients, the association between nondialysis chronic kidney disease (CKD) and OSA has not been fully investigated. This cross-sectional study aimed to investigate the prevalence of OSA among nondialysis CKD patients in Japan and the association between renal function and OSA., Design, Setting, Participants, & Measurements: Consecutive nondialysis CKD patients hospitalized mainly for CKD educational program, regardless of their sleep complaints, were enrolled. The diagnosis of OSA and its severity were measured using a type 3 portable monitor., Results: Overall (n=100, 68.0% male, median age 66.5 years, body mass index [BMI] 23.1 kg/m(2), estimated GFR [eGFR] 28.5 ml/min per 1.73 m(2)), 65% were diagnosed as OSA: mild OSA (apnea-hypopnea index [AHI] 5.0 to 14.9) in 32%, moderate OSA (AHI 15.0 to 29.9) in 25%, and severe OSA (AHI ≥ 30.0) in 8%. Multivariate logistic regression analysis revealed that a 10-ml/min per 1.73 m(2) decrease in eGFR was associated with a 42% increased odds of OSA after adjustment for age, BMI, and diabetes mellitus. Moreover, in a generalized linear model, eGFR was inversely correlated with AHI after adjustment for covariates., Conclusions: This study demonstrated a high prevalence of OSA among nondialysis CKD patients in Japan and that the increased risk of OSA was significantly associated with decreased GFR among these patients. Further investigations are warranted to determine OSA's direct influence on cardiovascular disease., (Copyright © 2011 by the American Society of Nephrology)

An 80-year-old woman positive for myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) was admitted with a 3-month history of fever, general malaise, and weight loss, after unsuccessful treatment with antibiotics. Upon admission, her fever persisted, and there was concomitant deterioration of renal function without active urine sediments. Furthermore, she developed hemoptysis, and chest computed tomography (CT) scan revealed bilateral diffuse alveolar hemorrhage. Although a renal biopsy was not performed because of her dementia, we initially suspected microscopic polyangiitis (MPA) on the basis of her clinical course. Because of her poor general condition, she was administered a low dose of prednisolone. Although her fever subsided, she suffered from intractable alveolar hemorrhage and eventually died from respiratory failure. During the autopsy, fibrinoid necrosis was restricted to medium-sized arteries, including the arcuate arteries of the kidneys and the bronchial arteries, without necrotizing crescentic glomerulonephritis and alveolar capillaritis. Therefore, polyarteritis nodosa (PAN) was diagnosed. It is important to distinguish between MPA and PAN because they can lead to life-threatening complications, and their treatment strategies and prognosis are different. When a patient presents with MPO-ANCA, alveolar hemorrhage, and acute renal failure with little evidence of glomerulonephritis, a differential diagnosis of PAN should be made; however, it is difficult to do so without pathological findings. Therefore, pathological examination should be carried out whenever possible.

A 80-year-old man was admitted to our hospital because of coughing, hemosputum and dyspnea. As a chest X-ray showed infiltrates of the right lung, he was diagnosed as bacterial pneumonia and treated with antibiotics. However, after a few days, he exhibited hemoptysis and developed severe dyspnea, while laboratory findings showed rapid elevation of the serum creatinine level (5.55 mg dL). Computed tomography (CT) revealed large areas of ground glass opacity in the right lung, hence the hemoptysis was considered to be due to alveolar hemorrhage. As he had been diagnosed as chronic renal failure a few years before this admission and we also noticed that interstitial pneumonia with a slightly elevated level of C-reactive protein had existed from that time, ANCA-associated vasculitis was suspected to be the underlying pathogenesis. Accordingly, he was started on methylprednisolone pulse therapy and temporary hemodialysis resulted in improvement of dyspnea and renal function. PR3-ANCA was 12.4 EU, so he was diagnosed as PR3-ANCA-associated vasculitis. After a few days, he suddenly complained of abdominal pain, developing hypotension and anemia. Abdominal CT showed an irregular low-density mass in the right muscle, so he was diagnosed as rectus muscle hematoma. Surgery was performed and a massive hematoma was found in the rectus muscle without any ruptures of macroscopic vessels in the abdomen. Bleeding could not be stopped followed by multiple organ failure and the patient died four days postoperatively. Rectus muscle hematoma is an uncommon cause of acute abdomen, and has been reported in about 100 cases in Japan. It occurs because of a tear in epigastric vessels and is usually managed conservatively with a good prognosis, although hemodynamically unstable cases require surgery. To the best of the authors' knowledge, this is the first case of rectus muscle hematoma complicated with ANCA-associated vasculitis.