Mitsuru Yanai

Body mass index variations by age and sex, and prevalence of overweight in Japanese adults

OBJECTIVE: To determine the reference value of BMI for Japanese subjects and to estimate the prevalence of overweight based on this reference value. DESIGN: Epidemiological analysis with the LMS method, which provides a way of obtaining normalized BMI distributions. SUBJECTS: 7508 Japanese subjects aged 18–69 y in 1993. MEASUREMENTS: Height, age and body weight. CALCULATION: BMI was calculated and tables for percentiles of BMI were plotted against age and sex. Furthermore, the prevalence of overweight was estimated based on 85th percentile of BMI in the men and women 20–29 y of age, who were considered the reference group. RESULTS: The geometric mean BMI and the prevalence of overweight in men was highest in the 30–39 y age group. For women the maximum BMI and prevalence of overweight occurred in the decade 50–59 y. The cut-off points for overweight in this sample were 24.7 kg/m2 for men and 22.6 kg/m2 for women. These are considerably lower than the figures of 27.8 kg/m2 and 27.3 kg/m2 estimated for Americans. CONCLUSIONS: The prevalence of obesity in Japanese populations should be estimated using ethnic specific values of BMI, rather than those drawn from Caucasians who tend to have higher BMI in each age group. The prevalence of overweight is increased as age increased in both sexes, especially in women.

Dialysis-membrane-dependent reduction and adsorption of circulating hepatitis C virus during hemodialysis.

Background/Aims: Patients on chronic hemodialysis (HD) are often infected with hepatitis C virus (HCV), a common cause of chronic liver disease. In some cases, however, decreases in the serum HCV load after HD have been documented. To better understand this phenomenon, we investigated the effects of various types of dialysis membrane on virus load in the circulation in vivo and in vitro. Methods: HCV RNA levels in patients’ serum, filtrate and dialyzer membranes were analyzed semiquantitatively by reverse transcription-polymerase chain reaction (RT-PCR) before and after HD treatment with two to four different types of dialysis membrane. HCV RNA was also determined from each fraction in in vitro dialysis and ultrafiltration. Results: In HD patients treated with a polysulfone (PS) membrane and a hemophan membrane, the HCV RNA titer reproducibly decreased by a factor of 10–1–10–2. In contrast, a cuprophan (CU) membrane had no detectable effect on HCV viremia, and HD with the AN69 membrane reduced HCV RNA levels in only a subset of the patients. In addition, a PS membrane, but not a CU membrane, reduced the level of circulating HCV in an in vitro assay. In both in vivo and in vitro experiments, HCV RNA was recovered from the PS membrane itself, but not from the ultrafiltrate. Conclusions: Membrane-dependent adsorption of HCV occurs during HD, causing a transient reduction in HCV in the circulation of patients.

Aging and Chronic Kidney Disease

A recent report has dealt with geriatric nephrology, including epidemiology and pathophysiology of chronic kidney disease (CKD), attempting to get nephrologists to pay more attention to elderly CKD patients. The aims of this article are to summarize the morphological and functional properties of the aging kidney, and to better understand nephrology care for elderly CKD patients. The kidneys are affected by the aging process, which results in numerous effects on the renal system. In addition, the elderly population is hetereogenous - some have a decline in GFR explained by diseases that complicate aging such as arteriosclerosis with hypertension, whereas in the most of healthy adults the decline in GFR is much more modest and not inevitable. The values for normal estimated glomerular filtration rate (eGFR) in aging population have important implications for the diagnosis of CKD in the elderly. However, the MDRD equation underestimates mean eGFR by 25% and the CKD-EPI equation underestimates mean GFR by 16%. This bias may lead to misclassifying healthy older persons as having CKD. It is also still unknown whether and how age influences the predictive role of other risk factors for end-stage renal disease (ESRD) and death in referred as well as unreferred patients. The risk of ESRD was reported to be higher than the risk of death without ESRD for ages <60 years, and independent of eGFR. Proteinuria significantly increased the risk of ESRD with advancing age. In older patients on nephrology care, the risk of ESRD prevailed over mortality even when eGFR was not severely impaired. Proteinuria increases the risk of ESRD, while the predictive role of other modifiable risk factors was unchanged compared with younger patients. The decision to initiate renal replacement therapy in the elderly is complicated by more challenges than in younger patients. Calorie restriction and Klotho deficiency may be a candidate therapeutic target for attenuating kidney aging.

The Kidney Early Evaluation Program (KEEP) of Japan: results from the initial screening period

The International Kidney Evaluation Association Japan evaluated chronic kidney disease (CKD) in Japan, using a Japanese version of the US National Kidney Foundations Kidney Early Evaluation Program (KEEP). The screening criteria for the first 1065 participants were presence of diabetes or hypertension, or family history of diabetes, hypertension, or kidney disease. Mean age was 59.7+/-16.1 years; 501 participants were men, 564 women. Of participants, 26.9% had diabetes, 59.2% had hypertension (with an additional 21.5% diagnosed after the program), 16.9% had history of diabetes and hypertension together, and 30.6% had neither, but had family history of diabetes, hypertension, or kidney disease. CKD (stages 1-4) prevalence was 26.7%, defined by albumin-creatinine ratio and estimated glomerular filtration rate. CKD prevalence was 35.0% among diabetic participants, 34.8% among hypertensive participants, and 37.1% among participants with cardiovascular disease (CVD). The following baseline conditions were significantly associated with discovered CKD: diabetes, odds ratio 1.71 (95% confidence interval 1.28-2.30); hypertension, 3.42 (2.15-5.44); CVD, 1.88 (1.37-2.57). CKD prevalence was high compared with the general Japanese population. KEEP Japan seems to define a high-risk population with evidence of CKD based on the targeted nature of the program.

Development and performance of an enzyme immunoassay to detect creatine kinase isoenzyme MB activity using anti-mitochondrial creatine kinase monoclonal antibodies

Abstract Objective: The MB fraction of creatine kinase (CK-MB) has long been used as a cardiac marker. It is known that the CK-MB immunoinhibition method lacks selectivity and accuracy, because the appearance of macro CK type 2, corresponding to mitochondrial creatine kinase (MtCK) in some patient serum may render CK-MB activity measured by conventional method abnormally high. Thus, to improve the specificity and accuracy of the CK-MB assay, we developed two types of monoclonal anti-MtCK antibodies against sarcomeric MtCK and ubiquitous MtCK, and present herein the performance of a new method using these antibodies. Material and methods: The performance of our test for detecting CK-MB activity was compared with other methods, and the range of CK-MB activities in normal human serum was investigated. Results: The two types of monoclonal antibodies developed by us were isoenzyme-specific to sMtCK or uMtCK. The correlation coefficients of our method and conventional method to electrophoresis were 0.973 and 0.873, respectively. The mean CK-MB activity in normal human serum by our method and the conventional method was 2.4 and 11.7 U/L, respectively. Thus, our data indicated that about 80% of CK-MB activity, determined using the conventional method, seems to correspond to the MtCK activity. Conclusion: Our method is novel in offering higher accuracy of measuring true CK-MB contents in human serum as compared to the conventional method. The possibility of accurately estimating CK-MB activity by our method which can inhibit MtCKs in healthy person and patient serum is likely to bring a break-through in clinical diagnostics.

A case of gastric plasmacytoma associated with Helicobacter pylori infection: Improvement of abnormal endoscopic and EUS findings after H pylori eradication

Plasmacytoma is a tumor derived from plasma cells, the effector cells of the B lymphoid lineage. Among the extramedullary plasmacytomas, gastric plasmacytoma is rare and constitutes only 5% of these tumors.1 Recently Kinoshita et al.2 described an interesting patient with low-grade gastric mucosaassociated lymphoid tissue (MALT) lymphoma in whom monoclonal immunoglobulin (Ig) (IgM-λ) was detected in serum and gastric juice, suggesting a close pathogenic relationship between gastric MALT lymphoma and gastric plasmacytoma.2 Although a close causative association between Helicobacter pylori infection and gastric MALT lymphoma has been recognized,3 to our knowledge there has been only one report (in Spanish) detailing the relationship between H pylori and gastric plasmacytoma, which described a gastric plasmacytoma in a 14-yearold patient with H pylori infection in whom the tumor regressed after antibiotic therapy.4 This is the second case report of gastric plasmacytoma associated with H pylori infection.

Peritonitis Associated With Pasteurella multocida: Molecular Evidence of Zoonotic Etiology

A patient on continuous cyclic peritoneal dialysis for chronic kidney disease due to type 2 diabetes mellitus developed peritoneal dialysis‐associated peritonitis induced by Pasteurella multocida that was isolated from a sample of dialysis effluent. The route of infection was unknown for this case; however, P. multocida was also isolated from a culture of a pharyngeal swab obtained from the patients cat. There was no evidence that the cat had bitten and ruptured the peritoneal dialysis tubing or bags. Pulsed‐field gel electrophoresis (PFGE) showed that the P. multocida isolated from the patient was completely identical to the strain isolated from the domestic cat. As there is a rise in the pet‐keeping population, an increase in zoonoses is to be expected. It is necessary to be carefully informed of hygiene rules in keeping pets because a pet may transmit zoonoses, even on casual contact.

Surveillance of infection control procedures in dialysis units in Japan: a preliminary study.

Abstract:  As there is a high risk of indirect and direct transmission of infectious agents in chronic hemodialysis, infection control procedures should be established in dialysis units. This paper presents the findings of a questionnaire designed to survey the current status of infection control procedures in hemodialysis settings. Two hundred and forty‐three hemodialysis units in Japan were surveyed. Nearly 90% of hemodialysis units reported compliance with each procedure recommended by the Center for Disease Control and Prevention in the United States, including use of disposable gloves, handling of non‐disposable or non‐single‐use items, and routine serological testing of blood‐borne viruses. However, more than 50% of units reported that they did not comply with recommendations concerning some procedures, such as places for preparing medications and their delivery, clean areas in the units, vaccination for hepatitis B, and additional measures for hepatitis B surface antigen (HBs‐Ag) positive patients. Especially, the concept of universal precautions seemed to be misunderstood in units with a high prevalence of anti‐hepatitis C antibody‐positive (anti‐HCV Ab‐positive) patients. In conclusion, further intensive education and training will be necessary to establish infection control procedures.

Relationship between oligomer and functional serum mannose-binding lectin in chronic renal failure

Eur J Clin Invest 2010; 40 (10): 865–873

Circannual Rhythm of Laboratory Test Parameters among Chronic Haemodialysis Patients

Background/Aims: Seasonal variations in laboratory test results have been pointed out in dialysis patients. Although the mechanism for this phenomenon is not clear, this could result in changes in dialysis and medication prescriptions. We investigated the effect of the circannual rhythm on laboratory test parameters in chronic haemodialysis patients. Methods: Data of 38 laboratory test parameters were collected every month and analyzed for 150 stable haemodialysis patients, with non-linear sine wave regression and paired t test between data of peak and trough months. Results: Serum urea nitrogen, unsaturated iron binding capacity, lactate dehydrogenase, alkaline phosphatase, amylase, and neutrophil count showed significant circannual rhythms with high amplitudes. Additionally, serum creatinine, uric acid, chloride, calcium, phosphate, magnesium, total cholesterol, total protein, leucocyte count, mean corpuscular haemoglobin level, mean corpuscular haemoglobin concentration, and platelet count showed significant circannual rhythms with little amplitudes. Conclusions: The circannual rhythm of laboratory test parameters could be attributed to seasonal variations in food intake. Awareness of these variations should be taken into account in the interpretation of laboratory results.