The Asian project for collaborative derivation of reference intervals: (1) strategy and major results of standardized analytes.

BACKGROUND: A multicenter study conducted in Southeast Asia to derive reference intervals (RIs) for 72 commonly measured analytes (general chemistry, inflammatory markers, hormones, etc.) featured centralized measurement to clearly detect regionality in test results. The results of 31 standardized analytes are reported, with the remaining analytes presented in the next report. METHOD: The study included 63 clinical laboratories from South Korea, China, Vietnam, Malaysia, Indonesia, and seven areas in Japan. A total of 3541 healthy individuals aged 20-65 years (Japan 2082, others 1459) were recruited mostly from hospital workers using a well-defined common protocol. All serum specimens were transported to Tokyo at -80°C and collectively measured using reagents from four manufacturers. Three-level nested ANOVA was used to quantitate variation (SD) of test results due to region, sex, and age. A ratio of SD for a given factor over residual SD (representing net between-individual variations) (SDR) exceeding 0.3 was considered significant. Traceability of RIs was ensured by recalibration using value-assigned reference materials. RIs were derived parametrically. RESULTS: SDRs for sex and age were significant for 19 and 16 analytes, respectively. Regional difference was significant for 11 analytes, including high density lipoprotein (HDL)-cholesterol and inflammatory markers. However, when the data were limited to those from Japan, regionality was not observed in any of the analytes. Accordingly, RIs were derived with or without partition by sex and region. CONCLUSIONS: RIs applicable to a wide area in Asia were established for the majority of analytes with traceability to reference measuring systems, whereas regional partitioning was required for RIs of the other analytes.

[Decrease in number of venipuncture tubes enables us to shorten turnaround times of blood-based testing in clinical laboratories].

We are making efforts to reduce the number of venipuncture tubes for blood-based testing. On the reconstruction of hematology system in 2011, we planned the system to include hemoglobin A1c (HbA1c) assay and to replace the assay instrument for erythrocyte sedimentation rate (ESR) to use EDTA-2K based whole blood. Accordingly, the revised system required a single test tube for hematological testing, resulting in reduction of blood volume collected. It was estimated that the whole blood collected from outpatients in a year decreased from 143 L to 109 L. Also, the times required to complete venipuncture after outpatient accession were significantly shortened to 10(0.71 +/- 0.27) (2.75-9.55) min, and nearly 50% of outpatients experienced < 2 min of waiting. As the times required for venipuncture were shortened, the turnaround times (TATs) from outpatient accession to finally reporting the test results to physicians were also shortened in the blood-based laboratories. The TATs after outpatient accession to reporting the test results in biochemistry and serology ranged 59 to 80 min (90%-tile), indicating 8 to 16 min less when compared with those before system reconstruction. In conclusion, the decrease in number of venipuncture tubes in hematological testing enables us to reduce the blood volume collected, and to shorten (1) times required for venipuncture procedure, (2) waiting times, and (3) TATs for blood-based testing. However, as demonstrated in HbA1c, i.e., a 50%-tile of TAT for HbA1c delayed for 5 min, the configuration of assay system can greatly influence the TATs of individual test parameters.

Pharmacokinetics of low doses of colchicine in the leukocytes of Japanese healthy individuals.

The venerable drug colchicine has garnered significant recent attention due to its endorsement by the United States Food and Drug Administration as an anti-inflammatory medication for cardiovascular diseases. However, the administration of this drug at its minimal available dose of 0.5 mg has been associated with certain adverse reactions. Once colchicine is administered, the drug disappears from blood in a short time and distributes in the leukocytes for a certain period of time that elicits anti-inflammatory effect. Consequently, an in-depth comprehension of the pharmacokinetics of lower dosages within leukocytes assumes important for its broader application in routine clinical contexts. In this study, we present a comprehensive analysis of the pharmacological disposition of colchicine in the plasma, polymorphonuclear leukocytes, and mononuclear leukocytes among healthy Japanese male subjects, following both single and multiple oral administrations of 0.5 mg and 0.25 mg doses of colchicine. Our investigation reveals that colchicine persists within leukocyte populations even when administered at reduced dosages. The findings herein hold promise for mitigating the adverse effects associated with its use in the treatment of inflammatory cardiovascular disorders.

[Influence of sleep habit and nocturnal lifestyle on circadian rhythm of blood pressure among workers in Okinawa].

We estimated the influence of sleep habit and nocturnal lifestyle on circadian rhythm of blood pressure by use of ambulatory blood pressure monitoring (ABPM) and self-estimating questionnaire formats. A total of 30 workers aged 21 to 58 years old voluntarily participated. None had any chronic diseases or regular medication. The average subject daily worked for 8 hours, waked-up at 6:00, went-to-bed at 23:45, and had 6.25-hour sleep (median). The subjects were divided into 3 groups according to % dipping of sleep blood pressure; 10 to 20% dipping as a dipper, <10% as a non-dipper, and > or = 20% as an extreme-dipper. This characterization resulted in 15 dippers (50%), 8 non-dippers(27%) and 7 extreme-dippers (23%). Of the parameters estimated, (1) sleeping hours of non-dippers were significantly shorter than those of dippers (p=0.02), (2) nighttime blood pressure of extreme-dippers were significantly lower than dippers (p=0.04), (3) the lowest blood pressure in nighttime of non-dippers were significantly higher when compared with the remaining 2 groups, (4) morning surges of blood pressure of non-dippers were the significantly smallest, whereas those of extreme-dippers were the greatest, and (5)refreshing scores of OSA sleep inventory MA version of non-dippers were significantly poorer when compared to extreme-dippers. This study could indicate the significant influence of nocturnal lifestyle with short sleep on circadian rhythm of blood pressure, and the extended prospective-study might be promising for a precise conclusion.

[Evaluation of turnaround time (TAT) for outpatients from venipuncture accession to reporting test results of blood chemistry and blood cell analysis to physicians].

In response to the revision of social medical insurance policy, in which hospital clinics can additionally charge for laboratory testing when the test results are presented to an outpatient in a print-out form on a visiting day, we evaluated laboratory-spending times, so-called turnaround times (TATs). A total of 14,802 outpatients during the period from October 2010 to May 2011 were enrolled. TATs from venipuncture accession to completing blood collection revealed a log-normal distribution with 5 to 6 min of mode and 10(0.95 +/- 0.26) (4.90 to 16.2) min of mean +/- standard deviation. Order waiting time figured a half-normal distribution, 50% tile and 90%-tile being 4 and 16 min, respectively. TATs of blood collection and order waiting time were significantly influenced by days of the week and accession time. Through analysis of TATs from specimen receipt to reporting test results, it became apparent that the tests determined by immunoassay and erythrocyte sedimentation rate (ESR) required more minutes when compared to the remaining tests. Total TATs from venipuncture accession to reporting test results ranged 28 to 29 min (50%-tile) for complete blood count and hemoglobin A1c, whereas those of endocrinology and tumor markers were 65 to 73 min. In conclusion, the tests determined by immunoassay are rate-limiting for rapid reporting efforts in clinical laboratories. Secondly, TATs of blood collection are mostly influenced by order waiting time depending on days of the week and accession time. At present, there is no target value for TATs, however it is important to recognize the necessity to shorten laboratory-spending TATs.

Role of HCN4 channel in preventing ventricular arrhythmia.

Bradycardia is a trigger of ventricular arrhythmias in patients with arrhythmia including Brugada syndrome and long QT syndrome. The HCN4 channel controls the heart rate, and its mutations predispose to inherited sick sinus syndrome and long QT syndrome associated with bradycardia. We found a 4 base-insertion at the splice donor site of the HCN4 gene in a patient with idiopathic ventricular tachycardia, which was supposed to generate a truncated channel. To investigate the role of the HCN4 channel in ventricular arrhythmia, we introduced a ventricular action potential of I(f) channel produced by HCN4 in a computer simulation model and found that the I(f) channel generated a leaky outward current during the plateau phase of ventricular action potential. Currents through the I(f) channel were suggested to contribute to the shortening of the action potential duration and the prevention of early after-depolarization in bradycardia. These observations suggested that the HCN4 channel played a preventive role in triggering bradycardia-induced ventricular arrhythmias.

Risk Factors Associated with Cortical Thickness and White Matter Hyperintensities in Dementia Free Okinawan Elderly.

BACKGROUND: Cortical gray matter (GM) and white matter (WM) deterioration are signals of neurodegeneration and increased dementia risk; however, their specific etiologies in dementia-free aging is unclear. OBJECTIVE: The objective of this study was to examine potentially modifiable risk factors of GM and WM degeneration in a well-characterized cohort of dementia-free elderly. METHODS: 96 Okinawan elderly participants (age 83.6) from the Keys to Optimal Cognitive Aging Project (KOCOA) underwent MRI and cognitive evaluation. Serum markers of inflammation (interleukin-6 (IL-6), high sensitivity C-reactive protein), cerebrovascular disease (systolic blood pressure (SBP) 140+, hemoglobin A1C (HgbA1C), total cholesterol), and essential minerals (copper (Cu), magnesium, and calcium) were examined in relation to mean cortical thickness (MCT) and white matter hyperintensities (WMH), adjusting for age and gender. Voxel-based morphometry (VBM) analyses identified relationships between regional GM density and the above markers. RESULTS: Decreased MCT was associated with SBP 140 + (p = 0.029) and increased serum IL-6 (p = 0.036), HgbA1C (p = 0.002), and Cu (p = 0.025). In VBM analyses, increased IL-6, HgbA1C, and Cu were associated with decreased GM density in temporal lobe regions. HgbA1C (p = 0.004) was associated with greater WMH volume. CONCLUSIONS: Peripheral markers of Cu, CVD risk, and inflammation are associated with MRI-markers of decreased brain health in dementia-free Okinawan elderly, with regional cortical thinning in areas involved in early accumulation of Alzheimer's disease pathology. Results identify potentially modifiable biomarkers as targets in the prevention of dementia in older individuals.

Plasma aldosterone in hypertensive patients on chronic hemodialysis: distribution, determinants and impact on survival.

A high plasma aldosterone concentration (PAC) is known to be associated with poor outcome in patients with cardiac disease. However, the prognostic value of PAC in chronic hemodialysis (HD) patients is unknown. In 1996 we examined 128 hypertensive patients treated with antihypertensive drugs, excluding angiotensin-converting enzyme inhibitors, who were undergoing chronic HD (ages 61.8+/-13.8 years, 62% male), and for whom PAC (ng/dl) data were obtained. We followed up these patients until November 2003. During the follow-up period, 30 patients died. About half of all patients (48%) had PAC values above the normal range. We assigned the 128 patients to a lower (<22.9) or higher (> or = 22.9) PAC group according to the median baseline PAC. The survival rate as calculated by the Kaplan-Meier method was 90.6% in the higher PAC group and 62.5% in the lower PAC group (p=0.003). In multivariate analysis, serum potassium and plasma renin activity were independent determinants of PAC. Cox proportional hazards analysis, with adjustment for other variables including diabetes, showed that lower PAC was independently predictive of death. The adjusted hazard ratio (95% confidence interval) of the lower PAC group was 2.905 (1.187-7.112, p=0.020). The significance of PAC became marginal by adjustment with albumin or potassium. These results indicate that higher PAC is common, but not associated with an increase in total and cardiovascular deaths among hypertensive patients undergoing chronic HD. The association between lower PAC and poor survival may be driven by volume retention and/or lower potassium.

Proteinuria as a significant determinant of hypertension in a normotensive screened cohort in Okinawa, Japan.

To evaluate the influence of proteinuria on the development of hypertension in normotensive screened subjects. We studied 4,428 normotensive subjects without heart disease (2888 men, 1540 women, age 19-89 years) who were participants in a 1-day health evaluation in both 1997 and 2000. The 3-year frequency of developing hypertension was 6.0% in subjects without proteinuria, and 13.5% in subjects with proteinuria. The odds ratio for developing hypertension by age (year) increased approximately 1.6%. Obesity was associated with an approximately 40% increased risk of hypertension; proteinuria increased the risk of hypertension 2-fold. Proteinuria was a significant predictor of developing hypertension. Age, obesity, and initial blood pressure level also contributed to the development of hypertension. In conclusion, proteinuria is a powerful predictor of developing hypertension. Age and obesity are also associated with increased risk of hypertension. Lifestyle modification might thus be necessary, particularly in subjects with proteinuria.

Associations between Serum Omega-3 Fatty Acid Levels and Cognitive Functions among Community-Dwelling Octogenarians in Okinawa, Japan: The KOCOA Study.

BACKGROUND: Epidemiological studies have found frequent consumption of fatty fish is protective against cognitive decline. However, the association between circulating omega-3 polyunsaturated fatty acid (PUFA) levels and cognitive functions among the oldest old is not well known. OBJECTIVE: To examine the association between serum PUFA levels and cognitive function among community-dwelling, non-demented elderly aged over 80 years old. METHODS: The data came from the Keys to Optimal Cognitive Aging (KOCOA) study; an ongoing cohort of relatively healthy volunteers aged over 80 years old, living in Okinawa, Japan. One hundred eighty five participants (mean age 84.1±3.4 years) assessed in 2011 who were free from frank dementia (defined as Clinical Dementia Rating <1.0) were used for the current cross-sectional study. We examined whether serum omega-3 PUFAs (docosahexaenoic acid [DHA] and eicosapentaenoic acid [EPA]), arachidonic acid (AA), EPA/AA ratio, DHA/AA ratio, and DHA+EPA are associated with (1) age and (2) global cognitive function (Japanese MMSE) and executive function (Verbal Fluency Letter). Data was analyzed univariately by t-test and multivariately by cumulative logistic regression models controlling for age, gender, years of education, obesity, hypertension, diabetes, and dyslipidemia. RESULTS: Serum DHA levels decreased with increasing age (p = 0.04). Higher global cognitive function was associated with higher levels of serum EPA (p = 0.03) and DHA + EPA (p = 0.03) after controlling for confounders. CONCLUSIONS: Higher serum EPA and DHA + EPA levels were independently associated with better scores on global cognitive function among the oldest old, free from dementia. Longitudinal follow-up studies are warranted.

Impact of multiple risk factor clustering on the elevation of blood pressure.

A family history of hypertension, obesity, diabetes mellitus, hypercholesterolemia, and hypertriglyceridemia have all been associated with risk of hypertension. We retrospectively conducted a longitudinal study in a large screened cohort to explore the effect of the clustering of these five risk factors on the elevation of blood pressure (BP) in normotensive subjects at baseline. The study group comprised 4,857 normotensive subjects not treated with antihypertensive drugs (systolic BP < 140 mmHg, diastolic BP < 90 mmHg, 3,111 men and 1,746 women) who were followed up from 1997 to 1999. By 1999, 360 subjects had BP at the hypertensive level (systolic BP > or = 140 mmHg or diastolic BP > or = 90 mmHg). The incidence of subjects whose BP became hypertensive was 37 per 1,000 person-years. After adjusting for age, sex, systolic BP and other clinical factors, multiple logistic analysis showed that the relative risk of BP elevation was 1.49 (95% Cl: 1.09 to 2.05) in subjects with one risk factor; 1.65 (95% Cl: 1.15 to 2.27) in those with two risk factors; 1.42 (95% Cl: 0.91 to 2.32) in those with three; and 4.86 (95% Cl: 2.58 to 9.16) in those with four or more when compared with subjects with no risk factors. Multiple regression analysis showed that the number of risk factors was positively correlated with an increase in BP from 1997 to 1999; the regression coefficient was 0.51 (p = 0.001) for increase in systolic BP, and 0.31 (p = 0.008) for increase in diastolic BP after adjusting for age and sex. In conclusion, clustering of risk factors significantly predicted the development of hypertension.

End-stage renal disease associated with familial Mediterranean fever.

A 39-year-old man had been suffering from periodic fever since childhood. He was started on hemodialysis due to secondary amyloidosis on December 2000. The patient was believed to have Familial Mediterranean fever (FMF) because of recurrent fever with peritonitis, arthritis and inflammatory changes and secondary amyloidosis in his kidneys, heart and colon. No other family member had recurrent fever. IL-6, TNF, and dopamine beta-hydroxylase were not increased in the febril phase. The patient was homozygous for the M6941 mutation. We report the first Japanese case of FMF associated with amyloidosis and confirmed by a gene mutation.

Effective treatment of congestive heart failure using adaptive servo-ventilation in an end-stage renal disease patient on hemodialysis.

A 61-year-old man who was being treated with hemodialysis (HD) for end-stage renal disease presented with symptoms of severe congestive heart failure (CHF). Removing excess intravascular fluid during HD was difficult due to the patient's chronic hypotension induced by severe left ventricular (LV) dysfunction. The application of adaptive servo-ventilation (ASV) increased the patient's cardiac output and blood pressure during HD, thus resulting in the effective removal of excess intravascular fluid. Therefore, ASV may be effective for treating CHF in HD patients with LV dysfunction and chronic hypotension.

Very old adults with better memory function have higher low-density lipoprotein cholesterol levels and lower triglyceride to high-density lipoprotein cholesterol ratios: KOCOA Project.

We cross-sectionally examined which lipid profiles are associated with better cognitive function among those aged 80 and older, free of dementia (Clinical Dementia Rating ≤0.5), functionally independent, and community-dwelling. Our cohort consisted of 193 participants from the "Keys to Optimal Cognitive Aging (KOCOA) Project", a prospective cohort study in Okinawa, Japan. Higher low-density lipoprotein cholesterol levels and lower triglyceride/high-density lipoprotein cholesterol (TG/HDL-C) ratios were associated with higher scores in memory performance after controlling for confounders. Further research is required to clarify the associations among LDL-C levels, TG/HDL-C ratios, and healthy cognitive aging.

Metabolic syndrome and cognitive decline among the oldest old in Okinawa: in search of a mechanism. The KOCOA Project.

The study aim was to test whether the metabolic syndrome or its components predicted cognitive decline among persons aged 80 years and older (mean 85.0 years). Participants were members of the "Keys to Optimal Cognitive Aging Project," a prospective cohort study in Okinawa, Japan. Metabolic syndrome was assessed at baseline. Cognitive functions were assessed annually for up to 3 years. One hundred and forty-eight participants completed at least one follow-up with 101 participating in all three assessments and 47 participating in two of the three assessments. The mean and median duration of follow-up were 1.8 and 2 years, respectively. Metabolic syndrome and four components were not associated with decline in global and executive cognitive functions. However, high glycosylated hemoglobin was associated with decline in memory function at the second follow-up. Our study supports accumulating evidence that the positive association between metabolic syndrome and cognitive function might not hold for the oldest old.

Autologous peripheral blood mononuclear cell implantation for patients with peripheral arterial disease improves limb ischemia.

BACKGROUND: Implantation of bone marrow mononuclear cells, including endothelial progenitor cells, into ischemic limbs has been shown to improve collateral vessel formation. In the present study the safety and feasibility of autologous peripheral blood mononuclear cells (PBMNCs) implantation after granulocyte-colony stimulating factor (G-CSF)-induced mobilization was investigated in patients with severe peripheral arterial disease. METHODS AND RESULTS: Six cases were enrolled: 5 of thromboangitis obliterans and 1 of arteriosclerosis obliterans. Following administration of G-CSF (10 microg . kg(-1) . day(-1)), PBMNCs were harvested and injected intramuscularly (5 legs and 1 arm) for 2 days for the patients with ischemia of the legs. No serious adverse events related to G-CSF administration, harvest or implantation were observed during this study period. Improvement in the ankle - brachial pressure index (ABI: >0.1) was seen in 4 patients at 4 weeks and ischemic ulcers improved in 3 of 3 patients. The mean maximum walking distance significantly increased from 203 m to 559 m (p=0.031) at 4 weeks and was sustained for 24 weeks. Significant improvement was seen in physiological functioning subscale of Short Form-36. CONCLUSION: Implantation of PBMNCs collected after G-CSF administration could be an alternative to therapeutic angioplasty in patients with severe peripheral arterial disease.

Analysis of drug prescription in chronic haemodialysis patients.

BACKGROUND: Information concerning medication use in Asian haemodialysis patients is sparse. We surveyed prescribed medications and examined the relation between the number of medications and mortality and clinical characteristics in chronic haemodialysis patients, in Okinawa, Japan. METHODS: We conducted a cross-sectional multicentre survey in August 1999 and patients were observed during 13 months of follow up. RESULTS: The clinical demographics of 850 chronic haemodialysis patients in seven dialysis units were obtained. Compared with the mean number of medications prescribed in ambulatory patients treated in general practice reported from Ministry of Health and Welfare of Japan (2.7 (n=20 716)), the mean number medications in haemodialysis patients was larger (7.2 (n=850)). The three most prescribed drug types in haemodialysis patients were those related to calcium and phosphate metabolism (88%), antihypertensive agents (71%), and erythropoietin (60%). Among the 850 patients, 38 died during the 13-month follow-up period. The number of medications was positively associated with mortality after adjusting for age, sex, and other clinical factors: the hazard ratio was 1.14 (95% confidence interval 1.03-1.26, P=0.007). A multiple linear regression analysis using the number of medications as a dependent factor and sex and other clinical characteristics as independent factors revealed that male sex (P=0.04), diabetes mellitus (P<0.0001), and duplication of drugs (P<0.0001) were positively correlated with the number of medications. CONCLUSIONS: Multiple drug use was observed in haemodialysis patients. The number of prescribed drugs was a significant predictor of short-term mortality. Male sex, diabetes mellitus, and duplication of drugs were correlated with increases in the number of medications.

Evidence for elevated pulse pressure in patients on chronic hemodialysis: a case-control study.

BACKGROUND: Few analyses have compared pulse pressure (PP) values in hemodialysis patients with healthy individuals, and they have provided only limited data. We retrospectively examined PP in a large cohort of hemodialysis patients and healthy control subjects. METHODS: The relationships of systolic blood pressure (SBP), diastolic blood pressure (DBP), and PP to mean arterial pressure (MAP) levels were investigated in 234 chronic hemodialysis patients and in 682 control subjects matched for age, sex, diabetes mellitus, and body mass index. RESULTS: In both control and patients, PP was positively correlated with MAP, and the two regression lines were parallel (beta of control subjects = 0.52; beta of hemodialysis patients = 0.57, P = 0.48). According to the regression line, at any MAP level, the PP in hemodialysis patients was significantly higher than that in control subjects: the mean PP difference between control and patients was 19.2 mm Hg (95% CI, 17.2 to 21.1 mm Hg, P < 0.0001). When the relationships between MAP and SBP and that between MAP and DBP were analyzed, the regression lines were also parallel. However, at any MAP level, SBP was higher and DBP was lower in hemodialysis patients than control subjects; the mean SBP difference was 12.8 mm Hg (95% CI, 11.5 to 14.1 mm Hg, P < 0.0001) and mean DBP difference was 6.4 mm Hg (95% CI, 5.7 to 7.0 mm Hg, P < 0.0001). CONCLUSIONS: At any MAP level, hemodialysis patients had a higher SBP, lower DBP, and higher PP values than those control subjects with a normal renal function who were matched for age, sex, diabetes mellitus, and body mass index. Further study is needed to determine whether preventing or reducing an elevated PP improves the prognosis for hemodialysis patients.

Functional characterization of a trafficking-defective HCN4 mutation, D553N, associated with cardiac arrhythmia.

Hyperpolarization-activated cyclic nucleotide-gated channel 4 gene HCN4 is a pacemaker channel that plays a key role in automaticity of sinus node in the heart, and an HCN4 mutation was reported in a patient with sinus node dysfunction. Expression of HCN4 in the heart is, however, not confined to the sinus node cells but is found in other tissues, including cells of the conduction system. On the other hand, mutations in another cardiac ion channel gene, SCN5A, also cause sinus node dysfunction as well as other cardiac arrhythmias, including long QT syndrome, Brugada syndrome, idiopathic ventricular fibrillation, and progressive cardiac conduction disturbance. These observations imply that HCN4 abnormalities may be involved in the pathogenesis of various arrhythmias, similar to the SCN5A mutations. In this study, we analyzed patients suffering from sinus node dysfunction, progressive cardiac conduction disease, and idiopathic ventricular fibrillation for mutations in HCN4. A missense mutation, D553N, was found in a patient with sinus node dysfunction who showed recurrent syncope, QT prolongation in electrocardiogram, and polymorphic ventricular tachycardia, torsade de pointes. In vitro functional study of the D553N mutation showed a reduced membranous expression associated with decreased If currents because of a trafficking defect of the HCN4 channel in a dominant-negative manner. These data suggest that the loss of function of HCN4 is associated with sinus nodal dysfunction and that a consequence of pacemaker channel abnormality might underlie clinical features of QT prolongation and polymorphic ventricular tachycardia developed under certain conditions.