Attention Performance Decline After Age 40 in Clinically Normal Community Dwellers: Evidence from a 10-Year Follow-Up of the Yakumo Study

Age-related changes in attention ability and differences by gender in the rates of change from middle age were investigated. Digit Cancellation Test (D-CAT1 and D-CAT3 conditions, which involve low and high cognitive load, respectively) scores and individually calculated decline rates (DRs) in 10-year follow-up among four age groups (40s, 50s, 60s, and 70s) were examined. Performance in both D-CAT conditions declined with increasing age from the 50s to the 70s, whereas there was no difference between the 40s and 50s, and a gender difference (with the women showing an advantage) was demonstrated in the 40s and 50s groups on the D-CAT3. In the D-CAT1 condition, the DR remained stable from the 40s to the 50s but increased from the 50s and to the 60s and then remained the same. In the D-CAT3 condition, the DR became larger even after the 70s. The DRs did not differ between men and women from middle age onward. Although DRs showed no gender difference, D-CAT performance showed a gender difference, with men being about 20% less capable by the age of 40. We suggest that data showing concrete declines in attentional performance after middle age may be used to reduce accidents encountered in the daily life of older adults.

486Serum levels of miRNA-221 and -222 may be predictive biomarkers for cognitive decline

Background

Although dementia is a huge problem in public health, no fundamental biomarker has been established to detect cognitive decline at the early stage. MicroRNAs (miRNAs) regulate gene expression, and are associated with the development of various diseases.

Methods

The subjects of this prospective study were 162 (75 men, 87 women) residents who attended a health examination in Yakumo town in Hokkaido, in 2012 and re-attended at least once while 2013 to 2015. Serum samples were collected in 2012 and serum miRNA were measured by qRT-PCR. We used a short version of the Mini-Mental State Examination (SMMSE) to screen cognitive function, and calculated the change in SMMSE score per year. We calculated odds ratios (ORs) and 95% confidence intervals (CIs) of serum miRNA levels for cognitive decline (decrease of greater than 0.5 points per year) using the lowest tertile group of miRNAs as the reference by logistic regression analysis.

Results

The mean age and change in SMMSE score of the subjects was 63.9±9.6 years and -0.03±1.19 points. Odds ratios (ORs) for cognitive decline were significantly higher in the highest tertile of serum miR-221 (OR = 3.24, 95%CI=1.20-8.72) and miR-222 (OR = 4.01, 95%CI=1.36-11.80) even if confounding factors were adjusted.

Conclusions

High serum levels of miR-221 and -222 were significantly associated with cognitive decline.

Key messages

High serum levels of miR-221 and -222 may be potential candidate biomarkers for prediction of cognitive decline.

Measurement of the absolute gamma emission intensities from the decay of Th-229 in equilibrium with progeny

There are few long-lived radionuclides yielding high intensity gamma-rays emission with energies ranging from 100 keV to 500 keV that can be applied as radioactive gamma standard to calibrate HPGe detectors. Furthermore, this energy range represents the main emitted energies of the majority of radionuclides used in nuclear medicine. The Brazilian National Laboratory for Ionizing Radiation Metrology (LNMRI/IRD/CNEN) has attempted to identify radionuclides that have the potential to be used as a calibration source due to their long half-life as well as their emission spectrum. Hence, LNMRI promotes standardization studies of gamma-emitting radionuclides that meet these criteria on order to disseminate them. Thorium-229, with its well-defined energies and relatively high intensities, is one such candidate radionuclide for the energy and full-energy peak efficiency calibration of high-purity gamma spectrometers. Thorium-229 was standardized by the method of 4παβ(LS)-γ(NaI(Tl)) live timed anticoincidence counting. The emission intensities of gamma-rays associated with the decay of ²²⁹Th have been determined by HPGe gamma ray spectrometry with accuracy and precision. The results are in agreement with current literature data.

Dissociation in Age-Related Developmental Trajectories Between Phonetic Fluency and Semantic Fluency Tests: Analysis of Longitudinal Data From the Yakumo Study

Possible age-related differences in Phonemic Fluency Test (PFT) and Semantic Fluency Test (SFT) performance were examined by using longitudinal data of healthy older adults. The performance trajectories of 81 older adults in the 2 tests were analyzed for 11 years, from 65 to 75 years of age, via individually calculated linear regression coefficients. The results indicated that the PFT and SFT performance showed an age-related decline. However, the declining slope of the SFT was steeper than that of the PFT performance. These findings correspond with those of previous cross-sectional studies and suggest a future need to examine neurobiological substrates underlying the two domains of verbal fluency abilities.

Metabolic Syndrome and Cognitive Function: Cross-Sectional Study on Community-Dwelling Non-Demented Older Adults in Japan

AIM

This is a cross-sectional study of relation between metabolic syndrome and cognitive function in community-dwelling non-demented older adults in Japan. We examine the effect of metabolic syndrome and its components on global cognitive function. We also aim to clarify differences of specific cognitive domains between the subjects with and without metabolic syndrome.

METHODS

We studied 2150 subjects aged between 60 and 90 years whose scores on mini mental state examination (MMSE) were over 23 points. We analyzed difference in MMSE scores between the subjects with and without metabolic syndrome. Logistic regression analysis was performed with MMSE score as the dependent variable and metabolic syndrome components as the independent variable adjusted with age. We also examined differences in attention, logical memory, and verbal and category fluency between the subjects with and without metabolic syndrome.

RESULTS

MMSE scores were not significantly different between subjects with and without metabolic syndrome. In logistic regression analysis, the score of MMSE was significantly negatively associated with triglycerides in males and significantly negatively associated with abdominal circumference in females. Subjects with metabolic syndrome showed significantly lower performance of attention tasks compared to subjects without metabolic syndrome.

CONCLUSIONS

Our results suggest that in community-dwelling non-demented Japanese older adults, attention but not global cognitive function may be impaired by metabolic syndrome. Inverted association between some components of metabolic syndrome and global cognitive function indicate necessity of further studies on the relation between undernutrition and cognitive function.

Associations of serum microRNA-20a, -27a, and -103a with cognitive function in a Japanese population: The Yakumo study

OBJECTIVES

MicroRNAs (miRNAs) dysregulate gene expression by binding to target messenger RNAs, and play an important role in the pathogenesis of various diseases, including cancers, cardiovascular diseases and diabetes. Circulating miRNAs have increasingly been recognized as biomarkers for detecting and diagnosing those diseases. Few studies have investigated the association of circulating miRNA with the early stages of cognitive impairment, such as mild cognitive impairment, in the general population. The purpose of this study was to examine the association between cognitive function and several serum miRNAs levels related to amyloid precursor protein (APP) proteolysis in a Japanese general population who had never been diagnosed with dementia.

METHODS

We conducted a cross-sectional study of 337 Japanese subjects (144 men, 193 women) who attended a health examination. The short form of the Mini-Mental State Examination (SMMSE) was used to assess cognitive function. Serum levels of 6 miRNAs (let-7d, miR-17, miR-20a, miR-27a, miR-34a, miR-103a) were measured by quantitative real-time polymerase chain reaction.

RESULTS

Multivariable-adjusted odds ratios (ORs) for lower SMMSE score (SMMSE score < 28) were significantly increased in the lowest tertile of serum miR-20a (OR, 2.08; 95% confidence interval (CI), 1.09-4.04) and miR-103a (OR, 1.91; 95%CI, 1.00-3.69) compared to the highest tertile. Moreover, serum levels of miR-20a, -27a, and -103a were linearly and positively associated with SMMSE scores after adjustment for confounding factors.

CONCLUSION

Low serum levels of miR-20a, -27a, and -103a are independently associated with cognitive impairment.

Relation between cognitive and cerebello-thalamo-cortical functions in healthy elderly people: Evidence from the Yakumo Study

Relations between cognitive and cerebello-thalamo-cortical functions in healthy elderly people (65-75 years old) were examined by longitudinal behavioral data. Based on the individually calculated cognitive decline ratio in D-CAT (digit cancelation test) and in LMT (Logical Memory Test) during the period of 11 years, participants were classified into the Decline and the Maintain groups and group differences in the postural tremor measures (Quotient of Romberg) were compared. Significant group differences were shown in the postural tremor measure in D-CAT that reflects prefrontal function, but it was not the case in LMT. These results strengthened our previous findings that suggest a strong relation between the cerebello-thalamo-cortical function and the prefrontal cortex function using behavioral measures. Findings provide evidence that to strengthen postural function such as physical exercise is effective for slowing cognitive decline with age.

Relations Between Exercise Habit and Visual Attentional Ability in Older Adult Community Dwellers: Evidences From the Yakumo Study

Objective:

The relation between mild everyday exercise and cognitive ability in healthy older people was examined using cohort study database.

Methods:

Individually calculated linear regression coefficients in digit cancelation task performances for 11 years age from 65 to 75 years were compared between mild exercise habit holders and non-holders.

Results:

Exercise habit holders showed significantly smaller age-related decline than non-holders, irrespective of task difficulty.

Discussion:

The results suggested that even mild exercise habit for long years possesses benefits on sustaining cognitive function in older people as well as the physical activities such as programmed in a sport gym. It also becomes clear that it is difficult for ordinary older adult to continue exercising habits for many years. Therefore, more substantial ways are required for local health officials to advertise the effectiveness of mild exercise habits and to devise the necessary work to become a habit.

Results of an international comparison of activity measurements of 68Ge

An international key comparison, identifier CCRI(II)-K2.Ge-68, has been performed. The National Institute of Standards and Technology (NIST) served as the pilot laboratory, distributing aliquots of a 68Ge/68Ga solution. Results for the activity concentration, CA, of 68Ge at a reference date of 12h00 UTC 14 November 2014 were submitted by 17 laboratories, encompassing many variants of coincidence methods and liquid-scintillation counting methods. The first use of 4π(Cherenkov)β-γ coincidence and anticoincidence methods in an international comparison is reported. One participant reported results by secondary methods only. Two results, both utilizing pure liquid-scintillation methods, were identified as outliers. Evaluation using the Power-Moderated Mean method results in a proposed Comparison Reference Value (CRV) of 621.7(11)kBqg-1, based on 14 results. The degrees of equivalence and their associated uncertainties are evaluated for each participant. Several participants submitted 3.6mL ampoules to the BIPM to link the comparison to the International Reference System (SIR) which may lead to the evaluation of a Key Comparison Reference Value and associated degrees of equivalence.

Severity of Premenstrual Symptoms Predicted by Second to Fourth Digit Ratio

Women of reproductive age often experience a variety of unpleasant symptoms prior to the onset of menstruation. While genetics may influence the variability of these symptoms and their severity among women, the exact causes remain unknown. We hypothesized that symptom variability originates from differences in the embryonic environment and thus development caused by variation in exposure to sex hormones. We measured the second to fourth digit ratios (2D:4D) in 402 young women and investigated the potential relationships of this ratio premenstrual symptoms using a generalized linear model. We found that two models (one with two predictors such as both hands' digit ratios and the other with the difference between the two digit ratios, Dr-l) were significantly different from the constant model as assessed by chi-square test. The right digit ratio and Dr-l were negatively related to the symptom scores, and the left digit ratio was related to the scores. When premenstrual symptoms were classified into eight categories, five categories, including pain, concentration, autonomic reaction, negative affect, and control were associated with the digit ratios and Dr-l. Behavioral changes and water retention were not predicted by them. Arousal was predicted by Dr-l. The right 2D:4D is thought to be determined by the balance of testosterone and estrogen levels during early embryogenesis and is not affected by postpartum levels of sex hormones, while the left 2D:4D might be affected by the other prenatal environmental factors. We conclude that the embryonic environment, including the relative concentration of sex hormones an embryo is exposed to, is associated with the severity of premenstrual symptoms once menarche is reached.

Age and gender differences in the influences of eNOS T-786C polymorphism on arteriosclerotic parameters in general population in Japan

OBJECTIVE

The influence of T-786C polymorphism in the promoter region of endothelial nitric oxide synthase (eNOS) on arteriosclerotic parameters by age and gender were examined.

METHODS

Brachial-ankle pulse wave velocity (baPWV), heart-rate adjusted augmentation index (AIx@75), pulse pressure (PP) and albumin-creatinine ratio (ACR) were assessed as arteriosclerotic parameters in addition to non-high-density lipoprotein cholesterol (non-HDL-C) to HDL-C (non-HDL-C/HDL-C) ratio in 1499 participants. T-786C polymorphism (rs2070744) was screened using a TaqMan allelic discrimination assay. Analyses of covariance were carried.

RESULTS

Women with the non-C allele showed significantly lower AIx@75 in participants aged <65 years and baPWV in participants aged ≥65 years than those with C allele. In contrast, men with the non-C allele showed significantly higher PP in participants aged <65 years, and higher ACR and non-HDL-C/HDL-C ratio in participants aged ≥65 years. In men on cholesterol-lowering medication, the non-C allele carriers showed significantly higher non-HDL-C compared to those in the C allele carriers.

CONCLUSIONS

eNOS T-786C polymorphism is significantly associated with arteriosclerotic parameters accompanied with age and gender differences, possibly involving antioxidative and/or endothelial signaling other than inflammatory signaling.

Traceability from governmental producers of radiopharmaceuticals in measuring (18)F in Brazil

Since the inception of its proficiency test program to evaluate radionuclide measurement in hospitals and clinics, the National Metrology Laboratory of Ionizing Radiation-LNMRI, that represents Brazilian National Metrology Institute (NMI) for ionizing radiation has expanded its measurement and calibration capability. Requirements from the National Health Surveillance Agency from Ministry of Health (ANVISA), to producers of radiopharmaceuticals provided an opportunity to improve the full traceability chain to the highest level. Fluorodeoxyglucose (FDG-(18)F) is the only radiopharmaceutical simultaneously produced by all Brazilian radiopharmaceutical production centers (RPCs). By running this proficiency test, LNMRI began to provide them with the required traceability. For evaluation, the ratio of RPC to reference value results and ISO/IEC17043:2010 criteria were used. The reference value established as calibration factor on the secondary standard ionization chamber was obtained from three absolute measurements systems, and routinely confirmed in each round of proficiency test by CIEMAT/NIST liquid scintillation counting. The γ-emitting impurities were checked using a High-Purity Germanium (HPGe) detector. The results show that Brazilian RPCs are in accordance with (accuracy within ±10%) the Brazilian standard for evaluation of measurements with radionuclide calibrators (CNEN NN 3.05., 2013). Nevertheless, the RPCs should improve the methodology of uncertainty estimates, essential when using the statistical criteria of ISO/IEC 17043 standard, in addition to improving accuracy to levels consistent with their position in the national traceability chain.

Calibration of ionization chamber for ¹⁸F and ⁶⁸Ga

In order to maintain the results of primary activity standardizations carried out in 2011 the LNMRI has determined the calibration factors for a pressurized 4π-ionization chamber for the nuclides (18)F and (68)Ga. This ionization chamber is coupled to a 6517A Keithley electrometer which is controlled by a homemade LabVIEW program. This paper will describe the main issues related to the calibration of an ionization chamber system for positron emitters and short half-life radionuclides such as timing, current measurement, background, decay, and (226)Ra check source measurements.

Abstract 363: Better Control of Blood Pressure in Midlife was Associated with Cognitive Function in Old Age: The Minabe Study in Japan

Several studies show that hypertension in midlife is also related to cognitive impairment in old age. However, the associations between blood pressure and cognitive functions have been inconclusive. In this study, we examined this association in the sexagenarian and the septuagenarian separately to test our hypothesis that different risk factors were related to cognitive decline in each generation respectively. Participants were 1476 community-dwelling persons without dementia (708 men and 768 women). Resting systolic and diastolic blood pressures were measured in the seated position using an automated sphygmomanometer (HEM-907; Omron). The cognitive functions were measured by means of logical memory test, D-CAT (digit cancellation test; neuropsychological test for attention) and verbal fluency test. We asked participants about their use of antihypertensive drug and collected their data about blood pressure measured at a health examination conducted ten years ago. We constructed a series of multiple linear regression models to examine the association of blood pressure with each cognitive function. Separate analyses were conducted for each combination of predictor (SBP, DBP, past SBP, past DBP, and use of antihypertensive drug) and dependent value (logical memory test, D-CAT, and verbal fluency test). Regression models included the following covariates: age, education, gender, and body mass index. Results indicated the following two points: (1) Higher levels of past DBP (β = -.121, p < .05) was associated with decline in logical memory test and higher level of past SBP (β = -.127, p < .05) was associated with decline in verbal fluency test in the sexagenarian, (2) The use of antihypertensive drug was associated with decline in D-CAT (β = -.194, p < .001) and verbal fluency test (β = -.196, p < .05) in the septuagenarian. Our findings suggest that high blood pressure in the past decade is risk factor for cognitive decline in the sexagenarian but is not risk factor in the septuagenarian. The treatment of high blood pressure in midlife is important for the maintenance of cognitive functions. Early control of high blood pressure might reduce the risk of cognitive impairment in old age.

Standardization of 65Zn by sum-peak method

A commercial solution of (65)Zn was standardized by the sum peak-method using a planar HPGe detector. The activity results were compared with measurements made with a well type 4πγ ionization chamber, which is traceable to BIPM.RI (II)-K2.Zn-65 key-comparison performed in 2002. The sum-peak value was 42.79 kBq/g and the ionization chamber value was 42.74 kBq/g both at the reference date. The uncertainty obtained in the sum peak standardization was 0.25% (k=1), and in the ionization chamber was 0.85% (k=1). The results showed that sum-peak method can be used in (65)Zn standardization and this method is easier, simpler and more practical than others methods.

Standardization of (166m)Ho and 243Am/239Np by live-timed anti-coincidence counting with extending dead time

The National Laboratory for Metrology of Ionizing Radiation (LNMRI)/Brazil acquired (166m)Ho and (243)Am/(239)Np solutions from commercial suppliers in order to realize primary standardization and therefore reducing the associated uncertainties. The method used in the standardization was the live-timed 4πβ(LS)-γ(ΝaI(Tl)) anticoincidence counting. The live-timed anticoincidence system is operated since 2006 in LNMRI and is composed of two MTR2 modules donated by Laboratoire National Henri Becquerel (LNE-LNHB)/France. The data acquisition system uses a homemade LabView program and an Excel file for calculus. These systems have been used for primary standardization at LNMRI for many radionuclides and recently took part in the (124)Sb and (177)Lu International Key Comparisons with good performance.

57Co half-life determination

The National Laboratory for Metrology of Ionizing Radiation (LNMRI)/Brazil participated in the last (57)Co activity measurement comparison organized by IAEA, in 2008. This was made in order to realize primary standardization of this radionuclide and to reduce the measuring uncertainties in the laboratory. Additionally, one sample with 2.6g was taken from the IAEA master solution of (57)Co and was prepared to be used in the measurement of the radionuclide's half-life in an ionization chamber system. The (57)Co half-life was measured to be 271.82 (17) days.

Primary activity standardization of (57)Co by sum-peak method

The sum-peak method was applied to standardize a (57)Co solution within the framework of an international comparison organized by International Atomic Energy Agency, in 2008, aimed toward international traceability of activity measurements. A planar germanium detector was used with the sources placed on top of the detector for activity determination measurements. An analytical expression for accidental summing correction was derived and the effect of the germanium characteristic KX-ray escape peak of 112keV was taken into account. The standard uncertainty associated to the activity concentration value was 0.37% and the result was compared with other measurement methods.

Standardization of 67Ga, 51Cr and 55Fe by live-timed anti-coincidence counting with extending dead time

In this work, the activity standardization of 51Cr, 55Fe and 67Ga by live-timed anti-coincidence counting with extending dead time is described. The difficulties of the method, the uncertainties of the results of the measurements and the comparison of these results with others measurement methods are discussed.

Standardization and decay data determinations of 125I, 54Mn and 203Hg

The absolute 4pi-betagamma coincidence counting has been used to measure the activity concentrations of 54Mn and 203Hg, and the Sum-Peak method was used for 125I. 54Mn and 125I radionuclides have been part of international key-comparisons coordinated by the Bureau International des Poids et Measures (BIPM) in 2003/2004, while 203Hg is part of the traceability programme of the National Laboratory for Ionizing Radiation Metrology (LNMRI)/Brazil. Three different detectors were used for the Sum-Peak method: 3''x3'' NaI(Tl) and 5''x5'' well NaI(Tl) scintillation detectors and a planar germanium detector. Direct measurements were made of the photon emission probabilities of the 35.5-, 834.8- and 279.2-keV gamma-rays of 125I, 54Mn and 203Hg to give values of (0.0667+/-0.0014), (0.9997+/-0.0055) and (0.8161+/-0.0005), respectively. The half-lives of 203Hg and 54Mn were also determined by means of a 4pigamma ionization chamber (203Hg) and by the reference source method using a HPGe detector (54Mn) to give values of (46.639+/-0.023) days and (312.1+/-0.9) days, respectively.

Performance of dose calibrators in Brazilian hospitals for activity measurements

In order to obtain information on the accuracy of activity measurements in Brazilian hospitals, several intercomparison exercises have been organized since 1998. The first exercise consisted of two intercomparison runs of 131I and 99mTc and had the participation of 21 hospitals localized in Rio de Janeiro city and surroundings. The second, with 131I (47 hospitals) and 123I (12 hospitals), had the participation of hospitals localized in the whole country. The results were analyzed under the statistical point of view and conformity to the norms of Regulatory Authority. These results have shown that such exercises are necessary to improve the quality of the measurements and to identify those instruments that are producing incorrect values.

Absolute measurements of photon emission probabilities of 169Yb

A solution of 169Yb was absolutely standardized by the 4pi(EC,X)-gamma coincidence counting method and the result was used to obtain direct measurements of gamma-ray emission probabilities with a coaxial HPGe detector. The empirical relation proposed by (Vaño, F., Gonzalez, L., Gaeta R., Gonzalez, J.A., 1975. An empirical function which relates the slope of the Ge efficiency curves and the active volume Nucl. Instr. Meth. 123, 573) was tested using the gamma spectral response above 200 keV. The half-life of 169Yb was also measured with a 4pi gamma ionization chamber.

Intercomparison of 131I and 99mTc activity measurements in Brazilian nuclear medicine services

This work outlines the quality assurance program for the activity measurements of the most used radionuclides at Brazilian Nuclear Medicine Services (NMS). The program aims to guarantee that the patient is given the correct prescribed amount of activity in diagnostic or therapeutic applications. This accurate administration depends upon proper use and calibration of the activity meters by the NMS. Underestimation of administered activity in diagnostic practices could delay correct diagnosis disturbing the value of the investigation. On the other hand, the overestimation would be worse, mainly in therapeutic applications, because an unnecessarily high absorbed dose would be delivered to the patient. The preliminary results of intercomparison for 131I and 99mTc showed that many activity meters used at NMS's present problems giving results up to 41% greater than the reference values determined at the National Metrology Laboratory for Ionizing Radiation (LNMRI) which is recognized as the Brazilian authorized metrology laboratory for ionizing radiation. These results have demonstrated that the NMS should improve the accuracy of the activity measurements of the radionuclides administered to the patients and establish the traceability to the national standards of measurements. These standards are based on a pressurized well-type ionization chamber installed at LNMRI and calibrated with reference sources standardized by absolute methods. The protocol of the intercomparison and recommendations made in order to minimize errors in measuring procedures are described and results are discussed.

How Japanese students characterize information from web-sites

How 352 Japanese university students regard web-site information was investigated by two kinds of survey. Application of correspondence analysis and cluster analysis to the questionnaire responses to the web-site advertisement showed students regarded a web-site as a new alien medium which is different from current media. Students regarded web-sites as simply complicated, intellectual, and impermanent, or not memorable. Students got precise information from web-sites but they did not use it in making decisions to purchase goods.