Gamma-Ray Observation of the Cygnus Region in the 100-TeV Energy Region.

We report observations of gamma-ray emissions with energies in the 100-TeV energy region from the Cygnus region in our Galaxy. Two sources are significantly detected in the directions of the Cygnus OB1 and OB2 associations. Based on their positional coincidences, we associate one with a pulsar PSR J2032+4127 and the other mainly with a pulsar wind nebula PWN G75.2+0.1, with the pulsar moving away from its original birthplace situated around the centroid of the observed gamma-ray emission. This work would stimulate further studies of particle acceleration mechanisms at these gamma-ray sources.

First Detection of sub-PeV Diffuse Gamma Rays from the Galactic Disk: Evidence for Ubiquitous Galactic Cosmic Rays beyond PeV Energies.

We report, for the first time, the long-awaited detection of diffuse gamma rays with energies between 100 TeV and 1 PeV in the Galactic disk. Particularly, all gamma rays above 398 TeV are observed apart from known TeV gamma-ray sources and compatible with expectations from the hadronic emission scenario in which gamma rays originate from the decay of π^{0}'s produced through the interaction of protons with the interstellar medium in the Galaxy. This is strong evidence that cosmic rays are accelerated beyond PeV energies in our Galaxy and spread over the Galactic disk.

First Detection of Photons with Energy beyond 100 TeV from an Astrophysical Source.

We report on the highest energy photons from the Crab Nebula observed by the Tibet air shower array with the underground water-Cherenkov-type muon detector array. Based on the criterion of a muon number measured in an air shower, we successfully suppress 99.92% of the cosmic-ray background events with energies E>100 TeV. As a result, we observed 24 photonlike events with E>100 TeV against 5.5 background events, which corresponds to a 5.6σ statistical significance. This is the first detection of photons with E>100 TeV from an astrophysical source.

Evaluation of the Interplanetary Magnetic Field Strength Using the Cosmic-Ray Shadow of the Sun.

We analyze the Sun's shadow observed with the Tibet-III air shower array and find that the shadow's center deviates northward (southward) from the optical solar disk center in the "away" ("toward") interplanetary magnetic field (IMF) sector. By comparing with numerical simulations based on the solar magnetic field model, we find that the average IMF strength in the away (toward) sector is 1.54±0.21_{stat}±0.20_{syst} (1.62±0.15_{stat}±0.22_{syst}) times larger than the model prediction. These demonstrate that the observed Sun's shadow is a useful tool for the quantitative evaluation of the average solar magnetic field.

TTF-1/NKX2-1 binds to DDB1 and confers replication stress resistance to lung adenocarcinomas.

TTF-1, also known as NKX2-1, is a transcription factor that has indispensable roles in both lung development and physiology. We and others have reported that TTF-1 frequently exhibits high expression with increased copy number in lung adenocarcinomas, and also has a role as a lineage-survival oncogene through transcriptional activation of crucial target genes including ROR1 and LMO3. In the present study, we employed a global proteomic search for proteins that interact with TTF-1 in order to provide a more comprehensive picture of this still enigmatic lineage-survival oncogene. Our results unexpectedly revealed a function independent of its transcriptional activity, as TTF-1 was found to interact with DDB1 and block its binding to CHK1, which in turn attenuated ubiquitylation and subsequent degradation of CHK1. Furthermore, TTF-1 overexpression conferred resistance to cellular conditions under DNA replication stress (RS) and prevented an increase in consequential DNA double-strand breaks, as reflected by attenuated induction of pCHK2 and γH2AX. Our findings suggest that the novel non-transcriptional function of TTF-1 identified in this study may contribute to lung adenocarcinoma development by conferring tolerance to DNA RS, which is known to be inherently elicited by activation of various oncogenes.

Probe of the solar magnetic field using the "cosmic-ray shadow" of the sun.

We report on a clear solar-cycle variation of the Sun's shadow in the 10 TeV cosmic-ray flux observed by the Tibet air shower array during a full solar cycle from 1996 to 2009. In order to clarify the physical implications of the observed solar cycle variation, we develop numerical simulations of the Sun's shadow, using the potential field source surface model and the current sheet source surface (CSSS) model for the coronal magnetic field. We find that the intensity deficit in the simulated Sun's shadow is very sensitive to the coronal magnetic field structure, and the observed variation of the Sun's shadow is better reproduced by the CSSS model. This is the first successful attempt to evaluate the coronal magnetic field models by using the Sun's shadow observed in the TeV cosmic-ray flux.

Intravenous immunoglobulin does not increase FcγRIIB expression levels on monocytes in children with immune thrombocytopenia.

Intravenous immunoglobulin (IVIG) produces a rapid and prolonged increase in the platelet counts of children with immune thrombocytopenia (ITP). The mechanism of IVIG efficacy in a murine model of ITP has been reported to operate through an IVIG-mediated increase in the expression of the inhibitory Fc receptor FcγRIIB(CD32B) on splenic macrophages. This investigation examined whether IVIG administration results in a similar increase in FcγRIIB expression on peripheral blood CD14(+) monocytes in 20 children with ITP. FcγRIIB expression on peripheral blood monocytes was measured by flow cytometry in ITP patients, before and after IVIG therapy, as well as in control subjects. Peripheral blood monocytes were labelled with fluorescent-specific antibodies. There were no significant differences in the absolute number of [corrected] CD14(+) CD32B(+) monocytes, and [corrected] the percentages of CD14(+) CD32B(+) cells in mononuclear cells or monocytes. [corrected]. We suggest that IVIG does not increase FcγRIIB expression in peripheral blood monocytes in children with ITP.

Long-term clinical effects of epalrestat, an aldose reductase inhibitor, on progression of diabetic neuropathy and other microvascular complications: multivariate epidemiological analysis based on patient background factors and severity of diabetic neuropathy.

AIMS: The goal of the study was to evaluate the efficacy of epalrestat, an aldose reductase inhibitor, on diabetic retinopathy and diabetic nephropathy, based on analysis of the results of the Aldose Reductase Inhibitor-Diabetes Complications Trial, a 3-year multicentre comparative clinical trial of conventional therapy (control group) and epalrestat therapy (epalrestat group) in Japanese patients with mild diabetic neuropathy. METHODS: The subjects of the study were patients enrolled in the Aldose Reductase Inhibitor-Diabetes Complications Trial for whom data for major patient characteristics, severity of diabetic neuropathy at the end of the study and time-courses of diabetic retinopathy and diabetic nephropathy were available (57 and 52 patients from the control and epalrestat groups, respectively). Progression of diabetic retinopathy/nephropathy (a primary endpoint) in relation to major patient characteristics, severity of diabetic neuropathy at the end of the study (assessed from the mean of z-scores in four neurological function tests) and epalrestat treatment were analysed using univariate analysis and multiple logistic regression analysis. RESULTS: Progression of diabetic retinopathy/nephropathy was significantly inhibited in the epalrestat group compared with the control group (odds ratio = 0.323, P = 0.014) and was dependent on the severity of diabetic neuropathy at the end of the study (odds ratio = 2.131, P = 0.025). CONCLUSIONS: Epalrestat prevented progression of diabetic neuropathy and retinopathy/nephropathy. The effect on diabetic retinopathy/nephropathy may have occurred indirectly because of the prevention of progression of diabetic neuropathy, in addition to the inhibitory action of epalrestat on aldose reductase.

Endothelial and inflammatory markers in relation to progression of ischaemic cerebral small-vessel disease and cognitive impairment: a 6-year longitudinal study in patients with type 2 diabetes mellitus.

BACKGROUND: Progression of silent brain infarctions (SBIs) and white-matter lesions (WMLs) seen on brain MRI is associated with an increased risk of cognitive impairment, but their relation to endothelial and inflammatory markers is unknown in type 2 diabetes mellitus. METHODS: In 190 type 2 diabetic outpatients (mean age 62.7 years), the authors related baseline levels of soluble intercellular adhesion molecule-1 (sICAM-1) and high-sensitivity C-reactive protein (hs-CRP) to subsequent brain MRI findings and cognitive function. The authors assessed incident SBIs and changes in periventricular and subcortical WMLs (PVWMLs and SCWMLs) on MRI performed at baseline and 3 and 6 years. Neuropsychological tests were administered to 83 patients older than 65 years at 6 years. This present study represents an extension of the authors' previously published study. RESULTS: SBIs were observed in 46 patients (24.2%), PVWMLs in 93 (48.9%) and SCWMLs in 87 (45.8%) on baseline MRI. After adjustment for age, gender, hypertension, duration of diabetes, baseline MRI findings and medication use, the relative odds associated with a 1SD increase in sICAM-1 levels at baseline were 1.67 (95% CI 1.02 to 3.05) for SBI progression and 2.17 (95% CI 1.29 to 3.62) for PVWML progression at 6 years. In contrast, baseline hs-CRP levels were significantly associated with SBI progression only at 3 years. Significant trends were observed between quartiles of sICAM-1 at baseline and scores in Digit Symbol substitution (p for trend=0.01). CONCLUSIONS: The findings suggest that higher sICAM-1 levels are associated with SBI and PVWML progression, and may predict impairment in psychomotor function in type 2 diabetes.

Effects of deconditioning on the initial ventilatory and circulatory responses at the onset of exercise in man.

In order to elucidate the effects of deconditioning (inactivity) on the ventilatory and circulatory responses at the onset of exercise within 20 s, we initiated head-down bed rest and unilateral lower limb suspension experiments, and measured these responses to dynamic voluntary leg exercise and passive movements. Initial ventilatory and heart rate responses to voluntary exercise were attenuated after bed rest but showed no change after suspension or during passive movements, suggesting the minimal role of peripheral neural reflex.

The adaptive responses in several mediators linked with hypertrophy and atrophy of skeletal muscle after lower limb unloading in humans.

AIM: To determine the adaptive changes in several molecules regulating muscle hypertrophy and atrophy after unloading, we examined whether unilateral lower limb suspension changes the mRNA and protein levels of SRF-linked (RhoA, RhoGDI, STARS and SRF), myostatin-linked (myostatin, Smad2, Smad3 and FLRG) and Foxo-linked (P-Akt, Foxo1, Foxo3a and Atrogin-1) mediators. METHODS: A single lower limb of each of eight healthy men was suspended for 20 days. Biopsy specimens were obtained from the vastus lateralis muscle pre- and post-suspension. RESULTS: The volume of the vastus lateralis muscle was significantly decreased after unloading. The amount of RhoA, RhoGDI or SRF protein in the muscle was not significantly changed post-suspension. An RT-PCR semiquantitative analysis showed increased levels of myostatin mRNA but not Smad2, Smad3 or FLRG mRNA. Unloading did not elicit significant changes in the amount of p-Smad3 or myostatin protein in the muscle. The amount of p-Akt protein was markedly reduced in the unloaded muscle. Lower limb SUSPENSION DID NOT INFLUENCE THE EXPRESSION PATTERN OF FOXO1, FOXO3A OR ATROGIN-1. CONCLUSION: Unloading inducing a mild degree of muscle atrophy may decrease p-Akt and increase myostatin but not SRF-linked mediators.

Effect of intensive interval training during unloading on muscle deoxygenation kinetics.

The present study investigated the effects of intensive interval training during 20-day of unloading on local muscle oxygenation kinetics evaluated by near infrared spectroscopy technique (NIRS). Eleven adult men completed 20-day unloading and were divided into two groups; the control (CON) group and training (TR) group. The TR group engaged in exercise training sessions that consisted of one-legged submaximal cycle exercise using the unloaded leg at 60 approximately 80% of VO(2peak) with intermittent rest periods, 25 min/day every other day. All subjects performed isometric knee extension exercise at 50% of their maximum voluntary contraction force before and after unloading. NIRS Delta[deoxy-Hb/Mb] signal was recorded from m. vastus lateralis and was fitted to an exponential equation in order to determine the kinetics parameters. The time constant (tau) of the % Delta[deoxy-Hb/Mb] was unchanged in the TR group, while it significantly increased in the CON group after unloading (pre, 5.0+/-1.0; post, 7.4+/-1.0 s). It is concluded that 20-day unloading increased the tau, suggesting deterioration of capacity for oxidative phosphorylation and oxygen utilization in a skeletal muscle. Additionally, the preservation of tau in the TR group suggested that intensive interval training could have an impact on the maintenance of muscle oxidative metabolism during unloading.

Stratified analyses for selecting appropriate target patients with diabetic peripheral neuropathy for long-term treatment with an aldose reductase inhibitor, epalrestat.

AIMS: The long-term efficacy of epalrestat, an aldose reductase inhibitor, in improving subjective symptoms and nerve function was comprehensively assessed to identify patients with diabetic peripheral neuropathy who responded to epalrestat treatment. METHODS: Stratified analyses were conducted on data from patients in the Aldose Reductase Inhibitor-Diabetes Complications Trial (ADCT). The ADCT included patients with diabetic peripheral neuropathy, median motor nerve conduction velocity > or = 40 m/s and with glycated haemoglobin (HbA(1c)) < or = 9.0%. Longitudinal data on HbA(1c) and subjective symptoms of the patients for 3 years were analysed (epalrestat n = 231, control subjects n = 273). Stratified analyses based on background variables (glycaemic control, grades of retinopathy or proteinuria) were performed to examine the relationship between subjective symptoms and nerve function. Multiple logistic regression analyses were conducted. RESULTS: Stratified subgroup analyses revealed significantly better efficacy of epalrestat in patients with good glycaemic control and less severe diabetic complications. In the control group, no improvement in nerve function was seen regardless of whether symptomatic benefit was obtained. In the epalrestat group, nerve function deteriorated less or improved in patients whose symptoms improved. The odds ratio of the efficacy of epalrestat vs. control subjects was approximately 2 : 1 (4 : 1 in patients with HbA(1c) < or = 7.0%). CONCLUSION: Our results suggest that epalrestat, an aldose reductase inhibitor, will provide a clinically significant means of preventing and treating diabetic neuropathy if used in appropriate patients.

Influence of work rate on dynamics of O2 uptake under hypoxic conditions in humans.

AIM: It was the purpose of the investigation to determine whether an altered work rate could influence the oxygen uptake (V.O(2)) and heart rate (HR) dynamics at hypoxia and normoxia. METHODS: Ten males performed a cycle exercise with 2 repetitions of 6 min each at a constant work load while breathing one of two inspiratory O(2) fractions (FIO(2)): 0.12 (moderate hypoxia) and 0.21 (normoxia). Each test began with unloaded pedaling. This was followed by three constant loads, which were 40%, 60%, and 80% of the subject's gas exchange threshold (GET) in hypoxia (F(I)O(2) = 0.12), with the 80% GET load repeated under normoxia (room air). V.O(2) was measured on a breath-by-breath basis and beat-by-beat HR via ECG, and the half time (t1/2) of each parameter was established, following interpolation data. RESULTS: There were no remarkable differences in t1/2 V.O(2) dynamics among the 40%, 60% and 80% GET; however, the differences became significant at hypoxia compared with normoxia. The HR dynamics were significantly faster in normoxia compared with hypoxia, independent of work rates. During steady-state exercise, the alterations in HR and cardiac output (Q) using the acetylene rebreathing method depended on increases in the work rate, and a significantly increase in at 80% GET was observed when compared with normoxia. Increases of stroke volume (SV) were unaffected by altered work rates and inspired O(2) concentrations. The arteriovenous oxygen difference (Ca-vO(2)) at a steady-state of exercise increased proportionally with the work rate under hypoxia, and a much greater Ca-vO(2) was observed during normoxic exercise than under hypoxia. CONCLUSION: These results seem to suggest that in humans, O(2) uptake dynamics are affected by lower O(2), not by changing work rates at hypoxia, to which the interaction between lower O(2) utilization in exercising muscles and hypoxic-induced greater blood flow can be attributed.

Intermittent hypoxia does not increase exercise ventilation at simulated moderate altitude.

Recent human studies have shown that resting hypoxic ventilatory response (HVR), which is an index of ventilatory chemosensitivity to hypoxia, increased after short-term intermittent hypoxia at rest. In addition, intermittent hypoxia leads to increases in ventilation and arterial oxygen saturation (SaO (2)) during exercise at simulated high altitude, with the increase in ventilation correlated to the change in HVR. However, no study has been made to clarify the relationship between ventilatory chemosensitivity and the exercise ventilation at moderate altitude following intermittent hypoxia during a resting state. The purpose of the present study, therefore, was to elucidate whether intermittent hypoxia at rest induces the increase in ventilation during exercise at moderate altitude that is accompanied by an increase in hypoxic chemosensitivity. Eighteen trained male runners were assigned to three groups, i.e., the first hypoxic group (H-1 group, n = 6), the second hypoxic group (H-2 group, n = 6), and a control group (C group, n = 6). The hypoxic tent system was utilized for intermittent hypoxia, and the oxygen levels in the tent were maintained at 15.5 +/- 0.1 % (simulated 2500 m altitude) for the H-1 group and 12.3 +/- 0.2 % (simulated 4300 m altitude) for the H-2 group. The H-1 and H-2 groups spent 1 hour per day in the hypoxic tent for 1 week. Maximal and submaximal exercise tests while breathing 15.5 +/- 0.01 % O (2) (simulated altitude of 2500 m) were performed before and after intermittent hypoxia. Resting HVR was also determined in each subject using a progressive isocapnic hypoxic method. In the H-2 group, HVR increased significantly (p < 0.05) following intermittent hypoxia, while no change in HVR was found in the H-1 or C group. Neither ventilation nor SaO (2) during maximal and submaximal exercise at a simulated altitude of 2500 m were changed in either group after 1 hour per day for 1 week of intermittent hypoxia. These results suggest that the change in resting hypoxic chemosensitivity after short-term intermittent hypoxia does not affect ventilation during exercise at moderate altitude.

Anisotropy and corotation of galactic cosmic rays.

The intensity of Galactic cosmic rays is nearly isotropic because of the influence of magnetic fields in the Milky Way. Here, we present two-dimensional high-precision anisotropy measurement for energies from a few to several hundred teraelectronvolts (TeV), using the large data sample of the Tibet Air Shower Arrays. Besides revealing finer details of the known anisotropies, a new component of Galactic cosmic ray anisotropy in sidereal time is uncovered around the Cygnus region direction. For cosmic-ray energies up to a few hundred TeV, all components of anisotropies fade away, showing a corotation of Galactic cosmic rays with the local Galactic magnetic environment. These results have broad implications for a comprehensive understanding of cosmic rays, supernovae, magnetic fields, and heliospheric and Galactic dynamic environments.

Depressive mood is independently related to stroke and cardiovascular events in a community.

By means of a multivariate Cox model, we investigated the predictive value of a depressive mood on vascular disease risk in middle-aged community-dwelling people. In 224 people (88 men and 136 women; mean age: 56.8 +/- 11.2 years) of U town, Hokkaido (latitude: 43.45 degrees N, longitude: 141.85 degrees E), a chronoecological health watch was started in April 2001. Consultations were repeated every 3 months. Results at the November 30, 2004 follow-up are presented herein. 7-day/24-h blood pressure (BP) and heart rate (HR) monitoring started on a Thursday, with readings taken at 30-min intervals between 07:00 h and 22:00 h and at 60-min intervals between 22:00 h and 07:00 h. Data stored in the memory of the monitor (TM-2430-15, A and D company, Japan) were retrieved and analyzed on a personal computer with a commercial software for this device. Subjects were asked to answer a self-administered questionnaire inquiring about 15 items of a depression scale, at the start of study and again after 1-2 years. Subjects with a score higher by at least two points at the second versus first screening were classified as having a depressive mood. The other subjects served as the control group. The mean follow-up time was 1064 days, during which four subjects suffered an adverse vascular outcome (myocardial infarction: one man and one woman; stroke: two men). Among the variables used in the Cox proportional hazard models, a depressive mood, assessed by the Geriatric Depression Scale (GDS), as well as the MESOR of diastolic (D) BP (DBP-MESOR) and the circadian amplitude of systolic (S) BP (SBP-Amplitude) showed a statistically significant association with the occurrence of adverse vascular outcomes. The GDS score during the second but not during the first session was statistically significantly associated with the adverse vascular outcome. In univariate analyses, the relative risk (RR) of developing outcomes was predicted by a three-point increase in the GDS scale (RR = 3.088, 95% CI: 1.375-6.935, P = 0.0063). Increases of 5 mmHg in DBP-MESOR and of 3 mmHg in SBP-Amplitude were associated with RRs of 2.143 (95% CI: 1.232-3.727, P = 0.0070) and 0.700 (95% CI: 0.495-0.989, P = 0.0430), respectively. In multivariate analyses, when both the second GDS score and the DBP-MESOR were used as continuous variables in the same model, GDS remained statistically significantly associated with the occurrence of cardiovascular death. After adjustment for DBP-MESOR, a three-point increase in GDS score was associated with a RR of 2.172 (95% CI: 1.123-4.200). Monday endpoints of the 7-day profile showed a statistically significant association with adverse vascular outcomes. A 5 mmHg increase in DBP on Monday was associated with a RR of 1.576 (95% CI: 1.011-2.457, P = 0.0446). The main result of the present study is that in middle-aged community-dwelling people, a depressive mood predicted the occurrence of vascular diseases beyond the prediction provided by age, gender, ABP, lifestyle and environmental conditions, as assessed by means of a multivariate Cox model. A depressive mood, especially enhanced for 1-2 years, was associated with adverse vascular outcomes. Results herein suggest the clinical importance of repetitive assessments of a depressive mood and the need to take sufficient care of depressed subjects. Another result herein is that circadian and circaseptan characteristics of BP variability measured 7-day/24-h predicted the occurrence of vascular disease beyond the prediction provided by age, gender, depressive mood and lifestyle, as assessed by means of a multivariate Cox model. Earlier, we showed that the morning surge in BP on Mondays was statistically significantly higher compared with other weekdays. Although a direct association between the Monday surge in BP and cardiovascular events could not be demonstrated herein, it is possible that the BP surge on Monday mornings may also trigger cardiovascular events. We have shown that depressive people exhibit a more prominent circaseptan variation in SBP, DBP and the double product (DP) compared to non-depressed subjects. In view of the strong relation between depression and adverse cardiac events, studies should be done to ascertain that depression is properly diagnosed and treated. Chronodiagnosis and chronotherapy can reduce an elevated blood pressure and improve the altered variability in BP and HR, thus reducing the incidence of adverse cardiac events. This recommendation stands at the basis of chronomics, focusing on prehabilitation in preference to rehabilitation, as a public service offered in several Japanese towns.

Arterial stiffness independently predicts cardiovascular events in an elderly community -- Longitudinal Investigation for the Longevity and Aging in Hokkaido County (LILAC) study.

We investigated the predictive value of arterial stiffness to assess cardiovascular risk in elderly community-dwelling people by means of a multivariate Cox model. In 298 people older than 75 years (120 men and 178 women, average age: 79.6 years), brachial-ankle pulse wave velocity (baPWV) was measured between the right arm and ankle in a supine position. The LILAC study started on July 25, 2000, consultation was repeated yearly, and the last follow-up ended on November 30, 2004. During this follow-up span of 1227 days, there were nine cardiovascular deaths, the cause of death being myocardial infarction for two men and three women or stroke for two men and two women. In Cox proportional hazard models, baPWV as well as age, Mini-Mental State Examination (MMSE), Hasegawa Dementia Scale Revised (HDSR) and the low-frequency/high-frequency (LF/HF) ratio showed a statistically significant association with the occurrence of cardiovascular death. A two-point increase in MMSE and HDSR score significantly protected against cardiovascular death, the relative risk (RR) being 0.776 (P = 0.0369) and 0.753 (P = 0.0029), respectively. The LF/HF ratio also was significant (P = 0.025), but the other indices of HRV were not. After adjustment for age and HDSR, a 200 cm/s increase in baPWV was associated with a 30.2% increase in risk (RR = 1.302, 95% CI: 1.110-1.525), and a 500 cm/s increase in baPWV with a 93.3% increase in risk (RR = 1.933, 95% CI: 1.300-2.874, P = 0.0011), whereas the LF/HF ratio was no longer associated with a statistically significant increase in cardiovascular mortality. In elderly community-dwelling people, arterial stiffness measured by means of baPWV predicted the occurrence of cardiovascular death beyond the prediction provided by age, gender, blood pressure and cognitive functions. baPWV should be added to the cardiovascular assessment in various clinical settings, including field medical surveys and preventive screening. The early detection of risk by chronomics allows the timely institution of prophylactic measures, thereby shifting the focus from rehabilitation to prehabilitation medicine, as a public service to several Japanese towns.

Fractal analysis of heart rate variability and mortality in elderly community-dwelling people -- Longitudinal Investigation for the Longevity and Aging in Hokkaido County (LILAC) study.

AIM: Fractal analysis of heart rate (HR) variability (HRV) has been used as a new approach to evaluate the risk of mortality in various patient groups. Aim of this study is to examine the prognostic power of detrended fluctuation analysis (DFA) and traditional time- and frequency-domain analyses of HR dynamics as predictors of mortality among elderly people in a community. METHODS: We examined 298 people older than 75 years (average age: 79.6 years) and 1-h ambulatory ECG was monitored. During the last 10 min, deep respiration (6-s expiration and 4-s inspiration) was repeated six times in a supine position. Time-domain and frequency-domain measures were determined by the maximum entropy method. Scaling exponents of short-term (<11 beats, alpha 1) and longer-term (>11 beats, alpha 2) were determined by the DFA method. Six estimates, obtained from 10-min segments, were averaged to derive mean values for the entire recording span. These average values were denoted Alpha 1 and Alpha 2, estimates obtained during the first 10-min segment Alpha 1 S and Alpha 2 S, and those during the last 10-min segment Alpha 1E and Alpha 2E, respectively. The LILAC study started on July 25, 2000 and ended on November 30, 2004. We used Cox regression analysis to calculate relative risk (RR) and 95% confidence interval (CI) for all-cause mortality. Significance was considered at a value of P < 0.05. RESULTS: Gender, age and Alpha 2E showed a statistically significant association with all-cause mortality. In univariate analyses, gender was significantly associated with all-cause mortality, being associated with a RR of 3.59 (P = 0.00136). Age also significantly predicted all-cause mortality and a 5-year increase in age was associated with a RR of 1.49 (P = 0.01809). The RR of developing all-cause mortality predicted by a 0.2-unit increase in Alpha 2E was 0.58 (P = 0.00390). Other indices of fractal analysis of HRV did not have predictive value. In multivariate analyses, when both Alpha 2E and gender were used as continuous variables in the same model, Alpha 2E remained significantly associated with the occurrence of all-cause mortality (P = 0.02999). After adjustment for both gender and age, a 0.2-unit increase in Alpha 2E was associated with a RR of 0.61 (95% CI: 0.42-0.90, p = 0.01151). CONCLUSION: An intermediate-term fractal-like scaling exponent of RR intervals was a better predictor of death than the traditional measures of HR variability in elderly community-dwelling people. It is noteworthy that the longer-term (alpha 2) rather than the short-term fractal component (alpha 1) showed predictive value for all-cause mortality, which suggests that an increase in the randomness of intermediate-term HR behavior may be a specific marker of neurohumoral and sympathetic activation and therefore may also be associated with an increased risk of mortality.

Common carotid intima-media thickness is predictive of all-cause and cardiovascular mortality in elderly community-dwelling people: Longitudinal Investigation for the Longevity and Aging in Hokkaido County (LILAC) study.

Several cohort studies have examined the association of carotid intima-media thickness (IMT) with the risk of stroke or myocardial infarction in apparently healthy persons. We investigated the predictive value of IMT of cardiovascular mortality in elderly community-dwelling people, beyond the prediction provided by age and MMSE, assessed by means of a multivariate Cox model. Carotid IMT and plaque were evaluated bilaterally with ultrasonography in 298 people older than 75 years (120 men and 178 women, average age: 79.6 years). The LILAC study started on July 25, 2000. Consultations were repeated every year. The follow-up ended on November 30, 2004. During the mean follow-up span of 1152 days, 30 subjects (21 men and nine women) died. Nine deaths were attributable to cardiovascular causes (myocardial infarction: two men and three women; stroke: two men and two women). The age- and MMSE-adjusted relative risk (RR) and 95% confidence interval (95% CI) of developing all-cause mortality was assessed. A 0.3 mm increase in left IMT was associated with a RR of predicted 1.647 (1.075-2.524), and a similar increase in right IMT with a RR of 3.327 (1.429-7.746). For cardiovascular mortality, the corresponding RR values were 2.351 (1.029-5.372) and 2.890 (1.059-7.891), respectively. Carotid IMT assessed by ultrasonography is positively associated with an increased risk of all-cause and cardiovascular death in elderly community-dwelling people.