Faster Rate Of Decline Research Articles

ORAL HEALTH AND COGNITION AMONG U.S. COMMUNITY-DWELLING CHINESE OLDER ADULTS

The purpose of this study was to examine the associations between tooth/gums symptoms and changes in cognitive function. We used data from the Population Study of Chinese Elderly in Chicago, a two-wave epidemiological study of 2,713 U.S. Chinese older adults. We selected self-reported oral (tooth and gum) symptoms as independent variables. We measured global function and three cognitive domains: episodic memory, executive function and working memory. Adjusting for sociodemographic and health-related characteristics, participants who reported having teeth symptoms at baseline, experienced their global cognition and episodic memory decrease (both p<0.05). Participants who reported having teeth symptoms at baseline, experienced a faster rate of decline in global cognition for every additional year. However, this effect disappeared once we adjusted for all covariates. We found no significant relationship between baseline gum symptoms and change of cognitive function. Future research directions, clinical and policy implications will be discussed.

Radiographic lung volumes predict progression to COPD in smokers with preserved spirometry in SPIROMICS.

The characteristics that predict progression to overt chronic obstructive pulmonary disease (COPD) in smokers without spirometric airflow obstruction are not clearly defined.We conducted a post hoc analysis of 849 current and former smokers (≥20 pack-years) with preserved spirometry from the Subpopulations and Intermediate Outcome Measures in COPD Study (SPIROMICS) cohort who had baseline computed tomography (CT) scans of lungs and serial spirometry. We examined whether CT-derived lung volumes representing air trapping could predict adverse respiratory outcomes and more rapid decline in spirometry to overt COPD using mixed-effect linear modelling.Among these subjects with normal forced expiratory volume in 1 s (FEV1) to forced vital capacity (FVC) ratio, CT-measured residual volume (RVCT) to total lung capacity (TLCCT) ratio varied widely, from 21% to 59%. Over 2.5±0.7 years of follow-up, subjects with higher RVCT/TLCCT had a greater differential rate of decline in FEV1/FVC; those in the upper RVCT/TLCCT tertile had a 0.66% (95% CI 0.06%-1.27%) faster rate of decline per year compared with those in the lower tertile (p=0.015) regardless of demographics, baseline spirometry, respiratory symptoms score, smoking status (former versus current) or smoking burden (pack-years). Accordingly, subjects with higher RVCT/TLCCT were more likely to develop spirometric COPD (OR 5.7 (95% CI 2.4-13.2) in upper versus lower RVCT/TLCCT tertile; p<0.001). Other CT indices of air trapping showed similar patterns of association with lung function decline; however, when all CT indices of air trapping, emphysema, and airway disease were included in the same model, only RVCT/TLCCT retained its significance.Increased air trapping based on radiographic lung volumes predicts accelerated spirometry decline and progression to COPD in smokers without obstruction.

Association of Cortical β-Amyloid Protein in the Absence of Insoluble Deposits With Alzheimer Disease

β-Amyloid deposits are a pathologic hallmark of Alzheimer disease (AD). However, the extent to which cortical β-amyloid protein in the absence of insoluble deposits is associated with classic features of AD appear to be unknown. To examine the associations of cortical β-amyloid protein in the absence of insoluble deposits with cognitive decline, neurofibrillary tangles, other age-associated neuropathologic conditions, and APOE. This analysis combines data from 2 community-based clinicopathologic cohort studies of aging. The Religious Orders Study started in 1994, and the Rush Memory and Aging Project started in 1997. Both studies are ongoing. Participants without known dementia were enrolled and agreed to annual clinical evaluations and brain donation after death. Primary analyses focused on individuals without β-amyloid deposits. Data analyses occurred in mid-September 2018. β-Amyloid protein abundance was measured by targeted proteomics using selected reaction monitoring. β-Amyloid deposits were detected using immunohistochemistry. Other neuropathologic indices were quantified via uniform structured evaluation. Linear mixed models were used to examine the association of β-amyloid protein with cognitive decline. Regression models examined the protein associations with neuropathologic outcomes and the APOE genotype. By mid-September 2018, 3575 older persons were enrolled, and 1559 had died and undergone brain autopsy. Proteomic data were collected in 1208 individuals, and 5 with missing cognitive scores were excluded. Of the remaining 1203, primary analyses focused on 148 individuals (12.3%) without β-amyloid deposits. In this group, the mean (SD) age at death was 87.0 (7.0) years, and 84 individuals (56.8%) were women. In the absence of β-amyloid deposits, we did not observe an association of β-amyloid protein with decline in episodic memory, but the protein was associated with faster rates of decline in processing speed (mean [SE] change, -0.014 [0.005]; P = .008) and visuospatial abilities (mean [SE] change, -0.013 [0.005]; P = .006). We did not observe protein association with paired helical filament tau tangle density. The protein was associated with amyloid angiopathy (odds ratio, 1.38 [95% CI, 1.15-1.67]; P < .001) but no other brain pathology. The associations with cognitive decline were unchanged after controlling for amyloid angiopathy. Neither APOE ε4 nor a polygenic Alzheimer risk score was associated with β-amyloid protein. Cortical β-amyloid protein was associated with faster cognitive decline in the absence of β-amyloid deposits, which supports the role of cortical soluble β-amyloid as a neurotoxic agent in aging. The lack of protein association with paired helical filament tau tangles, episodic memory decline, or strong genetic drivers of deposited β-amyloid suggests an underlying neuropathologic change that may differ from that of AD.

Cytokines are associated with longitudinal changes in cognitive performance among urban adults

BackgroundChronic systemic inflammation has been positively associated with structural and functional brain changes representing early markers of Alzheimer’s Disease (AD) and cognitive decline. The current study examined associations between systemic inflammation and cognitive performance among African-Americans and Whites urban adults. MethodsParticipants were selected from the Healthy Aging in Neighborhoods of Diversity across the Life Span (HANDLS) study (2004–2013, baseline age: 30–64 y, mean ± SD follow-up time of 4.64 ± 0.93 y, N = 189–222, k = 1.5–1.7 observations/participant). Cytokines known to be positively linked to AD incidence among others were tested against cross-sectional and longitudinal cognitive function, stratifying by age group (≤50 y vs. >50 y), sex and race. A series of mixed-effects regression models were conducted, adjusting for key confounders. ResultsAmong key findings, IL1β was positively associated with a faster rate of decline on a test of executive functioning, among older adults (age >50 y, γ11 = +2.49 ± 0.89, p = 0.005), while in the total population, IL-6 was linked to a faster decline on a test of verbal memory (γ11 = −0.011 ± 0.004, p = 0.009). Among younger participants, IL-18 was linked to a poorer performance on a test of attention at baseline (age ≤50 y, γ01 = −0.007 ± 0.0025, p = 0.004) though a slower rate of decline with higher IL-18 was detected for a test of psychomotor speed in older adults (age >50 y, γ11 = +0.0010 ± 0.0004, p = 0.008). Finally, among Whites, unlike among African-Americans, IL-6 was associated with a better baseline performance on two tests of verbal and working memory. ConclusionsCytokines were shown to be associated with age-related cognitive decline among middle-aged and older urban adults in an age group and race-specific manner. Further longitudinal studies are needed to replicate our findings and mediation through relevant biological and psychosocial factors need to be studied as well.

Amyloid PET and cognitive decline in cognitively normal individuals: the SCIENCe project

We examined the relationships between amyloid-β PET and concurrent and longitudinal cognitive performance in 107 cognitively normal individuals with subjective cognitive decline (age: 64 ± 8 years, 44% female, Mini-Mental State Examination score 29 ± 1). All underwent 90-minute dynamic [18F]florbetapir PET scanning and longitudinal neuropsychological tests with a mean follow-up of 3.4 ± 3.0 years. Receptor parametric mapping was used to calculate [18F]florbetapir binding potential (BPND), and we performed linear mixed models to assess the relationships between global [18F]florbetapir BPND and neuropsychological performance. Higher [18F]florbetapir BPND was related to lower concurrent Mini-Mental State Examination (β ± SE: −1.69 ± 0.63 p < 0.01) and to steeper rate of decline on tasks capturing memory (Rey Auditory Verbal Learning Task immediate [β ± SE −1.81 ± 0.81, p < 0.05] and delayed recall [β ± SE −1.19 ± 0.34, p < 0.01]), attention/executive functions (Stroop II [color] [β ± SE −0.02 ± 0.01, p < 0.05], Stroop III [word-color] [β ± SE −0.03 ± 0.02, p < 0.05]), and language (category fluency [β ± SE −0.04 ± 0.01, p < 0.01]). These findings suggest that higher amyloid-β load in cognitively normal individuals with subjective cognitive decline from a memory clinic is associated with lower concurrent global cognition and with faster rate of decline in a variety of cognitive domains.

An increased rate of longitudinal cognitive decline is observed in Parkinson's disease patients with low CSF Aß42 and an APOE ε4 allele

ObjectiveLow concentrations of cerebrospinal fluid (CSF) amyloid-beta (Aβ-42) are associated with increased risk of cognitive decline in Parkinson's disease (PD). We sought to determine whether APOE genotype modifies the rate of cognitive decline in PD patients with low CSF Aβ-42 compared to patients with normal levels. MethodsThe Parkinson's Progression Markers Initiative is a longitudinal, ongoing study of de novo PD participants, which includes APOE genotyping, CSF Aβ-42 determinations, and neuropsychological assessments. We used linear mixed effects models in three PD groups (PD participants with low CSF Aβ at baseline, PD participants with normal CSF Aβ, and both groups combined). Having at least one copy of the APOE ɛ4 allele, time, and the interaction of APOE ɛ4 and time were predictor variables for cognitive change, adjusting for age, gender and education. Results423 de novo PD participants were followed up to 5 years with annual cognitive assessments. 103 participants had low baseline CSF Aβ-42 (39 APOE ε4+, 64 APOE ε4-). Compared to participants with normal CSF Aβ-42, those with low CSF Aβ-42 declined faster on most cognitive tests. Within the low CSF Aβ-42 group, APOE ε4+ participants had faster rates of decline on the Montreal Cognitive Assessment (primary outcome; 0.57 points annual decline, p = .005; 5-year standardized change of 1.2) and the Symbol Digit Modalities Test (1.4 points annual decline, p = .002; 5-year standardized change of 0.72). DiscussionPD patients with low CSF Aβ-42 and APOE ε4+ showed a higher rate of cognitive decline early in the disease. Tests of global cognition (Montreal Cognitive Assessment) and processing speed (Symbol Digit Modalities Test) were the most sensitive to early cognitive decline. Results suggest that CSF Aβ-42 and APOE ε4 might interact to promote early cognitive changes in PD patients.

Associations of lifestyle and vascular risk factors with Alzheimer’s brain biomarker changes during middle age: a 3-year longitudinal study in the broader New York City area

ObjectiveTo investigate the associations between lifestyle and vascular risk factors and changes in Alzheimer’s disease (AD) biomarkers (beta-amyloid load via 11C-PiB PET, glucose metabolism via 18F-FDG PET and neurodegeneration via...

The EMIF-AD Multimodal Biomarker Discovery study: design, methods and cohort characteristics

BackgroundThere is an urgent need for novel, noninvasive biomarkers to diagnose Alzheimer’s disease (AD) in the predementia stages and to predict the rate of decline. Therefore, we set up the European Medical Information Framework for Alzheimer’s Disease Multimodal Biomarker Discovery (EMIF-AD MBD) study. In this report we describe the design of the study, the methods used and the characteristics of the participants.MethodsParticipants were selected from existing prospective multicenter and single-center European studies. Inclusion criteria were having normal cognition (NC) or a diagnosis of mild cognitive impairment (MCI) or AD-type dementia at baseline, age above 50 years, known amyloid-beta (Aβ) status, availability of cognitive test results and at least two of the following materials: plasma, DNA, magnetic resonance imaging (MRI) or cerebrospinal fluid (CSF). Targeted and untargeted metabolomic and proteomic analyses were performed in plasma, and targeted and untargeted proteomics were performed in CSF. Genome-wide SNP genotyping, next-generation sequencing and methylation profiling were conducted in DNA. Visual rating and volumetric measures were assessed on MRI. Baseline characteristics were analyzed using ANOVA or chi-square, rate of decline analyzed by linear mixed modeling.ResultsWe included 1221 individuals (NC n = 492, MCI n = 527, AD-type dementia n = 202) with a mean age of 67.9 (SD 8.3) years. The percentage Aβ+ was 26% in the NC, 58% in the MCI, and 87% in the AD-type dementia groups. Plasma samples were available for 1189 (97%) subjects, DNA samples for 929 (76%) subjects, MRI scans for 862 (71%) subjects and CSF samples for 767 (63%) subjects. For 759 (62%) individuals, clinical follow-up data were available. In each diagnostic group, the APOE ε4 allele was more frequent amongst Aβ+ individuals (p < 0.001). Only in MCI was there a difference in baseline Mini Mental State Examination (MMSE) score between the A groups (p < 0.001). Aβ+ had a faster rate of decline on the MMSE during follow-up in the NC (p < 0.001) and MCI (p < 0.001) groups.ConclusionsThe characteristics of this large cohort of elderly subjects at various cognitive stages confirm the central roles of Aβ and APOE ε4 in AD pathogenesis. The results of the multimodal analyses will provide new insights into underlying mechanisms and facilitate the discovery of new diagnostic and prognostic AD biomarkers. All researchers can apply for access to the EMIF-AD MBD data by submitting a research proposal via the EMIF-AD Catalog.

Apolipoprotein-E (Apoe) \u03b54 and cognitive decline over the adult life course

We tested the association between APOE-ε4 and processing speed and memory between ages 43 and 69 in a population-based birth cohort. Analyses of processing speed (using a timed letter search task) and episodic memory (a 15-item word learning test) were conducted at ages 43, 53, 60–64 and 69 years using linear and multivariable regression, adjusting for gender and childhood cognition. Linear mixed models, with random intercepts and slopes, were conducted to test the association between APOE and the rate of decline in these cognitive scores from age 43 to 69. Model fit was assessed with the Bayesian Information Criterion. A cross-sectional association between APOE-ε4 and memory scores was detected at age 69 for both heterozygotes and homozygotes (β = −0.68 and β = −1.38, respectively, p = 0.03) with stronger associations in homozygotes; no associations were observed before this age. Homozygous carriers of APOE-ε4 had a faster rate of decline in memory between ages 43 and 69, when compared to non-carriers, after adjusting for gender and childhood cognition (β = −0.05, p = 0.04). There were no cross-sectional or longitudinal associations between APOE-ε4 and processing speed. We conclude that APOE-ε4 is associated with a subtly faster rate of memory decline from midlife to early old age; this may be due to effects of APOE-ε4 becoming manifest around the latter stage of life. Continuing follow-up will determine what proportion of this increase will become clinically significant.

Measles, mumps, and rubella antibody patterns of persistence and rate of decline following the second dose of the MMR vaccine

BackgroundAntibodies to measles, mumps, and rubella decline 3% per year on average, and have a high degree of individual variation. Yet, individual variations and differences across antigens are not well understood. To better understand potential implications on individual and population susceptibility, we reanalyzed longitudinal data to identify patterns of seropositivity and persistence. MethodsChildren vaccinated with the second dose of measles, mumps, rubella vaccine (MMR2) at 4–6 years of age were followed up to 12 years post-vaccination. The rates of antibody decline were assessed using regression models, accounting for differences between and within subjects. ResultsMost of the 302 participants were seropositive throughout follow-up (96% measles, 88% mumps, 79% rubella). The rate of antibody decline was associated with MMR2 response and baseline titer for measles and age at first dose of MMR (MMR1) for rubella. No demographic or clinical factors were associated with mumps rate of decline. One month post-MMR2, geometric mean titer (GMT) to measles was high (3892 mIU/mL), but declined on average 9.7% per year among those with the same baseline titer and <2-fold increase post-MMR2. Subjects with ≥2-fold experienced a slower decline (≤7.4%). GMT to rubella was 149 one month post-MMR2, declining 2.6% and 5.9% per year among those who received MMR1 at 12–15 months and >15 months, respectively. GMT to mumps one month post-MMR2 was 151, declining 9.2% per year. Only 14% of subjects had the same persistence trends for all antigens. ConclusionsThe rate of antibody decay varied substantially among individuals and the 3 antigen groups. A fast rate of decline coupled with high variation was observed for mumps, yet no predictors were identified. Future research should focus on better understanding waning titers to mumps and its impacts on community protection and individual susceptibility, in light of recent outbreaks in vaccinated populations.

Effects of temperature and burial on seed germination and persistence of the restricted invasive Stevia ovata in northern Queensland

Stevia ovata Willd. is an invasive weed that has become naturalised in northern Queensland, Australia. To aid management of current infestations, this study evaluated seed germination under a range of constant (13−48°C) and alternating (11/7 to 52/42°C) temperature regimes and quantified the potential longevity of soil seed banks. The effect of different soil types, levels of pasture cover and burial depths on seed longevity was investigated in both the dry- and wet-tropics of North Queensland. Germination of S. ovata occurred under a wide range of both constant (13−39°C) and alternating day/night temperatures (16/12 to 52/42°C), but optimum conditions ranged between 24 and 27°C and 24/20 and 37/31°C respectively. As temperatures declined below the optimum, an increasing proportion of seeds went into a state of enforced dormancy. In contrast, higher than optimum temperatures caused a proportion of seeds to lose viability. Differential responses in seed longevity of S. ovata occurred between the two experimental sites. In the wet-tropics, seed viability was &lt;1% after 12 months and fully expired after 18 months, irrespective of burial depth. In the dry-tropics, seeds persisted for longer (nil viability after 24–42 months) and burial depth had a significant effect. Surface located seeds tended to exhibit a faster rate of decline in viability than seeds buried below ground. These findings have implications for the duration of control/eradication programs and also suggest that S. ovata has the potential to greatly expand its current distribution, particularly into cooler areas of Australia.

Measles, Mumps, and Rubella Antibody: Patterns of Persistence and Rate of Decline Following the Second Dose of the MMR Vaccine

BackgroundAntibodies to measles, mumps, and rubella decline an estimated average of 3% per year, and have a high degree of variation among individuals. Yet, this variation and differences in individual-level response to the 3 antigens are not well understood. To better understand potential implications on individual and population-level susceptibility, we reanalyzed existing longitudinal data to identify patterns of seropositivity and antibody persistence.MethodsWisconsin children given the second dose of measles, mumps, and rubella vaccine (MMR2) at age 4–6 years were followed up to 12 years postvaccination. The rate of antibody decline and factors associated with the rate of decline were assessed using regression models that accounted for differences between and among subjects.ResultsMost of the 302 participants were seropositive throughout follow-up (96% measles, 88% mumps, 79% rubella). The rate of antibody decline was associated with MMR2 response and baseline titer for measles and age at first dose of MMR (MMR1) for rubella. None of the demographic or clinical factors examined were associated with rate of decline for mumps. One month after MMR2, geometric mean titer (GMT) to measles was high (3892 mIU/mL), but declined on average 9.7% per year among subjects with the same baseline titer and <2-fold increase in antibody titer after MMR2. Subjects with ≥2-fold increase experienced a slower decline (≤7.4%). GMT to rubella was 149 IU/mL one month after MMR2 and declined 2.6% and 5.9% per year among those who received MMR1 at 12–15 months and >15 months, respectively. GMT to mumps one month after MMR2 was 151 and declined 9.2% per year. Only 14% of participants had the same trends in antibody persistence for all 3 antigens.ConclusionThe rate of antibody decay varied substantially among individuals and among the 3 antigens. Despite waning titers, measles and rubella antibody levels remained high 12 years post MMR2. However, a fast rate of decline and high degree of variation was observed for mumps, yet no predictors of the decline were identified. Future research should focus on better understanding waning antibody titers to mumps and its impact on community protection and individual susceptibility, in light of recent mumps outbreaks in vaccinated populations.Figure 1.MeaslesFigure 2.MumpsFigure 3.RubellaDisclosures All authors: No reported disclosures.

Bayesian Piecewise Linear Mixed Models With a Random Change Point: An Application to BMI Rebound in Childhood.

Background:Body mass index (BMI) rebound refers to the beginning of the second rise in BMI during childhood. Accurate estimation of an individual’s timing of BMI rebound is important because it is associated with health outcomes in later life.Methods:We estimated BMI trajectories for 6545 children from the Avon Longitudinal Study of Parents and Children. We used a novel Bayesian two-phase piecewise linear mixed model where the “change point” was an individual-level random effect corresponding to the individual-specific timing of BMI rebound. The model’s individual-level random effects (intercept, prechange slope, postchange slope, change point) were multivariate normally distributed with an unstructured variance–covariance matrix, thereby, allowing for correlation between all random effects.Results:Average age at BMI rebound (mean change point) was 6.5 (95% credible interval: 6.4 to 6.6) years. The standard deviation of the individual-specific timing of BMI rebound (random effects) was 2.0 years for females and 1.6 years for males. Correlation between the prechange slope and change point was 0.57, suggesting that faster rates of decline in BMI prior to rebound were associated with rebound occurring at an earlier age. Simulations showed that estimates from the model were less biased than those from models, assuming a common change point for all individuals or a nonlinear trajectory based on fractional polynomials.Conclusions:Our model flexibly estimated the individual-specific timing of BMI rebound, while retaining parameters that are meaningful and easy to interpret. It is applicable in any situation where one wishes to estimate a change-point process which varies between individuals.

Change of Cognitive Function in U.S. Chinese Older Adults: A Population-Based Study.

This study aims to assess cognitive change in a 2-year period among U.S. Chinese older adults and examine sociodemographic characteristics associated with the change. Data were from the Population Study of Chinese Elderly (PINE) in which 2,713 participants (aged 60 and older) received in-home interviews at both the baseline and 2-year follow-up. A battery of cognitive tests that assessed episodic memory, working memory, perceptual speed, and overall cognitive status were administered in both times. A composite global cognition was constructed using all tests. Mixed-effect regression was conducted. Older age was associated with worse baseline cognition (ie, in all cognitive abilities) and faster decline in global cognition, episodic memory, and perceptual speed-rates of decline increased by .006, .004, and .009 standard score units, respectively, for each year older. More education was associated with better baseline cognition, but each year of additional schooling increased rates of decline in global cognition and episodic memory by .004 and .012 standard score units, respectively. Men performed better than women in most cognitive abilities at baseline but had faster rates of decline in working memory. Higher income was associated with better cognition at baseline and reduced rates of decline in working memory. Findings suggest differences in the rates of cognitive change by age, sex, education, and income. Those in advancing age are vulnerable to cognitive decline. The effects of education and sex on baseline performance versus change suggest a role for life experiences in cognition.

Early childhood lung function is a stronger predictor of adolescent lung function in cystic fibrosis than early Pseudomonas aeruginosa infection.

ObjectivePseudomonas aeruginosa has been suggested as a major determinant of poor pulmonary outcomes in cystic fibrosis (CF), although other factors play a role. Our objective was to investigate the association of early childhood Pseudomonas infection on differences in lung function in adolescence with CF.MethodsTwo populations of subjects with CF were studied: from the Gene Modifier Study (GMS), 346 F508del homozygotes with severe vs. mild adolescent lung disease, and from the Colorado Newborn Screen Study (NBS) 172 subjects diagnosed with CF by newborn screening. Associations of Pseudomonas infection and lung function in early childhood with lung function in adolescence were investigated using multivariate linear regression analyses.ResultsAmong GMS subjects, those with severe adolescent lung disease had worse lung function in childhood (FEV1 25 percentage points lower) compared to subjects with mild adolescent lung disease, regardless of early childhood Pseudomonas status. Among NBS subjects, those with lowest adolescent lung function had significantly lower early childhood lung function and faster rate of decline in FEV1 than subjects with highest adolescent lung function; early Pseudomonas infection was not associated with rate of FEV1 decline. The strongest predictor of adolescent lung function was early childhood lung function. Subjects with a higher percentage of cultures positive for Pseudomonas before age 6 or a lower BMI at 2–4 years old also had lower adolescent lung function, though these associations were not as strong as with early childhood lung function.ConclusionsIn separate analyses of two distinct populations of subjects with CF, we found a strong correlation between lower lung function in early childhood and adolescence, regardless of early childhood Pseudomonas status. Factors in addition to early Pseudomonas infection have a strong impact on lung function in early childhood in CF. Further exploration may identify novel underlying genetic or environmental factors that predispose children with CF to early loss of lung function.

U-shaped relationship between uric acid and residual renal function decline in continuous ambulatory peritoneal dialysis patients.

There is little information on the relationship between uric acid (UA) and residual renal function (RRF) in continuous ambulatory peritoneal dialysis (CAPD). The aim of this research is to study the influence of UA on RRF decline in CAPD patients. A retrospective observational cohort study of 304 patients who started CAPD without anuria between 2001 and 2010 was conducted at a single medical center. The outcomes measured in the study included the rate of RRF decline and anuria. A multiple ordinal logistic regression model with backward elimination was conducted to determine the independent factors of the slope of RRF decline. A Cox proportional hazard model was conducted to determine the independent variables of time to anuria. The average rate of RRF decline was -0.12 ± 0.22 mL/min per month. Multivariate analysis showed that lower UA group (<0.372 mmol/L), higher UA group (≧0.421 mmol/L), male gender, diabetes mellitus (DM), the use of calcium channel blocker (CCB), and RRF at baseline were linked positively with the rate of RRF decline; on the other hand, independence in dialysate exchanges and BUN were negatively associated with the risk of RRF decline. In addition, male gender, DM, diuretics, and CCB were associated with a higher risk of progression to anuria, whereas 24-h urine amount at baseline conferred a protective role in the development of anuria. A U-shaped relationship was found between UA levels and the rate of RRF decline in patients on CAPD, with a faster decline rate in those of higher and lower UA groups.

The effect of dietary restriction on reproduction: a meta-analytic perspective.

BackgroundDietary restriction (DR), a reduction in the amount of food or particular nutrients eaten, is the most consistent environmental manipulation to extend lifespan and protect against age related diseases. Current evolutionary theory explains this effect as a shift in the resolution of the trade-off between lifespan and reproduction. However, recent studies have questioned the role of reproduction in mediating the effect of DR on longevity and no study has quantitatively investigated the effect of DR on reproduction across species.ResultsHere we report a comprehensive comparative meta-analysis of the effect of DR on reproduction. In general, DR reduced reproduction across taxa, but several factors moderated this effect. The effect of DR on reproduction was greater in well-studied model species (yeast, nematode worms, fruit flies and rodents) than non-model species. This mirrors recent results for longevity and, for reproduction, seems to result from a faster rate of decline with decreasing resources in model species. Our results also suggested that not all reproductive traits are affected equally by DR. High and moderate cost reproductive traits suffered a significant reduction with DR, but low cost traits, such as ejaculate production, did not. Although the effect of DR on reproduction was stronger in females than males, this sex difference reduced to near zero when accounting for other co-factors such as the costliness of the reproductive trait. Thus, sex differences in the effect of DR on longevity may be due to a failure to expose males to as complete a range of the costs of reproduction as females.ConclusionsWe suggest that to better understand the generality of the effect of DR, future studies should attempt to address the cause of the apparent model species bias and ensure that individuals are exposed to as many of the costs of reproduction as possible. Furthermore, our meta-analytic approach reveals a general shortage of DR studies that record reproduction, particularly in males, as well as a lack of direct side-by-side comparisons of the effect of DR on males and females.Electronic supplementary materialThe online version of this article (doi:10.1186/s12862-016-0768-z) contains supplementary material, which is available to authorized users.

The impact of dam removal and climate change on the abundance of the Formosan landlocked salmon

The Wuling basin in central Taiwan is the last refuge of the critically endangered Formosan landlocked salmon Oncorhynchus masou formosanus, but the habitat has been degraded by human interference, including agricultural practices and dam construction. Four check dams were removed in Kaoshan Stream between 1999 and 2001 to help restore the natural habitat, and we construct an age-structured stochastic simulation model to quantify the effect of this dam removal on salmon abundance. Typhoons are an important factor in the population dynamics, and the presence of dams may augment the mortality associated with typhoons. We define an annual typhoon score that measures the impact of typhoons on salmon survival. We found that habitat restoration resulting from dam removal is a more significant factor than the creation of upstream passage in increasing survival and that juveniles receive the largest benefit. The model predicts that the salmon in Kaoshan Stream would have disappeared by 2007 if the dams had not been removed, indicating that dam removal was effective in increasing abundance. To project the model forward 20 years, we use historical data to forecast future typhoon scores. The model projects that after dam removal, the salmon population will stabilize just below 400 by 2018, which indicates growth from the most recent observed value of 262 in 2014. We then modify the forecasted typhoon scores to include anticipated increases in typhoon intensity associated with climate change. All of these scenarios result in a downward rather than stable trend in abundance, with larger increases in the typhoon score associated with faster rates of decline in the population. However, the population remains above 100 over the next 20 years even in scenarios with high typhoon scores. The model suggests that dam removal reversed the salmon population decline, but the anticipated increase in rain intensity associated with climate change poses a future threat to the salmon.

Phenotyping Adults with Non-Cystic Fibrosis Bronchiectasis: A 10-Year Cohort Study in a French Regional University Hospital Center

Background: Data concerning phenotypes in bronchiectasis are scarce. Objective: The aim of this study was to describe the clinical, functional and microbiological phenotypes of patients with bronchiectasis. Methods: A monocentric retrospective study in a university hospital in France was conducted over 10 years (2002-2012). Non-cystic fibrosis patients with tomographic confirmation of bronchiectasis were included. The clinical, functional and microbiological data of patients were analyzed relying on the underlying etiology. Results: Of the 311 included patients, an etiology was found for 245 of them. At the time of diagnosis, the median age was 61 years and the mean FEV₁ was 63% of predicted. The main causes of bronchiectasis were post-infectious (50%, mostly related to tuberculosis), chronic obstructive pulmonary disease (COPD; 13%) and idiopathic (11%). Other causes were immune deficiency (6%), asthma (4%), autoimmunity (3%), tumor (2%) and other causes (4%). The comparison of phenotypic traits shows significant differences between COPD, congenital and idiopathic groups in term of sex (p = 0.0175), tobacco status (p < 0.0001), FEV₁ (p = 0.0412) and age at diagnosis (p < 0.001), Pseudomonas aeruginosa (PA) colonization (p = 0.0276) and lobectomy (0.0093). Functional follow-up was available in 30% of patients with a median duration of 2.7 years. Presence of PA was associated with a lower median FEV₁ at diagnosis (43% p < 0.003) but not with a faster rate of decline in FEV₁. Conclusion: Distinctive clinical, functional and microbiological features were found for idiopathic, congenital and COPD-related bronchiectasis. A prospective follow-up of these subgroups is necessary to validate their relevance in the management of bacterial colonization and specific complications of these bronchiectases.

Improvement in the biological standard of living in 20th century Korea: Evidence from age at menarche.

We used age at menarche to understand improvement in the biological standard of living in South Korea during the 20th century. The main dataset, the Korean National Health and Nutrition Examination Survey, provided a consistent source of nationally representative data with a large number of observations over a long period of time. We calculated mean ages at menarche by birth year and estimated the rate of decrease in age at menarche, while avoiding survival bias. The mean age at menarche decreased from 16.64 for the birth year 1941 to 12.68 for the birth year 1992, decreasing 0.78 (or 0.81 in a regression) years per decade for the period. Comparisons with other populations demonstrate that this is the fastest rate of decline ever known. In contrast to other developed countries, the decreasing rate in Korea does not appear to slow. We also compared the trend in age at menarche to that of height and found that the rate of increase in height is also the fastest in history. Age at menarche is an appropriate index of change in the general standard of living in South Korea over the 20th century. Am. J. Hum. Biol. 29:e22882, 2017. © 2016 Wiley Periodicals, Inc.