Experience Lower Mortality Research Articles

Association of Daily Step Patterns With Mortality in US Adults

Previous studies have shown that individuals who regularly walk, particularly 8000 daily steps or more, experience lower mortality. However, little is known about the health benefits of walking intensively only a few days a week. To evaluate the dose-response association between the number of days an individual takes 8000 steps or more and mortality among US adults. This cohort study evaluated a representative sample of participants aged 20 years or older in the National Health and Nutrition Examination Surveys 2005-2006 who wore an accelerometer for 1 week and their mortality data through December 31, 2019. Data were analyzed from April 1, 2022, to January 31, 2023. Participants were grouped by the number of days per week they took 8000 steps or more (0 days, 1-2 days, and 3-7 days). Multivariable ordinary least squares regression models were used to estimate adjusted risk differences (aRDs) for all-cause and cardiovascular mortality during the 10-year follow-up, adjusting for potential confounders (eg, age, sex, race and ethnicity, insurance status, marital status, smoking, comorbidities, and average daily step counts). Among 3101 participants (mean [SD] age, 50.5 [18.4] years; 1583 [51.0%] women and 1518 [49.0%] men; 666 [21.5%] Black, 734 [23.7%] Hispanic, 1579 [50.9%] White, and 122 [3.9%] other race and ethnicity), 632 (20.4%) did not take 8000 steps or more any day of the week, 532 (17.2%) took 8000 steps or more 1 to 2 days per week, and 1937 (62.5%) took 8000 steps or more 3 to 7 days per week. Over the 10-year follow-up, all-cause and cardiovascular deaths occurred in 439 (14.2%) and 148 (5.3%) participants, respectively. Compared with participants who walked 8000 steps or more 0 days per week, all-cause mortality risk was lower among those who took 8000 steps or more 1 to 2 days per week (aRD, -14.9%; 95% CI -18.8% to -10.9%) and 3 to 7 days per week (aRD, -16.5%; 95% CI, -20.4% to -12.5%). The dose-response association for both all-cause and cardiovascular mortality risk was curvilinear; the protective association plateaued at 3 days per week. Different thresholds for the number of daily steps between 6000 and 10 000 yielded similar results. In this cohort study of US adults, the number of days per week taking 8000 steps or more was associated with a lower risk of all-cause and cardiovascular mortality in a curvilinear fashion. These findings suggest that individuals may receive substantial health benefits by walking just a couple days a week.

Mortality in relation to hepatitis B virus (HBV) infection status among HIV-HBV co-infected patients in sub-Saharan Africa after immediate initiation of antiretroviral therapy.

It is unknown how past and active hepatitis B virus (HBV) infection affect immunorecovery and mortality in people with HIV who initiate tenofovir-based antiretroviral therapy (ART). Using data collected between 2008 and 2015, we studied people with HIV in sub-Saharan Africa initiating immediate ART in the Temprano randomized control trial. We classified participants into HBV groups at ART initiation: hepatitis B surface antigen (HBsAg)-positive with HBV DNA≥2,000IU/ml; HBsAg-positive with HBV DNA<2,000IU/ml; isolated HBcAb-positive; resolved infection (HBsAb-positive/HBcAb-positive); and HBV non-immune/vaccinated (HBcAb-negative). We compared square-root CD4-cell count increases using mixed-effect, non-linear regression adjusted for age, sex, baseline CD4 cell count, and HIV RNA. We compared all-cause mortality using Bayesian parametric survival regression. Among 879 participants, 24 (2.7%) had HBsAg with high HBV DNA, 76 (8.6%) HBsAg with low HBV DNA, 325 (37.0%) isolated anti-HBcAb, 226 (25.7%) resolved HBV infection and 228 (25.9%) HBV non-immune/vaccinated. We found no significant difference in CD4 cell increases between HBV-infection groups after adjustment (p=0.16). Participants with HBsAg and high HBV DNA had the highest incidence of all-cause mortality (1.9/100 person-years, 95% Credibile Interval [CrI]=1.0-3.4). By comparison, incidence rates of mortality were reduced by 57% (95%CrI=-79%, -13%), 60% (95%CrI=-82%, -12%) and 66% (95%CrI=-84%, -23%) in those who had isolated anti-HBcAb-positive, resolved HBV infection and HBV non-immune/vaccinated, respectively. In conclusion, individuals with HIV and past HBV infection or isolated anti-HBcAb-positive serology, much like HBV non-immune/vaccinated, experience lower mortality than those with HBsAg and high HBV DNA. Additional HBV-related management would not be necessary for these individuals.

Environmental degradation and population health outcomes: a global panel data analysis.

This study investigates the relationship between environmental degradation and population health using a global panel data of 180 countries from 1990 to 2016. The empirical analysis is conducted using fixed-effects approach based on Hausman test. Moreover, two-stage least squares (2SLS) and system-generalized method of moments (SGMM) are used to deal with the endogenous nature of environmental degradation. The indicators of life expectancy and infant mortality are used to measure population health, whereas environmental degradation is measured by CO2 emissions. The empirical findings show that environmental degradation negatively influences population health outcomes. It implies that countries having a high level of environmental degradation experience low life expectancy and high infant mortality rates. Findings of the study suggest that health-related reforms need to be aligned with policies which ensure lower environmental degradation.

Gendered mortality differentials over the rural-urban continuum: The analysis of census linked longitudinal data from England and Wales

Previous research shows that mortality varies significantly by residential context; however, the nature of this variation is unclear. Some studies report higher mortality levels in urban compared to rural areas, whereas others suggest elevated mortality in rural areas or a complex U-shaped relationship. Further, the extent to which compositional factors explain urban-rural mortality variation, the extent to which contextual factors play a role and whether and how the patterns vary by gender also remain unclear. This study investigates urban-rural mortality variation in England and Wales and the causes of this variation. The study applies survival analysis to the Office for National Statistics Longitudinal Study; the population aged 20 and older in 2001 is followed for 10 years. The analysis demonstrates a clear urban-rural mortality gradient, with the risk of dying increasing with each level of urbanisation. The exceptions are those living in areas adjacent to London, who consistently exhibit lower mortality than anticipated. Once the models are adjusted to individuals' socio-economic characteristics, the variation across the urban-rural continuum reduces substantially, although the gradient persists suggesting contextual effects. Females are found to be influenced more by their surrounding environment and males by their socio-economic position, although both experience lower mortality in rural compared to urban areas.

Adopted daughters and adopted daughters-in-law in Taiwan: a mortality analysis.

Adoption is sometimes considered paradoxical from an evolutionary perspective because the costs spent supporting an adopted child would be better spent on rearing one's own. Kin selection theory is commonly used to solve this paradox, because the adoption of closely related kin contributes to the inclusive fitness of the adoptive parent. In this paper, we perform a novel test of kin selection theory in the context of adoption by asking whether adopted daughters-in-law, who contribute directly (i.e. genealogically) to the perpetuation of their adoptive families' lineages, experience lower mortality than daughters adopted for other purposes in historical Taiwan. We show that both classes of adopted daughter suffer lower mortality than biological daughters, but that the protective effect of adoption is stronger among daughters who were not adopted with the intention of perpetuating the family lineage. We speculate as to the possible benefits of such a pattern and emphasize the need to move beyond typological definitions of adoption to understand the specific costs and benefits involved in different forms of caring for others' children.

No carbon “bet hedging” in pine seedlings under prolonged summer drought and elevated CO2

Abstract More frequent drought episodes are expected to cause higher mortality in isohydric tree species such as pines, because individuals close their stomata early during drought in order to maintain constant needle water potentials. It has been suggested that trees delay the ensuing carbon starvation by actively storing carbon at the expense of growth (“bet hedging”). Because such a strategy is only adaptive in drought‐prone regions, we hypothesise that the degree of carbon “bet hedging” should differ between ecotypes. We repeatedly measured the allocation of biomass, starch and soluble sugars to needles, stem and roots in seedlings of nine populations of Pinus sylvestris and Pinus nigra along a gradient from Central Europe to the Mediterranean. During two consecutive growing seasons, seedlings grown from seed were exposed to factorial combinations of 4 months of drought (D1, D2) and ambient/elevated CO2 (aCO2/eCO2). Drought‐stressed pine seedlings did neither increase starch concentrations, nor change biomass production or experience lower mortality under eCO2 compared to aCO2. By the end of D2, seedlings from drier origin had accumulated more starch but at the same time also more biomass than seedlings from wetter origin. Surprisingly, seedlings acclimatised to dry conditions after D1 so that mortality dropped to zero and drought effects on needle starch (P. sylvestris) and overall starch (P. nigra), respectively, disappeared after D2. Synthesis. The absence of a trade‐off between carbon storage (starch) and growth (biomass), and the patterns of mortality observed in seedlings growing under combined drought and eCO2 do not support the theory of carbon “bet hedging” in isohydric Pinus sylvestris and Pinus nigra. Results suggest that reduced growth and acclimatisation minimised seedling mortality in the second year. Acclimatisation might thus enable pine seedlings to resist a moderate increase in summer drought frequency expected in the future.

Observation of an Eastern Wolf (&lt;i&gt;Canis&lt;/i&gt; sp. cf. &lt;i&gt;lycaon&lt;/i&gt;) Caching Food in a Sphagnum Bog in Algonquin Provincial Park, Ontario

We report summer caching of a partial carcass of a White-tailed Deer (Odocoileus virginianus) fawn by an Eastern Wolf (Canis sp. cf. lycaon) in a Sphagnum bog in Algonquin Provincial Park, Ontario, Canada. The microhabitat conditions in bogs (i.e., low temperature, acidity, and organochemical compounds) likely inhibit food spoilage, making bogs potentially important sites for food caching. Wolves in Algonquin Park experience low summer food availability and high pup mortality from starvation. Caches likely serve as necessary reserve food stores for adults and pups. Recent research has shown that wetland habitats are important den and rendezvous sites for Algonquin Eastern Wolves based on prey availability and, we suggest, perhaps for food storage and accessibility. This caching behaviour was recorded on video. We recommend that future research investigate Eastern Wolf selection of food-caching sites, as a complement to other spatial ecology studies.

The natural and unnatural history of the systemic right ventricle in adult survivors

The study objective was to evaluate long-term trends in morbidity and mortality in a national cohort of adult patients with a systemic right ventricle due to the atrial switch for transposition of the great arteries or congenitally corrected transposition of the great arteries. We performed a retrospective cohort study from a baseline of 18 years, including life table and Kaplan-Meier analysis for probability of death/transplant, arrhythmia, surgical or percutaneous intervention, and permanent pacemaker insertion. A total of 97 adults with transposition of the great arteries-atrial switch (Mustard procedure in 80/Senning procedure in 17) and 32 adults with congenitally corrected transposition of the great arteries survived. The median ages at latest follow-up were 29 and 34 years, respectively. At 40 years of follow-up, freedom from death or transplant was 0.90 for those with transposition of the great arteries-atrial switch and 0.84 for those with congenitally corrected transposition of the great arteries (P=.833). Freedom from arrhythmia at 40 years of follow-up was 0.51 for those with transposition of the great arteries-atrial switch and 0.93 for those with congenitally corrected transposition of the great arteries (P=.007). Freedom from intervention at 40 years of follow-up was 0.33 for those with transposition of the great arteries-atrial switch after initial repair and 0.53 for those with congenitally corrected transposition of the great arteries (P=.938). Freedom from pacemaker insertion at 40 years of follow-up was 0.77 for those with transposition of the great arteries-atrial switch and 0.62 for those with congenitally corrected transposition of the great arteries (P=.161). Those patients who survive to adulthood with a systemic right ventricle experience low mortality and good functional status up to 40 years of age. However, there is a substantial burden of atrial tachyarrhythmia, and this occurs significantly earlier in those with transposition of the great arteries-atrial switch. Management of atrial tachyarrhythmia, along with systemic right ventricular dysfunction and systemic atrioventricular valve regurgitation, is likely to be the major challenge for this group of patients over the next decade.

Complementary effect of natural and sexual selection against immigrants maintains differentiation between locally adapted fish

Adaptation to ecologically heterogeneous environments can drive speciation. But what mechanisms maintain reproductive isolation among locally adapted populations? Using poeciliid fishes in a system with naturally occurring toxic hydrogen sulfide, we show that (a) fish from non-sulfidic sites (Poecilia mexicana) show high mortality (95 %) after 24 h when exposed to the toxicant, while locally adapted fish from sulfidic sites (Poecilia sulphuraria) experience low mortality (13 %) when transferred to non-sulfidic water. (b) Mate choice tests revealed that P. mexicana females exhibit a preference for conspecific males in non-sulfidic water, but not in sulfidic water, whereas P. sulphuraria females never showed a preference. Increased costs of mate choice in sulfidic, hypoxic water, and the lack of selection for reinforcement due to the low survival of P. mexicana may explain the absence of a preference in P. sulphuraria females. Taken together, our study may be the first to demonstrate independent-but complementary-effects of natural and sexual selection against immigrants maintaining differentiation between locally adapted fish populations.

External Validity of Clinical Trials in Acute Myocardial Infarction

Patients enrolled in randomized clinical trials (RCTs) may not reflect those seen in real-life practice. Our goal was to compare patients eligible for enrollment but not enrolled in contemporary RCTs of reperfusion therapy with patients who would have been ineligible and also with patients with acute myocardial infarction (AMI) participating in RCTs. Consecutive patients with AMI (n = 8469) enrolled in the GRACE registry (Global Registry of Acute Coronary Events) were divided into 3 groups: RCT participants (11%; n = 953), eligible nonenrolled patients (55%; n = 4669), and ineligible patients (34%; n = 2847). Our main outcome measures were hospital mortality rates. Based on baseline characteristics or GRACE risk-score distribution, RCT participants had the lowest a priori risk of death; eligible patients had a higher risk; and ineligible patients had the highest risk. Actual hospital mortality showed a similar gradient (3.6%, 7.1%, and 11.4%, respectively) (P<.001). Multivariable analysis adjusting for baseline risk, use and type of reperfusion therapy, and delay from symptom onset to admission consistently showed a higher mortality rate for eligible nonenrolled patients than for RCT participants (odds ratio, 1.61; 95% confidence interval, 1.06-2.43; and odds ratio, 1.97; 95% confidence interval, 1.24-3.13, respectively). Patients with AMI participating in RCTs have a lower baseline risk and experience lower mortality than nonenrolled patients, even when they are trial eligible. This difference is not entirely explained by differences in baseline risk, use and type of reperfusion therapy, and/or delays in presentation. Caution is necessary when extending the findings obtained in RCTs to the general population with AMI.

Do we need species-specific guidelines for catch-and-release recreational angling to effectively conserve diverse fishery resources?

Catch-and-release recreational angling has become very popular as a conservation strategy and as a fisheries management tool for a diverse array of fishes. Implicit in catch-and-release angling strategies is the assumption that fish experience low mortality and minimal sub-lethal effects. Despite the importance of this premise, research on this topic has focused on several popular North American sportfish, with negligible efforts directed towards understanding catch-and-release angling effects on alternative fish species. Here, we summarise the existing literature to develop five general trends that could be adopted for species for which no data are currently available: (1) minimise angling duration, (2) minimise air exposure, (3) avoid angling during extremes in water temperature, (4) use barbless hooks and artificial lures/flies, and (5) refrain from angling fish during the reproductive period. These generalities provide some level of protection to all species, but do have limitations. Therefore, we argue that a goal of conservation science and fisheries management should be the creation of species-specific guidelines for catch-and-release. These guidelines would take into account the inter-specific diversity of fishes and variation in fishing techniques. As recreational angling continues to grow in popularity, expanding to many developing countries, and targeting alternative species, it is important that reasonable data appropriate for specific fish and fisheries are available. The sustainable use and conservation of recreational fishery resources will depend upon the development and dissemination of effective catch-and-release angling strategies based upon sound science to stakeholders around the world.

Old pythons stay fit; effects of haematozoan infections on life history traits of a large tropical predator

We document the impact of blood parasite infections caused by Hepatozoon sp. on water python (Liasis fuscus) life history traits such as growth rates, condition, reproductive output and survival. Individual snakes maintained similar among-year parasite loads. Hepatozoon infections affected python growth rate, i.e. snakes suffering from high infection levels exhibited significantly slower growth compared to individuals with low parasite loads. Our results suggest that the parasites also affected the pythons' nutritional status (condition), as snakes with low condition scores suffered from higher parasite infection levels than snakes with high scores. Furthermore, our data suggest that parasitaemia may affect female reproductive output, as reproductive female pythons harboured lower parasite loads compared to non-reproductive adult females. High levels of parasite infections also affected juvenile python survival, as recaptured snakes harboured significantly lower parasite loads compared to non-recaptured yearling pythons. In our study area, water python have very few natural predators and, hence, experience low mortality rates and commonly reach an age of >15 years. In contrast to results obtained in other studies, parasite loads in larger/older pythons were lower compared to younger snakes, suggesting that only snakes harbouring lower levels of parasitaemia were able to survive to old age. We suggest that a possible cause for the opposing results regarding parasite prevalence and host age may be due to different levels of extrinsic mortality rates and longevity. Long-lived organisms, such as water pythons, may invest relatively more into crucial self-maintenance functions such as parasite defence, compared to short-lived organisms.

To Help or To Harm? Food Stamp Receipt and Mortality Risk Prior to the 1996 Welfare Reform Act

We use data from the National Health Interview Survey-Family Resources Supplement to examine the relationship between Food Stamp receipt and prospective adult mortality, among eligible households. We specify a switching probit model to adjust for observed and unobserved factors that correlate with selection into the Food Stamp Program and mortality, and to estimate mortality under counterfactual conditions that we do not observe. The average individual, based on observed characteristics, has higher mortality when participating than when not participating. But due to unobserved differences between participants and nonparticipants, those who self-select into participation experience lower mortality than if they did not participate. Our findings suggest that Food Stamps provide an important safety net that protects the health of those who are most likely to participate.

Mouse models of chronic lung infection with Pseudomonas Aeruginosa: Models for the study of cystic fibrosis

The discovery of the CFTR gene in 1989 has lead to rapid progress in understanding the molecular basis of cystic fibrosis (CF) and the biological properties of the cystic fibrosis transmembrane conductance regulator (CFTR) protein. However, more than 10 years later, recurrent lung infections with Pseudomonas aeruginosa, which lead to chronic lung disease and eventual respiratory failure, remain the major cause of morbidity and mortality among CF patients. A distinguishing feature of lung disease in CF is an exaggerated and persistent inflammatory response, characterized by the accumulation of excessive numbers of neutrophils and dysregulated cytokine production. The events leading to the establishment of lung infection with P. aeruginosa, especially the inflammatory and immunological events, and the relation between the CF defect and infection, remain largely undefined. Progress in this area has been hampered by the lack of a suitable animal model. An exciting achievement in the past few years has been the development of a number of variants of CFTR-deficient mice which exhibit defective cAMP-mediated Cl− conductance and have a range of clinical phenotypes from mild to severe. In parallel, a model of chronic P. aeruginosa lung infection has been established in genetically and immunologically well-defined inbred mouse strains which differ in susceptibility to this infection in the lung. BALB/c mice are resistant, while DBA/2 mice are extremely susceptible, with high mortality within 3 days of infection. C57BL/6 and A/J mice are relatively susceptible and experience low mortality. Furthermore, the bacterial load correlates with the magnitude and quality of the inflammatory response in the infected lungs of BALB/c and C57BL/6 mice. Although results of infection studies in CFTR-deficient mice have been variable, C57BL/6-Cftrm1UNC/Cftrm1UNC knockout mice compared to littermate control mice are highly susceptible to chronic P. aeruginosa infection in the lung. The availability of CFTR knockout mice and non-CF inbred mice differing in susceptibility to chronic P. aeruginosa infection offers useful tools for progress in understanding the genesis of chronic P. aeruginosa infection and the ensuing inflammation in the CF lung, as well as the relation between the CF defect and infection. Information generated from these studies will provide the rationale for the development of novel immunomodulatory measures capable of ameliorating or modulating the chronic inflammation associated with CF lung disease. Pediatr Pulmonol. 2000;30:413–424. © 2000 Wiley-Liss, Inc.

Mouse models of chronic lung infection with Pseudomonas aeruginosa: models for the study of cystic fibrosis.

The discovery of the CFTR gene in 1989 has lead to rapid progress in understanding the molecular basis of cystic fibrosis (CF) and the biological properties of the cystic fibrosis transmembrane conductance regulator (CFTR) protein. However, more than 10 years later, recurrent lung infections with Pseudomonas aeruginosa, which lead to chronic lung disease and eventual respiratory failure, remain the major cause of morbidity and mortality among CF patients. A distinguishing feature of lung disease in CF is an exaggerated and persistent inflammatory response, characterized by the accumulation of excessive numbers of neutrophils and dysregulated cytokine production. The events leading to the establishment of lung infection with P. aeruginosa, especially the inflammatory and immunological events, and the relation between the CF defect and infection, remain largely undefined. Progress in this area has been hampered by the lack of a suitable animal model. An exciting achievement in the past few years has been the development of a number of variants of CFTR-deficient mice which exhibit defective cAMP-mediated Cl(-) conductance and have a range of clinical phenotypes from mild to severe. In parallel, a model of chronic P. aeruginosa lung infection has been established in genetically and immunologically well-defined inbred mouse strains which differ in susceptibility to this infection in the lung. BALB/c mice are resistant, while DBA/2 mice are extremely susceptible, with high mortality within 3 days of infection. C57BL/6 and A/J mice are relatively susceptible and experience low mortality. Furthermore, the bacterial load correlates with the magnitude and quality of the inflammatory response in the infected lungs of BALB/c and C57BL/6 mice. Although results of infection studies in CFTR-deficient mice have been variable, C57BL/6-Cftr(m1UNC)/Cftr(m1UNC) knockout mice compared to littermate control mice are highly susceptible to chronic P. aeruginosa infection in the lung. The availability of CFTR knockout mice and non-CF inbred mice differing in susceptibility to chronic P. aeruginosa infection offers useful tools for progress in understanding the genesis of chronic P. aeruginosa infection and the ensuing inflammation in the CF lung, as well as the relation between the CF defect and infection. Information generated from these studies will provide the rationale for the development of novel immunomodulatory measures capable of ameliorating or modulating the chronic inflammation associated with CF lung disease.

Use of Rainfall Cues by Abedus herberti (Hemiptera: Belostomatidae): A Mechanism for Avoiding Flash Floods

Unlike most aquatic invertebrate taxa in desert streams, adults and juveniles of the giant water bug Abedus herberti Hidalgo experience low mortality from flash floods ( 90%). One explanation is that A. herberti use periods of torrential rainfall (>15 cm · hr−1) that often precede flash floods as a cue to abandon streams. “Stream abandonment behavior” consisted of exiting the stream after some threshold duration of torrential rainfall (8.0 min for adults, 29 min for juveniles), moving in a negatively geotactic direction away from the stream, and stopping in a sheltered area away from the active stream channel. Individuals crawled as far as 23 m from the stream, but returned within 24 h. Experiments with simulated rainfall demonstrated that the behavioral cue for stream abandonment behavior is probably related to the impact of rain on the stream surface, and not to other chemical or physical cues associated with inputs of rainwater (i.e., changes in pH, ion concentrations, water temperature, turbidity, or discharge) or approaching thunderstorms (i.e., pressure drops, thunder, lightning, or cloud cover). These other cues may play an auxiliary role in the behavior, however. Stream abandonment behavior can only account for part of the high survival rates observed for A. herberti during flash floods, since less than a third of observed individuals responded to either natural or simulated rainfall.

Live blind snakes (Leptotyphlops dulcis) in eastern screech owl (Otus asio) nests: a novel commensalism.

Eastern screech owls bring live blind snakes to their nestlings, whereas all other prey are delivered dead. Some of the snakes are eaten but most live in nest debris, where they eat soft-bodied insect larvae from the decomposer community in fecal matter, pellets, and uneaten prey. Consumption of larvae may reduce larval parasitism on owl nestlings or larval competition with nestlings for food stored in the nest, because nestlings with live-in blind snakes grow faster and experience lower mortality than same-season broods lacking snakes. We propose a commensalistic association in which the screech owl benefits reproductively and the live-in blind snake is not affected.