2,787 research outputs found
The Association Between the Long-Term Change in Directly Measured Cardiorespiratory Fitness and Mortality Risk
Introduction: There is a strong inverse association between cardiorespiratory fitness (CRF) and mortality outcomes. This relationship has predominantly been assessed cross-sectionally, however low CRF is a modifiable risk factor, thus assessing this association using a single baseline measure may be sub-optimal. Purpose: To examine the association of the long-term change in CRF, measured using cardiopulmonary exercise testing (CPX) with all-cause and disease-specific mortality.
Methods: Participants included 833 apparently healthy men and women (42.9±10.8 years) who underwent two maximal CPXs, the second CPX being ≥ 1 year following the baseline assessment. Participants were followed for 17.7 ± 11.8 years for allcause, cardiovascular disease (CVD), and cancer mortality. Cox-proportional hazard models were performed to determine the association between the change in CRF, computed as visit 1 (V1) peak oxygen consumption (VO2peak (ml·kg-1·min-1)) – visit 2 (V2) VO2peak, and mortality outcomes.
Results: During follow-up, 172 participants died. Overall, the change in CPX-derived CRF was inversely related to all-cause, CVD, and cancer mortality (p\u3c0.05). Each 1 ml·kg-1·min-1 increase was associated with a 10.8, 14.7, and 15.9% reductions in allcause, CVD, and cancer mortality, respectively. The inverse relationship between CRF and all-cause mortality remained significant (p\u3c0.05) when men and women were examined independently, after adjusting for years since first CPX, baseline VO2peak, and age.
Conclusion: Long-term changes in CRF were inversely related to mortality outcomes, and mortality was better predicted by CRF measured at subsequent examination than baseline CRF. These findings support the recent American Heart Association scientific statement advocating CRF as a clinical vital sign that should be assessed routinely in clinical practice, as well as support regular participation in physical activity to maintain adequate CRF levels across the lifespan
Electrochemical Generation of Superoxide in Room-Temperature Ionic Liquids
We have demonstrated that superoxide ion can be generated electrochemically in room-temperature ionic-liquid solvents. In the absence of impurities, cyclic voltammetry showed that the super oxide ion is stable in these solvents. Similar superoxide ion chemistry has previously been demonstrated in volatile and environmentally suspect aprotic solvents such as dimethyl formamide and acetonitrile. However, ionic liquids are nonvolatile and should minimize the problems of secondary solvent waste. It is proposed that the resultant superoxide ion can be used to perform low temperature oxidation of wastes. Low-temperature oxidation of waste solvents can provide a much needed alternative to high-temperature waste incinerators, whose use is greatly complicated by regulatory requirements and locating suitable sites
1+1 Dimensional Compactifications of String Theory
We argue that stable, maximally symmetric compactifications of string theory
to 1+1 dimensions are in conflict with holography. In particular, the finite
horizon entropies of the Rindler wedge in 1+1 dimensional Minkowski and anti de
Sitter space, and of the de Sitter horizon in any dimension, are inconsistent
with the symmetries of these spaces. The argument parallels one made recently
by the same authors, in which we demonstrated the incompatibility of the
finiteness of the entropy and the symmetries of de Sitter space in any
dimension. If the horizon entropy is either infinite or zero the conflict is
resolved.Comment: 11 pages, 2 figures v2: added discussion of AdS_2 and comment
Cardiorespiratory Fitness and Mortality in Healthy Men and Women
Background There is a well-established inverse relationship between cardiorespiratory fitness (CRF) and mortality. However, this relationship has almost exclusively been studied using estimated CRF. Objectives This study aimed to assess the association of directly measured CRF, obtained using cardiopulmonary exercise (CPX) testing with all-cause, cardiovascular disease (CVD), and cancer mortality in apparently healthy men and women. Methods Participants included 4,137 self-referred apparently healthy adults (2,326 men, 1,811 women; mean age: 42.8 ± 12.2 years) who underwent CPX testing to determine baseline CRF. Participants were followed for 24.2 ± 11.7 years (1.1 to 49.3 years) for mortality. Cox-proportional hazard models were performed to determine the relationship of CRF (ml·kg-1·min-1) and CRF level (low, moderate, and high) with mortality outcomes. Results During follow-up, 727 participants died (524 men, 203 women). CPX-derived CRF was inversely related to all-cause, CVD, and cancer mortality. Low CRF was associated with higher risk for all-cause (hazard ratio [HR]: 1.73; 95% confidence interval [CI]: 1.20 to 3.50), CVD (HR: 2.27; 95% CI: 1.20 to 3.49), and cancer (HR: 2.07; 95% CI: 1.18 to 3.36) mortality compared with high CRF. Further, each metabolic equivalent increment increase in CRF was associated with a 11.6%, 16.1%, and 14.0% reductions in all-cause, CVD, and cancer mortality, respectively. Conclusions Given the prognostic ability of CPX-derived CRF for all-cause and disease-specific mortality outcomes, its use should be highly considered for apparently healthy populations as it may help to improve the efficacy of the individualized patient risk assessment and guide clinical decisions
Atypical and Severe Nonsuicidal Self-Injury as an Indicator of Severe Psychopathology: Findings From a Sample of High-Risk Community Mental Health Clients
This study examined whether atypical/severe nonsuicidal self-injury (NSSI; e.g., foreign body ingestion, cutting necessitating sutures) serves as a marker of severe psychopathology among 467 adult community mental health clients (n = 33 with an atypical/severe NSSI history). Information regarding psychiatric risk indicators was extracted from participants’ psychiatric records. Generalized linear models with negative binomial distribution and log link function, as well as chi-square tests, were used to address study aims. Clients with a lifetime atypical/severe NSSI history met criteria for a significantly greater number of psychiatric risk indicators than clients with a lifetime history of common NSSI only; however, these clients were not significantly more likely to report recent suicidal actions. Individuals with an atypical/severe NSSI history may demonstrate more severe psychopathology than those with a history of common NSSI only. Thus, it may be clinically useful to consider individuals with an atypical/severe NSSI history as a high-risk subgroup
Relationship Between Body Composition, Body Fat Distribution, and Blood Lipids Among Law Enforcement Officers: Part 1
Law enforcement officers (LEOs) have a high-stress occupation which is prone to cardiovascular disease (CVD). In fact, data suggest that LEOs have a 1.7-fold higher CVD prevalence versus the general public, in addition to 40.5% of LEOs being classified as obese. However, research is lacking regarding the relationship between body composition, body fat distribution, and blood lipid panels as it pertains to CVD risk in LEOs. PURPOSE: To determine if body composition and fat distribution measures correlate with predictive lipid markers in LEOs. METHODS: Forty-three LEOs (age = 41.7±9.6 yrs; weight = 91.9±15.4 kg; height = 179.8±8.7 cm; VO2max: 37.0±6.16 ml/kg/min) from a local police department were evaluated. Fasting blood samples were collected to assess biomarkers of CVD risk: low-density lipoprotein (LDL), high-density lipoprotein (HDL), total cholesterol (TC), and triglycerides (TG). Dual-energy x-ray absorptiometry was used to measure body composition and body fat distribution. Bivariate Pearson correlation matrix was used to determine correlations (p\u3c0.05* and p\u3c0.01**). To further assess the relationship between body composition, fat distribution measures, and blood lipids, ordinary least square (OLS) regression analyses were used. RESULTS: Lower body weight correlated with greater HDL concentrations (r=-0.432**). Higher fat mass correlated with greater TG concentrations (r=0.338*), while greater lean mass was inversely correlated with HDL concentrations (r=-0.496**). Android and gynoid adiposity were positively correlated with greater TG (r=0.359*) and HDL (r=0.320*) concentrations, respectively. Lastly, higher visceral adipose tissue was correlated with greater TG concentrations (r=0.430**). The OLS regression analysis revealed (p\u3c0.05) 1) weight was inversely predictive of HDL, 2) Fat mass was positively predictive of TG, 3) lean mass was inversely predictive of HDL, 4) android adiposity was positively predictive of TG, 5) gynoid adiposity was positively predictive of HDL, and 6) visceral adipose tissue was positively predictive of TG. CONCLUSION: Measures of body composition seen in LEOs with increased body fat showed positive correlations with blood lipid markers (TG and HDL), which can be predictive of high CVD risk and other potential medical conditions. These data provide insight into the association of body composition and fat distribution with markers of CVD risk
Normalizing Cardiorespiratory Fitness To Fat-free Mass Improves Mortality Risk Prediction In Overweight Adults From The Ball St Cohort: 2361 Board #280 May 28 3:00 PM - 4:30 PM
Cardiorespiratory fitness(CRF) is a significant predictor of mortality outcomes in various populations, including overweight and obese adults. However, CRF is commonly expressed normalized to total body weight (VO2peakTBW) which may weaken the relationship in obese adults as fat-free mass (FFM) is directly related to CRF, and increased body fat is associated with lower CRF in adults. Therefore, this study aimed to assess the relationship between CRF normalized for FFM(VO2peakFFM) and all-cause mortality, as well as compare the predictive ability of VO2peakFFM and VO2peakTBW in a cohort of self-referred overweight and obese adults
The Association between the Change in Directly Measured Cardiorespiratory Fitness across Time and Mortality Risk
Background
The relationship between cardiorespiratory fitness (CRF) and mortality risk has typically been assessed using a single measurement, though some evidence suggests the change in CRF over time influences risk. This evidence is predominantly based on studies using estimated CRF (CRFe). The strength of this relationship using change in directly measured CRF over time in apparently healthy men and women is not well understood.
Purpose
To examine the association of change in CRF over time, measured using cardiopulmonary exercise testing (CPX), with all-cause and disease-specific mortality and to compare baseline and subsequent CRF measurements as predictors of all-cause mortality.
Methods
Participants included 833 apparently healthy men and women (42.9 ± 10.8 years) who underwent two maximal CPXs, the second CPX being ≥1 year following the baseline assessment (mean 8.6 years, range 1.0 to 40.3 years). Participants were followed for up to 17.7 (SD 11.8) years for all-cause-, cardiovascular disease- (CVD), and cancer mortality. Cox-proportional hazard models were performed to determine the association between the change in CRF, computed as visit 1 (CPX1) peak oxygen consumption (VO2peak [mL·kg−1·min−1]) – visit 2 (CPX2) VO2peak, and mortality outcomes. A Wald-Chi square test of equality was used to compare the strength of CPX1 to CPX2 VO2peak in predicting mortality.
Results
During follow-up, 172 participants died. Overall, the change in CPX-CRF was inversely related to all-cause, CVD, and cancer mortality (p < 0.05). Each 1 mL·kg−1·min−1 increase was associated with a ~11, 15, and 16% (all p < 0.001) reduction in all-cause, CVD, and cancer mortality, respectively. The inverse relationship between CRF and all-cause mortality was significant (p < 0.05) when men and women were examined independently, after adjusting for years since first CPX, baseline VO2peak, and age. Further, the Wald Chi-square test of equality found CPX2 VO2peak to be a significantly stronger predictor of all-cause mortality than CPX1 VO2peak (p < 0.05).
Conclusion
The change in CRF over time was inversely related to mortality outcomes, and mortality was better predicted by CRF measured at subsequent test than CPX1 CRF. These findings emphasize the importance of adopting lifestyle behaviors that promote CRF, as well as support the need for routine assessment of CRF in clinical practice to better assess risk
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