6,894 research outputs found

    Television viewing time and risk of incident obesity and central obesity: the English longitudinal study of ageing

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    Background Research suggests television viewing time may be associated with incident obesity and central obesity in young adults. No study has investigated these associations in older English adults. The aim of this study was to investigate longitudinal associations between television viewing time and incident obesity and central obesity in a sample of older English adults. Analyses of data from the English Longitudinal Study of Ageing. At baseline (2008), participants reported their television viewing time. Research nurses recorded obesity and central obesity by body mass index and waist circumference, respectively, at four year follow-up. Associations between television viewing time and incident obesity (BMI > 30 kg/m2) and central obesity (waist >102 cm men; > 88 cm women) at four year follow-up were examined using adjusted logistic regression. Participants gave full written informed consent to participate in the study and ethical approval was obtained from the London Multicentre Research Ethics Committee. Results A total of 3777 initially non-obese participants (aged 64.8 ± 8.6 yrs, 46.4% male) were included in the analyses using BMI as an outcome and 2947 for the analyses using waist circumference. No significant associations were found between television viewing time and incident obesity. A significant association was found between watching ≥6 hrs/d of television (compared to <2 hrs/d) and central obesity (Odds Ratio 1.48; 95% confidence interval 1.07 to 2.03) after adjustment for covariables including physical activity. Conclusions In this sample of older community dwelling English adults greater television viewing time was associated with incident central obesity, but not total obesity when measured by BMI. Interventions to reduce the incidence of central obesity in this age group that focus on reducing TV time, as well as targeting other health behaviours (eg, increasing physical activity levels, improving dietary intake) might prove useful

    Quantum phase transitions in the J-J' Heisenberg and XY spin-1/2 antiferromagnets on square lattice: Finite-size scaling analysis

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    We investigate the critical parameters of an order-disorder quantum phase transitions in the spin-1/2 JJJ-J' Heisenberg and XY antiferromagnets on square lattice. Basing on the excitation gaps calculated by exact diagonalization technique for systems up to 32 spins and finite-size scaling analysis we estimate the critical couplings and exponents of the correlation length for both models. Our analysis confirms the universal critical behavior of these quantum phase transitions: They belong to 3D O(3) and 3D O(2) universality classes, respectively.Comment: 7 pages, 3 figure

    Prospective study of coffee and tea consumption in relation to risk of type 2 diabetes mellitus among men and women: The Whitehall II study

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    At least fourteen cohort studies have documented all inverse association between coffee consumption and risk of type 2 diabetes. We examined the prospective association between coffee and tea consumption and the risk of type 2 diabetes mellitus among British men (n 4055) and women (n 1768) from the Whitehall II cohort. During 11.7 years follow-up there were a total of 387 incident cases of diabetes confirmed by Self-report of doctor's diagnosis or glucose tolerance tests. Despite an inverse association between coffee intake and 2 h post-load glucose concentration at the baseline assessment, combined caffeinated and decaffeinated coffee (hazard ratio (HR) 0-80 95% CI 0.54, 1.18) or only decaffeinated coffee intake (HR 0.65: 95% CI 0.36, 1.16) was not significantly associated with diabetes risk at follow-up after adjustment for possible confounders. There was all association between tea intake and diabetes (HR 0.66: 95% CI 0.61, 1.22: P<0.05) after adjustment for age. gender. ethnicity and social status, which was not robust to further adjustments. There was. however, an association between combined intake of tea and coffee (two or more cups per clay of both beverage) and diabetes (HR 0.68: 95% CI 0.46, 0.99: P<0.05) after full adjustment. In conclusion, relatively moderate intake (more than three CLIPS per (lay) of coffee and tea were not prospectively associated with incidence of type 2 diabetes although there was evidence of a combined effect. The limited range of exposure and beverage consumption according to socio-economic class may explain these conflicting findings

    Hamiltonian Study of Improved U(1U(1 Lattice Gauge Theory in Three Dimensions

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    A comprehensive analysis of the Symanzik improved anisotropic three-dimensional U(1) lattice gauge theory in the Hamiltonian limit is made. Monte Carlo techniques are used to obtain numerical results for the static potential, ratio of the renormalized and bare anisotropies, the string tension, lowest glueball masses and the mass ratio. Evidence that rotational symmetry is established more accurately for the Symanzik improved anisotropic action is presented. The discretization errors in the static potential and the renormalization of the bare anisotropy are found to be only a few percent compared to errors of about 20-25% for the unimproved gauge action. Evidence of scaling in the string tension, antisymmetric mass gap and the mass ratio is observed in the weak coupling region and the behaviour is tested against analytic and numerical results obtained in various other Hamiltonian studies of the theory. We find that more accurate determination of the scaling coefficients of the string tension and the antisymmetric mass gap has been achieved, and the agreement with various other Hamiltonian studies of the theory is excellent. The improved action is found to give faster convergence to the continuum limit. Very clear evidence is obtained that in the continuum limit the glueball ratio MS/MAM_{S}/M_{A} approaches exactly 2, as expected in a theory of free, massive bosons.Comment: 13 pages, 15 figures, submitted to Phys. Rev.

    Post-menopausal women exhibit greater interleukin-6 responses to mental stress than older men

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    BACKGROUND: Acute stress triggers innate immune responses and elevation in circulating cytokines including interleukin-6 (IL-6). The effect of sex on IL-6 responses remains unclear due to important limitations of previous studies. PURPOSE: The purpose of this study was to examine sex differences in IL-6 responses to mental stress in a healthy, older (post-menopausal) sample accounting for several moderating factors. METHODS: Five hundred six participants (62.9 ± 5.60 years, 55 % male) underwent 10 min of mental stress consisting of mirror tracing and Stroop task. Blood was sampled at baseline, after stress, and 45 and 75 min post-stress, and assayed using a high sensitivity kit. IL-6 reactivity was computed as the mean difference between baseline and 45 min and between baseline and 75 min post-stress. Main effects and interactions were examined using ANCOVA models. RESULTS: There was a main effect of time for the IL-6 response (F 3,1512 = 201.57, p = <.0001) and a sex by time interaction (F 3,1512 = 17.07, p = <.001). In multivariate adjusted analyses, IL-6 reactivity was significantly greater in females at 45 min (M = 0.37 ± 0.04 vs. 0.20 ± 0.03 pg/mL, p = .01) and at 75 min (M = 0.57 ± 0.05 vs. 0.31 ± 0.05 pg/mL, p = .004) post-stress compared to males. Results were independent of age, adiposity, socioeconomic position, depression, smoking and alcohol consumption, physical activity, statin use, testing time, task appraisals, hormone replacement, and baseline IL-6. Other significant predictors of IL-6 reactivity were lower household wealth, afternoon testing, and baseline IL-6. CONCLUSIONS: Healthy, post-menopausal females exhibit substantially greater IL-6 responses to acute stress. Inflammatory responses if sustained over time may have clinical implications for the development and maintenance of inflammatory-related conditions prevalent in older women

    Adult attachment style and cortisol responses across the day in older adults.

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    The association between cortisol and adult attachment style, an important indicator of social relationships, has been relatively unexplored. Previous research has examined adult attachment and acute cortisol responses to stress in the laboratory, but less is known about cortisol levels in everyday life. The present study examined adult romantic attachment style and cortisol responses across the day. Salivary cortisol was collected at six time points during the course of the day in 1,807 healthy men and women from a subsample of the Whitehall II cohort. Significant associations were found between attachment on cortisol across the day and slope of cortisol decline. The lowest cortisol output was associated with fearful attachment, with preoccupied attachment having the highest levels and a flatter cortisol profile. The results tentatively support the proposition that attachment style may contribute to HPA dysregulation

    Path Integral Monte Carlo Approach to the U(1) Lattice Gauge Theory in (2+1) Dimensions

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    Path Integral Monte Carlo simulations have been performed for U(1) lattice gauge theory in (2+1) dimensions on anisotropic lattices. We extractthe static quark potential, the string tension and the low-lying "glueball" spectrum.The Euclidean string tension and mass gap decrease exponentially at weakcoupling in excellent agreement with the predictions of Polyakov and G{\" o}pfert and Mack, but their magnitudes are five times bigger than predicted. Extrapolations are made to the extreme anisotropic or Hamiltonian limit, and comparisons are made with previous estimates obtained in the Hamiltonian formulation.Comment: 12 pages, 16 figure

    Associations Between Financial Strain and Emotional Well-Being With Physiological Responses to Acute Mental Stress

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    OBJECTIVE: To investigate associations between financial strain and emotional wellbeing, health, and physiological responses to acute mental stress. METHODS: Participants were 542 healthy men and women aged 53-76y from the Whitehall II study divided into those who reported no (n = 316), some (n =135) or moderate/severe (n = 91) financial strain. Emotional wellbeing and self-reported health were assessed at baseline and 3 years later. Laboratory mental stress testing involved assessment of blood pressure (BP), heart rate, and lipid reactivity and recovery, and plasma interleukin 6 (IL-6) responses to challenging behavioral tasks. Analyses adjusted for objective financial status, age, sex, socioeconomic status (SES) and marital status. RESULTS: Financial strain was positively associated with more depressive symptoms, lower positive affect, greater loneliness, and lower optimism, self-esteem and sense of control, and with poorer self-reported physical health, mental health and sleep (all p <.001). Longitudinally, financial strain predicted poorer outcomes 3 years later, but associations were attenuated after baseline levels were taken into account. Financial strain was associated with reduced systolic and diastolic BP reactivity to acute stress (mean systolic BP increase 32.34 ± 15.2, 28.95 ± 13.1 and 27.26 ± 15.2 mmHg in the none, some, and moderate/severe financial strain groups), but not with heart rate, IL-6 or lipid responses. CONCLUSIONS: Financial strain was correlated with a range of emotional and health-related outcomes independently of objective financial status. The diminished BP reactions to acute mental stress suggest that financial strain may contribute to dynamic chronic allostatic load

    Blood Pressure and Fibrinogen Responses to Mental Stress as Predictors of Incident Hypertension over an 8-Year Period.

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    BACKGROUND: Heightened blood pressure (BP) responses to mental stress predict raised BP levels over subsequent years, but evidence for associations with incident hypertension is limited, and the significance of inflammatory responses is uncertain. PURPOSE: We investigated the relationship between BP and plasma fibrinogen responses to stress and incident hypertension over an average 8-year follow-up. METHOD: Participants were 636 men and women (mean age 59.1 years) from the Whitehall II epidemiological cohort with no history of cardiovascular disease and hypertension. They performed standardized behavioral tasks (color/word conflict and mirror tracing), and hypertension was defined by clinic measures and medication status. RESULTS: Of participants in the highest systolic BP reactivity tertile, 29.3 % became hypertensive over the follow-up period compared with 16.5 % of those in the lowest tertile, with an odds ratio of 2.02 (95 % CI 1.17-3.88, p = 0.012) after adjustment for age, sex, grade of employment, body mass index, smoking, alcohol consumption, physical activity, follow-up time, subjective stress response, perceived task difficulty, perceived task engagement, and baseline BP. Similar associations were observed for diastolic BP reactivity (odds ratio 2.05, 95 % CI 1.23-3.40, p = 0.006) and for impaired systolic BP post-stress recovery (odds ratio 2.06, 95 % CI 1.19-3.57, p = 0.010). Fibrinogen reactions to tasks also predicted future hypertension in women (odds ratio 2.64, 95 % CI 1.11-6.30, p = 0.029) but not men. CONCLUSIONS: These data suggest that heightened cardiovascular and inflammatory reactivity to mental stress is associated with hypertension risk, and may be a mechanism through which psychosocial factors impact on the development of hypertension
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