Physical activity and sedentary behavior assessment: A laboratory-based evaluation of agreement between commonly used actigraph and omron accelerometers

Different models of accelerometer have the potential to provide a different estimate of the same physical activity or sedentary behavior. Our study compared the outputs of the Active Style Pro (ASP) and ActiGraph (AG) devices in assessing predicted metabolic equivalents (METs) for specific activities under laboratory conditions. Thirty healthy young adults wore two hip accelerometers (ASP and AG), simultaneously while performing twenty-two activities (eight sedentary, eight household, and six ambulatory activities) in a controlled laboratory setting. For the AG, predicted METs for each activity was calculated using four equations based on vertical-axis and vector magnitude data. Separate paired t-tests and Bland–Altman analysis examined the difference and agreement in METs between AG using four commonly used equations and ASP measurements for each activity. AG devices using different equations calculated significantly different outcomes for most activities compared with ASP devices. The smallest differences in predicted METs estimates between ASP and AG were observed for ambulatory activities. Ambulatory activities demonstrated the best agreement between ASP and AG regardless of which AG equation was used. Our findings can be used to assist researchers in their selection of accelerometer and output estimation equations for measuring physical activity and sedentary behavior in adults

Dog-walking in dense compact areas: The role of neighbourhood built environment

There is a dearth of evidence about how high-density living may influence dog-walking behaviour. We examined associations between neighbourhood built environment attributes and dog-ownership and dog-walking behaviour in Japan. Data from 1058 participants were used. The dog-ownership was 18.8%. All neighbourhood built attributes (excluding availability of parks) were negatively associated with dog-ownership. Among dog-owners, these same attributes were positively associated with any dog-walking in a usual week and with achieving 150-min per week of physical activity through dog-walking alone. These findings provided evidence on the importance of neighbourhood built environment attributes on dog-ownership and dog-walking behaviour in dense and compact areas. The urban design and public health implication of these findings is that the built environment attributes in high-density living areas may have different impacts on dog-ownership and dog-walking: while living in a walkable neighbourhood may not be conducive to dog-ownership, it may support dog-walking in such areas. Programs targeting dog-owners in high-density areas might be needed to encourage them to walk their dogs more. If successful, these programs could contribute to higher physical activity levels among dog-owners

Built environment correlates of objectively-measured sedentary behaviours in densely-populated areas

Few studies examine associations between objectively-calculated neighbourhood built environment attributes and objectively-assessed sedentary behaviour in different geographical locations, especially in highly-populated environments. Additionally, no study, to our knowledge, has investigated associations between objective measures of neighbourhood built environment attributes and objectively-assessed sedentary behaviours in middle-aged adults, despite the fact that this is a critical stage of life when age-related functional decline begins. We examined the associations between neighbourhood built environment attributes with the total, and patterns of, objectively-assessed sedentary behaviours in a densely-populated area in Asia. Data from 866 adults (ages 40 to 64) living in Japan were included. Four classifications of sedentary behaviours, including daily total sedentary time, duration and number of long (≥30 min) sedentary bouts and breaks per sedentary hour, were estimated using hip-worn accelerometers. Individual (population density, availability of destinations, number of intersections, and distance to the nearest park) and composite (walkability and Walk Score®) neighbourhood built environment indices were calculated using geographic information systems. Covariate-adjusted multilevel linear mixed effects models were used to estimate the associations between the neighbourhood built environment attributes and sedentary behaviours. Population density and availability of destinations were positively associated with sedentary behaviours; however, the number of intersections was negatively associated with sedentary behaviours. No associations were observed between the distance to the nearest park and sedentary behaviours. There were positive associations between walkability and total sedentary time, and duration and the number of long sedentary bouts. Walk Score® was positively associated with total sedentary time and the number of long sedentary bouts. These findings suggest that urban design attributes supportive of walking (except for the number of intersections) may encourage sedentary behaviour among middle-aged adults living in densely-populated environments.</p

Urban design and Japanese older adults\u27 depressive symptoms

Despite associations found between physical activity and depression, and the built environment and physical activity, there appears to be inconclusive evidence regarding the role of built environment attributes with preventing depression among the elderly. This is mainly because few studies exist on this topic. In addition, the majority of existing studies have been conducted in Western countries; and there is a dearth of studies in other regions, where the built, social, and cultural environment is different than Western countries. Using data from Japanese older adults, this study examined the associations between objectively-assessed built environment attributes and depressive symptoms. We examined these associations stratified by gender, since research has well-documented gender differences in depression. Data were from 328 older adults living in Japan. Built environment attributes were objectively calculated and Walk Score® ratings were obtained from the website. Depressive symptoms were assessed using the GDS-15. Gender-stratified regression models were used to estimate the associations. We found that a walkable environment characterized by a high population density and proximate local destinations to be supportive for a better mental health among older adults, in particular for women. These findings suggest that walkable built environment attributes may influence depression among older women in an Asian urban context. This study contributed to the literature by examining how walkable urban design may influence elderly\u27s depression in a setting with extreme level of environmental attributes. Investing in urban design to promote walkability may help in reducing the observed gender gap in depression in the Japanese population

Perceived Environmental Factors Associated with Physical Activity among Normal-Weight and Overweight Japanese Men

Although it is crucial to examine the environmental correlates of physical activity (PA) for developing more effective interventions for overweight populations, limited studies have investigated differences in the environmental correlates on body mass index (BMI). The purpose of the present study was to examine the perceived environmental correlates of PA among normal-weight and overweight Japanese men. Data were analyzed for 1,420 men (aged 44.4 ± 8.3 years), who responded to an internet-based cross-sectional survey of answering the short version of the International Physical Activity Questionnaire and its Environment Module. Binary logistic regression analyses were utilized to examine the environmental factors associated with meeting the PA recommendation (150 minutes/week) between the normal-weight and overweight men. After adjusting for socio-demographic variables, common and different environmental correlates of PA were observed among normal-weight and overweight men. Furthermore, significant interactions regarding PA were observed between BMI status and two environmental correlates: access to public transportation (P = 0.03) and crime safety during the day (P = 0.01). The results indicated that BMI status is a potential moderator between perceived environmental factors and PA and suggested that different environmental intervention approaches should be developed for overweight populations

The Mitochondrial Ca(2+) Uniporter: Structure, Function, and Pharmacology.

Mitochondrial Ca(2+) uptake is crucial for an array of cellular functions while an imbalance can elicit cell death. In this chapter, we briefly reviewed the various modes of mitochondrial Ca(2+) uptake and our current understanding of mitochondrial Ca(2+) homeostasis in regards to cell physiology and pathophysiology. Further, this chapter focuses on the molecular identities, intracellular regulators as well as the pharmacology of mitochondrial Ca(2+) uniporter complex

The Flagellum of Pseudomonas aeruginosa Is Required for Resistance to Clearance by Surfactant Protein A

Surfactant protein A (SP-A) is an important lung innate immune protein that kills microbial pathogens by opsonization and membrane permeabilization. We investigated the basis of SP-A-mediated pulmonary clearance of Pseudomonas aeruginosa using genetically-engineered SP-A mice and a library of signature-tagged P. aeruginosa mutants. A mutant with an insertion into flgE, the gene that encodes flagellar hook protein, was preferentially cleared by the SP-A(+/+) mice, but survived in the SP-A(-/-) mice. Opsonization by SP-A did not play a role in flgE clearance. However, exposure to SP-A directly permeabilized and killed the flgE mutant, but not the wild-type parental strain. P. aeruginosa strains with mutation in other flagellar genes, as well as mucoid, nonmotile isolates from cystic fibrosis patients, were also permeabilized by SP-A. Provision of the wild-type fliC gene restored the resistance to SP-A-mediated membrane permeabilization in the fliC-deficient bacteria. In addition, non-mucoid, motile revertants of CF isolates reacquired resistance to SP-A-mediated membrane permeability. Resistance to SP-A was dependent on the presence of an intact flagellar structure, and independent of flagellar-dependent motility. We provide evidence that flagellar-deficient mutants harbor inadequate amounts of LPS required to resist membrane permeabilization by SP-A and cellular lysis by detergent targeting bacterial outer membranes. Thus, the flagellum of P. aeruginosa plays an indirect but important role resisting SP-A-mediated clearance and membrane permeabilization

Serum albumin and osmolality inhibit Bdellovibrio bacteriovorus predation in human serum

We evaluated the bactericidal activity of Bdellovibrio bacteriovorus, strain HD100, within blood sera against bacterial strains commonly associated with bacteremic infections, including E. coli, Klebsiella pneumoniae and Salmonella enterica. Tests show that B. bacteriovorus HD100 is not susceptible to serum complement or its bactericidal activity. After a two hour exposure to human sera, the prey populations decreased 15- to 7,300-fold due to the serum complement activity while, in contrast, the B. bacteriovorus HD100 population showed a loss of only 33%. Dot blot analyses showed that this is not due to the absence of antibodies against this predator. Predation in human serum was inhibited, though, by both the osmolality and serum albumin. The activity of B. bacteriovorus HD100 showed a sharp transition between 200 and 250 mOsm/kg, and was progressively reduced as the osmolality increased. Serum albumin also acted to inhibit predation by binding to and coating the predatory cells. This was confirmed via dot blot analyses and confocal microscopy. The results from both the osmolality and serum albumin tests were incorporated into a numerical model describing bacterial predation of pathogens. In conclusion, both of these factors inhibit predation and, as such, they limit its effectiveness against pathogenic prey located within sera

Mammographic density and risk of breast cancer according to tumor characteristics and mode of detection: a Spanish population-based case-control study

It is not clear whether high mammographic density (MD) is equally associated with all subtypes of breast cancer (BC). We investigated the association between MD and subsequent BC, considering invasiveness, means of detection, pathologic subtype, and the time elapsed since mammographic exploration and BC diagnosis. METHODS: BC cases occurring in the population of women who attended screening from 1997 through 2004 in Navarre, a Spanish region with a fully consolidated screening program, were identified via record linkage with the Navarre Cancer Registry (n = 1,172). Information was extracted from the records of their first attendance at screening in that period. For each case, we randomly selected four controls, matched by screening round, year of birth, and place of residence. Cases were classified according to invasiveness (ductal carcinoma in situ (DCIS) versus invasive tumors), pathologic subtype (considering hormonal receptors and HER2), and type of diagnosis (screen-detected versus interval cases). MD was evaluated by a single, experienced radiologist by using a semiquantitative scale. Data on BC risk factors were obtained by the screening program in the corresponding round. The association between MD and tumor subtype was assessed by using conditional logistic regression. RESULTS: MD was clearly associated with subsequent BC. The odds ratio (OR) for the highest MD category (MD >75%) compared with the reference category (MD <10%) was similar for DCIS (OR = 3.47; 95% CI = 1.46 to 8.27) and invasive tumors (OR = 2.95; 95% CI = 2.01 to 4.35). The excess risk was particularly high for interval cases (OR = 7.72; 95% CI = 4.02 to 14.81) in comparison with screened detected tumors (OR = 2.17; 95% CI = 1.40 to 3.36). Sensitivity analyses excluding interval cases diagnosed in the first year after MD assessment or immediately after an early recall to screening yielded similar results. No differences were seen regarding pathologic subtypes. The excess risk associated with MD persisted for at least 7 to 8 years after mammographic exploration. CONCLUSIONS: Our results confirm that MD is an important risk factor for all types of breast cancer. High breast density strongly increases the risk of developing an interval tumor, and this excess risk is not completely explained by a possible masking effect.This work was supported by research grants from Eli Lilly and Company (EV1 1082/08); and the Spanish Federation of Breast Cancer Patients (Federación Española de Cáncer de Mama) (FECMA 485 EPY 1170-10).S

Mammographic density and risk of breast cancer by age and tumor characteristics

Introduction: Understanding whether mammographic density (MD) is associated with all breast tumor subtypes and whether the strength of association varies by age is important for utilizing MD in risk models. Methods: Data were pooled from six studies including 3414 women with breast cancer and 7199 without who underwent screening mammography. Percent MD was assessed from digitized film-screen mammograms using a computer-assisted threshold technique. We used polytomous logistic regression to calculate breast cancer odds according to tumor type, histopathological characteristics, and receptor (estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor (HER2)) status by age (51%) versus average density (11-25%). Women ages 2.1 cm) versus small tumors and positive versus negative lymph node status (P’s < 0.01). For women ages <55 years, there was a stronger association of MD with ER-negative breast cancer than ER-positive tumors compared to women ages 55–64 and ≥65 years (Page-interaction = 0.04). MD was positively associated with both HER2-negative and HER2-positive tumors within each age group. Conclusion: MD is strongly associated with all breast cancer subtypes, but particularly tumors of large size and positive lymph nodes across all ages, and ER-negative status among women ages <55 years, suggesting high MD may play an important role in tumor aggressiveness, especially in younger women