The Associations Between Seven Different Types of Physical Activity and the Incidence of Fracture at Seven Sites in Healthy Postmenopausal UK Women.

There is a paucity of information on associations between specific types of physical activity and fracture risk at different sites in otherwise healthy postmenopausal women. Therefore, we examined risk of fracture at seven different sites associated with seven different types of physical activity in the population-based prospective UK Million Women Study. A total of 371,279 postmenopausal women (mean age 59.8 years), rating their health as good or excellent and reporting participation in walking, cycling, gardening, doing housework, yoga, dance, and sports club activities, were followed for site-specific incident fracture through record linkage to national databases on day-case and overnight hospital admissions. Cox regression yielded adjusted relative risks (RRs) and, because of the large number of statistical tests done, 99% confidence intervals (CIs) for fracture at seven different sites in relation to seven different physical activities. During an average follow-up of 12 years, numbers with a first site-specific fracture were as follows: humerus (2341), forearm (1238), wrist (7358), hip (4354), femur (not neck) (617), lower leg (1184), and ankle (3629). For upper limb fractures there was significant heterogeneity across the seven activity types (test for heterogeneity p = 0.004), with gardening more than 1 hour/week associated with a lower risk (RR = 0.91; 99% CI, 0.86 to 0.96; p < 0.0001), whereas cycling more than 1 hour/week was associated with an increased risk (RR = 1.11; 99% CI, 1.00 to 1.23; p = 0.008). For fractures of the lower limb (including hip) there was no significant heterogeneity by type of activity, with significant approximately 5% to 15% reductions in risk associated with most activities, except cycling. For hip fractures, there was no significant heterogeneity by type of activity, but with significant 15% to 20% reductions in risk associated with walking for 1 hour/day and participating in yoga and sporting activities. Physical activity is a modifiable risk factor for fracture, but the effects differ between different types of activities and different fracture sites. © 2019 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

The impact of physical activity and an additional behavioural risk factor on cardiovascular disease, cancer and all-cause mortality: a systematic review.

BACKGROUND: Regular physical activity improves overall health, and has the capacity to reduce risk of chronic diseases and death. However, better understanding of the relationship between multiple lifestyle risk behaviours and disease outcomes is pertinent for prioritising public health messaging. The aim of this systematic review is to examine the association between physical inactivity in combination with additional lifestyle risk behaviours (smoking, alcohol, diet, or sedentary behaviour) for cardiovascular disease, cancer, and all-cause mortality. METHODS: We searched Ovid Medline, EMBASE, and the Cochrane Register from 1 January 2010 to 12 December 2017, for longitudinal observational studies of adults (18+ years) in the general population with a publication date of 2010 onwards and no language restriction. Main exposure variables had to include a physical activity measure plus at least one other lifestyle risk factor. In total, 25,639 studies were identified. Titles, abstracts and full-text articles of potentially relevant papers were screened for eligibility. Data was extracted and quality assessment was completed using a modified Newcastle-Ottawa Scale (NOS). RESULTS: Across the 25 eligible studies, those participants who reported being physically active combined with achieving other health behaviour goals compared to those who were categorised as physically inactive and did not achieve other positive lifestyle goals, were at least half as likely to experience an incident cardiovascular disease (CVD) event, die from CVD, or die from any cause. These findings were consistent across participant age, sex, and study length of follow-up, and even after excluding lower quality studies. We also observed a similar trend among the few studies which were restricted to cancer outcomes. Most studies did not consider epidemiological challenges that may bias findings, such as residual confounding, reverse causality by pre-existing disease, and measurement error from self-report data. CONCLUSIONS: High levels of physical activity in combination with other positive lifestyle choices is associated with better health outcomes. Applying new approaches to studying the complex relationships between multiple behavioural risk factors, including physical activity, should be a priority.

Profiling sedentary behavior in breast cancer survivors: Links with depression symptoms during the early survivorship period.

OBJECTIVE: Depression symptoms are prevalent among breast cancer survivors (BCS). Reducing sedentary behavior (SED) may be a non-pharmaceutical strategy for alleviating depression symptoms. However, little is known about SED among BCS. The present study aimed to: (i) describe SED behaviors among BCS and identify unique SED groups based on different SED dimensions; (ii) identify personal and cancer-specific factors that discriminate SED clusters; and (iii) examine the association between SED clusters and depression symptoms. METHODS: Baseline self-report demographic and medical information was collected from 187 BCS. SED and physical activity were assessed over seven days using an accelerometer. Self-reported depression symptoms were reported three months later. Multiple dimensions of SED were identified and examined in cluster analysis. The clusters were examined for differences using multivariate analysis of variance and chi-square analyses. The difference in depression symptoms among SED groups was assessed using an analysis of covariance. RESULTS: High and low SED groups were identified. Survivors in the high SED cluster were significantly older, heavier, less physically active, reported less education, and were more likely to have undergone lymph/axial node dissection. Women in the high SED cluster reported significantly higher depression symptoms prospectively (M = 9.50, SD = 6.07) compared to women in the low SED group (M = 6.89, SD = 5.18), F(8,179) = 4.97, p = 0.03, R2  = 0.34. CONCLUSIONS: The importance of understanding multiple dimensions of SED among BCS was highlighted. Reducing SED during the early survivorship period may alleviate depression symptoms.

The Effects of Age, Adiposity, and Physical Activity on the Risk of Seven Site-Specific Fractures in Postmenopausal Women.

Risk factors for fracture of the neck of the femur are relatively well established, but those for fracture at other sites are little studied. In this large population study we explore the role of age, body mass index (BMI), and physical activity on the risk of fracture at seven sites in postmenopausal women. As part of the Million Women Study, 1,154,821 postmenopausal UK women with a mean age of 56.0 (SD 4.8) years provided health and lifestyle data at recruitment in 1996 to 2001. All participants were linked to National Health Service (NHS) hospital records for day-case or overnight admissions with a mean follow-up of 11 years per woman. Adjusted absolute and relative risks for seven site-specific incident fractures were calculated using Cox regression models. During follow-up, 4931 women had a fracture of the humerus; 2926 of the forearm; 15,883 of the wrist; 9887 of the neck of the femur; 1166 of the femur (not neck); 3199 a lower leg fracture; and 10,092 an ankle fracture. Age-specific incidence rates increased gradually with age for fractures of forearm, lower leg, ankle, and femur (not neck), and steeply with age for fractures of neck of femur, wrist, and humerus. When compared to women with desirable BMI (20.0 to 24.9 kg/m(2) ), higher BMI was associated with a reduced risk of fracture of the neck of femur, forearm, and wrist, but an increased risk of humerus, femur (not neck), lower leg, and ankle fractures (p < 0.001 for all). Strenuous activity was significantly associated with a decreased risk of fracture of the humerus and femur (both neck and remainder of femur) (p < 0.001), but was not significantly associated with lower leg, ankle, wrist, and forearm fractures. Postmenopausal women are at a high lifetime risk of fracture. BMI and physical activity are modifiable risk factors for fracture, but their associations with fracture risk differ substantially across fracture sites. © 2016 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research (ASBMR).

The use of the Godin-Shephard Leisure-Time Physical Activity Questionnaire in oncology research: a systematic review.

BACKGROUND: The Godin-Shephard Leisure-Time Physical Activity Questionnaire (GSLTPAQ) is one of the most often used questionnaires in oncology research, yet modifications to the scale are done with little evidence of psychometric testing. This study aimed to (i) document the frequency of use of the questionnaire for ranking (i.e., level of activity) and classification (i.e., active versus insufficiently active) purposes, (ii) summarize how the GSLTPAQ is used in terms of item content and scoring, and (iii) evaluate the extent to which validity evidence supports the use of the scale among cancer survivors. METHODS: A systematic review was conducted with evidence drawn from English-written articles published between January 1(st) 1985 (year the GSLTPAQ was published) and December 31, 2014. A search of six databases, a scan of reference list of included articles, and a cited reference search identified articles that reported using the GSLTPAQ among cancer survivors. RESULTS: A total of 212 articles were retrieved. The GSLTPAQ was used for classifying cancer survivors into active and insufficiently active categories in 51 % of the articles. Moreover, a modified version of the questionnaire was used in 81 % of the research studies. Three studies reported validity evidence based on the relationship between the scores on the GSLTPAQ (i.e., leisure score index, LSI) and accelerometer or pedometer-derived activity data. Validity evidence supporting the use of the GSLTPAQ for assessing changes in LSI was computed from six randomized trials. CONCLUSIONS: The use of the GSLTPAQ for classification purpose in oncology research is common. Standardization in the use and interpretation of the GSLTPAQ in oncology research is warranted. Although limited, there is support for using the original form of the GSLTPAQ and interpreting the LSI for ranking cancer survivors from the lowest to highest levels of leisure-time physical activity.

Validation of the Godin-Shephard Leisure-Time Physical Activity Questionnaire classification coding system using accelerometer assessment among breast cancer survivors.

PURPOSE: The aim of this research was to provide convergent validity evidence for the use of the Godin-Shephard Leisure-Time Physical Activity Questionnaire (GSLTPAQ) to classify breast cancer survivors into active and insufficiently active categories. METHODS: Data were collected among a sample of breast cancer survivors (N = 199; mean age = 55 years) to examine the association between physical activity assessed with a GT3X triaxial accelerometer and the use of the GSLTPAQ's coding system recently proposed by Godin (2011). Participants self-reported moderate and vigorous physical activity (MVPA) performed in a typical week on the GSLTPAQ and those with MVPA leisure score index ≥ 24 were classified as active. RESULTS: ANCOVA revealed that the adjusted mean [95% CI] number of recorded MVPA minutes was higher for respondents classified as active (145.54 [127.26; 163.83]) compared to respondents classified as insufficiently active (86.99 [74.04; 99.94]). The GSLTPAQ and accelerometer classified 33.8 and 27.2% of participants as active, respectively (agreement = 70.8%). Sensitivity and specificity values were 75.3 and 58.5%, respectively. CONCLUSION: The GSLTPAQ can be used to classify cancer survivors into active and insufficiently active categories in reference to cancer survivors' physical activity guidelines. However, it has greater capacity to correctly identify insufficiently active respondents. IMPLICATIONS FOR CANCER SURVIVORS: The use of the GSLTPAQ's classification coding in oncology research could improve the quality of physical activity recommendations and interventions handed out to cancer survivors.

Physical and psychological health among breast cancer survivors: interactions with sedentary behavior and physical activity.

BACKGROUND: Reducing sedentary behavior (SED) may be one promising strategy to reduce treatment-related side effects in breast cancer given the unique health benefits distinct from the beneficial effects of moderate-to-vigorous intensity physical activity (MVPA). OBJECTIVES: To examine the associations between SED and the late-effects symptoms of pain, fatigue, and depression among breast cancer survivors (BCS), and the interactive associations between SED, light PA, and MVPA on these symptoms. METHODS: One hundred and ninety-five BCS provided baseline data 3 to 4 months post-systemic treatment, as part of the Life After Breast Cancer: Moving On longitudinal study. Pain, fatigue, and depression symptoms were assessed using validated self-report questionnaires. Objective measures of MVPA, light PA, and SED (i.e. sitting time) were assessed by accelerometers over the same period. Self-reported demographic and medical variables were collected. RESULTS: In hierarchical multiple regression analyses, the interaction effect of MVPA by SED was significantly associated with pain (p = .02), fatigue (p = .01), and depression (p = .006). Follow-up simple slope analyses demonstrated that among BCS with lower levels of MVPA, higher levels of SED significantly predicted higher levels of fatigue (p < .001), higher levels of pain (p = .06), and higher levels of depression (p = .08). CONCLUSIONS: SED was associated with higher levels of fatigue, pain, and depression in BCS, and was more pronounced among those with lower levels of MVPA. However, SED was not associated with these symptoms among BCS with higher levels of MVPA. Pairing health promotion messages to reduce SED and increase MVPA are likely to result in better symptom management. Copyright © 2015 John Wiley & Sons, Ltd.

Selfing for the design of genomic selection experiments in biparental plant populations.

Self-fertilization (selfing) is commonly used for population development in plant breeding, and it is well established that selfing increases genetic variance between lines, thus increasing response to phenotypic selection. Furthermore, numerous studies have explored how selfing can be deployed to maximal benefit in the context of traditional plant breeding programs (Cornish in Heredity 65:201-211,1990a, Heredity 65:213-220,1990b; Liu et al. in Theor Appl Genet 109:370-376, 2004; Pooni and Jinks in Heredity 54:255-260, 1985). However, the impact of selfing on response to genomic selection has not been explored. In the current study we examined how selfing impacts the two key aspects of genomic selection-GEBV prediction (training) and selection response. We reach the following conclusions: (1) On average, selfing increases genomic selection gains by more than 70 %. (2) The gains in genomic selection response attributable to selfing hold over a wide range population sizes (100-500), heritabilities (0.2-0.8), and selection intensities (0.01-0.1). However, the benefits of selfing are dramatically reduced as the number of QTLs drops below 20. (3) The major cause of the improved response to genomic selection with selfing is through an increase in the occurrence of superior genotypes and not through improved GEBV predictions. While performance of the training population improves with selfing (especially with low heritability and small population sizes), the magnitude of these improvements is relatively small compared with improvements observed in the selection population. To illustrate the value of these insights, we propose a practical genomic selection scheme that substantially shortens the number of generations required to fully capture the benefits of selfing. Specifically, we provide simulation evidence that indicates the proposed scheme matches or exceeds the selection gains observed in advanced populations (i.e. F 8 and doubled haploid) across a broad range of heritability and QTL models. Without sacrificing selection gains, we also predict that fully inbred candidates for potential commercialization can be identified as early as the F 4 generation.

Location-dependent empirical thresholds for quantitative trait mapping.

The Churchill-Doerge approach toward constructing empirical thresholds has received widespread use in the genetic mapping literature through the past 16 years. The method is valued for both its simplicity and its ability to preserve the genome-wide error rate at a prespecified level. However, the Churchill-Doerge method is not designed to maintain the local (comparison-wise) error rate at a constant level except in situations that are unlikely to occur in practice. In this article, we introduce the objective of preserving the local error rate at a constant level in the context of mapping quantitative trait loci in linkage populations. We derive a method that preserves the local error rate at a constant level, provide an application via simulation on a Hordeum vulgare population, and demonstrate evidence of the relationship between recombination and location bias. Furthermore, we indicate that this method is equivalent to the Churchill-Doerge method when several assumptions are satisfied.

On the choice of prior density for the Bayesian analysis of pedigree structure.

This article is concerned with the choice of structural prior density for use in a fully Bayesian approach to pedigree inference. It is found that the choice of prior has considerable influence on the accuracy of the estimation. To guide this choice, a scale invariance property is introduced. Under a structural prior with this property, the marginal prior distribution of the local properties of a pedigree node (number of parents, offspring, etc.) does not depend on the number of nodes in the pedigree. Such priors are found to arise naturally by an application of the Minimum Description Length (MDL) principle, under which construction of a prior becomes equivalent to the problem of determining the length of a code required to encode a pedigree, using the principles of information theory. The approach is demonstrated using simulated and actual data, and is compared to two well-known applications, CERVUS and COLONY.