Showing papers by "Charles E. Matthews published in 2015"
TL;DR: In this article, the authors quantify the dose-response association between leisure time physical activity and mortality and define the upper limit of benefit or harm associated with increased levels of physical activity.
Abstract: Importance The 2008 Physical Activity Guidelines for Americans recommended a minimum of 75 vigorous-intensity or 150 moderate-intensity minutes per week (7.5 metabolic-equivalent hours per week) of aerobic activity for substantial health benefit and suggested additional benefits by doing more than double this amount. However, the upper limit of longevity benefit or possible harm with more physical activity is unclear. Objective To quantify the dose-response association between leisure time physical activity and mortality and define the upper limit of benefit or harm associated with increased levels of physical activity. Design, Setting, and Participants We pooled data from 6 studies in the National Cancer Institute Cohort Consortium (baseline 1992-2003). Population-based prospective cohorts in the United States and Europe with self-reported physical activity were analyzed in 2014. A total of 661 137 men and women (median age, 62 years; range, 21-98 years) and 116 686 deaths were included. We used Cox proportional hazards regression with cohort stratification to generate multivariable-adjusted hazard ratios (HRs) and 95% CIs. Median follow-up time was 14.2 years. Exposures Leisure time moderate- to vigorous-intensity physical activity. Main Outcomes and Measures The upper limit of mortality benefit from high levels of leisure time physical activity. Results Compared with individuals reporting no leisure time physical activity, we observed a 20% lower mortality risk among those performing less than the recommended minimum of 7.5 metabolic-equivalent hours per week (HR, 0.80 [95% CI, 0.78-0.82]), a 31% lower risk at 1 to 2 times the recommended minimum (HR, 0.69 [95% CI, 0.67-0.70]), and a 37% lower risk at 2 to 3 times the minimum (HR, 0.63 [95% CI, 0.62-0.65]). An upper threshold for mortality benefit occurred at 3 to 5 times the physical activity recommendation (HR, 0.61 [95% CI, 0.59-0.62]); however, compared with the recommended minimum, the additional benefit was modest (31% vs 39%). There was no evidence of harm at 10 or more times the recommended minimum (HR, 0.69 [95% CI, 0.59-0.78]). A similar dose-response relationship was observed for mortality due to cardiovascular disease and to cancer. Conclusions and Relevance Meeting the 2008 Physical Activity Guidelines for Americans minimum by either moderate- or vigorous-intensity activities was associated with nearly the maximum longevity benefit. We observed a benefit threshold at approximately 3 to 5 times the recommended leisure time physical activity minimum and no excess risk at 10 or more times the minimum. In regard to mortality, health care professionals should encourage inactive adults to perform leisure time physical activity and do not need to discourage adults who already participate in high-activity levels.
1,086 citations
University of Cambridge1, University of Queensland2, University of South Carolina3, University of Western Australia4, Glasgow Caledonian University5, Baker IDI Heart and Diabetes Institute6, Norwegian School of Sport Sciences7, Loughborough University8, University of South Australia9, University of Massachusetts Amherst10, RMIT University11, Children's Hospital of Eastern Ontario12, University of Ottawa13
TL;DR: This research highlights the need to understand more fully the rationale behind the continued use of these devices, as well as their applications in the field of medicine and sport.
Abstract: WIJNDAELE, K., K. WESTGATE, S. K. STEPHENS, S. N. BLAIR, F. C. BULL, S. F. M. CHASTIN, D. W. DUNSTAN, U. EKELUND, D. W. ESLIGER, P. S. FREEDSON, M. H. GRANAT, C. E. MATTHEWS, N. OWEN, A. V. ROWLANDS, L. B. SHERAR, M. S. TREMBLAY, R. P. TROIANO, S. BRAGE, and G. N. HEALY. Utilization and Harmonization of Adult Accelerometry Data: Review and Expert Consensus. Med. Sci. Sports Exerc., Vol. 47, No. 10, pp. 2129–2139, 2015. Purpose: This study aimed to describe the scope of accelerometry data collected internationally in adults and to obtain a consensus from measurement experts regarding the optimal strategies to harmonize international accelerometry data. Methods: In March 2014, a comprehensive review was undertaken to identify studies that collected accelerometry data in adults (sample size, n Q 400). In addition, 20 physical activity experts were invited to participate in a twophase Delphi process to obtain consensus on the following: unique research opportunities available with such data, additional data required to address these opportunities, strategies for enabling comparisons between studies/countries, requirements for implementing/progressing such strategies, and value of a global repository of accelerometry data. Results: The review identified accelerometry data from more than 275,000 adults from 76 studies across 36 countries. Consensus was achieved after two rounds of the Delphi process; 18 experts participated in one or both rounds. The key opportunities highlighted were the ability for cross-country/cross-population comparisons and the analytic options available with the larger heterogeneity and greater statistical power. Basic sociodemographic and anthropometric data were considered a prerequisite for this. Disclosure of monitor specifications and protocols for data collection and processing were deemed essential to enable comparison and data harmonization. There was strong consensus that standardization of data collection, processing, and analytical procedures was needed. To implement these strategies, communication and consensus among researchers, development of an online infrastructure, and methodological comparison work were required. There was consensus that a global accelerometry data repository
212 citations
TL;DR: Physical activity intervention strategies for older adults often focus on aerobic exercise, but the findings suggest that reducing sitting time and engaging in a variety of activities is also important, particularly for inactive adults.
Abstract: MATTHEWS, C. E., S. C. MOORE, J. SAMPSON, A. BLAIR, Q. XIAO, S. K. KEADLE, A. HOLLENBECK, and Y. PARK. Mortality Benefits for Replacing Sitting Time with Different Physical Activities. Med. Sci. Sports Exerc., Vol. 47, No. 9, pp. 1833–1840, 2015. Purpose: Prolonged sitting has emerged as a risk factor for early mortality, but the extent of benefit realized by replacing sitting time with exercise or activities of everyday living (i.e., nonexercise activities) is not known. Methods: We prospectively followed 154,614 older adults (59–82 yr) in the National Institutes of Health-AARP Diet and Health Study who reported no major chronic diseases at baseline and reported detailed information about sitting time, exercise, and nonexercise activities. Proportional hazard models were used to estimate adjusted hazard ratios and 95% confidence intervals (HR (95% confidence interval)) for mortality. An isotemporal modeling approach was used to estimate associations for replacing sitting time with specific types of physical activity, with separate models fit for less active and more active participants to accou nt for nonlinear associations. Results: During 6.8 yr (SD, 1.0) of follow-up, 12,201 deaths occurred. Greater sitting time (Q12 vs G 5h Id j1 ) was associated with increased risk for all-cause and cardiovascular mortality. In less active adults (G 2h Id j1 total activity), replacing 1 hId j1 of sitting with an equal amount of activity was associated with lower all-cause mortality for both exercise (HR, 0.58 (0.54–0.63)) and nonexercise activities (HR, 0.70 (0.66–0.74)), including household chores, lawn and garden work, and daily walking. Among more active participants (2+ hId j1 total activity), replacement of sitting time with purposeful exercise was associated with lower mortality (HR, 0.91 (0.88–0.94)) but not with nonexercise activity (HR, 1.00 (0.98–1.02)). Similar results were noted for cardiovascular mortality. Conclusions: Physical activity intervention strategies for older adults often focus on aerobic exercise, but our findings suggest that reducing sitting time and
152 citations
TL;DR: In both men and women, adherence to the ACS guidelines was associated with reductions in all-cancer incidence and the incidence of cancer at specific sites, as well as with reduction in cancer mortality and total mortality, and these data suggest that, after accounting for cigarette smoking, adhere to a set of healthy behaviors may have considerable health benefits.
121 citations
TL;DR: A novel liquid chromatography-tandem mass spectrometry (LC-MS/MS) assay was developed to measure concurrently all 15 estrogens and estrogen metabolites in human serum and urine, as unconjugated and total concentrations, and demonstrated that enhanced 2-hydroxylation of parent estrogens (estrone+estradiol) is associated with reduced risk of postmenopausal breast cancer.
77 citations
TL;DR: In this paper, the authors examined the association between TV viewing and leading causes of death in the U.S. and found that TV viewing is the most prevalent sedentary behavior and is associated with increased risk of cardiovascular disease and cancer mortality.
50 citations
TL;DR: It is confirmed that prolonged television viewing time was associated with greater mortality in older adults and it is demonstrated for the first time that individuals who reduced the amount of time they spent watching television had lower mortality.
Abstract: Television viewing is a highly prevalent sedentary behavior among older adults, yet the mortality risks associated with hours of daily viewing over many years and whether increasing or decreasing viewing time affects mortality is unclear. This study examined: 1) the long-term association between mortality and daily viewing time; 2) the influence of reducing and increasing in television viewing time on longevity and 3) combined effects of television viewing and moderate-to-vigorous physical activity (MVPA) on longevity. Participants included 165,087 adults in the NIH-AARP Diet and Health (aged 50–71 yrs) who completed questionnaires at two-time-points (Time 1: 1994–1996, and Time 2: 2004–2006) and were followed until death or December 31, 2011. Multivariable-adjusted Cox proportional hazards regression was used to estimate Hazard Ratios and 95 % confidence intervals (CI) with self-reported television viewing and MVPA and all-cause mortality. Over 6.6 years of follow-up, there were 20,104 deaths. Compared to adults who watched < 3 h/day of television at both time points, mortality risk was 28 % greater (CI:1.21,1.34) those who watched 5+ h/day at both time-points. Decreasing television viewing from 5 + h/day to 3–4 h/d was associated with a 15 % reduction in mortality risk (CI:0.80, 0.91) and decreasing to <3 h/day resulted in an 12 % lower risk (CI:0.79, 0.97). Conversely, adults who increased their viewing time to 3–4 h/day had an 17 % greater mortality risk (CI:1.10, 1.24) and those who increased to 5+ h/day had a 45 % greater risk (CI:1.32, 1.58), compared to those who consistently watched <3 h/day. The lowest mortality risk was observed in those who were consistently active and watched < 3 h/day of television. We confirm that prolonged television viewing time was associated with greater mortality in older adults and demonstrate for the first time that individuals who reduced the amount of time they spent watching television had lower mortality. Our findings provide new evidence to support behavioral interventions that seek to reduce sedentary television viewing in favor of more physically active pursuits, preferably MVPA. Given the high prevalence of physical inactivity and prolonged television viewing in older adults, favorable changes in these two modifiable behaviors could have substantial public health impact. ClinicalTrials.gov number, NCT00340015
33 citations
TL;DR: Neither of the surveys should be used as the sole measure of SB in a study; though the YPAS has the ability to rank individuals, providing it with some merit for use in correlational SB research.
Abstract: Background: The purpose of this study was to examine the reliability and validity of 2 currently available physical activity surveys for assessing time spent in sedentary behavior (SB) in older adults. Methods: Fifty-eight adults (≥65 years) completed the Yale Physical Activity Survey for Older Adults (YPAS) and Community Health Activities Model Program for Seniors (CHAMPS) before and after a 10-day period during which they wore an ActiGraph accelerometer (ACC). Intraclass correlation coefficients (ICC) examined test-retest reliability. Overall percent agreement and a kappa statistic examined YPAS validity. Lin’s concordance correlation, Pearson correlation, and Bland-Altman analysis examined CHAMPS validity. Results: Both surveys had moderate test-retest reliability (ICC: YPAS = 0.59 (P < .001), CHAMPS = 0.64 (P < .001)) and significantly underestimated SB time. Agreement between YPAS and ACC was low (κ = −0.0003); however, there was a linear increase (P < .01) in ACC-derived SB time across YPAS response...
32 citations
TL;DR: The finding does not support an association between sleep duration and overall breast cancer risk, however, the effect of sleep on different subtypes of breast cancer deserves further investigation.
Abstract: Short sleep has been hypothesised to increase the risk of breast cancer. However, little is known about the association between sleep and different subtypes of breast cancer defined by hormone receptor status. Among 40 013 women in the Breast Cancer Detection Demonstration Project, including 1846 incident breast cancer cases, we prospectively examined self-reported weekday and weekend sleep duration in relation to breast cancer risk. We used multivariate Cox proportional hazards regression models to estimate relative risks (RRs) and 95% confidence intervals (CIs). We found no association between sleep and overall breast cancer. However, we observed a decreased risk of ER+PR+ breast cancer (RR <6 vs 8 – 9 h (95% CI): 0.54 (0.31, 0.93), P for trend, 0.003) with shorter sleep duration. Our finding does not support an association between sleep duration and overall breast cancer risk. However, the effect of sleep on different subtypes of breast cancer deserves further investigation.
25 citations
TL;DR: It is suggested that increasing PA and decreasing ST may help extend survival among individuals with diabetes irrespective of race and sex.
21 citations
TL;DR: It is suggested that a single spot urine sample is not sufficient to rank exposures to phthalates over several years in an adult urban Chinese population.
TL;DR: No statistically significant associations were observed between OC use, menarche age, age at first birth, parity, menopausal age, and mortality, but an inverse association among baseline current users was found, for both all-cause and CRC-specific mortality.
Abstract: Reproductive and hormonal factors and mortality among women with colorectal cancer in the NIH-AARP Diet and Health Study
TL;DR: Correcting measurement error in self-reported physical activity levels strengthened the associations of physical activity with both obesity and diabetes by 30%-50% compared with using the self- reported questionnaire data alone.
Abstract: Measurement error in self-reported data from questionnaires is a well-recognized challenge in studies of physical activity and health. In this issue of the Journal, Lim et al. (Am J Epidemiol. 2015;181(9):648-655) used data from accelerometers in a small measurement study to correct self-reported physical activity data from a larger study of adults from New York City and to develop an error correction model. They showed that correction of measurement error in self-reported physical activity levels strengthened the associations of physical activity with both obesity and diabetes by 30%-50% compared with using the self-reported questionnaire data alone. Thus, Lim et al. demonstrated a method to improve potentially biased estimates of the association between self-reported physical activity and disease. However, as this field develops, we feel it is important to call attention to a sometimes overlooked problem that occurs when comparing these instruments: Questionnaires and accelerometers are often calibrated (i.e., designed) to measure different types of physical activity, and accelerometers are still subject to measurement error. Thus, physical activity estimates corrected with an imperfect accelerometer measurement might over- or undercorrect the strength of the associations. We take this opportunity to further comment on physical activity measurement in epidemiologic studies and the implications for research.
TL;DR: Physical activity alone may not confer protection against male breast cancer risk and neither medium nor high PA was associated with risk among high BMI men, but normal BMI men with low or medium LTPA were at a nonsignificant reduced risk.
Abstract: The association between leisure-time physical activity (LTPA) and male breast cancer risk is unclear. In the Male Breast Cancer Pooling Project, with 449 cases and 13,855 matched controls, we used logistic regression with study stratification to generate adjusted ORs and 95% confidence intervals (CI) for LTPA tertiles and male breast cancer risk. Compared with low LTPA, medium and high LTPA were not associated with male breast cancer risk (OR, 1.01; 95% CI, 0.79-1.29; 0.90, 0.69-1.18, respectively). In joint-effects analyses, compared with the referent of high body mass index (BMI; ≥25 kg/m(2))/low LTPA, neither medium nor high PA was associated with risk among high BMI men, but normal BMI men (<25 kg/m(2)) with low or medium LTPA were at a nonsignificant ∼16% reduced risk and those with high LTPA were at a 27% reduced risk (OR, 0.73; 95% CI, 0.50-1.07). Physical activity alone may not confer protection against male breast cancer risk.
TL;DR: The study found no association between sleep duration and hormone receptor-positive tumours, which is consistent with the only two studies that examined sleep duration in relation to breast cancer subtypes defined by hormone receptor status, and found an increased risk associated with short sleep durations for hormones receptor-negative breast cancers.
Abstract: Sir,
We thank Yang et al (2015) for their interest in and thoughtful review of our study. We agree with the correspondents that certain limitations should be considered when interpreting findings on sleep duration and breast cancer risk. As we acknowledged in our paper, self-reported sleep duration involving measurement error could lead to misclassification of our main exposure. We agree with Yang et al that misclassification can lead to bias in either direction. However, in our case, we believe the bias is more likely to be towards the null. A validation study by Lauderdale et al (2008) compared self-reported sleep duration to an objective measure (actigraphy), and found that the validity of self-reported sleep varied by the amount of sleep recorded. In general people tended to over-report their sleep duration, but the extent of over-reporting increased as sleep duration decreased. Therefore, short sleepers were at a higher risk of being misclassified as normal or long sleepers, which might have led to an inability to detect an increased risk of breast cancer among such individuals. Of course, regardless of the direction of the bias, misclassification of exposure is an important problem to consider, and we appreciate that Yang et al highlighted this particular element of our report. Moreover, we also agree with the correspondents that it is important to measure sleep at different time points in order to get a better estimate of long-term sleep duration, and to consider other sleep characteristics and sleep-related factors, such as sleep quality and exposure to light at night.
We are aware of the discrepancy between our findings and the melatonin hypothesis, which suggests that short sleep duration is associated with decreased levels of melatonin. Because melatonin is a molecule with anti-oestrogenic effects, decreased levels of melatonin may increase the risk of ER+ tumours (Blask, 2009). We found no association between sleep duration and hormone receptor-positive tumours, which is consistent with the only two studies that examined sleep duration in relation to breast cancer subtypes defined by hormone receptor status. Notably, both studies, an Australian case–control study and a study in the Women's Health Initiative, showed no relationship between sleep duration and ER+ tumours (Girschik et al, 2013; Vogtmann et al, 2013). In contrast, we found an increased risk associated with short sleep durations for hormone receptor-negative breast cancers. Although we cannot exclude the possibility that our finding is due to bias or chance, we believe that there are biological mechanisms that support this observed association. For example, short sleep and sleep deprivation have been associated with factors that may influence breast cancer risk independent of oestrogen pathways, such as metabolic dysfunction (Gangwisch et al, 2007) and chronic inflammation (Irwin et al, 2006).
Again, we thank Yang et al for this letter and are glad that more studies, such as the population-based case–control study in Jiujiang city mentioned by Yang et al, are using objective measures along with questionnaires to better assess both the quantity and quality of sleep in relation to breast cancer risk and other health outcomes.