Physical Activity, Cognition, and Brain Outcomes: A Review of the 2018 Physical Activity Guidelines.

PURPOSE: Physical activity (PA) is known to improve cognitive and brain function, but debate continues regarding the consistency and magnitude of its effects, populations and cognitive domains most affected, and parameters necessary to achieve the greatest improvements (e.g., dose). METHODS: In this umbrella review conducted in part for the 2018 Health and Human Services Physical Activity Guidelines for Americans Advisory Committee, we examined whether PA interventions enhance cognitive and brain outcomes across the life span, as well as in populations experiencing cognitive dysfunction (e.g., schizophrenia). Systematic reviews, meta-analyses, and pooled analyses were used. We further examined whether engaging in greater amounts of PA is associated with a reduced risk of developing cognitive impairment and dementia in late adulthood. RESULTS: Moderate evidence from randomized controlled trials indicates an association between moderate- to vigorous-intensity PA and improvements in cognition, including performance on academic achievement and neuropsychological tests, such as those measuring processing speed, memory, and executive function. Strong evidence demonstrates that acute bouts of moderate- to vigorous-intensity PA have transient benefits for cognition during the postrecovery period after exercise. Strong evidence demonstrates that greater amounts of PA are associated with a reduced risk of developing cognitive impairment, including Alzheimer's disease. The strength of the findings varies across the life span and in individuals with medical conditions influencing cognition. CONCLUSIONS: There is moderate-to-strong support that PA benefits cognitive functioning during early and late periods of the life span and in certain populations characterized by cognitive deficits.

Physical Activity to Prevent and Treat Hypertension: A Systematic Review.

PURPOSE: This systematic umbrella review examines and updates the evidence on the relationship between physical activity (PA) and blood pressure (BP) presented in the 2008 Physical Activity Guidelines Advisory Committee Scientific Report. METHODS: We performed a systematic review to identify systematic reviews and meta-analyses involving adults with normal BP, prehypertension, and hypertension published from 2006 to February 2018. RESULTS: In total, 17 meta-analyses and one systematic review with 594,129 adults ≥18 yr qualified. Strong evidence demonstrates: 1) an inverse dose-response relationship between PA and incident hypertension among adults with normal BP; 2) PA reduces the risk of cardiovascular disease (CVD) progression among adults with hypertension; 3) PA reduces BP among adults with normal BP, prehypertension, and hypertension; and 4) the magnitude of the BP response to PA varies by resting BP, with greater benefits among adults with prehypertension than normal BP. Moderate evidence indicates the relationship between resting BP and the magnitude of benefit does not vary by PA type among adults with normal BP, prehypertension, and hypertension. Limited evidence suggests the magnitude of the BP response to PA varies by resting BP among adults with hypertension. Insufficient evidence is available to determine if factors such as sex, age, race/ethnicity, socioeconomic status, and weight status or the frequency, intensity, time, and duration of PA influence the associations between PA and BP. CONCLUSIONS: Future research is needed that adheres to standard BP measurement protocols and classification schemes to better understand the influence of PA on the risk of comorbid conditions, health-related quality of life, and CVD progression and mortality; the interactive effects between PA and antihypertensive medication use; and the immediate BP-lowering benefits of PA.

Physical Activity and the Prevention of Weight Gain in Adults: A Systematic Review.

PURPOSE: To conduct a systematic literature review to determine if physical activity is associated with prevention of weight gain in adults. METHODS: The primary literature search was conducted for the 2018 Physical Activity Guidelines Advisory Committee and encompassed literature through June 2017, with an additional literature search conducted to include literature published through March 2018 for inclusion in this systematic review. RESULTS: The literature review identified 40 articles pertinent to the research question. There is strong evidence of an association between physical activity and prevention of weight gain in adults, with the majority of the evidence from prospective cohort studies. Based on limited evidence in adults, however, there is a dose-response relationship and the prevention of weight gain is most pronounced when moderate-to-vigorous intensity physical activity (≥3 METs) is above 150 min·wk. Although there is strong evidence to demonstrate that the relationship between greater time spent in physical activity and attenuated weight gain in adults is observed with moderate-to-vigorous intensity physical activity, there is insufficient evidence available to determine if there is an association between light-intensity activity (<3 METs) and attenuated weight gain in adults. CONCLUSIONS: The scientific evidence supports that physical activity can be an effective lifestyle behavior to prevent or minimize weight gain in adults. Therefore, public health initiatives to prevent weight gain, overweight, and obesity should include physical activity as an important lifestyle behavior.

Benefits of Physical Activity during Pregnancy and Postpartum: An Umbrella Review.

PURPOSE: This study aimed to summarize the evidence from the 2018 Physical Activity Guidelines Advisory Committee Scientific Report, including new evidence from an updated search of the effects of physical activity on maternal health during pregnancy and postpartum. METHODS: An initial search was undertaken to identify systematic reviews and meta-analyses published between 2006 and 2016. An updated search then identified additional systematic reviews and meta-analyses published between January 2017 and February 2018. The searches were conducted in PubMed®, CINAHL, and Cochrane Library and supplemented through hand searches of reference lists of included articles and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. RESULTS: The original and updated searches yielded a total of 76 systematic reviews and meta-analyses. Strong evidence demonstrated that moderate-intensity physical activity reduced the risk of excessive gestational weight gain, gestational diabetes, and symptoms of postpartum depression. Limited evidence suggested an inverse relationship between physical activity and risk of preeclampsia, gestational hypertension, and antenatal anxiety and depressive symptomology. Insufficient evidence was available to determine the effect of physical activity on postpartum weight loss, postpartum anxiety, and affect during both pregnancy and postpartum. For all health outcomes, there was insufficient evidence to determine whether the relationships varied by age, race/ethnicity, socioeconomic status, or prepregnancy weight status. CONCLUSIONS: The gestational period is an opportunity to promote positive health behaviors that can have both short- and long-term benefits for the mother. Given the low prevalence of physical activity in young women in general, and the high prevalence of obesity and cardiometabolic diseases among the U.S. population, the public health importance of increasing physical activity in women of childbearing age before, during, and after pregnancy is substantial.

Effects of Physical Activity in Knee and Hip Osteoarthritis: A Systematic Umbrella Review.

INTRODUCTION: We conducted a systematic umbrella review to evaluate the literature relating to effects of physical activity on pain, physical function, health-related quality of life, comorbid conditions and osteoarthritis (OA) structural disease progression in individuals with lower-extremity OA. METHODS: Our primary search encompassed 2011 to February 2018 for existing systematic reviews (SR), meta-analyses (MA) and pooled analyses dealing with physical activity including exercise (not mixed with any other intervention and compared to a no-activity control group). A supplementary search encompassed 2006 to February 2018 for original research related to physical activity (including exercise) and lower limb OA progression. Study characteristics were abstracted, and risk of bias was assessed. RESULTS: Physical activity decreased pain and improved physical function (strong evidence) and improved health-related quality of life (moderate evidence) among people with hip or knee OA relative to less active adults with OA. There was no evidence to suggest accelerated OA progression for physical activity below 10,000 steps per day. Both physical activity equivalent to the 2008 Physical Activity Guidelines for Americans (150 min·wk of moderate-intensity exercise in bouts ≥10 min) and lower levels of physical activity (at least 45 total minutes per week of moderate-intensity) were associated with improved or sustained high function. No SR/MA addressing comorbid conditions in OA were found. Measurable benefits of physical activity appeared to persist for periods of up to 6 months following cessation of a defined program. CONCLUSIONS: People with lower-extremity OA should be encouraged to engage in achievable amounts of physical activity, of even modest intensities. They can choose to accrue minutes of physical activity throughout the entire day, irrespective of bout duration, and be confident in gaining some health and arthritis-related benefits.

Physical Activity in Cancer Prevention and Survival: A Systematic Review.

PURPOSE: This article reviews and updates the evidence on the associations between physical activity and risk for cancer, and for mortality in persons with cancer, as presented in the 2018 Physical Activity Guidelines Advisory Committee Scientific Report. METHODS: Systematic reviews of meta-analyses, systematic reviews, and pooled analyses were conducted through December 2016. An updated systematic review of such reports plus original research through February 2018 was conducted. This article also identifies future research needs. RESULTS: In reviewing 45 reports comprising hundreds of epidemiologic studies with several million study participants, the report found strong evidence for an association between highest versus lowest physical activity levels and reduced risks of bladder, breast, colon, endometrial, esophageal adenocarcinoma, renal, and gastric cancers. Relative risk reductions ranged from approximately 10% to 20%. Based on 18 systematic reviews and meta-analyses, the report also found moderate or limited associations between greater amounts of physical activity and decreased all-cause and cancer-specific mortality in individuals with a diagnosis of breast, colorectal, or prostate cancer, with relative risk reductions ranging almost up to 40% to 50%. The updated search, with five meta-analyses and 25 source articles reviewed, confirmed these findings. CONCLUSIONS: Levels of physical activity recommended in the 2018 Guidelines are associated with reduced risk and improved survival for several cancers. More research is needed to determine the associations between physical activity and incidence for less common cancers and associations with survival for other cancers. Future studies of cancer incidence and mortality should consider these associations for population subgroups, to determine dose-response relationships between physical activity and cancer risk and prognosis, and to establish mechanisms to explain these associations.

Physical Activity, Injurious Falls, and Physical Function in Aging: An Umbrella Review.

PURPOSE: To review and update the evidence of the relationship between physical activity, risk of fall-related injury, and physical function in community-dwelling older people that was presented in the 2018 Physical Activity Guidelines Advisory Committee Scientific Report (PAGAC Report). METHODS: Duplicate independent screenings of 1415 systematic reviews and meta-analyses published between 2006 and 2016 identified from PubMed®, Cochrane Library, and CINAHL databases yielded 111 articles used for the PAGAC Report. The PAGAC Aging Subcommittee members graded scientific evidence strength based upon a five-criteria rubric and assigned one of four grades: strong, moderate, limited, or not assignable. An updated search of 368 articles published between January 2017 and March 2018 yielded 35 additional pertinent articles. RESULTS: Strong evidence demonstrated that physical activity reduced the risk of fall-related injuries by 32% to 40%, including severe falls requiring medical care or hospitalization. Strong evidence also supported that physical activity improved physical function and reduced the risk of age-related loss of physical function in an inverse graded manner among the general aging population, and improved physical function in older people with frailty and with Parkinson's disease. Aerobic, muscle-strengthening, and/or multicomponent physical activity programs elicited the largest improvements in physical function in these same populations. Moderate evidence indicated that for older adults who sustained a hip fracture or stroke, extended exercise programs and mobility-oriented physical activity improved physical function. CONCLUSIONS: Regular physical activity effectively helps older adults improve or delay the loss of physical function and mobility while reducing the risk of fall-related injuries. These important public health benefits underscore the importance of physical activity among older adults, especially those living with declining physical function and chronic health conditions.

Acceptability of Localized Cancer Risk Reduction Interventions Among Individuals at Average or High Risk for Cancer.

Individuals at high risk for cancer, including those already diagnosed with premalignant lesions, can potentially benefit from chemopreventive interventions to reduce cancer risk. However, uptake and acceptability have been hindered due to the risk of systemic toxicity and other adverse effects. Locally delivered chemopreventive agents, where direct action on the primary organ may limit systemic toxicity, are emerging as an option for high-risk individuals. While a number of clinical trials support the development of chemopreventive agents, it is crucial to understand the factors and barriers that influence their acceptability and use. We conducted 36 focus groups with 198 individuals at average and high risk of breast/ovarian, gynecologic, and head/neck/oral and lung cancers to examine the perceptions and acceptability of chemopreventive agents. Participants' willingness to use chemopreventive agents was influenced by several factors, including perceived risk of cancer, skepticism around prevention, previous knowledge of chemopreventive agents, support from trusted sources of health information, participation in other cancer-related risk-reduction activities, previous experience with similar modalities, cost, regimen, side effects, and perceived effectiveness of the preventive intervention. Our findings indicate that individuals may be more receptive to locally delivered chemopreventive agents if they perceive themselves to be at high risk for cancer and are given the necessary information regarding regimen and side effects to make an informed decision. Clinical trials that collect additional patient-centered data including side effects and how these interventions fit into an individual's lifestyle are imperative to improve uptake of chemopreventive agents.

Umbrella and Systematic Review Methodology to Support the 2018 Physical Activity Guidelines Advisory Committee.

INTRODUCTION: In 2016, the 2018 Physical Activity Guidelines Advisory Committee, a group of experts in exercise science and health, began an extensive review of the literature to inform the second edition of the Physical Activity Guidelines for Americans. METHODS: The purpose of this paper is to describe the evidence-based methodology used to review, evaluate, and synthesize published, peer-reviewed physical activity research. The protocol-driven methodology was designed to maximize transparency, minimize bias, and ensure relevant, timely, and high-quality systematic reviews. Training protocols, quality control procedures, search strategies, assessment instruments, abstraction guides and forms, and reporting templates were developed. RESULTS: A systematic approach was used to select the evidence for the 2018 Physical Activity Guidelines Advisory Committee Scientific Report that included umbrella reviews and systematic reviews. Within 16 months, 38 searches were conducted; and 20,838 titles, 4913 abstracts, and 2139 full texts were triaged. Of those, 1130 articles were abstracted to answer 38 research questions. CONCLUSIONS: To inform population-based physical activity guidelines, this systematic process facilitated a vast review of the literature on physical activity and health in a short period of time. This flexible, yet rigorous and transparent process included a clear and detailed methodology with a focus on training and quality control.

Geospatial approaches to cancer control and population sciences at the United States cancer centers.

PURPOSE: Geospatial, contextual, and multilevel research is integral to cancer prevention and control. NCI-designated Cancer Centers are at the forefront of cancer research; therefore, this paper sought to review the geospatial, contextual, and multilevel research at these cancer centers. METHODS: Investigators used PubMed and Web of Science to compile geospatial publications from 1971 to February 2016 with cancer center-affiliated authors. Relevant abstracts were pulled and classified by six geospatial approaches, eight geospatial scales, and eight cancer sites. RESULTS: The searches identified 802 geospatial, contextual, and multilevel publications with authors affiliated at 60 of the 68 NCI-designated Cancer Centers. Over 90% were published after 2000. Five cancer centers accounted for approximately 50% of total publications, and 30 cancer centers accounted for over 85% of total publications. Publications covered all geospatial approaches and scales to varying degrees, and 90% dealt with cancer. CONCLUSIONS: The NCI-designated Cancer Center network is increasingly pursuing geospatial, contextual, and multilevel cancer research, although many cancer centers still conduct limited to no research in this area. Expanding geospatial efforts to research programs across all cancer centers will further enrich cancer prevention and control. Similar reviews may benefit other domestic and international cancer research institutions.

Exploration of awareness, knowledge, and perceptions of traumatic brain injury among American youth athletes and their parents.

PURPOSE: Although much effort is underway by the Centers for Disease Control and Prevention (CDC) and other organizations to highlight the seriousness of traumatic brain injury, including concussions, among young athletes, little is known about how these athletes and their parents view this injury and how much they know about it. METHODS: Online surveys were conducted with youth who participate in sports (n = 252) and with the parents of youth who participate in sports (n = 300) to explore the ways in which these audiences view concussion and messaging related to concussion. RESULTS: More than four out of five youth and parents reported that they had heard about concussions, although awareness was significantly higher for some subgroups, including parents of children 10-13 years old, and parents who reported using the Internet several times daily. Youth ages 13-15 years were significantly more likely to strongly agree that concussions are a "critical issue," as compared with youth ages 16-18 years. Among parents, significantly more mothers than fathers agreed that concussions are a critical issue. More than half of youth participants strongly disagreed that their friends would think they were "dumb for caring about concussions," with girls significantly more likely to strongly disagree than boys. When parents were asked to identify organizations they would trust as a reliable source of information for concussions, the most frequently cited organization was the CDC. CONCLUSIONS: Results of this study demonstrate a high level of awareness about concussion among youth athletes and parents of youth athletes. However, important distinctions among subgroups of both youth and parents-such as by race/ethnicity, age, sex, and Internet use-suggest directions for future communication and research efforts.

Exploring the feasibility of alternative STD-testing venues and results delivery channels for a national screening campaign.

UNLABELLED: Annual chlamydia screening is recommended for sexually active women aged 25 years and younger, though less than half of eligible women are screened each year. If acceptable to young women, nontraditional testing venues and new communication technologies could promote efficiencies in sexually transmitted disease (STD) screening and facilitate screening by overcoming barriers at systems and patient levels. OBJECTIVE: This study sought to explore young women's technology use, preferences for STD-testing venues, attitudes toward nontraditional venues, and acceptability of test results delivery options. METHOD: A total of 80 ethnographic one-on-one telephone interviews were conducted with African American, Caucasian, and Latina women, aged 15 to 25 years, in 10 metropolitan areas of the United States. Interviews were recorded, transcribed, and analyzed using NVivo2. RESULTS: Alternative STD-testing venues and results delivery channels are valued by young women for their convenience and accessibility, but they must also offer privacy, confidentiality, and emotional/informational support to be acceptable. Assuring provider (or self) competence and valid/accurate test results is also important. CONCLUSIONS: Although new technologies have been embraced by young women for personal and social uses, they may not be as readily embraced for the provision of STD-related services. Additional social marketing efforts may be needed to promote acceptance of nontraditional STD-testing settings and results delivery methods.

"something we'd rather not talk about": findings from CDC exploratory research on sexually transmitted disease communication with girls and women.

BACKGROUND: Chlamydia is a leading cause of pelvic inflammatory disease (PID), which can lead to ectopic pregnancy, chronic pelvic pain, and infertility. Annual Chlamydia screening is recommended for all sexually active women aged ≤ 25 years, yet only about 40% of eligible women are screened each year in the United States. To promote Chlamydia screening for the prevention of infertility, the Centers for Disease Control and Prevention (CDC) is developing direct-to-consumer efforts for sexually active young women and key influencers. To inform this effort, CDC sought to explore girls'/women's understandings of sexually transmitted disease (STD) and Chlamydia testing and STD communications and information sources. METHODS: Two waves of one-on-one interviews (n = 125) were conducted in 10 metropolitan areas with African American, Caucasian, and Latina females, aged 15-25 years. RESULTS: Most participants were not knowledgeable about Chlamydia or its screening; their discussions about it suggested low levels of perceived susceptibility or relevance to Chlamydia and screening. STDs are rarely discussed in home or social settings or with partners or close friends; yet young women may turn to interpersonal sources if concerned about an STD. Providers are the primary and preferred source of STD information for girls and women, although missed opportunities for engaging young women in STD/sexual health discussions were identified in clinical and other settings. CONCLUSIONS: Providers, family members, friends, and partners may serve as important intermediaries for reaching young women and encouraging STD/Chlamydia screening. Resources are identified that could be leveraged and/or developed to facilitate such interactions.

A marketing perspective on disseminating evidence-based approaches to disease prevention and health promotion.

Evidence-based disease prevention practice guidelines can provide a rationale for health programming decisions, which should, in turn, lead to improved public health outcomes. This logic has stimulated the creation of a growing number of evidence-based prevention practice guidelines, including the Guide to Community Preventive Services. Few systematic efforts have been made to document the degree of adoption and implementation of these approaches, although the evidence on translation of research into practice in other health fields indicates that the adoption and implementation rate is low. Drawing on the marketing literature, we suggest three approaches to enhance the adoption and implementation of evidence-based approaches: 1) conducting consumer research with prospective adopters to identify their perspectives on how evidence-based prevention programs can advance their organization's mission, 2) building sustainable distribution channels to promote and deliver evidence-based programs to prospective adopters, and 3) improving access to easily implemented programs that are consistent with evidence-based guidelines. Newly emerging paradigms of prevention research (e.g., RE-AIM) that are more attuned to the needs of the marketplace will likely yield a new generation of evidence-based preventive approaches that can be more effectively disseminated. We suggest that the public health community prioritize the dissemination of evidence-based prevention approaches, because doing so is a potent environmental change strategy for enhancing health.