Food deserts exposure, density of fast-food restaurants, and park access: Exploring the association of food and recreation environments with obesity and diabetes using global and local regression models

To prevent obesity and diabetes environmental interventions such as eliminating food deserts, restricting proliferation of food swamps, and improving park access are essential. In the United States, however, studies that examine the food and park access relationship with obesity and diabetes using both global and local regression are lacking. To guide county, state, and federal policy in combating obesity and diabetes, there is a need for cross-scale analyses to identify that relationship at national and local levels. This study applied spatial regression and geographically weighted regression to the 3,108 counties in the contiguous United States. Global regression show food deserts exposure and density of fast-food restaurants have non-significant association with obesity and diabetes while park access has a significant inverse association with both diseases. Geographically weighted regression that takes into account spatial heterogeneity shows that, among southern states that show high prevalence of obesity and diabetes, Alabama and Mississippi stand out as having opportunity to improve park access. Results suggest food deserts exposure are positively associated with obesity and diabetes in counties close to Alabama, Georgia, and Tennessee while density of fast-food restaurants show positive association with two diseases in counties of western New York and northwestern Pennsylvania. These findings will help policymakers and public health agencies in determining which geographic areas need to be prioritized when implementing public interventions such as promoting healthy food access, limiting unhealthy food options, and increasing park access.

Association of composite park quality with park use in four diverse cities

Park use has numerous health benefits. However, little research has investigated how the combination of park facilities, amenities, and conditions are related to park visitation. This study examined the association between a novel composite park quality metric and the use of specific parks, including variations by demographics. Data were collected in 128 census block groups across four diverse cities in the USA. Adults (n = 262) used an online, map-based survey to indicate which parks within one half-mile they had used within the past 30 days. All parks (n = 263) were audited using the Community Park Audit Tool, and a composite quality metric was calculated by standardizing and averaging six key components: access, facilities, amenities, aesthetic features, quality concerns, and neighborhood concerns. A total of 2429 participant-park pairs were analyzed. The average park quality score was 40.4/100 (s.d. = 30.2). For the full sample, a greater park quality score was significantly related to park use (OR = 1.02, 95% CI = 1.01-1.03) such that for each one unit increase in a park's quality score, there was a 2% increase in the likelihood of the park being used. There was also a significant interaction by gender, with park quality associated with park use among females (OR = 1.03, 95% CI = 1.02-1.05) but not males (OR = 1.00, 95% CI = 0.99-1.02). Enhancing overall park quality may increase the likelihood of a park being used. Future research can explore the utility of this comprehensive quality metric for predicting other health behaviors and outcomes and how interventions to enhance park quality augment park use and health over time.

Latent profile analysis of accelerometer-measured sleep, physical activity, and sedentary time and differences in health characteristics in adult women

Objectives

Independently, physical activity (PA), sedentary behavior (SB), and sleep are related to the development and progression of chronic diseases. Less is known about how rest-activity behaviors cluster within individuals and how rest-activity behavior profiles relate to health. In this study we aimed to investigate if adult women cluster into profiles based on how they accumulate rest-activity behavior (including accelerometer-measured PA, SB, and sleep), and if participant characteristics and health outcomes differ by profile membership.

Methods

A convenience sample of 372 women (mean age 55.38 + 10.16) were recruited from four US cities. Participants wore ActiGraph GT3X+ accelerometers on the hip and wrist for a week. Total daily minutes in moderate-to-vigorous PA (MVPA) and percentage of wear-time spent in SB was estimated from the hip device. Total sleep time (hours/minutes) and sleep efficiency (% of in bed time asleep) were estimated from the wrist device. Latent profile analysis (LPA) was performed to identify clusters of participants based on accumulation of the four rest-activity variables. Adjusted ANOVAs were conducted to explore differences in demographic characteristics and health outcomes across profiles.

Results

Rest-activity variables clustered to form five behavior profiles: Moderately Active Poor Sleepers (7%), Highly Actives (9%), Inactives (41%), Moderately Actives (28%), and Actives (15%). The Moderately Active Poor Sleepers (profile 1) had the lowest proportion of whites (35% vs 78–91%, p < .001) and college graduates (28% vs 68–90%, p = .004). Health outcomes did not vary significantly across all rest-activity profiles.

Conclusions

In this sample, women clustered within daily rest-activity behavior profiles. Identifying 24-hour behavior profiles can inform intervention population targets and innovative behavioral goals of multiple health behavior interventions.

Comparison of Accelerometry Methods for Estimating Physical Activity

PURPOSE

This study aimed to compare physical activity estimates across different accelerometer wear locations, wear time protocols, and data processing techniques.

METHODS

A convenience sample of middle-age to older women wore a GT3X+ accelerometer at the wrist and hip for 7 d. Physical activity estimates were calculated using three data processing techniques: single-axis cut points, raw vector magnitude thresholds, and machine learning algorithms applied to the raw data from the three axes. Daily estimates were compared for the 321 women using generalized estimating equations.

RESULTS

A total of 1420 d were analyzed. Compliance rates for the hip versus wrist location only varied by 2.7%. All differences between techniques, wear locations, and wear time protocols were statistically different (P < 0.05). Mean minutes per day in physical activity varied from 22 to 67 depending on location and method. On the hip, the 1952-count cut point found at least 150 min·wk of physical activity in 22% of participants, raw vector magnitude found 32%, and the machine-learned algorithm found 74% of participants with 150 min of walking/running per week. The wrist algorithms found 59% and 60% of participants with 150 min of physical activity per week using the raw vector magnitude and machine-learned techniques, respectively. When the wrist device was worn overnight, up to 4% more participants met guidelines.

CONCLUSION

Estimates varied by 52% across techniques and by as much as 41% across wear locations. Findings suggest that researchers should be cautious when comparing physical activity estimates from different studies. Efforts to standardize accelerometry-based estimates of physical activity are needed. A first step might be to report on multiple procedures until a consensus is achieved.

Increasing the field of view in grating based X-ray phase contrast imaging using stitched gratings

Grating based X-ray differential phase contrast imaging (DPCI) allows for high contrast imaging of materials with similar absorption characteristics. In the last years' publications, small animals or parts of the human body like breast, hand, joints or blood vessels have been studied. Larger objects could not be investigated due to the restricted field of view limited by the available grating area. In this paper, we report on a new stitching method to increase the grating area significantly: individual gratings are merged on a carrier substrate. Whereas the grating fabrication process is based on the LIGA technology (X-ray lithography and electroplating) different cutting and joining methods have been evaluated. First imaging results using a 2×2 stitched analyzer grating in a Talbot-Lau interferometer have been generated using a conventional polychromatic X-ray source. The image quality and analysis confirm the high potential of the stitching method to increase the field of view considerably.

Energy-resolved visibility analysis of grating interferometers operated at polychromatic X-ray sources

Grating interferometry has been successfully adapted at standard X-ray tubes and is a promising candidate for a broad use of phase-contrast imaging in medical diagnostics or industrial testing. The achievable image quality using this technique is mainly dependent on the interferometer performance with the interferometric visibility as crucial parameter. The presented study deals with experimental investigations of the spectral dependence of the visibility in order to understand the interaction between the single contributing energies. Especially for the choice which type of setup has to be preferred using a polychromatic source, this knowledge is highly relevant. Our results affirm previous findings from theoretical investigations but also show that measurements of the spectral contributions to the visibility are necessary to fully characterize and optimize a grating interferometer and cannot be replaced by only relying on simulated data up to now.

Quantitative breast tissue characterization using grating-based x-ray phase-contrast imaging

X-ray phase-contrast imaging has received growing interest in recent years due to its high capability in visualizing soft tissue. Breast imaging became the focus of particular attention as it is considered the most promising candidate for a first clinical application of this contrast modality. In this study, we investigate quantitative breast tissue characterization using grating-based phase-contrast computed tomography (CT) at conventional polychromatic x-ray sources. Different breast specimens have been scanned at a laboratory phase-contrast imaging setup and were correlated to histopathology. Ascertained tumor types include phylloides tumor, fibroadenoma and infiltrating lobular carcinoma. Identified tissue types comprising adipose, fibroglandular and tumor tissue have been analyzed in terms of phase-contrast Hounsfield units and are compared to high-quality, high-resolution data obtained with monochromatic synchrotron radiation, as well as calculated values based on tabulated tissue properties. The results give a good impression of the method's prospects and limitations for potential tumor detection and the associated demands on such a phase-contrast breast CT system. Furthermore, the evaluated quantitative tissue values serve as a reference for simulations and the design of dedicated phantoms for phase-contrast mammography.

Unwrapping differential x-ray phase-contrast images through phase estimation from multiple energy data

We present a spectral phase unwrapping approach for grating-based differential phase-contrast data where the unwrapped interferometer phase shift is estimated from energy discriminated measurements using maximum likelihood principles. We demonstrate the method on tomographic data sets of a test specimen taken at different x-ray energies using synchrotron radiation. The proposed unwrapping technique was demonstrated to successfully correct the data set for phase wrapping.

A model case of a positive outcome in super-super obesity

For an increasing number of obese patients, bariatric surgery is considered as the treatment of choice after the failure of conventional strategies. While numerous studies on bariatric surgery have shown substantial health benefits, there is a broad inter-individual variation in the long-term outcome, which is insufficiently understood. Here we show a favourable long-term outcome following multidisciplinary care in a super-super-obese patient. The patient suffered from numerous typically obesity-associated comorbidities and limitations. He underwent multidisciplinary care including two-step bariatric intervention. Endoscopic intragastric balloon positioning was followed by gastric sleeve surgery without Roux-en-Y gastric bypass. His body weight dropped from 260 kg (body mass index [BMI] 79.4 kg m(-2) ) to 85 kg (BMI 25.9 kg m(-2) ) within 16 months and continued to be stable at 90 kg (BMI 27.8 kg m(-2) ) at the end of the follow-up period of 48 months. The loss of excess body weight was associated with the remission of numerous obesity-related comorbidities and with a concomitant pronounced increase in the quality of life and in the socioeconomic status. Eventually, the patient was able to lead a normal life with a decreased risk of long-term complications. We attribute the positive long-term outcome to the following potential determinants: individualized bariatric surgery, multidisciplinary care, the patient's long-term compliance, adequate adherence to the aftercare, physical exercise after surgery, family support, the cooperation of the primary care physician and the financial coverage by the health insurance. Some of these factors remain to be evaluated as predictors of a favourable long-term outcome in prospective trials.

[Performance food in sports]

Performance food in sports is mainly represented by macronutrients and additional nutritional food components. Performance food is often used in sports as so-called ergogenic aids, which are believed to increase exercise capacity, delay fatigue, or enhance the response to training via different mechanisms. Nevertheless, beneficial effects of only a few of these substances is supported by clear scientific evidence. However, a sound scientific base is lacking for most ergogenic aids, and their intake cannot be recommended. This article focuses on some of the most popular macronutrients and nutritional food components which are consumed with the goal of enhancing performance. Some have been shown to exert a positive impact on exercise capacity under specific conditions, or in connection with an optimal timing of ingestion in context with training. Nevertheless, additional research is required to clarify the role of the different performance foods in increasing exercise capacity before more detailed recommendations are possible.

[Obesity--an interdisciplinary task]

In industrial nations, over the last five decades conditions concerning nutrition and physical exercise as well as socio-economic circumstances have changed radically. One of the consequences following from this development has been a rapid increase in the prevalence of obesity. Studies have shown that currently 20 percent of the German adult population suffer from obesity. Investigations into the etiology of obesity have to address complex interactions between genetic, socio-economic and psychosocial factors. A year ago, at the University Hospital Tübingen different departments joined to set up the "Plattform Adipositas". Endocrinologists, obesity surgeons, professionals in sports medicine and psychosomatic medicine as well as dieticians are collaborating to develop scientifically based therapy programs and treatment pathways for obese patients. The following article gives an account of this exemplary interdisciplinary cooperation.

[Lactate in cardiac rehabilitation]

BACKGROUND

Training increases work capacity and concomitantly quality of life, and also, according to new data, the life expectancy of patients with coronary heart disease and heart failure. At the same time, the importance of adequate training intensity increases aiming at low complications and high efficacy.

ASSESSMENT OF EXERCISE CAPACITY

The objective of the present work is to define objective training guidance parameters in cardiac rehabilitation. Maximal exercise capacity must be distinguished from the performance without symptoms of oxygen deficit. The latter used to be early surpassed in untreated stabile angina pectoris. Within the last decade optimized therapy often yields a cardiac performance limit above the anaerobic threshold derived from lactate measurements. The concepts of aerobic and anaerobic thresholds derived from the lactate performance curve are introduced and modified leaving the 4 mmol/l lactate threshold concept to meet the criteria for performance capacity and breaking point in cardiac patients. The relationship to threshold concepts derived from spirometric data is mentioned as well as from stress hormones. The heart rate at the anaerobic threshold measured at treadmill ergometry systematically lies above the one from bicycle ergometry. Lactate increases faster with advancing age and the anaerobic threshold is earlier reached and progressively so because of the reduced muscle mass and reduced endurance capacity of people of the industrialized countries.

IMPORTANCE

The determination of the anaerobic threshold as an objective criteria independent of motivation leads to training control, as shown by an example. Ineffective training above the threshold giving rise to catecholamines can be avoided by lactate performance diagnostic. Additionally, the success of rehabilitation measures can objectively be quantified and documented much better from the threshold work capacity than from maximal exercise tolerance. Preliminary reports indicate the importance of lactate diagnostics for rehabilitation guidance in heart failure.

The echocardiographic determination of volume and muscle mass of the heart

One- and two-dimensional echocardiography permits assessment of left ventricular size and muscle mass, whereas the validity and reliability differ. It is comparable to other methods, such as angiography, scintigraphy and magnetic resonance imaging, but has the advantage of being noninvasive and of lower cost. It therefore appears particularly well-suited for applications in sports medicine. However, changes of 10%-20%, depending on the parameter, are necessary in individual cases to permit assumption of a proven change. A further methodical improvement, especially in respect to reliability but also to validity may be expected in the future from three-dimensional, computer-supported examination techniques. Enlargement of the heart due to endurance sports is harmonic and affects all four cardiac chambers. Limits to the increase in left ventricular volume and muscle mass can be recognized in relation to body weight. They usually do not exceed 70% of the baseline value or the value obtained for untrained persons. Power training, even in extreme forms, results in no or only minimal dimensional changes.

Echocardiographic findings in endurance athletes with hypertrophic non-obstructive cardiomyopathy (HNCM) compared to non-athletes with HNCM and to physiological hypertrophy (athlete's heart)

Hypertrophic non-obstructive cardiomyopathy (HNCM) is one of the most frequent causes of sudden cardiac death in young athletes. Since the clinical findings in HNCM patients may be inconspicuous and the ECG changes found in endurance athletes may be similar to those of HNCM patients, echocardiography, as a non-invasive procedure, seems to take on an important role in differential diagnostics. To prove this hypothesis, conventional echocardiographic parameters were compared in three groups with confirmed diagnosis: Group I: HNCM (n = 9) without sports activity; Group II: HNCM (n = 9) with regular, intensive endurance training (3-5 hours/week). The diagnosis was invasively confirmed in both groups. Group III: healthy subjects (n = 9) with physiological hypertrophy and regular endurance training (3-6 hours/week). In the presence of HNCM, endurance sports activity appears to offset the reduction in the left ventricle and enlargement of the left atrium. The wall thickness of the septum and posterior wall do not differ in the two HNCM groups, but show a significant difference to the healthy athletes. The enddiastolic diameter, the absolute septum and posterior wall thickness and the ratio of septum+posterior wall/enddiastolic diameter can be taken as the most important differential diagnostic criterium in physiological hypertrophy, but not the ratio between septum/posterior wall. It is concluded that conventional echocardiographic examination can be considered a valuable non-invasive method for differentiating HNCM from athlete's heart, even in patients with HNCM who participate in endurance sports. However, a reliable diagnosis may not be possible in individual cases.