3D Convolutional Deep Learning for Nonlinear Estimation of Body Composition from Whole-Body Morphology

Total and regional body composition are strongly correlated with metabolic syndrome and have been estimated non-invasively from 3D optical scans using linear parameterizations of body shape and linear regression models. Prior works produced accurate and precise predictions on many, but not all, body composition targets relative to the reference dual X-Ray absorptiometry (DXA) measurement. Here, we report the effects of replacing linear models with nonlinear parameterization and regression models on the precision and accuracy of body composition estimation in a novel application of deep 3D convolutional graph networks to human body composition modeling. We assembled an ensemble dataset of 4286 topologically standardized 3D optical scans from four different human body shape databases, DFAUST, CAESAR, Shape Up! Adults, and Shape Up! Kids and trained a parameterized shape model using a graph convolutional 3D autoencoder (3DAE) in lieu of linear PCA. We trained a nonlinear Gaussian process regression (GPR) on the 3DAE parameter space to predict body composition via correlations to paired DXA reference measurements from the Shape Up! scan subset. We tested our model on a set of 424 randomly withheld test meshes and compared the effects of nonlinear computation against prior linear models. Nonlinear GPR produced up to 20% reduction in prediction error and up to 30% increase in precision over linear regression for both sexes in 10 tested body composition variables. Deep shape features produced 6-8% reduction in prediction error over linear PCA features for males only and a 4-14% reduction in precision error for both sexes. Our best performing nonlinear model predicting body composition from deep features outperformed prior work using linear methods on all tested body composition prediction metrics in both precision and accuracy. All coefficients of determination (R2) for all predicted variables were above 0.86. We show that GPR is a more precise and accurate method for modeling body composition mappings from body shape features than linear regression. Deep 3D features learned by a graph convolutional autoencoder only improved male body composition accuracy but improved precision in both sexes. Our work achieved lower estimation RMSEs than all previous work on 10 metrics of body composition.

234 PATIENT COLLABORATION TO DRIVE REFORM: EMBEDDING BRIDGES SELF-MANAGEMENT APPROACH IN AN ACUTE STROKE SERVICE

Background

Bridges Self-Management approach is an evidence-based set of self-management skills, practices and interventions which when implemented can deliver more collaborative and patient-centred care to people suffering stroke [1]. Our acute stroke service underwent training in this approach in 2020. In order to further embed this approach and adapt it to our local setting, patient experiences were captured to help inform ongoing service delivery and quality improvements.

Methods

Ethical approval was granted for this project. Following consent, 20 acute stroke inpatients (length of stay >/=3 days) participated in the study. Patient experiences of their time on the Stroke Unit were sought using a 10-item open-ended questionnaire, which was developed based on the guiding principles of Bridges i.e. what matters most to the person, reflecting on what was/wasn’t going well, what they believe would help them and others.

Results

Thematic analysis was used to analyse the responses, and a number of themes emerged. These include: Loss of autonomy and freedom; Environmental challenges (including boredom, sleep poverty, loss of social interaction, loss of dignity and privacy); Shock, and difficulty adjusting to diagnosis (the importance of being informed and being heard); Loneliness and the role of family and visitors in their recovery journey (coupled with a consistent desire to be in their own home).

Conclusion

Rich data emerged, providing us with a unique insight into the experience of patients. This will compel us to review our service and environment, to tailor changes that matter to patients, and deliver on the Bridges self-management principles of patient inclusion and empowerment.

Reference

1. Jones et al. Building bridges between healthcare professionals, patients and families: A coproduced and integrated approach to self-management support in stroke. Neurorehabilitation. 2016. 39(4), pp. 471–480.

235 EYES WIDE SHUT: A CASE OF BILATERAL PTOSIS FOLLOWING STROKE

Background

Bilateral ptosis is a rare manifestation of midbrain stroke. It has been reported in case studies only, with no data on incidence rate, and no published case report in Ireland to date.

Methods

This is a retrospective case study of a man admitted to an acute stroke unit following collapse and unresponsiveness. A review of his medical records and radiological database was conducted. A PUBMED database search was conducted to search for similar cases.

Results

We present the case of a man who had a witnessed collapse whilst farming and was brought to hospital and presented with a Glasgow Coma Scale of 3. Imaging showed a normal CT Brain. MRI revealed 2cm acute bilateral thalamic and midbrain infarction. Following a brief period in ICU he was transferred to the acute stroke unit for multidisciplinary care. Despite improvements in his medical status and communication efforts, his inability to open his eyes contributed to a persistently low GCS. Neurological assessment revealed bilateral ptosis, fixed dilated pupils and oculomotor paralysis. These symptoms had a profound impact on his stroke recovery, impeding assessments and interventions and engagement in all realms (swallow and communication; mobility and function, cognitive-perceptual) whilst also limiting opportunities for social interaction. Once staff became aware of the ophthalmoplegia, strategies were implemented to optimise his participation and provide opportunities of recovery. Three months post stroke, he began to experience some return of unilateral eye-opening and bilateral horizontal movements (with diplopia) which greatly improved his overall performance. He was then transferred to the rehabilitation unit where he continues to progress.

Conclusion

Bilateral ptosis post stroke is rare and has a debilitating effect on participation in all aspects of living and interaction with the environment. This presentation has previously been described as “reverse locked-in-syndrome” which accurately represents its impact.

POS1465-HPR THE RELATIONSHIP BETWEEN SEDENTARY BEHAVIOR AND SLEEP IN RHEUMATOID ARTHRITIS: A CROSS-SECTIONAL STUDY

Background:

Rheumatoid arthritis (RA) is a chronic, autoimmune inflammatory condition that affects 0.5% of the adult population worldwide (1). Sedentary behavior (SB) is any waking behavior characterized by an energy expenditure of ≤1.5 METs (metabolic equivalent) and a sitting or reclining posture, e.g. computer use (2) and has a negative impact on health in the RA population (3). Sleep is an important health behavior, but sleep quality is an issue for people living with RA (4, 5). Poor sleep quality is associated with low levels of physical activity in RA (4) however the association between SB and sleep in people who have RA has not been examined previously.

Objectives:

The aim of this study was to investigate the relationship between SB and sleep in people who have RA.

Methods:

A cross-sectional study was conducted. Patients were recruited from rheumatology clinics in a large acute public hospital serving a mix of urban and rural populations. Inclusion criteria were diagnosis of RA by a rheumatologist according to the American College of Rheumatology criteria age ≥ 18 and ≤ 80 years; ability to mobilize independently or aided by a stick; and to understand written and spoken English. Demographic data on age, gender, disease duration and medication were recorded. Pain and fatigue were measured by the Visual Analogue Scale (VAS), anxiety and depression were assessed using the Hospital Anxiety and Depression Scale (HADS), and sleep quality was assessed using the Pittsburgh Sleep Quality Index. SB was measured using the ActivPAL4™ activity monitor, over a 7-day wear period. Descriptive statistics were calculated to describe participant characteristics. Relationships between clinical characteristics and SB were examined using Pearson’s correlation coefficients and regression analyses.

Results:

N=76 participants enrolled in the study with valid data provided by N=72 participants. Mean age of participants was 61.5years (SD10.6) and the majority 63% (n = 47) were female. Participant mean disease duration was 17.8years (SD10.9). Mean SB time was 533.7 (SD100.1) minutes (8.9 hours per day/59.9% of waking hours). Mean sleep quality score was 7.2 (SD5.0) (Table 1). Correlation analysis and regression analysis found no significant correlation between sleep quality and SB variables. Regression analysis demonstrated positive statistical associations for SB time and body mass index (p-value=0.03846, R2 = 0.05143), SB time and pain VAS (p-value=0.009261, R2 = 0.07987), SB time and HADS (p-value = 0.009721, R2 = 0.08097) and SB time and HADSD (p-value = 0.01932, R2 = 0.0643).

Conclusion:

We found high levels of sedentary behavior and poor sleep quality in people who have RA, however no statistically significant relationship was found in this study. Future research should further explore the complex associations between sedentary behavior and sleep quality in people who have RA.

References:

[1]Carmona L, et al. Rheumatoid arthritis. Best Pract Res Clin Rheumatol 2010;24:733–745.

[2]Anon. Letter to the editor: standardized use of the terms “sedentary” and “sedentary behaviours”. Appl Physiol Nutr Metab = Physiol Appl Nutr Metab 2012;37:540–542.

[3]Fenton, S.A.M. et al. Sedentary behaviour is associated with increased long-term cardiovascular risk in patients with rheumatoid arthritis independently of moderate-to-vigorous physical activity. BMC Musculoskelet Disord 18, 131 (2017).

[4]McKenna S, et al. Sleep and physical activity: a cross-sectional objective profile of people with rheumatoid arthritis. Rheumatol Int. 2018 May;38(5):845-853.

[5]Grabovac, I., et al. 2018. Sleep quality in patients with rheumatoid arthritis and associations with pain, disability, disease duration, and activity. Journal of clinical medicine, 7(10)336.

Table 1.

Sleep quality in people who have RA

Sleep variableBed Time N(%) before 10pm13(18%) 10pm-12pm43 (60%) after 12pm16 (22%)Hours Sleep mean(SD)6.56 (1.54)Fall Asleep minutes mean(SD)33.3(27.7)Night Waking N(%)45(63%)Self-Rate Sleep mean(SD)2.74 (0.90)Hours Sleep mean(SD)6.56 (1.54)

Disclosure of Interests:

None declared

South Georgia blue whales five decades after the end of whaling

Blue whales Balaenoptera musculus at South Georgia were heavily exploited during 20th century industrial whaling, to the point of local near-extirpation. Although legal whaling for blue whales ceased in the 1960s, and there were indications of blue whale recovery across the wider Southern Ocean area, blue whales were seldom seen in South Georgia waters in subsequent years. We collated 30 yr of data comprising opportunistic sightings, systematic visual and acoustic surveys and photo-identification to assess the current distribution of blue whales in the waters surrounding South Georgia. Over 34000 km of systematic survey data between 1998 and 2018 resulted in only a single blue whale sighting, although opportunistic sightings were reported over that time period. However, since 2018 there have been increases in both sightings of blue whales and detections of their vocalisations. A survey in 2020 comprising visual line transect surveys and directional frequency analysis and recording (DIFAR) sonobuoy deployments resulted in 58 blue whale sightings from 2430 km of visual effort, including the photo-identification of 23 individual blue whales. Blue whale vocalisations were detected on all 31 sonobuoys deployed (114 h). In total, 41 blue whales were photo-identified from South Georgia between 2011 and 2020, none of which matched the 517 whales in the current Antarctic catalogue. These recent data suggest that blue whales have started to return to South Georgia waters, but continued visual and acoustic surveys are required to monitor any future changes in their distribution and abundance.

Have whales returned to a historical hotspot of industrial whaling? The pattern of southern right whale Eubalaena australis recovery at South Georgia

Around 176500 whales were killed in the sub-Antarctic waters off South Georgia (South Atlantic) between 1904 and 1965. In recent decades, whales have once again become summer visitors, with the southern right whale (SRW) the most commonly reported species until 2011. Here, we assess the distribution, temporal pattern, health status and likely prey of SRWs in these waters, combining observations from a summertime vessel-based expedition to South Georgia, stable isotope data collected from SRWs and putative prey and sightings reports collated by the South Georgia Museum. The expedition used directional acoustics and visual surveys to localise whales and collected skin biopsies and photo-IDs. During 76 h of visual observation effort over 19 expedition days, SRWs were encountered 15 times (~31 individuals). Photo-IDs, combined with publicly contributed images from commercial vessels, were reconciled and quality-controlled to form a catalogue of 6 fully (i.e. both sides) identified SRWs and 26 SRWs identified by either left or right sides. No photo-ID matches were found with lower-latitude calving grounds, but 3 whales had gull lesions supporting a direct link with Península Valdés, Argentina. The isotopic position of SRWs in the South Georgia food web suggests feeding on a combination of copepod and krill species. Opportunistic reports of SRW sightings and associated group sizes remain steady over time, while humpback whales provide a strong contrast, with increased sighting rates and group sizes seen since 2013. These data suggest a plateau in SRWs and an increasing humpback whale presence in South Georgia waters following the cessation of whaling.

Effects of Time-Restricted Eating on Weight Loss and Other Metabolic Parameters in Women and Men With Overweight and Obesity: The TREAT Randomized Clinical Trial

IMPORTANCE

The efficacy and safety of time-restricted eating have not been explored in large randomized clinical trials.

OBJECTIVE

To determine the effect of 16:8-hour time-restricted eating on weight loss and metabolic risk markers.

INTERVENTIONS

Participants were randomized such that the consistent meal timing (CMT) group was instructed to eat 3 structured meals per day, and the time-restricted eating (TRE) group was instructed to eat ad libitum from 12:00 pm until 8:00 pm and completely abstain from caloric intake from 8:00 pm until 12:00 pm the following day.

DESIGN, SETTING, AND PARTICIPANTS

This 12-week randomized clinical trial including men and women aged 18 to 64 years with a body mass index (BMI, calculated as weight in kilograms divided by height in meters squared) of 27 to 43 was conducted on a custom mobile study application. Participants received a Bluetooth scale. Participants lived anywhere in the United States, with a subset of 50 participants living near San Francisco, California, who underwent in-person testing.

MAIN OUTCOMES AND MEASURES

The primary outcome was weight loss. Secondary outcomes from the in-person cohort included changes in weight, fat mass, lean mass, fasting insulin, fasting glucose, hemoglobin A1c levels, estimated energy intake, total energy expenditure, and resting energy expenditure.

RESULTS

Overall, 116 participants (mean [SD] age, 46.5 [10.5] years; 70 [60.3%] men) were included in the study. There was a significant decrease in weight in the TRE (-0.94 kg; 95% CI, -1.68 to -0.20; P = .01), but no significant change in the CMT group (-0.68 kg; 95% CI, -1.41 to 0.05, P = .07) or between groups (-0.26 kg; 95% CI, -1.30 to 0.78; P = .63). In the in-person cohort (n = 25 TRE, n = 25 CMT), there was a significant within-group decrease in weight in the TRE group (-1.70 kg; 95% CI, -2.56 to -0.83; P < .001). There was also a significant difference in appendicular lean mass index between groups (-0.16 kg/m2; 95% CI, -0.27 to -0.05; P = .005). There were no significant changes in any of the other secondary outcomes within or between groups. There were no differences in estimated energy intake between groups.

CONCLUSIONS AND RELEVANCE

Time-restricted eating, in the absence of other interventions, is not more effective in weight loss than eating throughout the day.

TRIAL REGISTRATION

ClinicalTrials.gov Identifiers: NCT03393195 and NCT03637855.

Predictors of liver fat among children and adolescents from five different ethnic groups

Objectives

As rates of obesity around the world have increased, so has the detection of high level of liver fat in children and adolescents. This may put them at risk for cardiovascular disease later in life. This analysis of a cross‐sectional population‐based study of children and adolescents evaluated demographic and lifestyle determinants of percent liver fat.

Methods

Healthy participants (123 girls and 99 boys aged 5–17 years) recruited by convenience sampling in three locations completed questionnaires, anthropometric measurements, and dual X‐ray absorptiometry and magnetic resonance imaging (MRI) assessment. General linear models were applied to estimate the association of demographic, anthropometric, and dietary factors as well as physical activity with MRI‐based percent liver fat.

Results

The strongest predictor of liver fat was body mass index (BMI; p < 0.0001); overweight and obesity were associated with 0.5% and 1% higher liver fat levels. The respective adjusted mean percent values were 2.9 (95% CI 2.7, 3.1) and 3.4 (95% CI 3.2, 3.6) as compared to normal weight (2.4; 95% CI 2.3, 2.6). Mean percent liver fat was highest in Whites and African Americans, intermediate in Hispanic, and lowest among Asians and Native Hawaiians/Pacific Islanders (p < 0.0001). Age (p = 0.67), sex (p = 0.28), physical activity (p = 0.74), and diet quality (p = 0.70) were not significantly related with liver fat.

Conclusions

This study in multiethnic children and adolescents confirms the strong relationship of BMI with percent liver fat even in a population with low liver fat levels without detecting an association with age, sex, and dietary or physical activity patterns.

Predicting 3D body shape and body composition from conventional 2D photography

PURPOSE

Total and regional body composition are important indicators of health and mortality risk, but their measurement is usually restricted to controlled environments in clinical settings with expensive and specialized equipment. A method that approaches the accuracy of the current gold standard method, dual-energy x-ray absorptiometry (DXA), while only requiring input from widely available consumer grade equipment, would enable the measurement of these important biometrics in the wild, enabling data collection at a scale that would have previously been prohibitive in time and expense. We describe an algorithm for predicting three-dimensional (3D) body shape and composition from a single frontal 2-dimensional image acquired with a digital consumer camera.

METHODS

Duplicate 3D optical scans, two-dimensional (2D) optical images, and DXA whole-body scans were available for 183 men and 233 women from the Shape Up! Adults Study. A principal component analysis vector basis was fit to 3D point clouds of a training subset of 152 men and 194 women. The relationship between this vector space and DXA-derived body composition was modeled with linear regression. The principal component 3D shape was then fitted to match a silhouette extracted from a 2D photograph of a novel body. Body composition was predicted from the resulting 3D shape match using the linear mapping between the principal component parameters and the DXA metrics. Accuracy of body composition estimates from the silhouette method was evaluated against a simple model using height and weight as a baseline, and against DXA measurements as ground truth. Test-retest precision of the silhouette method was evaluated using the duplicate 2D optical images and compared against precision of the duplicate DXA scans. Paired t-tests were performed to detect significant differences between the sets.

RESULTS

Results were reported on a held-out set. Body composition prediction achieved R² s of 0.81 and 0.74 for percent fat prediction of males and females, respectively, on a held-out test set consisting of 31 males and 39 females. Precision estimates for fat mass were 2.31% and 2.06% for males and females, respectively, compared to 1.26% and 0.68% for DXA scans. The t-tests revealed no statistically significant differences between the silhouette method measurements and DXA measurements, or between retests.

CONCLUSION

Total and regional body composition measures can be estimated from a single frontal photograph of a human body. Body composition prediction using consumer level photography can enable early screening and monitoring of possible physiological indicators of metabolic disease in regions where medical imagery or clinical assessment is inaccessible.

A comparison of baleen whale density estimates derived from overlapping satellite imagery and a shipborne survey

As whales recover from commercial exploitation, they are increasing in abundance in habitats that they have been absent from for decades. However, studying the recovery and habitat use patterns of whales, particularly in remote and inaccessible regions, frequently poses logistical and economic challenges. Here we trial a new approach for measuring whale density in a remote area, using Very-High-Resolution WorldView-3 satellite imagery. This approach has capacity to provide sightings data to complement and assist traditional sightings surveys. We compare at-sea whale density estimates to estimates derived from satellite imagery collected at a similar time, and use suction-cup archival logger data to make an adjustment for surface availability. We demonstrate that satellite imagery can provide useful data on whale occurrence and density. Densities, when unadjusted for surface availability are shown to be considerably lower than those estimated by the ship survey. However, adjusted for surface availability and weather conditions (0.13 whales per km², CV = 0.38), they fall within an order of magnitude of those derived by traditional line-transect estimates (0.33 whales per km², CV = 0.09). Satellite surveys represent an exciting development for high-resolution image-based cetacean observation at sea, particularly in inaccessible regions, presenting opportunities for ongoing and future research.

Optical imaging technology for body size and shape analysis: evaluation of a system designed for personal use

BACKGROUND/OBJECTIVES

Three-dimensional optical (3DO) imaging systems that rapidly and accurately provide body shape and composition information are increasingly available in research and clinical settings. Recently, relatively low-cost and space efficient 3DO systems with the ability to report and track individual assessments were introduced to the consumer market for home use. This study critically evaluated the first 3DO imaging device intended for personal operation, the Naked Body Scanner (NBS), against reference methods.

PARTICIPANTS/METHODS

Circumferences at six standardized anatomic sites were measured with a flexible tape in 90 participants ranging in age (5-74 years), ethnicity, and adiposity. Regression analysis and Bland-Altman plots compared these direct measurements and dual-energy X-ray absorptiometry (DXA) %fat estimates to corresponding NBS values. Method precision was analyzed from duplicate anthropometric and NBS measurements in a subgroup of 51 participants.

RESULTS

The NBS exhibited greater variation in test-retest reliability (CV, 0.4-2.7%) between the six measured anatomic locations when compared with manually measured counterparts (0.2-0.4%). All six device-derived circumferences correlated with flexible tape references (R2s, 0.84-0.97; p < 0.0001). Measurement bias was apparent for three anatomic sites while mean differences were present for five. The NBS's %fat estimates also correlated with DXA results (R2 = 0.73, p < 0.0001) with no significant bias.

CONCLUSIONS

This system opens a new era of digital home-based assessments that can be incorporated into weight loss or exercise interventions accessible to clinical investigators as well as individual users.

Diet Quality and Visceral Adiposity among a Multiethnic Population of Young, Middle, and Older Aged Adults

BACKGROUND

Visceral adiposity, more so than overall adiposity, is associated with chronic disease and mortality. There has been, to our knowledge, little research exploring the association between diet quality and visceral adipose tissue (VAT) among a mulitethnic population aged 18-80 y.

OBJECTIVE

The primary objective of this cross-sectional analysis was to examine the association between diet quality [Healthy Eating Index-2010 (HEI-2010) scores] and VAT among a multiethnic population of young, middle, and older aged adults in the United States. Secondary objectives were to repeat these analyses with overall adiposity and blood-based biomarkers for type 2 diabetes and cardiovascular disease risk as outcome measures.

METHODS

A total of 540 adults (dropped out: n = 4; age: 18-40 y, n = 220; 40-60 y, n = 183; 60-80 y, n = 133) were recruited across 3 sites (Honolulu County, San Francisco, and Baton Rouge) for the Shape Up! Adults study. Whole-body DXA, anthropometry, fasting blood draw, and questionnaires (food frequency, physical activity, and demographic characteristics) were completed. Linear regression was used to assess the associations between HEI-2010 tertiles and VAT and secondary outcome measures among all participants and age-specific strata, while adjusting for known confounders.

RESULTS

VAT, BMI (kg/m2), body fat percentage, total body fat, trunk fat, insulin, and insulin resistance were inversely related to diet quality (all P values < 0.004). When stratified by age, diet quality was inversely associated with VAT among participants aged 60-80 y (P < 0.006) and VAT/subcutaneous adipose tissue (SAT) among participants aged 40-60 y (P < 0.008).

CONCLUSIONS

Higher-quality diet was associated with lower VAT, overall adiposity, and insulin resistance among this multiethnic population of young, middle, and older aged adults with ages ranging from 18 to 80 y. More specifically, adherence to a high-quality diet may minimize VAT accumulation in adults aged 60-80 y and preferentially promote storage of SAT compared with VAT in adults aged 40-60 y.This study was registered at clinicaltrials.gov as NCT03637855.

MON-LB107 Treat: A Randomized Controlled Trial Examining the Effects of Time Restricted Eating on Weight Loss and Metabolic Markers

Background: Studies indicate that time-restricted eating (TRE) can prevent weight gain and/or lead to weight loss [1,2]. The few human studies to date are small and/or non-randomized [3,4]. This is a prospective and randomized study in humans who are overweight and obese designed to determine if TRE leads to weight loss and to characterize the metabolic effects of TRE. Methods: 140 overweight and obese males and females with a body mass index between 27-43 kg/m2 were enrolled in the study. 100 participants completed the 12-week protocol. The study was conducted on a custom mobile study app on the Eureka Research Platform. Participants were given a Bluetooth weight scale to use daily, which was connected through the study app. Subjects were randomized to one of two eating plans and received daily reminders about their eating windows through the app. The control group was instructed to eat three structured meals per day. The TRE group was instructed to eat ad libitum from 12:00 pm until 8:00 pm and completely abstain from caloric intake from 8:00 pm until 12:00 pm the following day (16h fast:8h eat). Participants who lived within 60 miles of the study site were eligible to undergo extensive in-person metabolic testing. Results: Weight change in the TRE group was -1.3 kg compared to -0.6 kg in the control group (p=0.22). 46 (TRE n=22; control=24) of 50 participants who opted into the “in-person” visits completed all 4 visits. In that cohort, weight change in the TRE group was -1.62 kg compared to -0.57 kg in control (p=0.09). There were no significant differences in the changes in total fat mass, visceral or subcutaneous fat mass, waist or hip measurements, or resting metabolic rate. However, there was a trend towards reduced fat-free mass in the TRE group (-1.10kg) compared to controls (-0.35kg) (p=0.09). There was a significant change in the appendicular fat-free mass index of the TRE subjects compared to controls (p=0.011). This change in appendicular fat-free mass index was not associated with significant differences in strength measures. No changes were observed in plasma ketones, insulin, or glucose between treatment groups. Conclusion: These results indicate that TRE may lead to reductions in body weight in individuals who are overweight or obese. However, the majority of weight loss is attributed to reductions in fat-free mass rather than fat mass. Future analyses will determine if TRE leads to changes in metabolic blood markers or the plasma metabolome. References: 1.Hatori et al. Cell Metab. 2012 Jun 6;15(6):848-60. doi: 10.1016/j.cmet.2012.04.019. Epub 2012 May 17.2.

Chaix et al. Cell Metab. 2019 Feb 5;29(2):303-319.e4. doi: 10.1016/j.cmet.2018.08.004. Epub 2018 Aug 30.3.Moro et al. J Transl Med. 2016 Oct 13;14(1):290.4.Wilkinson et al.Cell Metab. 2020 Jan 7;31(1):92-104.e5. doi: 10.1016/j.cmet.2019.11.004. Epub 2019 Dec 5.

Detailed 3-dimensional body shape features predict body composition, blood metabolites, and functional strength: the Shape Up! studies

BACKGROUND

Three-dimensional optical (3DO) body scanning has been proposed for automatic anthropometry. However, conventional measurements fail to capture detailed body shape. More sophisticated shape features could better indicate health status.

OBJECTIVES

The objectives were to predict DXA total and regional body composition, serum lipid and diabetes markers, and functional strength from 3DO body scans using statistical shape modeling.

METHODS

Healthy adults underwent whole-body 3DO and DXA scans, blood tests, and strength assessments in the Shape Up! Adults cross-sectional observational study. Principal component analysis was performed on registered 3DO scans. Stepwise linear regressions were performed to estimate body composition, serum biomarkers, and strength using 3DO principal components (PCs). 3DO model accuracy was compared with simple anthropometric models and precision was compared with DXA.

RESULTS

This analysis included 407 subjects. Eleven PCs for each sex captured 95% of body shape variance. 3DO body composition accuracy to DXA was: fat mass R2 = 0.88 male, 0.93 female; visceral fat mass R2 = 0.67 male, 0.75 female. 3DO body fat test-retest precision was: root mean squared error = 0.81 kg male, 0.66 kg female. 3DO visceral fat was as precise (%CV = 7.4 for males, 6.8 for females) as DXA (%CV = 6.8 for males, 7.4 for females). Multiple 3DO PCs were significantly correlated with serum HDL cholesterol, triglycerides, glucose, insulin, and HOMA-IR, independent of simple anthropometrics. 3DO PCs improved prediction of isometric knee strength (combined model R2 = 0.67 male, 0.59 female; anthropometrics-only model R2 = 0.34 male, 0.24 female).

CONCLUSIONS

3DO body shape PCs predict body composition with good accuracy and precision comparable to existing methods. 3DO PCs improve prediction of serum lipid and diabetes markers, and functional strength measurements. The safety and accessibility of 3DO scanning make it appropriate for monitoring individual body composition, and metabolic health and functional strength in epidemiological settings.This trial was registered at clinicaltrials.gov as NCT03637855.

Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

BACKGROUND

Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery.

METHODS

This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy.

RESULTS

Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51-19.97) than planned admissions (OR: 2.32, 95% CI: 1.43-3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8-51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI.

CONCLUSIONS

After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies.

Temporal variability of readmission determinants in postoperative vascular surgery patients

Introduction:

Clinical information continues to be limited regarding changes in the temporal risk profile for readmissions during the initial postoperative year in vascular surgery patients. We set out to describe the associations between demographics, clinical outcomes, comorbidity indices, and hospital readmissions in a sample of patients undergoing common extremity revascularization or dialysis access (ERDA) procedures. We hypothesized that factors independently associated with readmission will evolve from “short-term” to “long-term” determinants at 30-, 180-, and 360-day postoperative cutoff points.

Methods:

Following IRB approval, medical records of patients who underwent ERDA at two institutions were retrospectively reviewed between 2008 and 2014. Abstracted data included patient demographics, procedural characteristics, the American Society of Anesthesiologists score, Goldman Criteria for perioperative cardiac assessment, the Charlson comorbidity index, morbidity, mortality, and readmission (at 30-, 180-, and 360-days). Univariate analyses were performed for readmissions at each specified time point. Variables reaching statistical significance of P < 0.20 were included in multivariate analyses for factors independently associated with readmission.

Results:

A total of 450 of 744 patients who underwent ERDA with complete medical records were included. Patients underwent either an extremity revascularization (e.g. bypass or endarterectomy, 406/450) or a noncatheter dialysis access procedure (44/450). Sample characteristics included 262 (58.2%) females, mean age 61.4 ± 12.9 years, 63 (14%) emergent procedures, and median operative time 164 min. Median hospital length of stay (index admission) was 4 days. Cumulative readmission rates at 30-, 180-, and 360-day were 12%, 27%, and 35%, respectively. Corresponding mortality rates were 3%, 7%, and 9%. Key factors independently associated with 30-, 180-, and 360-day readmissions evolved over the study period from comorbidity and morbidity-related issues in the short-term to cardiovascular and graft patency issues in the long-term. Any earlier readmission elevated the risk of subsequent readmission.

Conclusions:

We noted important patterns in the temporal behavior of hospital readmission risk in patients undergoing ERDA. Although factors independently associated with readmission were not surprising (e.g. comorbidity profile, cardiovascular status, and graft patency), the knowledge of temporal trends described in this study may help determine clinical risk profiles for individual patients and guide readmission reduction strategies. These considerations will be increasingly important in the evolving paradigm of value-based healthcare.

Implications of aligning full registration of doctors with medical school graduation: a qualitative study of stakeholder perspectives

OBJECTIVES

The Shape of Training report recommended that full registration is aligned with medical school graduation. As part of a General Medical Council-funded study about the preparedness for practice of UK medical graduates, we explored UK stakeholders' views about this proposal using qualitative interviews (30 group and 87 individual interviews) and Framework Analysis.

SETTING

Four UK study sites, one in each country.

PARTICIPANTS

185 individuals from eight stakeholder groups: (1) foundation year 1 (F1) doctors (n=34); (2) fully registered trainee doctors (n=33); (3) clinical educators (n=32); (4) undergraduate/postgraduate Deans, and Foundation Programme Directors (n=30); (5) other healthcare professionals (n=13); (6) employers (n=7); (7) policy and government (n=11); (8) patient and public representatives (n=25).

RESULTS

We identified four main themes: (1) The F1 year as a safety net: patients were protected by close trainee supervision and 'sign off' to prevent errors; trainees were provided with a safe environment for learning on the job; (2) Implications for undergraduate medical education: if the proposal was accepted, a 'radical review' of undergraduate curricula would be needed; undergraduate education might need to be longer; (3) Implications for F1 work practice: steps to protect healthcare team integration and ensure that F1 doctors stay within competency limits would be required; (4) Financial, structural and political implications: there would be cost implications for trainees; clarification of responsibilities between undergraduate and postgraduate medical education would be needed. Typically, each theme comprised arguments for and against the proposal.

CONCLUSIONS

A policy change to align the timing of full registration with graduation would require considerable planning and preliminary work. These findings will inform policymakers' decision-making. Regardless of the decision, medical students should take on greater responsibility for patient care as undergraduates, assessment methods in clinical practice and professionalism domains need development, and good practice in postgraduate supervision and support must be shared.

Microfluidic paper analytical device for the chromatographic separation of ascorbic acid and dopamine

Cellulose-based filter papers were used as base materials to construct microfluidic paper-based analytical devices (μPADs) coupling a separation channel with electrochemical detection.

Counting whales in a challenging, changing environment

Estimating abundance of Antarctic minke whales is central to the International Whaling Commission's conservation and management work and understanding impacts of climate change on polar marine ecosystems. Detecting abundance trends is problematic, in part because minke whales are frequently sighted within Antarctic sea ice where navigational safety concerns prevent ships from surveying. Using icebreaker-supported helicopters, we conducted aerial surveys across a gradient of ice conditions to estimate minke whale density in the Weddell Sea. The surveys revealed substantial numbers of whales inside the sea ice. The Antarctic summer sea ice is undergoing rapid regional change in annual extent, distribution, and length of ice-covered season. These trends, along with substantial interannual variability in ice conditions, affect the proportion of whales available to be counted by traditional shipboard surveys. The strong association between whales and the dynamic, changing sea ice requires reexamination of the power to detect trends in whale abundance or predict ecosystem responses to climate change.

Cementing techniques for the tibial component in primary total knee replacement

The optimum cementing technique for the tibial component in cemented primary total knee replacement (TKR) remains controversial. The technique of cementing, the volume of cement and the penetration are largely dependent on the operator, and hence large variations can occur. Clinical, experimental and computational studies have been performed, with conflicting results. Early implant migration is an indication of loosening. Aseptic loosening is the most common cause of failure in primary TKR and is the product of several factors. Sufficient penetration of cement has been shown to increase implant stability. This review discusses the relevant literature regarding all aspects of the cementing of the tibial component at primary TKR.

Light interception efficiency explained by two simple variables: a test using a diversity of small- to medium-sized woody plants

• Plant light interception efficiency is a crucial determinant of carbon uptake by individual plants and by vegetation. Our aim was to identify whole-plant variables that summarize complex crown architecture, which can be used to predict light interception efficiency. • We gathered the largest database of digitized plants to date (1831 plants of 124 species), and estimated a measure of light interception efficiency with a detailed three-dimensional model. Light interception efficiency was defined as the ratio of the hemispherically averaged displayed to total leaf area. A simple model was developed that uses only two variables, crown density (the ratio of leaf area to total crown surface area) and leaf dispersion (a measure of the degree of aggregation of leaves). • The model explained 85% of variation in the observed light interception efficiency across the digitized plants. Both whole-plant variables varied across species, with differences in leaf dispersion related to leaf size. Within species, light interception efficiency decreased with total leaf number. This was a result of changes in leaf dispersion, while crown density remained constant. • These results provide the basis for a more general understanding of the role of plant architecture in determining the efficiency of light harvesting.

A health and safety survey of Irish funeral industry workers

BACKGROUND

Those handling deceased individuals, including the funeral industry, face a variety of health and safety hazards including occupationally acquired infectious disease.

AIMS

To identify the knowledge, attitudes and beliefs of Irish funeral industry workers towards occupational hazards and infectious disease in 2009.

METHODS

The sample analysed consisted of all listed member premises of the Irish Association of Funeral Directors as at 1 July 2009. A postal survey was sent to each premises in July 2009, with two rounds of follow-up reviews sent to non-responders. Four main areas were covered--occupational hazards, embalming, industry expertise and demographics. The quantitative and qualitative results were analysed to assess knowledge, attitudes and beliefs. Data collection was completed on 31 December 2009.

RESULTS

Two hundred and thirty listed member premises were contacted. Twenty-two were unsuitable for the survey. One hundred and thirty-eight valid replies were received from 130 premises, representing a premises response rate of 63% (130/208). Seventy-three premises (56%) identified themselves as embalmers. Embalmers had variable vaccine uptake and variable knowledge, attitude and beliefs towards embalming those with blood-borne viruses. Fifteen per cent of respondents reported a work-related injury, back injury being the most common. Splash and sharps injuries were reported as a work-related injury, and infections believed to be work related were also reported.

CONCLUSIONS

This study demonstrates widespread occupational health concerns among this professional group. It confirms the need for occupational health advice and services. There is also a strong desire for regulation of this profession in Ireland.

Effect of dietary corn silage inclusion on visceral organ mass, cellularity, and the protein expression of ATP synthase, Na+/K+-ATPase, proliferating cell nuclear antigen and ubiquitin in feedlot steers

Twenty-four steers (initial body weight = 535 ± 5.0 kg) predominately of Angus breeding were used to determine the effect of dietary corn silage inclusion [20, 40, 60, or 80% of dry matter (DM)] on visceral mass, cellularity, and the protein expression of ATP synthase, Na+/K+-ATPase, proliferating cell nuclear antigen (PCNA) and ubiquitin. Steers were fed at similar energy levels (2.1 × NEm requirement). There were no significant treatment effects on specific visceral organ weights. Hepatic Na+/K+-ATPase expression linearly increased (P = 0.01) and ruminal Na+/K+-ATPase expression linearly decreased (P = 0.01) with increasing corn silage inclusion. Hepatic PCNA expression was quadratically affected (P = 0.05) with a decrease when corn silage inclusion increased from 20 to 60%, and an increase when corn silage inclusion increased from 60 to 80%. Renal ATP synthase (P = 0.02) and ubiquitin expression (P = 0.01) were quadratically affected in a similar pattern with an increase when corn silage inclusion increased from 20 to 60%, and a decrease when corn silage inclusion increased from 60 to 80%. These results indicate that different dietary corn silage inclusions, at similar dietary energy intake, may alter rumen, liver, and kidney energy expenditure, at least in part, through changes in specific metabolism rather than mass. Key words: Corn silage inclusion, visceral organ mass, cellular energy metabolism, steer

Pancreatic mass, cellularity, and α-amylase and trypsin activity in feedlot steers fed diets with increasing corn silage inclusion

Twenty-four yearling beef steers (initial BW = 535 ± 5.0 kg), predominately of Angus breeding, were used in a randomized complete block design to determine the effect of dietary inclusion of corn silage on pancreatic cellularity, mass, and α-amylase and trypsin activity. Using calan gates, steers were individually fed diets containing 20, 40, 60, or 80% corn silage (DM basis) with the rest of the diet made up of concentrate. Diets were formulated to maintain a constant CP:ME (g Mcal-1) and were fed at 2.1 × NEm requirement. After 28 d on treatment, the two heaviest steers from each treatment were slaughtered per week and pancreata collected. Pancreatic weight (g and g kg-1 BW) and content (kU and U kg-1 BW) of α-amylase activity did not differ among dietary treatments. Concentration (U g-1) of pancreatic α-amylase decreased (P = 0.03) with increasing corn silage inclusion. Pancreatic DNA and RNA content (g and mg kg-1 BW) increased linearly (P ≤ 0.04) with increasing corn silage inclusion. The content of pancreatic trypsin activity responded cubically (P = 0.03). These data indicate that increasing corn silage inclusion does not influence total pancreatic α-amylase activity and that cell number may influence pancreatic α-amylase concentration. Key words: Beef cattle, pancreas, α-amylase, trypsin, forage, concentrate