Relative Body Mass Research Articles

Likely causal effects of insulin resistance and IGF-1 bioaction on childhood and adult adiposity: a Mendelian randomization study

BackgroundCirculating insulin and insulin-like growth factor-1 (IGF-1) concentrations are positively correlated with adiposity. However, the causal effects of insulin and IGF-1 on adiposity are unclear.MethodsWe performed two-sample Mendelian randomization analyses to estimate the likely causal effects of fasting insulin and IGF-1 on relative childhood adiposity and adult body mass index (BMI). To improve accuracy and biological interpretation, we applied Steiger filtering (to avoid reverse causality) and ‘biological effect’ filtering of fasting insulin and IGF-1 associated variants.ResultsFasting insulin-increasing alleles (35 variants also associated with higher fasting glucose, indicative of insulin resistance) were associated with lower relative childhood adiposity (P = 3.8 × 10−3) and lower adult BMI (P = 1.4 × 10−5). IGF-1-increasing alleles also associated with taller childhood height (351 variants indicative of greater IGF-1 bioaction) showed no association with relative childhood adiposity (P = 0.077) or adult BMI (P = 0.562). Conversely, IGF-1-increasing alleles also associated with shorter childhood height (306 variants indicative of IGF-1 resistance) were associated with lower relative childhood adiposity (P = 6.7 × 10−3), but effects on adult BMI were inconclusive.ConclusionsGenetic causal modelling indicates negative effects of insulin resistance on childhood and adult adiposity, and negative effects of IGF-1 resistance on childhood adiposity. Our findings demonstrate the need to distinguish between bioaction and resistance when modelling variants associated with biomarker concentrations.

Relative Strength and Physical Performance in US Army Male and Female Soldiers.

Grier, T, Benedict, T, Mahlmann, O, and Canham-Chervak, M. Relative Strength and Physical Performance in U.S. Army Male and Female Soldiers. J Strength Cond Res 38(8): 1479-1485, 2024-In occupations with high physical demands, strength relative to bodymass is an important measure as it signifies an individual's ability to control and move their body mass through space. The purpose of this investigation was to examine physical characteristics, training, and performance based on different magnitudes of relative strength. Subjects were 1,806 male and 319 female US Army soldiers. Sex, age, height, body mass, and physical training data were obtained by an electronic survey. Physical performance was measured by the Army Combat Fitness Test (ACFT), which includes a three-repetition maximum deadlift, standing power throw, hand release push-up, sprint-drag-carry, leg tuck, and two-mile run. The relative body mass deadlifted was calculated and categorized into 4 groups for men and 3 groups for women. An analysis of variance and post hoc least significant difference test were used to evaluate the differences in relative strength and physical performance. Overall, 33% of men deadlifted ≥1.5 times their body mass, while 30% of women deadlifted ≥1.25 times their body mass. Men and women deadlifting the highest percentage of their body mass (≥1.5 times for men and ≥1.25 times for women) outperformed those with lower relative strength within their own sex in all 6 ACFT events. In 4 of the 6 ACFT events, women who deadlifted ≥1.25 times their body mass had similar performance compared with men deadlifting 1 to 1.24 times their body mass and outperformed men deadlifting <1 times their body mass. Greater strength relative to body mass was associated with higher physical performance.

Predicted body fat percentage, fat mass and lean body mass in relation to risk of prostate cancer: Results from the NHANES 1999 to 2010

Predicted body fat percentage, fat mass and lean body mass in relation to risk of prostate cancer: Results from the NHANES 1999 to 2010

Bacterial sepsis triggers stronger transcriptomic immune responses in larger primates.

Empirical data relating body mass to immune defence against infections remain limited. Although the metabolic theory of ecology predicts that larger organisms would have weaker immune responses, recent studies have suggested that the opposite may be true. These discoveries have led to the safety factor hypothesis, which proposes that larger organisms have evolved stronger immune defences because they carry greater risks of exposure to pathogens and parasites. In this study, we simulated sepsis by exposing blood from nine primate species to a bacterial lipopolysaccharide (LPS), measured the relative expression of immune and other genes using RNAseq, and fitted phylogenetic models to determine how gene expression was related to body mass. In contrast to non-immune-annotated genes, we discovered hypermetric scaling in the LPS-induced expression of innate immune genes, such that large primates had a disproportionately greater increase in gene expression of immune genes compared to small primates. Hypermetric immune gene expression appears to support the safety factor hypothesis, though this pattern may represent a balanced evolutionary mechanism to compensate for lower per-transcript immunological effectiveness. This study contributes to the growing body of immune allometry research, highlighting its importance in understanding the complex interplay between body size and immunity over evolutionary timescales.

A country‐wide examination of effects of urbanization on common birds

AbstractUrbanization forms one of the most drastic alterations of the environment and poses a major threat to wildlife. The human–induced modifications of the landscape may affect individual's fitness resulting in population declines. Research on how urbanization affects fitness traits has shown mixed results. However, studies typically contrasted data from a single species from few urban and non‐urban sites collected over short timeframes. Examining multiple species across a broad urbanization gradient enables a more robust comparison and understanding of how different species are impacted by urbanization‐knowledge crucial for generating population predictions, which are essential for conservation management. Here, we use data from a nation‐wide citizen science project to examine variation in survival and relative body mass and size (wing length) of common passerine birds, collected along an urbanization gradient in the Netherlands over an 8‐year period. Urbanization was measured as the distance from the city's border and the proportion of impervious surface area. Although the overall association between urbanization and survival was slightly negative, there was support for lower survival closer to the city in three species (chiffchaff Phylloscopus collybita, European robin Erithacus rubecula, European greenfinch Chloris chloris) and higher survival closer to the city in two (great tit Parus major and house sparrow Passer domesticus) of the 11 species examined. The contrasting survival successes among species suggest that ongoing urbanization may lead to shifts in community structure and loss of biodiversity. Impacts of urbanization on relative mass and size also exhibited varying effects, albeit less pronounced, and these effects were not correlated with the effects on survival. This implies that body mass and size cannot be used as indicators for urban‐associated patterns of survival. Our results further imply that effective conservation management targeting bird communities should involve a range of diverse actions, as focusing on single measures is unlikely to simultaneously impact multiple species due to the variation in responses to urbanization.

Abstract PO5-09-01: Relative low body mass index (BMI) and fat quantity predicts prognosis better than absolute BMI in hormone receptor-positive, HER2-negative breast cancer

Abstract Purpose: Most existing research about obesity and prognosis in breast cancer patients primarily compares obese and non-obese individuals according to standard body mass index (BMI) categories. With a notably high percentage of Asian patients presenting with young age onset and normal weight, the prevalence of overweight and obesity based on absolute BMI values is lower in Asia (according to WHO guideline, BMI under 18.5 means underweight, and BMI over 25 means overweight). Understanding the impact of relatively low and high weight on prognosis can provide more insightful data than assessments based on absolute BMI thresholds. This study aimed to investigate the impact of relative low/high BMI on the prognosis of breast cancer and to explore the influence of body fat quantity (FQ), which is closely related to BMI. Methods: The study population consisted of 3,663 patients who received surgery for primary breast cancer at Seoul National University Hospital from 2006 to 2015. Pre-treatment BMI was divided into quartiles, defining low-BMI (Q1) as ≤ 21.33, high-BMI (Q4) as &amp;gt; 25.53, and mid-BMI as values between the two. Fat quantity (FQ) was derived from chest CT using the deep learning-based FDA-approved DeepCatch software. It measures the fat volume at the L1 level then divides this value by the square of the patient's height. It was then also divided into quartiles, establishing the definitions of low-, mid-, and high-FQ. The associations of BMI and FQ with distant metastasis-free survival (DMFS) and overall survival (OS) were examined. Results: The high-BMI group demonstrated older median age and higher T and N stages (p&amp;lt; 0.001). The high- and low-BMI groups also showed a higher prevalence of estrogen receptor positive cancer compared to the mid-BMI group. A strong correlation (Pearson correlation coefficient 0.83) was observed between BMI and FQ. In HR-positive, HER2-negative breast cancer, high-BMI patients had a 1.55 times higher risk of distant metastasis (95% CI: 1.15-2.11, p = 0.005), and a 1.78 times higher risk of mortality (95% CI: 1.22-2.58, p = 0.003) compared to mid-BMI patients, while low-BMI patients demonstrated better outcomes regarding DMFS (HR 0.67, p=0.035) and OS (HR 0.59, p=0.04). Comparison of FQ with prognosis revealed that the low-FQ patients exhibited better DMFS (HR 0.59, p=0.005) and OS (HR = 0.44, p=0.002) compared to mid-FQ patients in HR-positive, HER2-negative breast cancer. However, when adjusted for T and N stages, low-BMI patients in the HR-positive, HER2-negative group showed no difference in prognosis from mid-BMI patients but better prognosis compared to high-BMI patients. In contrast, when defined using absolute BMI, underweight patients did not show a difference in DMFS (HR 0.72 vs. normal BMI, p = 0.515) and OS (HR 0.91 vs. normal BMI, p = 0.87) compared to those with normal weight and overweight. The low-FQ group had the best prognosis regarding DMFS (HR 0.66 vs. mid-FQ, p=0.032) and OS (HR 0.50 vs. mid-FQ, p=0.008). Conclusions: Low-BMI is a favorable prognostic factor compared to high-BMI for DMFS and OS in HR-positive, HER2-negative breast cancer. The relative BMI defined according to BMI quartiles was a better prognostic factor than to absolute BMI standards. Investigations with FQ showed similar tendencies, suggesting that low BMI's favorable prognostic influence may be associated with fat. Future investigations should aim to validate these results and delve deeper into the underlying mechanisms. Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Soon Ho Yoon work as chief medical officer in MEDICALIP. This author did not involve data/statistical analysis. Other authors have no competing interest to declare. Citation Format: Eunhye Kang, Ji-Jung Jung, Ik Beom Shin, Hawjeong Lee, Jin Young Byeon, Changjin Lim, Hong-Kyu Kim, Hyeong-Gon Moon, Wonshik Han, Jong-Ho Cheun, Soon Ho Yoon, Han-Byoel Lee. Relative low body mass index (BMI) and fat quantity predicts prognosis better than absolute BMI in hormone receptor-positive, HER2-negative breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-09-01.

Predictive values of relative fat mass and body mass index on cardiovascular health in community-dwelling older adults: Results from the Longevity Check-up (Lookup) 7+

ObjectivesTo assess the predictive value of relative fat mass compared to body mass index for hypertension, diabetes, hyperlipidemia, and heightened cardiovascular risk in a cohort of community-dwelling older adults from the Longevity Check-up 7+ cohort. Study designRetrospective cross-sectional study. Main outcome measuresHyperlipidemia was defined as total cholesterol ≥200 mg/dL or ongoing lipid-lowering treatment. Diabetes was defined either as self-reported diagnosis or fasting blood glucose >126 mg/dL or a random blood glucose >200 mg/dL. Hypertension was defined as blood pressure ≥ 140/90 mmHg or requiring daily antihypertensive medications. Heightened cardiovascular risk was operationalized as having at least two of these conditions. ResultsAnalyses were conducted in 1990 participants (mean age 73.2 ± 6.0 years; 54.1 % women). Higher proportions of men than women had hypertension and diabetes, while hyperlipidemia was more prevalent in women. Receiver operating curve analysis indicated relative fat mass was a better predictor of hypertension in women and diabetes in both sexes. Body mass index performed better in predicting hyperlipidemia in women. Relative fat mass thresholds of ≥27 % for men and ≥40 % for women were identified as optimal indicators of heightened cardiovascular risk and so were used to defined high adiposity. Moderate correlations were found between high adiposity or body mass index ≥25 kg/m2 and the presence of hypertension, hyperlipidemia and heightened cardiovascular risk, while a strong correlation was found with diabetes. Logistic regression analysis highlighted significant associations between high adiposity and increased odds of hypertension, diabetes, and heightened cardiovascular risk. ConclusionsProposed cut-offs for relative fat mass were more reliable indices than the usual cut-offs for body mass index for identifying individuals at heightened cardiovascular risk. Our findings support the role of anthropometric measures in evaluating body composition and the associated metabolic and cardiovascular conditions in older adults.

Relative Body Mass Index Improves the BMI Percentile Performance for Detection and Monitoring of Excess Adiposity in Adolescents.

Obesity is defined as excess adipose tissue; however, commonly used methods may under-detect adiposity in adolescents. This study compared the performance of body mass index percentile (BMI%) and relative body mass index (RBMI) in identifying excess body fat percentage (BF%) and estimated RBMI cut points to better stratify severity of adiposity. In 567 adolescents ages 11-19 year, BF% measured by DXA was used to compare BMI% and RBMI performance at different degrees of adiposity. RBMI cut points for adiposity detection were derived via ROC curve analysis. BF% was strongly correlated with BMI% (r = 0.889, p < 0.001) and RBMI (r = 0.901, p < 0.001). However, RBMI exhibited less dispersion and better discriminated the relationship with BF% independent of age, race, and gender. Both BMI% and RBMI performed similarly for detecting high BF% (≥25 BF% in males; ≥30 BF% in females). Nonetheless, the relationship of BMI% with BF% was diminished among leaner adolescents. RBMI detected overweight in 21.3% more females and 14.2% more males. RBMI improved the detection of excess adiposity in individuals otherwise classified as having normal weight or overweight by BMI%. RBMI is a valuable and accessible tool for earlier detection, intervention, and effective follow-up of excess adiposity in youth at higher risk for complications.

A Bayesian functional approach to test models of life course epidemiology over continuous time.

Life course epidemiology examines associations between repeated measures of risk and health outcomes across different phases of life. Empirical research, however, is often based on discrete-time models that assume that sporadic measurement occasions fully capture underlying long-term continuous processes of risk. We propose (i) the functional relevant life course model (fRLM), which treats repeated, discrete measures of risk as unobserved continuous processes, and (ii) a testing procedure to assign probabilities that the data correspond to conceptual models of life course epidemiology (critical period, sensitive period and accumulation models). The performance of the fRLM is evaluated with simulations, and the approach is illustrated with empirical applications relating body mass index (BMI) to mRNA-seq signatures of chronic kidney disease, inflammation and breast cancer. Simulations reveal that fRLM identifies the correct life course model with three to five repeated assessments of risk and 400 subjects. The empirical examples reveal that chronic kidney disease reflects a critical period process and inflammation and breast cancer likely reflect sensitive period mechanisms. The proposed fRLM treats repeated measures of risk as continuous processes and, under realistic data scenarios, the method provides accurate probabilities that the data correspond to commonly studied models of life course epidemiology. fRLM is implemented with publicly-available software.

Rapid Weight Loss Practices Within Olympic Weightlifters.

Gee, TI, Campbell, P, Bargh, MJ, and Martin, D. Rapid weight loss practices within Olympic weightlifters. J Strength Cond Res 37(10): 2046-2051, 2023-Rapid weight loss (RWL) practices are common among athletes to "make weight" for a chosen bodyweight class. This study's purpose was to investigate RWL prevalence, magnitude, and methods within Olympic weightlifters from Great Britain. Subjects (n = 39, male = 22, female = 17) were recruited from International Weightlifting Federation lifting populations (mandatory two-hour competition weigh-in). Subjects were categorized into competitive groups based on Sinclair coefficient total (high, mid, low) and also gender (male, female). The validated Rapid Weight Loss Questionnaire was used to establish RWL magnitude and practices. Of respondents, 33 of 39 (84.6%) had purposely acutely reduced body mass to compete, a higher proportion present within females (94.1%) than males (77.3%). The cohort's mean habitual precompetition acute body mass loss was 3.8 ± 1.7% and the "rapid weight loss score" (RWLS) was 23.6 ± 9.5. Across competitive groups there were no significant differences in habitual or highest precompetition body mass loss, postcompetition body mass gain or RWLS (p > 0.05). However, females attributed a significantly greater "highest" relative precompetition body mass loss compared with males (7.4 vs 4.9%, p = 0.045). For RWL methods used, frequencies of "always" and "sometimes" were reported highest for "restricting fluid ingestion" (81.8%), "gradual dieting" (81.8%), and "water loading" (54.5%). The prevalence of RWL is high among competitive Olympic weightlifters, and especially within the sampled female athletes. Magnitude of RWL was similar across different standards of athlete; however, female lifters demonstrated a higher maximum precompetition RWL.

Comparison of Several Anthropometric Indices Related to Body Fat in Predicting Cardiorespiratory Fitness in School-Aged Children-A Single-Center Cross-Sectional Study.

Body fat (BF) and cardiorespiratory fitness (CRF) are important health markers that ought to be considered in screening exams. The aim of this study was to assess the value of six indicators, i.e., tri-ponderal mass index (TMI), relative fat mass (RFM), waist-BMI ratio, waist-to-height ratio (WHtR), waist-to-hip ratio (WHR) and body mass index (BMI) in predicting CRF in school-aged children. The analysis was based on the data coming from the examination of 190 children participating in school physical education (PE) classes. Their body weight (BW) and height (BH), waist and hip circumference (WC; HC) and percentage of body fat (%BF) were measured; the CRF test was performed with the use of the 20 m shuttle run test (20 mSRT); peak heart rate (HRpeak) was measured; TMI, relative fat mass pediatric (RFMp), waist-BMI ratio, WHtR, BMI and WHR were calculated. Statistical analysis was mainly conducted using regression models. The developed regression models, with respect to the sex and age of the children, revealed RFMp as the strongest CRF indicator (R2 = 51.1%) and WHR as well as waist-BMI ratio as the weakest ones (R2 = 39.2% and R2 = 40.5%, respectively). In predicting CRF in school-aged children, RFMp turned out to be comparable to body fat percentage obtained by means of the bioimpedance analysis (BIA) (R2 = 50.3%), and as such it can be used as a simple screening measure in prophylactic exams of school children. All of these models were statistically significant (p < 0.001).

Physiological Profile and Correlations between VO2max and Match Distance Running Performance of Soccer Players with Visual Impairment

Aerobic capacity is crucial for the performance of soccer players; however, the relationship between VO2max and the running performance of soccer players with visual impairment is not known. Possibly finding relationships would help in the training process, as training would be more targeted. Additionally, both bodyweight and relative VO2max are factors that affect people’s health and wellness. From the literature, it appears that there are no studies that present the normal profile of soccer players with visual impairment. The aims of this study were to (a) determine the differences in VO2max between soccer players and sedentary men with visual impairment; (b) to assess the relationship between the VO2max of players with visual impairment and the distance covered in a soccer match and (c) to describe a profile of physiological parameters and distance running during a soccer match. Six male soccer players with VI and six male sedentary people with VI participated in this study. Anthropometric characteristics (age, height, bodyweight, body fat (BF), body mass index (BMI), cardiorespiratory markers (VO2max, maximum heart rate (HRmax), respiratory exchange ratio (RER)) and the running performance of soccer players during matches were measured, and the VO2max of all the participants was measured in a laboratory. Mann–Whitney U test was used to evaluate differences between sedentary and soccer players’ anthropometric characteristics and performance. A correlation analysis by Spearman’s’ method was used to examine relationships between VO2max and the rest of the physical values during the match. The level of statistical significance was set at p &lt; 0.05. The soccer players’ weight was 33% lower, and their BMI was 23% lower than that of sedentary men (p = 0.023, η2 = 0.457 and p = 0.048, η2 = 0.394, respectively). The relative body mass VO2max of the athletes was 42.9% higher in comparison with sedentary men with VI (p = 0.002, η2 = 0.755). No correlations were found between VO2max and match running performance (p = 0.957, r = −0.029) or other parameters during the match in soccer players with VI. In conclusion, relative VO2max is not related to the match running performance of soccer players. The tactics applied by the team, the style of play and the position of the player may affect the distances covered. Also, as expected, the soccer players showed lower bodyweight and higher relative VO2max. However, this is the first study to observe the level of these differences.

The Effect of Childhood Obesity on Psychomotor Behavior

Childhood obesity is a complex problem, and its prevalence among school-age children has been found to have a greater impact on their physical well-being compared to their learning difficulties. In some cases, teachers or schools may not pay enough attention to issues that have the potential to affect or delay the psychomotor development of children. Therefore, this study aimed to provide enhanced comprehension regarding the effect of childhood obesity on psychomotor behavior. This study used a systematic review methodology to synthesize information regarding the effect of obesity on children's health and development. The information and data presented in this study were obtained from several scientific sources accessed through online libraries such as PubMed, ScienceDirect, and the Cochrane Library. A comprehensive search was conducted to identify scholarly publications, which resulted in a total of 815 papers published between 2013 and 2022. The selected papers exclusively consisted of original research articles that primarily focused on investigating the relationship between obesity in children aged 5–14 years and their psychomotor abilities and development outcomes. Following the screening process, five studies were found to meet the specified criteria. The findings of the selected studies revealed a substantial resemblance, specifically the correlation between childhood obesity and poor motor skills. Furthermore, the selected studies discovered that an increase in body fat is commonly associated with a rise in total body weight, or the relative body mass index (BMI), in both adults and children. Some studies demonstrated significant differences in the performance of diverse psychomotor variables according to children's BMI. According to the results of the studies, children with a higher BMI showed inferior performance in motor activities as a result of compromised body control and balance that inhibited the children's movement. This systematic review concludes that obesity has an effect on the psychomotor behavior of children.

The provisioned primate: patterns of obesity across lemurs, monkeys, apes and humans.

Non-human primates are potentially informative but underutilized species for investigating obesity. I examined patterns of obesity across the Primate order, calculating the ratio of body mass in captivity to that in the wild. This index, relative body mass, for n = 40 non-human primates (mean ± s.d.: females: 1.28 ± 0.30, range 0.67-1.78, males: 1.24 ± 0.28, range 0.70-1.97) overlapped with a reference value for humans (women: 1.52, men: 1.44). Among non-human primates, relative body mass was unrelated to dietary niche, and was marginally greater among female cohorts of terrestrial species. Males and females had similar relative body masses, but species with greater sexual size dimorphism (male/female mass) in wild populations had comparatively larger female body mass in captivity. Provisioned populations in wild and free-ranging settings had similar relative body mass to those in research facilities and zoos. Compared to the wild, captive diets are unlikely to be low in protein or fat, or high in carbohydrate, suggesting these macronutrients are not driving overeating in captive populations. Several primate species, including chimpanzees, a sister-species to humans, had relative body masses similar to humans. Humans are not unique in the propensity to overweight and obesity. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part II)'.

Dollo meets Bergmann: morphological evolution in secondary aquatic mammals

Secondary transitions to aquatic environments are common among vertebrates, and aquatic lineages display several adaptations to this realm, some of which might make these transitions irreversible. At the same time, discussions about secondary transitions often focus only on the marine realm, comparing fully terrestrial with fully aquatic species. This, however, captures only a fraction of land-to-water transitions, and freshwater and semi-aquatic groups are often neglected in macroevolutionary studies. Here, we use phylogenetic comparative methods to unravel the evolution of different levels of aquatic adaptations across all extant mammals, testing if aquatic adaptations are irreversible and if they are related to relative body mass changes. We found irreversible adaptations consistent with Dollo's Law in lineages that rely strongly on aquatic environments, while weaker adaptations in semi-aquatic lineages, which still allow efficient terrestrial movement, are reversible. In lineages transitioning to aquatic realms, including semi-aquatic ones, we found a consistent trend towards an increased relative body mass and a significant association with a more carnivorous diet. We interpret these patterns as the result of thermoregulation constraints associated with the high thermal conductivity of water leading to body mass increase consistently with Bergmann's rule and to a prevalence of more nutritious diets.

Predicted lean body mass in relation to cognitive function in the older adults.

Previous findings about lean body mass (LBM) and cognitive function remain unclear. We aimed to examine this association by using data from the National Health and Nutrition Examination Survey (NHANES). Using data from the NHANES 2011-2014, we conducted logistic regression models to investigate the relation between the predicted LBM and domain-specific cognitive function assessed by Digit Symbol Substitution Test (DSST), Consortium to Establish a Registry for Alzheimer's Disease Word Learning test (CERAD-WL) and Delayed Recall test (CERAD-DR), and Animal Fluency (AF) for information processing speed, memory, and executive function, respectively. Cognitive impairment was defined as the lowest quartile of each cognitive test in the total population. Sex-stratified analysis was further made. A total of 2955 participants aged 60 and above (mean [SD] age, 69.17[0.20] years; 1511 female [51.13%]) were included in the study. After being adjusted for social economic factors, anthropometric parameters, and diseases, we found a positive association between predicted LBM and information processing speed (Odds ratio of DSST impairment= 0.95, 95%CI= 0.91 to 0.99) regardless of body mass index and sex. Compared with patients in the first quartile of predicted LBM, those in the fourth quartile had an odds ratio of 0.355 (95% confidence interval 0.153-0.822) for DSST impairment. No significant relation in other cognitive tests and predicted LBM was found whether stratified by sex or not. Our findings point to the association between predicted lean body mass and cognitive dysfunction in information processing speed, which could be used for early detection and prevention of deterioration of cognitive function among older adults.

Remote monitoring of short‐term body mass variation in savanna ungulates

AbstractLarge herbivores in seasonal environments often experience mass variation due to temporal changes in the availability of critical resources like water and forage, as well as due to breeding events. Yet the documentation of mass variation in mammals of highly seasonal savanna habitats, which host the highest densities of grazing ungulates globally, has rarely been explored. Here, we showcase a method to evaluate seasonal mass variation in bovids. Our method used mineral‐baited scales and camera traps to enable us to track the body mass of three species through a period of wet and dry seasons in a South African savanna ecosystem. To illustrate one potential application of the method, we related body mass data to time, weather and resource availability. This showed that individuals altered their body masses markedly between seasons with, for example, female Kudu (Tragelaphus strepsiceros) gaining, on average, &gt;21 kg over the 15‐week wet‐season period in 1 year. These changes were positively related to factors such as vegetation productivity (assessed using NDVI) and the frequency of rains. This method enables easy, non‐lethal and non‐invasive acquisition of mass data. The equipment is easy to deploy concurrently over large areas. Monitoring by this method has a variety of possible applications, potentially providing a useful early‐warning indicator of body condition to inform management, or providing information about ecological states, such as parturition or the reproductive effort of males. Given the longer and harsher dry seasons experienced in many arid systems in recent decades, and projected in future, this method may provide a straightforward means of monitoring long‐term body condition in animals as a result of environmental change.

The relationship between adiposity and cognitive function: a bidirectional Mendelian randomization study in UK Biobank.

There may be a bidirectional relationship between cognition and adiposity, whereby poor cognition leads to increased adiposity and vice versa. We aimed to determine whether these findings are causal, by undertaking a bidirectional Mendelian randomization (MR) study. A total of 378 877 UK Biobank participants had three adiposity indicators [body fat percentage (BF%), body mass index (BMI) and waist-hip ratio] and two cognitive function measures (reaction time, visual memory). We examined observational associations between each adiposity indicator and cognitive function and vice versa. Using bidirectional inverse-variance weighted MR, we estimated the strength of the adiposity-cognitive function association using genetic instruments for adiposity indicators as our exposures, and we repeated this in the opposite direction using instruments for cognitive function. In the direction adiposity to cognitive function, MR analyses were generally directionally consistent with observational findings, but all confidence intervals contained the null. In the opposite direction, MR estimates for all adiposity measures on reaction time were imprecise and directionally inconsistent. MR estimates for the effects of visual memory on all adiposity measures indicated worse visual memory was associated with lower adiposity. For example, a 1-unit worse visual memory score was associated with a 1.32% [β = -1.32; 95% confidence interval (CI): -0.77,-1.88] and 3.57% (β = -3.64; 95% CI: -1.84,-5.15) lower absolute body fat percentage and relative body mass index, respectively. Observational associations of adiposity on cognitive function are likely not causal. In the reverse direction, our consistent findings that worse visual memory is associated with three adiposity indicators provide support for a causal link between worse visual memory and lower adiposity.

The impact of an extreme climatic event on adder (Vipera berus) demography in southern Sweden

AbstractClimate change has been shown to have significant negative effects on wildlife populations owing to both gradual shifts in mean climatic conditions and an increased frequency of extreme climatic events. Based on a long-term study spanning 40 years, we explore the demographic effect of the exceptionally hot and dry summer of 2018 on the demography of an isolated adder (Vipera berus) population in southern Sweden. In spring 2019, we observed a dramatic decline in adder relative body mass and a concomitant 50% reduction in population size. Our results strongly suggest that the negative impacts on adder demography were the result of a combination of low prey abundance and adder dehydration caused by the extreme climatic conditions during the previous summer. The study provides an example of the significant negative effects of ongoing climate change on vertebrate populations and emphasizes the importance of long-term studies to document the demographic effects of extreme climatic events.

Effect of temperature on the post-diapause developmental rate, survival, and body mass of the solitary wasp Isodontia elegans: Implications for rearing of trap-nesting Hymenoptera

We examined the relationship of post-diapause rearing temperature to developmental rate, survival, and adult body mass of the solitary wasp Isodontia elegans using prepupae from trap-nests. Isodontia elegans is a member of a genus often found in trap-nests in North America and Europe. Trap-nests are commonly used tools for studying cavity-nesting solitary wasps and bees. In temperate zones, progeny in nests usually overwinter as prepupae before pupating and emerging as adults. An important aspect of properly using trap-nests is determining temperatures that affect survival and health of developing offspring. After overwintering >600 cocoons containing prepupae after the summers of 2015 and 2016, we placed cocoons on a laboratory thermal gradient where offspring experienced one of 19 constant temperatures from 6 to 43 °C; emergence of adults was monitored for 100 days. Our conservative estimate for the critical thermal minimum for development is 14 °C, whereas that for the critical maximum is ∼33 °C. Prepupae transitioned to adults most rapidly at 29–33 °C, but developmental rate was lower for some progeny exposed to temperatures ≥30 °C. Offspring successfully reached the adult stage in <100 days at of temperatures of ∼19–33 °C. Adults from cocoons reared at lower temperatures weighed on average 6–10% more than expected based on their head widths, whereas those reared at higher temperatures weighed 4–10% less than expected. The difference may be due to greater rates of water loss and lipid metabolism during development at higher temperatures. Pre-overwintering cocoon mass was a significant predictor of relative adult body mass, indicating that adult health is partly related to their condition before overwintering. The trends we observed were similar to those for the bee Megachile rotundata, which we previously studied on the same gradient apparatus. However, data is needed on many other species of wasps and bees from a diversity of environments.