Myocyte androgen receptors increase metabolic rate and improve body composition by reducing fat mass.
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ABSTRACT:
SUBMITTER: Fernando SM
PROVIDER: S-EPMC2903941 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Drugs that improve chronic hyperglycemia independently of insulin signaling or reduction of adiposity or dietary fat intake may be highly desirable. Ad36, a human adenovirus, promotes glucose uptake in vitro independently of adiposity or proximal insulin signaling. We tested the ability of Ad36 to improve glycemic control in vivo and determined if the natural Ad36 infection in humans is associated with better glycemic control. C57BL/6J mice fed a chow diet or made diabetic with a high-fat (HF) diet were mock infected or infected with Ad36 or adenovirus Ad2 as a control for infection. Postinfection (pi), systemic glycemic control, hepatic lipid content, and cell signaling in tissues pertinent to glucose metabolism were determined. Next, sera of 1,507 adults and children were screened for Ad36 antibodies as an indicator of past natural infection. In chow-fed mice, Ad36 significantly improved glycemic control for 12 wk pi. In HF-fed mice, Ad36 improved glycemic control and hepatic steatosis up to 20 wk pi. In adipose tissue (AT), skeletal muscle (SM), and liver, Ad36 upregulated distal insulin signaling without recruiting the proximal insulin signaling. Cell signaling suggested that Ad36 increases AT and SM glucose uptake and reduces hepatic glucose release. In humans, Ad36 infection predicted better glycemic control and lower hepatic lipid content independently of age, sex, or adiposity. We conclude that Ad36 offers a novel tool to understand the pathways to improve hyperglycemia and hepatic steatosis independently of proximal insulin signaling, and despite a HF diet. This metabolic engineering by Ad36 appears relevant to humans for developing more practical and effective antidiabetic approaches.
| S-EPMC3093976 | biostudies-literature
Project description:BackgroundAndrogen deprivation therapy (ADT) has adverse effects on body composition, including muscle wasting and body fat accumulation, which may be attenuated by nutrition therapy. This systematic review summarises available evidence on the effects of dietary interventions on lean mass, fat mass and body mass index (BMI) in men treated with ADT for prostate cancer.MethodsMEDLINE, Embase, Web of Science and ClinicalTrials.org were searched from inception through December 2020. We included all controlled trials evaluating effects of supplementation or dietary interventions on body composition in men with prostate cancer receiving continuous ADT. Methodological quality of the studies was assessed using the Cochrane Collaboration's risk of bias tool. Meta-analysis was performed using a random effects model to calculate standardised mean differences between intervention and comparator groups. (PROSPERO; CRD42020185777).ResultsEleven studies (n = 536 participants) were included. Seven studies investigated the effects of dietary advice interventions, e.g. individual or group counselling, and four studies included a nutritional supplement. Eight studies combined the dietary intervention with exercise. Nine studies reported sufficient data for inclusion in the meta-analysis. Dietary advice and supplementation interventions combined were not associated with significant changes in lean mass (0.05 kg; 95% CI: -0.17, 0.26; p = 0.674; n = 355), fat mass (-0.22 kg; 95% CI: -0.45, 0.01; p = 0.064; n = 336) or BMI (-0.16 kg*m-2; 95% CI: -0.37, 0.04; p = 0.121; n = 399). Dietary advice interventions alone were associated with a significant fat mass reduction (-0.29 kg; 95% CI: -0.54, -0.03; p = 0.028; n = 266).ConclusionsMost studies were dietary advice interventions targeting caloric restriction, which showed the potential to reduce fat mass but did not increase lean mass in men treated with ADT. Future interventions should investigate whether a combination of dietary advice and protein supplementation with concomitant resistance exercise could counteract ADT-induced muscle wasting.
| S-EPMC9184277 | biostudies-literature
Project description:New generation, multicomponent parenteral lipid emulsions provide key fatty acids for brain growth and development, such as docosahexaenoic acid (DHA) and arachidonic acid (AA), yet the content may be suboptimal for preterm infants. Our aim was to test whether DHA and AA-enriched lipid emulsions would increase activity, growth, and neurodevelopment in preterm piglets and limit brain inflammation. Cesarean-delivered preterm pigs were given three weeks of either enteral preterm infant formula (ENT) or TPN with one of three parenteral lipid emulsions: Intralipid (IL), SMOFlipid (SMOF) or an experimental emulsion (EXP). Activity was continuously monitored and weekly blood sampling and behavioral field testing performed. At termination of the study, whole body and tissue metrics were collected. Neuronal density was assessed in sections of hippocampus (HC), thalamus, and cortex. Frontal cortex (FC) and HC tissue were assayed for fatty acid profiles and expression of genes of neuronal growth and inflammation. After 3?weeks of treatment, brain DHA content in SMOF, EXP and ENT pigs was higher (P?<?0.01) in FC but not HC vs. IL pigs. There were no differences in brain weight or neuron density among treatment groups. Inflammatory cytokine TNF? and IL-1? expression in brain regions were increased in IL pigs (P?<?0.05) compared to other groups. Overall growth velocity was similar among groups, but IL pigs had higher percent body fat and increased insulin resistance compared to other treatments (P?<?0.05). ENT pigs spent more time in higher physical activity levels compared to all TPN groups, but there were no differences in exploratory behavior among groups. We conclude that a soybean oil emulsion increased select brain inflammatory cytokines and multicomponent lipid emulsions enriched with DHA and AA in parenteral lipids results in increased cortical DHA and improved body composition without affecting short term neurodevelopmental outcomes.
| S-EPMC6813879 | biostudies-literature
Project description:BackgroundAdipose tissue may have different metabolic and endocrine functions depending on the region of the body in which it is located. While visceral or intra-abdominal fat has been found to contribute to leptin concentrations, insulin resistance and obesity-related diseases, there are only a few imaging studies documenting the preferential distribution of body fat to either the intra-abdominal or subcutaneous compartments in dogs. This study aimed to determine if CT-measured abdominal fat distributed preferentially to the visceral space (V) relative to the subcutaneous space (SQ), with increasing DXA-determined total body fat percentage; and if ultrasound measurements of the ventral midline subcutaneous (SAT) and visceral adipose thickness (VAT) can be used to estimate the distribution of fat to the subcutaneous and visceral abdominal spaces, in a sample of 22 dogs with variable body condition.ResultsMultivariate analysis showed no statistically significant correlation between visceral to subcutaneous fat ratio (V/SQ) and increasing total body fat percentage (??=???0.07, p?=?0.733), but strong correlation with age (??=?0.71 p?=?0.002). A substantial amount of variation for the ultrasound visceral adipose thickness to subcutaneous fat thickness (VAT/SAT) could be explained by both CT V/SQ and sex (R2Adjusted?=?0.477, p?=?0.001), with female dogs having significant lower VAT/SAT ratios compared to the male dogs (p?=?0.047). The ultrasound fat measurements appeared moderately reliable, but a larger sample number is required to confirm this.ConclusionsThe findings suggest that dogs with a relatively healthy to slightly overweight body condition score, distribute fat relatively similarly between their peritoneal (visceral) and subcutaneous abdominal compartments with increasing total body fat percentage. However, there was increased fat distribution to the peritoneal space relative to the subcutaneous space with increasing age. Further, abdominal ultrasound may be useful in estimating the ratio of fat distribution to both the abdominal visceral and subcutaneous spaces.
| S-EPMC7106746 | biostudies-literature
Project description:ObjectiveIncreased infant birth weight and adiposity are associated with an altered risk of adult chronic diseases. The objective was to investigate the association between maternal dietary fat intake during pregnancy and newborn adiposity.Study designThe study included 79 singleton pregnancies. Associations between maternal dietary fat intake during each trimester and infant adiposity at birth were assessed.ResultAverage total grams of maternal total dietary fat and unsaturated fat intake during pregnancy correlated with infant percent body fat after adjusting for potential confounding variables (r = 0.23, p = 0.045; r = 0.24, p = 0.037). Maternal average daily intake of total fat, saturated fat, and unsaturated fat during the second trimester of pregnancy were each associated with infant percent body fat (r = 0.25, p = 0.029; r = 0.23, p = 0.046; r = 0.25, p = 0.031; respectively).ConclusionsThe second trimester of pregnancy is a key time period for fetal adipose tissue metabolic programming and therefore a target for nutritional intervention.
| S-EPMC8119319 | biostudies-literature
Project description:ContextHigh bone mass (HBM), detected in 0.2% of dual-energy x-ray absorptiometry (DXA) scans, is characterized by raised body mass index, the basis for which is unclear.ObjectiveTo investigate why body mass index is elevated in individuals with HBM, we characterized body composition and examined whether differences could be explained by bone phenotypes, eg, bone mass and/or bone turnover.Design, setting, and participantsWe conducted a case-control study of 153 cases with unexplained HBM recruited from 4 UK centers by screening 219 088 DXA scans. A total of 138 first-degree relatives (of whom 51 had HBM) and 39 spouses were also recruited. Unaffected individuals served as controls.Main outcome measuresWe measured fat mass, by DXA, and bone turnover markers.ResultsAmong women, fat mass was inversely related to age in controls (P = .01), but not in HBM cases (P = .96) in whom mean fat mass was 8.9 [95% CI 4.7, 13.0] kg higher compared with controls (fully adjusted mean difference, P < .001). Increased fat mass in male HBM cases was less marked (gender interaction P = .03). Compared with controls, lean mass was also increased in female HBM cases (by 3.3 [1.2, 5.4] kg; P < .002); however, lean mass increases were less marked than fat mass increases, resulting in 4.5% lower percentage lean mass in HBM cases (P < .001). Osteocalcin was also lower in female HBM cases compared with controls (by 2.8 [0.1, 5.5] μg/L; P = .04). Differences in fat mass were fully attenuated after hip bone mineral density (BMD) adjustment (P = .52) but unchanged after adjustment for bone turnover (P < .001), whereas the greater hip BMD in female HBM cases was minimally attenuated by fat mass adjustment (P < .001).ConclusionsHBM is characterized by a marked increase in fat mass in females, statistically explained by their greater BMD, but not by markers of bone turnover.
| S-EPMC3589712 | biostudies-literature
Project description:BackgroundAlthough response rates for physician surveys have been decreasing, it is not clear whether this trend is associated with an increase in survey nonresponse bias. One means for assessing potential bias is to conduct a level-of-effort analysis that compares data estimates for respondents interviewed during the first recruitment contact to respondents interviewed at later recontact cycles.MethodsWe compared early and later responders within the Survey of Physician Attitudes Regarding the Care of Cancer Survivors with respect to both demographic characteristics and aggregate survey responses to items on survivor care knowledge, attitudes, and practices.ResultsAccumulating additional completions across each of 4 respondent contact attempts improved weighted response rates (35.0%, 46.9%, 52.3%, and 57.6%, respectively). However, the majority of estimates for analyzed variables remained relatively unchanged over additional cycles of recontact.ConclusionsWe conclude that additional respondent recontact attempts, especially beyond a single recontact, had little influence on key data distributions, suggesting that these were ineffective in reducing nonresponse bias. Further, the conduct of additional recruitment recontacts was an inefficient means for increasing statistical power. For the conduct of physician surveys, a practice that may in some cases be cost-effective, while also controlling total survey error, is to establish a larger initial sample; to either eliminate nonresponse follow-up or to limit this to one recontact; and to accept a somewhat lower final overall survey response rate.
| S-EPMC3784997 | biostudies-literature
Project description:Abstract Objectives To examine the association between meal habits (i.e., eating breakfast every day, usually ≥80% fullness at breakfast, and not eating snacks at night), body composition and the subsequent changes in mood status in young adults. Methods This is a longitudinal follow-up study based on a randomized trial (ClinicalTrials.gov Identifier: NCT03828812). Young adults were recruited based in a university campus in Taipei City, Taiwan. In total, 125 participants were recruited and 103 completed the follow-ups. Measured body composition (TANITA BC-418) and moods (Depression Anxiety Stress Scale, DASS) were assessed at baseline, the third month and 15th month from baseline. Baseline meal habits were based on the participants’ recall of their diets in the month before interview. We used mixed-effect model to test the association of baseline total body fat percentage and trunk body fat percentage and moods during follow-ups, adjusting for age, sex, baseline body mass index (BMI), food security status. Results After controlling for sex, age, BMI, and food security status at baseline, having breakfast every day at baseline was associated with 2.04 (se = 0.78, P = 0.0098) lower anxiety score and with 2.58 (se = 1.26, P = 0.0409) lower stress score at baseline. Meal habits were not associated with the subsequent changes in mood status. As for body composition, one % of trunk body fat replacing one % of non-trunk body fat at baseline was associated with 1.19 (se = 0.57, P = 0.0381) higher depression score, 1.02 (se = 0.47, P = 0.0327) higher anxiety score, 2.06 (se = 0.76, P = 0.0075) higher anxiety score at baseline. One % of non-trunk body fat percentage was associated with 2.60 (se = 1.02, P = 0.0116) lower anxiety score, as trunk body fat % is controlled. Baseline body fat composition parameters were not associated with the temporal changes in mood scores. The significance patterns were similar after adjusting for baseline physical activity level, assessed by International Physical Activity Questionnaire. Conclusions Breakfast habits and body composition, especially trunk body fat, was associated with university-based young adults’ emotional health status. Funding Sources Ministry of Science and Technology, Taiwan.
| S-EPMC7258909 | biostudies-literature
Project description:Symbionts in the abdomen fat body of brown planthopper (BPH) play an important role in the growth and reproduction of their host, Nilaparvata lugens Stål (Hemiptera: Delphacidae). Thus, controlling BPH infection on rice by inhibiting symbionts with antimicrobials is feasible. However, the effect of antimicrobials on the microbiome in the fat body and the relationship between microbial community and mortality have not been fully elucidated. A decrease in the total number of yeast-like symbiotes in the fat body and elevated mortality were observed after exposure to toyocamycin, tebuconazole, and zhongshengmycin. Additionally, we found that the antimicrobials reduced bacterial diversity and increased fungal diversity in the fat body and altered the bacterial and fungal community structure. Although the total absolute abundance of bacteria and fungi decreased after antimicrobial exposure, the absolute abundance of Serratia increased, indicating that Serratia, which was the most dominant in the fat body, is an important symbiont involved in resistance to antimicrobials. After antimicrobial exposure, seven genera, which probably participated in the nutrition and development function of the host, were totally eliminated from the fat body. Overall, our study enriches the knowledge of microbiomes in the fat body of BPH under antimicrobial treatment and the disturbance of symbionts would be further used to help other pesticides to control pests.
| S-EPMC8005595 | biostudies-literature
Project description:Many organisms have several similar transporters with different affinities for the same substrate. Typically, high-affinity transporters are expressed when substrate is scarce and low-affinity ones when it is abundant. The benefit of using low instead of high-affinity transporters remains unclear, especially when additional nutrient sensors are present. Here, we investigate two hypotheses. It was previously hypothesized that there is a trade-off between the affinity and the catalytic efficiency of transporters, and we find some but no definitive support for it. Additionally, we propose that for uptake by facilitated diffusion, at saturating substrate concentrations, lowering the affinity enhances the net uptake rate by reducing substrate efflux. As a consequence, there exists an optimal, external-substrate-concentration dependent transporter affinity. A computational model of Saccharomyces cerevisiae glycolysis shows that using the low affinity HXT3 transporter instead of the high affinity HXT6 enhances the steady-state flux by 36%. We tried to test this hypothesis with yeast strains expressing a single glucose transporter modified to have either a high or a low affinity. However, due to the intimate link between glucose perception and metabolism, direct experimental proof for this hypothesis remained inconclusive. Still, our theoretical results provide a novel reason for the presence of low-affinity transport systems.
| S-EPMC5883050 | biostudies-literature