The thermoneutral zone in women takes an "arctic" shift compared to men.

Conventionally, women are perceived to feel colder than men, but controlled comparisons are sparse. We measured the response of healthy, lean, young women and men to a range of ambient temperatures typical of the daily environment (17 to 31 °C). The Scholander model of thermoregulation defines the lower critical temperature as threshold of the thermoneutral zone, below which additional heat production is required to defend core body temperature. This parameter can be used to characterize the thermoregulatory phenotypes of endotherms on a spectrum from "arctic" to "tropical." We found that women had a cooler lower critical temperature (mean ± SD: 21.9 ± 1.3 °C vs. 22.9 ± 1.2 °C, P = 0.047), resembling an "arctic" shift compared to men. The more arctic profile of women was predominantly driven by higher insulation associated with more body fat compared to men, countering the lower basal metabolic rate associated with their smaller body size, which typically favors a "tropical" shift. We did not detect sex-based differences in secondary measures of thermoregulation including brown adipose tissue glucose uptake, muscle electrical activity, skin temperatures, cold-induced thermogenesis, or self-reported thermal comfort. In conclusion, the principal contributors to individual differences in human thermoregulation are physical attributes, including body size and composition, which may be partly mediated by sex.

A randomized feasibility trial of medium chain triglyceride-supplemented ketogenic diet in people with Parkinson's disease.

BACKGROUND: A ketogenic diet (KD) may benefit people with neurodegenerative disorders marked by mitochondrial depolarization/insufficiency, including Parkinson's disease (PD). OBJECTIVE: Evaluate whether a KD supplemented by medium chain triglyceride (MCT-KD) oil is feasible and acceptable for PD patients. Furthermore, we explored the effects of MCT-KD on blood ketone levels, metabolic parameters, levodopa absorption, mobility, nonmotor symptoms, simple motor and cognitive tests, autonomic function, and resting-state electroencephalography (rsEEG). METHODS: A one-week in-hospital, double-blind, randomized, placebo-controlled diet (MCT-KD vs. standard diet (SD)), followed by an at-home two-week open-label extension. The primary outcome was KD feasibility and acceptability. The secondary outcome was the change in Timed Up & Go (TUG) on day 7 of the diet intervention. Additional exploratory outcomes included the N-Back task, Unified Parkinson's Disease Rating Scale, Non-Motor Symptom Scale, and rsEEG connectivity. RESULTS: A total of 15/16 subjects completed the study. The mean acceptability was 2.3/3, indicating willingness to continue the KD. Day 7 TUG time was not significantly different between the SD and KD groups. The nonmotor symptom severity score was reduced at the week 3 visit and to a greater extent in the KD group. UPDRS, 3-back, and rsEEG measures were not significantly different between groups. Blood ketosis was attained by day 4 in the KD group and to a greater extent at week 3 than in the SD group. The plasma levodopa metabolites DOPAC and dopamine both showed nonsignificant increasing trends over 3 days in the KD vs. SD groups. CONCLUSIONS: An MCT-supplemented KD is feasible and acceptable to PD patients but requires further study to understand its effects on symptoms and disease. TRIAL REGISTRATION: Trial Registration Number NCT04584346, registration dates were Oct 14, 2020 - Sept 13, 2022.

Lower subjective social status is associated with increased adiposity and self-reported eating in the absence of hunger due to negative affect among children reporting teasing distress.

OBJECTIVES: Low social standing and teasing are independently associated with increased body mass index (BMI) and overeating in children. However, children with low social status may be vulnerable to teasing. METHODS: We tested the statistical interaction of subjective social status (SSS) and subjective socioeconomic status (SSES) and teasing distress on BMI, fat mass index (FMI), and eating in the absence of hunger (EAH) in children (Mage = 13.09 years, SD = 2.50 years; 27.8% overweight/obese). Multiple linear regressions identified the main effects of self-reported SSS (compared to peers in school), distress due to teasing, and their interaction on BMI (n = 115), FMI (n = 114), and child- (n = 100) and parent-reported (n = 97) EAH. RESULTS: Teasing distress was associated with greater BMI, FMI, and child-reported EAH due to negative affect (a subscale of EAH) and total EAH scores. There were no associations of SSS with these outcomes. However, there was an interaction between SSS and teasing distress for BMI, FMI, and EAH from negative affect such that lower SSS was associated with higher BMI, FMI, and EAH from negative affect in the presence of teasing distress. However, there were no main effects or interactions (with teasing distress) of SSES on the outcomes. CONCLUSIONS: These findings suggest that the relationship between lower SSS and increased adiposity and overeating behaviors may be exacerbated by other threats to social standing, such as teasing. Children exposed to multiple social threats may be more susceptible to eating beyond physiological need and obesity than those who experience a single form of perceived social disadvantage.

Postprandial Plasma Lipidomics Reveal Specific Alteration of Hepatic-derived Diacylglycerols in Nonalcoholic Fatty Liver Disease.

BACKGROUND & AIMS: Hepatic energy metabolism is a dynamic process modulated by multiple stimuli. In nonalcoholic fatty liver disease (NAFLD), human studies typically focus on the static fasting state. We hypothesized that unique postprandial alterations in hepatic lipid metabolism are present in NAFLD. METHODS: In a prospective clinical study, 37 patients with NAFLD and 10 healthy control subjects ingested a standardized liquid meal with pre- and postprandial blood sampling. Postprandial plasma lipid kinetics were characterized at the molecular lipid species level by untargeted lipidomics, cluster analysis, and lipid particle isolation, then confirmed in a mouse model. RESULTS: There was a specific increase of multiple plasma diacylglycerol (DAG) species at 4 hours postprandially in patients with NAFLD but not in controls. This was replicated in a nonalcoholic steatohepatitis mouse model, where postprandial DAGs increased in plasma and concomitantly decreased in the liver. The increase in plasma DAGs appears early in the disease course, is dissociated from NAFLD severity and obesity, and correlates with postprandial insulin levels. Immunocapture isolation of very low density lipoprotein in human samples and stable isotope tracer studies in mice revealed that elevated postprandial plasma DAGs reflect hepatic secretion of endogenous, rather than meal-derived lipids. CONCLUSIONS: We identified a selective insulin-related increase in hepatic secretion of endogenously derived DAGs after a mixed meal as a unique feature of NAFLD. DAGs are known to be lipotoxic and associated with atherosclerosis. Although it is still unknown whether the increased exposure to hepatic DAGs contributes to extrahepatic manifestations and cardiovascular risk in NAFLD, our study highlights the importance of extending NAFLD research beyond the fasting state.

Retrieval-induced forgetting in children and adolescents with and without obesity.

BACKGROUND/OBJECTIVES: Previous research indicates that youth with obesity exhibit deficits in executive functioning (EF), which often take the form of impaired response inhibition. One aspect of EF not previously studied in obesity is the adaptive process known as retrieval-induced forgetting (RIF), the suppression/inhibition of intrusive or non-target items by the retrieval of specific items from memory. The present study investigated if child or adolescent obesity disrupts the ability to inhibit retrieval of intrusive memories. SUBJECTS/METHODS: We compared the manifestation of RIF in children (ages 8-12) and adolescents (ages 13-18) as a function of their weight status and sex. We also evaluated the effects of these variables on simple recall of items from episodic memory under conditions where competition from intrusive items was reduced. RESULTS: Children with obesity did not demonstrate significant RIF, whereas RIF was exhibited by preteens without obesity and by teenage participants with- and without obesity (Weight Status × Age Group interaction p = 0.028). This pattern of results did not differ as a function of sex for either age group. No differences in episodic memory were found. Additional analyses using Age as continuous covariate (and not as a nominal group) comparing participants who exhibited RIF with those who did not, found that the no RIF group consumed fast-food meals more frequently (p = 0.024) and had higher percentages of total body adiposity and android fat compared to the RIF group (p's < 0.05). CONCLUSIONS: The findings expand what is known about the effects of childhood obesity on cognitive functioning, identify impaired RIF with specific behavioral and dietary factors and increased adiposity, and suggest the possibility that impairments in the ability to inhibit intrusive memories of food and eating may contribute to poor early-life weight control.

Sleep timing and consistency are associated with the standardised test performance of Icelandic adolescents.

Sleep has been shown to affect cognitive function in laboratory studies; however, its association to the academic performance of adolescents has largely been demonstrated using self-reported measures. Studies with objective measures of both sleep and academic performance are limited. The aim of the present study was to determine whether the free-living sleep quantity, quality, and timing of 15-year-old adolescents measured with wrist actiography are associated with their scores on national standardised examinations as an objective measure of academic achievement. We measured sleep with wrist actiography for 1 week in 253 (150 girls) Icelandic adolescents with a mean (SD) age of 15.9 (0.3) years. Multiple linear regression was used to assess associations between sleep parameters and combined standardised examination scores in mathematics, English, and Icelandic obtained from the Icelandic Directorate of Education. We found that students went to bed at 00:49 hours (± 51.8 min) and slept for a mean (SD) of 6.6 (0.7) hr/night, with a median (interquartile range) night-to-night variation in sleep duration of 1.2 (0.7) hr and an efficiency of 88.1 (5.3)%. Combined analyses adjusted for sex, demonstrated that both bedtime and night-to-night variability in total sleep time were negatively associated with the average score across all topics. Sex-specific associations did not indicate clear differences between boys and girls. These findings suggest that, in addition to appropriate sleep duration, public health guidance should also highlight the importance of early and consistent sleep schedules to academic achievement for both boys and girls.

Effects of interrupting daily sedentary behavior on children's glucose metabolism: A 6-day randomized controlled trial.

BACKGROUND: Metabolic disease risk in youth is influenced by sedentary behaviors. Acute in-lab studies show that, during a single day, interrupting a sedentary period with short bouts of physical activity improves glucometabolic outcomes. OBJECTIVE: To determine if acutely improved glucose metabolism persists after multi-day interruptions of sitting with walking brief bouts. We hypothesized that children who underwent interrupting sitting on multiple days would demonstrate lower insulin area under the curve during an oral glucose tolerance test compared to uninterrupted sitting. METHODS: Healthy, normoglycemic children (N = 109) ages 7-11 years were randomized to one of two conditions: Control (3 h of daily Uninterrupted Sitting) or Interrupted Sitting (3-min of moderate-intensity walking every 30 min for 3 h daily); with dietary intake controlled through provision of foodstuffs for the entire experiment. Participants attended six consecutive daily visits at a research ambulatory unit. The primary outcome was insulin area under the curve during the oral glucose tolerance test on day 6 during interrupted or uninterrupted sitting; secondary outcomes included glucose and c-peptide area under the curve, energy intake at a buffet meal on day 6, and free-living activity. RESULTS: Among 93 children (42 uninterrupted sitting, 51 interrupted sitting), daily interrupted sitting resulted in 21% lower insulin (ß = 0.102 CI:0.032-0.172, p = 0.005) and a 10% lower C-peptide (ß = 0.043, CI:0.001-0.084, p = 0.045) area under the curve. Matsuda and Glucose Effectiveness Indices were also improved (p's < 0.05). There were no group differences in energy intake or expenditure. CONCLUSIONS: Sustained behavioral change by interrupting sedentary behaviors is a promising intervention strategy for improving metabolic risk in children.

Opportunities and challenges in the therapeutic activation of human energy expenditure and thermogenesis to manage obesity.

The current obesity pandemic results from a physiological imbalance in which energy intake chronically exceeds energy expenditure (EE), and prevention and treatment strategies remain generally ineffective. Approaches designed to increase EE have been informed by decades of experiments in rodent models designed to stimulate adaptive thermogenesis, a long-term increase in metabolism, primarily induced by chronic cold exposure. At the cellular level, thermogenesis is achieved through increased rates of futile cycling, which are observed in several systems, most notably the regulated uncoupling of oxidative phosphorylation from ATP generation by uncoupling protein 1, a tissue-specific protein present in mitochondria of brown adipose tissue (BAT). Physiological activation of BAT and other organ thermogenesis occurs through ß-adrenergic receptors (AR), and considerable effort over the past 5 decades has been directed toward developing AR agonists capable of safely achieving a net negative energy balance while avoiding unwanted cardiovascular side effects. Recent discoveries of other BAT futile cycles based on creatine and succinate have provided additional targets. Complicating the current and developing pharmacological-, cold-, and exercise-based methods to increase EE is the emerging evidence for strong physiological drives toward restoring lost weight over the long term. Future studies will need to address technical challenges such as how to accurately measure individual tissue thermogenesis in humans; how to safely activate BAT and other organ thermogenesis; and how to sustain a negative energy balance over many years of treatment.

Energy expenditure due to gluconeogenesis in pathological conditions of insulin resistance.

Gluconeogenesis (GNG), the formation of glucose from noncarbohydrate precursors, requires adenosine triphosphate (ATP). Previous studies have estimated the energetic cost of GNG in humans based on theoretical calculations of rates of GNG, moles of oxygen consumption by GNG, and average oxygen consumption. Few human studies have measured the energy expenditure (EE) due to GNG. We estimated EE attributable to GNG in patients with three insulin resistance conditions and high GNG rates (insulin receptor pathogenic variants, lipodystrophy, and type 2 diabetes) and obesity without diabetes. Fractional GNG was measured by incorporation of deuterium from body water into newly formed glucose, endogenous glucose production (EGP) as glucose appearance following administration of [6,6-2H2]glucose, and total GNG as fractional GNG × EGP. EE was measured by indirect calorimetry and compared with predicted EE from the Mifflin St. Jeor equation. EE attributable to GNG was estimated using linear regression after accounting for age and fat-free mass (FFM). EE in patients with insulin resistance was significantly higher than predicted by the Mifflin St. Jeor equation. GNG correlated with resting EE (REE). EE attributable to GNG in patients with insulin resistance was almost one-third of REE, substantially higher than theorized in healthy subjects. Our findings demonstrate that GNG is a significant contributor to EE in insulin-resistant states. Prediction equations may underestimate caloric needs in patients with insulin resistance. Therefore, targeting caloric needs to account for higher EE due to increased GNG should be considered in energy balance studies in patients with insulin resistance.NEW & NOTEWORTHY Gluconeogenesis is an energy-requiring process that is upregulated in diabetes, contributing to hyperglycemia. Previous studies have estimated that gluconeogenesis accounts for less than 10% of resting energy expenditure. This study estimates the energy expenditure attributable to gluconeogenesis in uncommon and severe forms of insulin resistance and common, milder forms of insulin resistance. In these populations, gluconeogenesis accounts for almost one-third of resting energy expenditure, substantially higher than previously theorized in the literature.

Proton MR Spectroscopy Measurements of White and Brown Adipose Tissue in Healthy Humans: Relaxation Parameters and Unsaturated Fatty Acids.

Background Activation of brown adipose tissue (BAT) in rodents increases lipolysis in white adipose tissue (WAT) and improves glucose tolerance. Adult humans can have metabolically active BAT. Implications for diabetes and obesity in humans require a better characterization of BAT in humans. Purpose To study fat depots with localized proton MR spectroscopy relaxometry and to identify differences between WAT and fluorine 18 fluorodeoxyglucose (FDG) PET/CT proven cold-activated BAT in humans. Materials and Methods Participants were consecutively enrolled in this prospective study (ClinicalTrials.gov identifiers: NCT01568671 and NCT01399385) from August 2016 to May 2019. Supraclavicular potential BAT regions were localized with MRI. Proton densities, T1, and T2 were measured with localized MR spectroscopy in potential BAT and in subcutaneous WAT. FDG PET/CT after cold stimulation was used to retrospectively identify active supraclavicular BAT or supraclavicular quiescent adipose tissue (QAT) regions. MR spectroscopy results from BAT and WAT were compared with grouped and paired tests. Results Of 21 healthy participants (mean age, 36 years ± 16 [standard deviation]; 13 men) FDG PET/CT showed active BAT in 24 MR spectroscopy-targeted regions in 16 participants (eight men). Four men had QAT. The T2 for methylene protons was shorter in BAT (mean, 69 msec ± 6, 24 regions) than in WAT (mean, 83 msec ± 3, 18 regions, P < .01) and QAT (mean, 78 msec ± 2, five regions, P < .01). A T2 cut-off value of 76 msec enabled the differentiation of BAT from WAT or QAT with a sensitivity of 85% and a specificity of 95%. Densities of protons adjacent and between double bonds were 33% and 24% lower, respectively, in BAT compared with those in WAT (P = .01 and P = .03, respectively), indicating a lower content of unsaturated and polyunsaturated fatty acids, respectively, in BAT compared with WAT. Conclusion Proton MR spectroscopy showed shorter T2 and lower unsaturated fatty acids in brown adipose tissue (BAT) than that in white adipose tissue in healthy humans. It was feasible to identify BAT with MR spectroscopy without the use of PET/CT or cold stimulation. © RSNA, 2021 See also the editorial by Barker in this issue. Online supplemental material is available for this article.

Severity modeling of propionic acidemia using clinical and laboratory biomarkers.

PURPOSE: To conduct a proof-of-principle study to identify subtypes of propionic acidemia (PA) and associated biomarkers. METHODS: Data from a clinically diverse PA patient population ( https://clinicaltrials.gov/ct2/show/NCT02890342 ) were used to train and test machine learning models, identify PA-relevant biomarkers, and perform validation analysis using data from liver-transplanted participants. k-Means clustering was used to test for the existence of PA subtypes. Expert knowledge was used to define PA subtypes (mild and severe). Given expert classification, supervised machine learning (support vector machine with a polynomial kernel, svmPoly) performed dimensional reduction to define relevant features of each PA subtype. RESULTS: Forty participants enrolled in the study; five underwent liver transplant. Analysis with k-means clustering indicated that several PA subtypes may exist on the biochemical continuum. The conventional PA biomarkers, plasma total 2-methylctirate and propionylcarnitine, were not statistically significantly different between nontransplanted and transplanted participants motivating us to search for other biomarkers. Unbiased dimensional reduction using svmPoly revealed that plasma transthyretin, alanine:serine ratio, GDF15, FGF21, and in vivo 1-13C-propionate oxidation, play roles in defining PA subtypes. CONCLUSION: Support vector machine prioritized biomarkers that helped classify propionic acidemia patients according to severity subtypes, with important ramifications for future clinical trials and management of PA.

1-13C-propionate breath testing as a surrogate endpoint to assess efficacy of liver-directed therapies in methylmalonic acidemia (MMA).

PURPOSE: To develop a safe and noninvasive in vivo assay of hepatic propionate oxidative capacity. METHODS: A modified 1-13C-propionate breath test was administered to 57 methylmalonic acidemia (MMA) subjects, including 19 transplant recipients, and 16 healthy volunteers. Isotopomer enrichment (13CO2/12CO2) was measured in exhaled breath after an enteral bolus of sodium-1-13C-propionate, and normalized for CO2 production. 1-13C-propionate oxidation was then correlated with clinical, laboratory, and imaging parameters collected via a dedicated natural history protocol. RESULTS: Lower propionate oxidation was observed in patients with the severe mut0 and cblB subtypes of MMA, but was near normal in those with the cblA and mut- forms of the disorder. Liver transplant recipients demonstrated complete restoration of 1-13C-propionate oxidation to control levels. 1-13C-propionate oxidation correlated with cognitive test result, growth indices, bone mineral density, renal function, and serum biomarkers. Test repeatability was robust in controls and in MMA subjects (mean coefficient of variation 6.9% and 12.8%, respectively), despite widely variable serum methylmalonic acid concentrations in the patients. CONCLUSION: Propionate oxidative capacity, as measured with 1-13C-propionate breath testing, predicts disease severity and clinical outcomes, and could be used to assess the therapeutic effects of liver-targeted genomic therapies for MMA and related disorders of propionate metabolism. TRIAL REGISTRATION: This clinical study is registered in www.clinicaltrials.gov with the ID: NCT00078078. Study URL: http://clinicaltrials.gov/ct2/show/NCT00078078.

Mapping of human brown adipose tissue in lean and obese young men.

Human brown adipose tissue (BAT) can be activated to increase glucose uptake and energy expenditure, making it a potential target for treating obesity and metabolic disease. Data on the functional and anatomic characteristics of BAT are limited, however. In 20 healthy young men [12 lean, mean body mass index (BMI) 23.2 ± 1.9 kg/m2; 8 obese, BMI 34.8 ± 3.3 kg/m2] after 5 h of tolerable cold exposure, we measured BAT volume and activity by 18F-labeled fluorodeoxyglucose positron emission tomography/computerized tomography (PET/CT). Obese men had less activated BAT than lean men (mean, 130 vs. 334 mL) but more fat in BAT-containing depots (mean, 1,646 vs. 855 mL) with a wide range (0.1-71%) in the ratio of activated BAT to inactive fat between individuals. Six anatomic regions had activated BAT-cervical, supraclavicular, axillary, mediastinal, paraspinal, and abdominal-with 67 ± 20% of all activated BAT concentrated in a continuous fascial layer comprising the first three depots in the upper torso. These nonsubcutaneous fat depots amounted to 1.5% of total body mass (4.3% of total fat mass), and up to 90% of each depot could be activated BAT. The amount and activity of BAT was significantly influenced by region of interest selection methods, PET threshold criteria, and PET resolutions. The present study suggests that active BAT can be found in specific adipose depots in adult humans, but less than one-half of the fat in these depots is stimulated by acute cold exposure, demonstrating a previously underappreciated thermogenic potential.

The Effects of Interrupting Sitting Time on Affect and State Anxiety in Children of Healthy Weight and Overweight: A Randomized Crossover Trial.

PURPOSE: Sedentary time relates to higher anxiety and more negative affect in children. This study assessed whether interrupting sitting over 3 hours is sufficient to influence state anxiety, positive affect, or negative affect, and tested weight status as a moderator. METHODS: Analyses were the second (preplanned) purpose of a larger study. Children (N = 61; age: mean [SD] = 9.5 [1.3]; 43% healthy weight) completed 2 experimental conditions: continuous sitting for 3 hours and sitting for 3 hours interrupted with walking for 3 minutes in every 30 minutes. State anxiety, positive affect, and negative affect were reported at pretest and posttest. Multilevel models for repeated measures assessed whether experimental condition predicted posttest scores. RESULTS: Experimental condition was unrelated to posttest state anxiety or positive affect. Weight status moderated how experimental condition influenced posttest negative affect (P = .003). Negative affect was lower in the children of healthy weight after interrupted sitting (vs continuous sitting; ß = -0.8; 95% confidence interval, -1.5 to 0.0, P = .05), but it was higher in the children with overweight/obesity after interrupted sitting (vs continuous sitting; ß = 0.6; 95% confidence interval, 0.0 to 1.2, P = .06). CONCLUSIONS: Interrupting sitting acutely reduced negative affect in children of healthy weight, but not in children with overweight. Further research is needed to better understand the potential emotional benefits of sitting interruptions in youth.

Depressive symptoms in adolescent girls at-risk for type 2 diabetes and their parents.

Few studies have characterized the relation between parent's depression symptoms and adolescent's depression symptoms in adolescents at-risk for type 2 diabetes (T2D). We evaluated the associations of parental depression symptoms with the depression symptoms and metabolic functioning of adolescent offspring at-risk for T2D. One-hundred sixteen parents and adolescent girls with a family history of diabetes completed surveys of depression symptoms. Adolescents' degree of metabolic risk for T2D was estimated from body mass index (BMI; kg/m2) standard score, percent adiposity from dual-energy x-ray absorptiometry scan, and whole body insulin sensitivity index determined from glucose/insulin concentrations during a two-hour oral glucose tolerance test. Parents' and adolescents' depression symptoms were significantly associated, even after accounting for race/ethnicity, age, puberty, body composition, and parental diabetes/BMI. Adjusting for similar covariates, parent depression symptoms also were positively related to adolescents' BMI standard score and had a trend-level association with adiposity. There was an inverse relation between parental depression symptoms and adolescent insulin sensitivity, which was entirely accounted for by adolescent body composition. The associations of parental depression symptoms with more elevated depression symptoms and higher BMI in adolescents at-risk for T2D has potential implications for interventions addressing these co-morbid health conditions.

Safety and efficacy of low-dose sirolimus in the PIK3CA-related overgrowth spectrum.

PURPOSE: PIK3CA-related overgrowth spectrum (PROS) encompasses a range of debilitating conditions defined by asymmetric overgrowth caused by mosaic activating PIK3CA variants. PIK3CA encodes the p110α catalytic subunit of phosphatidylinositol-3-kinase (PI3K), a critical transducer of growth factor signaling. As mTOR mediates the growth-promoting actions of PI3K, we hypothesized that the mTOR inhibitor sirolimus would slow pathological overgrowth. METHODS: Thirty-nine participants with PROS and progressive overgrowth were enrolled into open-label studies across three centers, and results were pooled. For the primary outcome, tissue volumes at affected and unaffected sites were measured by dual energy X-ray absorptiometry during 26 weeks of untreated run-in and 26 weeks of sirolimus therapy. RESULTS: Thirty participants completed the study. Sirolimus led to a change in mean percentage total tissue volume of -7.2% (SD 16.0, p = 0.04) at affected sites, but not at unaffected sites (+1.7%, SD 11.5, p = 0.48) (n = 23 evaluable). Twenty-eight of 39 (72%) participants had ≥1 adverse event related to sirolimus of which 37% were grade 3 or 4 in severity and 7/39 (18%) participants were withdrawn consequently. CONCLUSION: This study suggests that low-dose sirolimus can modestly reduce overgrowth, but cautions that the side-effect profile is significant, mandating individualized risk-benefit evaluations for sirolimus treatment in PROS.

Effects of colchicine in adults with metabolic syndrome: A pilot randomized controlled trial.

AIM: To evaluate the efficacy and safety of colchicine for improving metabolic and inflammatory outcomes in people with obesity and metabolic syndrome (MetS). MATERIALS AND METHODS: Adults with obesity and MetS, but who did not have diabetes, were randomized to colchicine 0.6 mg or placebo capsules twice daily for 3 months. The primary outcome was change in insulin sensitivity (SI ) as estimated by insulin-modified frequently sampled intravenous glucose tolerance tests. Secondary outcomes included changes in other metabolic variables and inflammatory markers. RESULTS: Of 40 participants randomized (21 colchicine, 19 placebo), 37 completed the trial. Compared with placebo, colchicine significantly reduced C-reactive protein (P <0.005), erythrocyte sedimentation rate (P <0.01), white blood cell count (P <0.005), and absolute neutrophil count (P <0.001). Change in SI was not significantly different between colchicine and placebo arms (difference: +0.21 × 10-5 ; CI -1.70 to +2.13 × 10-5 min-1 mU-1 mL; P = 0.82). However, changes in some secondary outcomes, including homeostatic model assessment of insulin resistance (P = 0.0499), fasting insulin (P = 0.07) and glucose effectiveness (P = 0.08), suggested metabolic improvements in the colchicine versus placebo group. Adverse events were generally mild and similar in both groups. CONCLUSIONS: This pilot study found colchicine significantly improved obesity-associated inflammatory variables and showed a good safety profile among adults with obesity and MetS who did not have diabetes. These results suggest a larger, adequately powered study should be conducted to determine whether colchicine improves insulin resistance and other measures of metabolic health in at-risk individuals.

Indirect Effects of a Cognitive-Behavioral Intervention on Adolescent Weight and Insulin Resistance Through Decreasing Depression in a Randomized Controlled Trial.

OBJECTIVE: Depression is linked to excess weight, insulin resistance, and type 2 diabetes (T2D). We previously reported that in adolescent girls at-risk for T2D with moderately elevated depression, randomization to cognitive-behavioral therapy (CBT) produced greater decreases in depression at post-treament and greater decreases in fasting/2-h insulin at 1 year, compared to health education (HE). The current study is a secondary analysis of this parallel-group randomized controlled trial. We examined whether decreasing depression explained intervention effects on body composition and insulin outcomes. We hypothesized that decreases in depression would be an explanatory mediator and that indirect effects would be strongest at higher levels of baseline depression. METHODS: Participants were 12-17 years girls with overweight/obesity and family history of T2D randomized to 6-week group CBT (n = 58) or HE (n = 61). Procedures took place at an outpatient pediatric clinic. At baseline, post-treatment, and 1 year, adolescents completed the Center for Epidemiologic Studies-Depression Scale to assess depression symptoms; body mass index (BMI [kg/m2]) was measured from height/fasting weight; insulin resistance was derived from 2-h oral glucose testing. Adiposity was assessed with dual-energy X-ray absorptiometry at baseline and 1 year. Indirect effects of intervention were tested on 1-year changes in BMI, adiposity, and insulin through decreases in depression. Baseline depression was tested as a moderator of mediation. RESULTS: There was an indirect effect of CBT on decreased 1-year fasting insulin via decreases in depression during treatment, among adolescents with more elevated baseline depression. CONCLUSIONS: Decreasing elevated depression may be one mechanism in the targeted prevention of T2D in at-risk adolescents.

Exercise modulates the interaction between cognition and anxiety in humans.

Despite interest in exercise as a treatment for anxiety disorders the mechanism behind the anxiolytic effects of exercise is unclear. Two observations motivate the present work. First, engagement of attention control during increased working memory (WM) load can decrease anxiety. Second, exercise can improve attention control. Therefore, exercise could boost the anxiolytic effects of increased WM load via its strengthening of attention control. Anxiety was induced by threat of shock and was quantified with anxiety-potentiated startle (APS). Thirty-five healthy volunteers (19 male, age M = 26.11, SD = 5.52) participated in two types of activity, exercise (biking at 60-70% of heart rate reserve) and control-activity (biking at 10-20% of heart rate reserve). After each activity, participants completed a WM task (n-back) at low- and high-load during safe and threat. Results were not consistent with the hypothesis: exercise vs. control-activity increased APS in high-load (p = .03). However, this increased APS was not accompanied with threat-induced impairment in WM performance (p = .37). Facilitation of both task-relevant stimulus processing and task-irrelevant threat processing, concurrent with prevention of threat interference on cognition, suggests that exercise increases cognitive ability. Future studies should explore how exercise affects the interplay of cognition and anxiety in patients with anxiety disorders.

Comparing ActiGraph equations for estimating energy expenditure in older adults.

Accurate estimation of energy expenditure (EE) from accelerometer outputs remains a challenge in older adults. The aim of this study was to validate different ActiGraph (AG) equations for predicting EE in older adults. Forty older adults (age = 77.4 ± 8.1 yrs) completed a set of household/gardening activities in their residence, while wearing an AG at the hip (GT3X+) and a portable calorimeter (MetaMax 3B - criterion). Predicted EEs from AG were calculated using five equations (Freedson, refined Crouter, Sasaki and Santos-Lozano (vertical-axis, vectormagnitude)). Accuracy of equations was assessed using root-mean-square error (RMSE) and mean bias. The Sasaki equation showed the lowest RMSE for all activities (0.47 METs) and across physical activity intensities (PAIs) (range 0.18-0.48 METs). The Freedson and Santos-Lozano equations tended to overestimate EE for sedentary activities (range: 0.48 to 0.97 METs), while EEs for moderate-to-vigorous activities (MVPA) were underestimated (range: -1.02 to -0.64 METs). The refined Crouter and Sasaki equations showed no systematic bias, but they respectively overestimated and underestimated EE across PAIs. In conclusion, none of the equations was completely accurate for predicting EE across the range of PAIs. However, the refined Crouter and Sasaki equations showed better overall accuracy and precision when compared with the other methods.