Sedentary children have greater risk of developing abnormalities in glucose homeostasis. We investigated whether interrupting sedentary behavior (sitting) with very short periods of walking would ...improve glucose metabolism without affecting dietary intake in children with overweight or obesity. We hypothesized that interrupting sitting with short bouts of moderate-intensity walking would decrease insulin area under the curve (AUC) during an oral glucose tolerance test (OGTT) compared with uninterrupted sitting.
Overweight/obese (BMI ≥85th percentile) children 7-11 years of age underwent two experimental conditions in random order: prolonged sitting (3 h of continuous sitting) and interrupted sitting (3 min of moderate-intensity walking at 80% of ventilatory threshold every 30 min for 3 h). Insulin, C-peptide, and glucose were measured every 30 min for 3 h during an OGTT. Each session was followed by a buffet meal. Primary outcomes were differences in OGTT hormones and substrates and in buffet meal intake by condition.
Among 35 children with complete data, mixed-model results identified lower insulin and C-peptide in the interrupted condition (
= 0.007 and
= 0.029, respectively); the intervention reduced insulin AUC by 21% (
< 0.001) and C-peptide AUC 18% (
= 0.001) and improved estimated insulin sensitivity (
= 0.013). Neither buffet total energy intake (1,262
480 vs. 1,260
475 kcal;
= 0.89) nor macronutrient composition of the meal (
values >0.38) differed between conditions significantly.
Interrupting sitting with brief moderate-intensity walking improved glucose metabolism without significantly increasing energy intake in children with overweight or obesity. Interrupting sedentary behavior may be a promising intervention strategy for reducing metabolic risk in such children.
Disparities in prostate cancer (PCa) exist at all stages: screening, diagnosis, treatment, outcomes, and mortality. Although there are a multitude of complex biological (e.g., genetics, age at ...diagnosis, PSA levels, Gleason score) and nonbiological (e.g., socioeconomic status, education level, health literacy) factors that contribute to PCa disparities, nonbiological factors may play a more significant role. One understudied aspect influencing PCa patients is mental health related to the quality of life. Overall, PCa patients report poorer mental health than non-PCa patients and have a higher incidence of depression and anxiety. Racial disparities in mental health, specifically in PCa patients, and how poor mental health impacts overall PCa outcomes require further study.
Soon after initial marketing in March 1997, troglitazone, the first thiazolidinedione antidiabetic agent, was found to cause life-threatening acute liver failure. The drug was removed from the market ...in March 2000.
To evaluate the effect of US Food and Drug Administration (FDA) risk management efforts, including repeated labeling changes and "Dear Healthcare Professional" letters, on periodic liver enzyme monitoring of patients taking troglitazone.
Claims data from a large, multistate managed care organization were used to establish 4 cohorts of patients (N = 7603) with at least 90 days of health plan enrollment before first troglitazone prescription during 4 consecutive periods spanning April 1997 to September 1999 and representing 4 progressively stringent liver monitoring recommendations.
Percentage of eligible troglitazone users in each cohort with baseline, monthly (for up to 6 months of continuous use), and complete (baseline and monthly) enzyme monitoring, based on computerized records of laboratory claims.
Baseline testing increased from 15% before any FDA monitoring recommendations (cohort 1) to 44.6% following 4 separate FDA interventions (cohort 4; P<.001). In cohort 4, 33.4% of users had follow-up testing after 1 month of therapy, falling to 13% after 5 months of continuous use. In all cohorts, less than 5% received all recommended liver enzyme tests by the third month of continuous use.
The FDA risk management efforts did not achieve meaningful or sustained improvement in liver enzyme testing. Evaluation of the impact of regulatory actions is needed before such actions can be regarded as effective or sufficient.
Context:
Limited data suggest that interrupting sedentary behaviors with activity improves metabolic parameters in adults.
Objective:
We tested whether interrupting sitting with short, ...moderate-intensity walking bouts improved glucose tolerance in children.
Design:
Participants underwent two experimental conditions in random order on different days: continuous sitting for 3 hours or sitting interrupted by walking (3 min of moderate-intensity walking every 30 min). Insulin, C-peptide, glucose, and free fatty acids were measured every 30 minutes for 3 hours during an oral glucose tolerance test. Area under the curve (AUC) was calculated from hormone and substrate measurements. Children were given a buffet meal after each condition.
Setting:
The study was conducted at the National Institutes of Health Hatfield Clinical Research Center.
Participants:
Twenty-eight normal-weight 7–11 year olds participated.
Main Outcomes:
Patterns of substrate/hormone secretion and AUC, as well as energy intake, were examined by experimental condition.
Results:
Interrupting sitting resulted in a 32% lower insulin AUC (P < .001), 17% lower C-peptide AUC (P < .001), and 7% lower glucose AUC (P = .018) vs continuous sitting. Mixed model results indicated that insulin (P = .036) and free fatty acid concentrations (P = .009) were significantly lower in the interrupted vs the continuous sitting condition. Lunchtime buffet meal energy intake did not significantly differ between the conditions (975 ± 387 vs 963 ± 309 kcal; P = .85).
Conclusions:
Interrupting sedentary time with brief moderate-intensity walking improved short-term metabolic function in non-overweight children without increasing subsequent energy intake. These findings suggest that interrupting sedentary behavior may be a promising prevention strategy for reducing cardiometabolic risk in children.
Study Objective. To investigate the occurrence of tramadol‐associated seizures.
Design. Retrospective cohort and case‐control studies.
Setting. UnitedHealth Group‐affiliated independent practice ...model health plans, from different regions of the United States, contracting with large networks of physicians.
Intervention. Analysis of administrative data from a large U.S. managed care population.
Patients. A cohort of 9218 adult tramadol users and 37,232 concurrent nonusers.
Measurements and Main Results. Fewer than 1% of users (80) had a presumed incident seizure claim after the first tramadol prescription. Risk of seizure claim was increased 2‐ to 6‐fold among users adjusted for selected comorbidities and concomitant drugs. Risk was highest among those aged 25–54 years, those with more than four tramadol prescriptions, and those with history of alcohol abuse, stroke, or head injury. A case‐control study among users was conducted to validate incident seizure outcomes from medical records. Only eight cases were confirmed, and all had cofactors associated with increased seizure risk.
Conclusion. In a general population, risk of seizure may be associated with long‐term therapy with tramadol or the presence of cofactors, or confined to a small sensitive population subset.
Relatively little is known about how excess body mass affects adolescents' capacity to perform sustained exercise. We hypothesized that most of the difficulty that severely overweight adolescents ...have with sustained exercise occurs because the metabolic costs of moving excess mass result in use of a high proportion of their total oxygen reserve.
We compared results from a maximal cycle ergometry fitness test in 129 severely overweight adolescents who had BMIs of 41.5 +/- 9.7 kg/m2 and ages of 14.5 +/- 1.8 years (range: 12.1-17.8 years) and 34 nonoverweight adolescents who had BMIs of 20.1 +/- 2.9 kg/m2 and ages of 14.5 +/- 1.5 years (range: 12.0-18.1 years). Oxygen uptake (Vo2) was compared at 3 times: during a 4-minute period of unloaded cycling (ULVo2), at the lactate threshold estimated by gas exchange (LTVo2), and at maximal exertion (Vo2 max). Heart rate was obtained at rest and at Vo2 max. Participants also completed a 12-minute walk/run performance test to obtain distance traveled (D12) and heart rate.
Absolute LTVo2 and Vo2 max and LTVo2 as a percentage of Vo2 max were not different in overweight and nonoverweight adolescents during the cycle test. However, absolute ULVo2 was significantly greater in overweight adolescents: ULVo2 accounted for 35 +/- 8% of Vo2 max (and 63 +/- 15% of LTVo2) in overweight adolescents but only 20 +/- 5% of Vo2 max (and 39 +/- 12% of LTVo2) in nonoverweight adolescents. Resting heart rate before initiating the cycle test was significantly greater in overweight than nonoverweight adolescents (94 +/- 14 vs 82 +/- 15 beats per minute). However, maximal heart rate during the cycle test was significantly lower in overweight adolescents (186 +/- 13 vs 196 +/- 11 beats per minute). During the walk/run test, mean D12 was significantly shorter for overweight than for nonoverweight adolescents (1983 +/- 323 vs 1159 +/- 194 m). D12 was negatively related to BMI SDS (r = -0.81) and to ULVo2 (r = -0.98).
Overweight and nonoverweight adolescents had similar absolute Vo2 at the lactate threshold and at maximal exertion, suggesting that overweight adolescents are more limited by the increased cardiorespiratory effort required to move their larger body mass through space than by cardiorespiratory deconditioning. The higher percentage of oxygen consumed during submaximal exercise indicates that overweight adolescents are burdened by the metabolic cost of their excess mass. Their greater oxygen demand during an unloaded task predicted poorer performance during sustained exercise. Exercise prescriptions for overweight adolescents should account for the limited exercise tolerance imposed by excess body mass, focusing on activities that keep demands below lactate threshold so that exercise can be sustained.
To determine the exercise capacity of children and adolescents with Friedreich's Ataxia (FA) and to evaluate the effects of 6 months of idebenone treatment on exercise capacity.
Exploratory endpoint ...in a randomized double-blind, placebo-controlled, phase II clinical trial designed to investigate the effects of idebenone on a biomarker of oxidative stress.
Exercise physiology laboratory in a single clinical research center.
Ambulatory subjects (N=48; age range, 9-17 y) with genetically confirmed FA.
Idebenone administered orally 3 times a day for a total daily dose of approximately 5, 15, and 45 mg/kg or matching placebo for 6 months.
Peak oxygen consumption per unit time (peak VO(2)) and peak work rate (WR) were measured during incremental exercise testing at baseline and after treatment. Echocardiography and neurologic assessments were also completed before and after treatment.
Baseline mean peak VO(2) +/- SD was 746+/-246 mL/min (16.2+/-5.8 mL/kg/min), and WR was 40+/-23 W for all subjects. Peak VO(2) and WR were correlated with short guanine-adenine-adenine allele length and neurologic function. Relative left ventricular wall thickness was increased but left ventricular ejection fraction was normal in most subjects; there was no relationship between any exercise and echocardiographic measures. There were no significant changes in mean peak VO(2) or WR after idebenone treatment at any dose level relative to placebo.
Exercise capacity in children and adolescents with FA was significantly impaired. The basis for the impairment appears to be multifactorial and correlated to the degree of neurologic impairment. Although idebenone has previously been shown potentially to improve features of FA, idebenone treatment did not increase exercise capacity relative to placebo.
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