Effects of Diet, Aerobic Exercise, or Both on Non-HDL-C in Adults: A Meta-Analysis of Randomized Controlled Trials

Purpose. To use the meta-analytic approach to examine the effects of diet (D), aerobic exercise (E), or both (DE) on non-high-density lipoprotein cholesterol (non-HDL-C) in adults. Methods. Randomized controlled trials in adults ≥18 years of age were included. A mixed-effect model was used to combine effect size (ES) results within each subgroup and to compare subgroups (Qb). Heterogeneity was examined using the Q and I2 statistics, and 95% confidence intervals (CI) were also calculated. Statistical significance was set at P≤0.05, while a trend for statistical significance was set between P>0.05, and ≤0.10. Results. A statistically significant exercise minus control group decrease in non-HDL-C was found for DE (7 ESs, 389 participants, x¯=-11.1 mg/dL, 95%  CI=−21.7 to −0.6, P=0.04, Q=2.4, P=0.88, I2=0%), a trend for the D group (7 ESs, 402 participants, x¯=−8.5 mg/dL, 95%  CI=−18.6 to 1.6, P=0.10, Q=0.76, P=0.99, I2=0%), and no change for the E group (7 ESs, 387 participants, x¯=3.0 mg/dL, 95%   CI=−7.1 to 13.1, P=0.56, Q=0.78, P=0.99, I2=0%). Overall, no statistically significant between-group differences were found (Qb=4.1, P=0.12). Conclusions. Diet combined with aerobic exercise may reduce non-HDL-C among adults in some settings

Brief Report: Exercise and Blood Pressure in Older Adults—An Updated Look

Background/Objectives. Raised blood pressure is a major problem in older adults. Using a random-effects model, a recent meta- analysis reported statistically significant reductions in both resting systolic blood pressure (SBP) and diastolic blood pressure (DBP) as a result of aerobic, resistance, and combined aerobic and resistance exercise in adults ≥65 years. To provide more objective information regarding this nonpharmacologic approach, this study applied more robust methods to this data. Design. Meta-analysis of 41 randomized controlled trials representing 96 groups (52 exercise; 44 control). Setting. Any location where a randomized controlled trial could be conducted. Participants. Adults ≥65 years. Intervention. Trials ≥2 weeks that included aerobic, resistance, and/or combined aerobic and resistance exercise as the intervention. Measurements. The recently developed inverse heterogeneity model (IVhet) was used to pool findings and the Doi plot was used to examine for small-study effects. Absolute and relative differences between the IVhet and random-effects model were also calculated. Data were reported using the mean difference (exercise minus control) with nonoverlapping 95% confidence intervals considered statistically significant. Results. Statistically significant reductions in resting blood pressure were found as a result of aerobic exercise (SBP, -4.7 mmHg, 95% CI, -7.7 to -1.8; DBP, -2.0 mmHg, 95% CI -3.13 to -0.9), SBP but not DBP for resistance training (SBP, -7.0 mmHg, 95% CI, -10.5 to -3.4; DBP, -1.2 mmHg, 95% CI -2.7 to 0.3), and both SBP and DBP for combined aerobic and resistance training (SBP, -5.5 mmHg, 95% CI, -8.3 to -2.7; DBP, -3.7 mmHg, 95% CI -4.8 to -2.7). Conclusions. Exclusive of changes in DBP congruent with resistance training, exercise (aerobic, resistance, and combined aerobic and resistance) reduces resting SBP and DBP in older adults. These findings have practical implications when considering exercise for the prevention and treatment of raised blood pressure in older adults

Community-deliverable exercise and depression in adults with arthritis: Confirmatory evidence of a meta-analysis using the IVhet model

Objective—Using the traditional random-effects model, a recently reported standardized effect size (g) reduction of −0.42 (95% CI, −0.58 to −0.27) was observed as a result of communitydeliverable exercise in adults with arthritis and other rheumatic diseases (AORD). However, a recently proposed alternative model (IVhet) has been shown to have superior coverage probability to the random-effects model. The purpose of this brief report was to compare these previous random-effects results with the IVhet model. Methods—Based on a previous meta-analysis of 35 g’s representing 2,449 participants, results were pooled using the IVhet model. Influence analysis, number needed-to-treat (NNT), percentile improvement, and gross estimates of the number of inactive adults with arthritis who could benefit from exercise were also calculated. Results—The IVhet model yielded statistically significant reductions in depressive symptoms (g = −0.30, 95% CI, −0.49 to −0.11), a difference that was −0.12 (28.7%) smaller than the randomeffects model. With each study deleted from the model once, results remained statistically significant, ranging from −0.28 to −0.34. The percentile improvement, NNT, and estimated number of people with arthritis in the United States who could improve their depressive symptoms by participating in a regular exercise program was, respectively, 11.8% (95% CI, 4.5% to 18.8%), 8 (95% CI, 5 to 23) and 2.7 million (95% CI, 1.0 to 4.4 million). Conclusions—These findings provide more conservative and accurate evidence that community-deliverable exercise improves depressive symptoms in adults with AORD. Future meta-analyses may want to consider using the IVhet versus traditional random-effects model

Evidential Value That Exercise Improves BMI -Score in Overweight and Obese Children and Adolescents

Background. Given the cardiovascular disease (CVD) related importance of understanding the true effects of exercise on adiposity in overweight and obese children and adolescents, this study examined whether there is evidential value to rule out excessive and inappropriate reporting of statistically significant results, a major problem in the published literature, with respect to exercise-induced improvements in BMI -score among overweight and obese children and adolescents. Methods. Using data from a previous meta-analysis of 10 published studies that included 835 overweight and obese children and adolescents, a novel, recently developed approach (-curve) was used to test for evidential value and rule out selective reporting of findings. Chi-squared tests () were used to test for statistical significance with alpha () values \u3c0.05 considered statistically significant. Results. Six of 10 findings (60%) were statistically significant. Statistically significant right-skew to rule out selective reporting was found ( = 38.8, = 0.0001). Conversely, studies neither lacked evidential value ( = 6.8, = 0.87) nor lacked evidential value and were intensely -hacked ( = 4.3, = 0.98). Conclusion. Evidential value results confirm that exercise reduces BMI -score in overweight and obese children and adolescents, an important therapeutic strategy for treating and preventing CVD

An Empirical Survey of Price Fixing Conspiracies

This paper reports on a study of recent Antitrust Division horizontal price fixing cases. The objective of the study was to determine if there has been a specific set of characteristics associated with the product or product markets that have been the subjects of price fixing. If such a pattern exists, it might provide empirical insight into some aspects of oligopoly behavior. From a policy point of view, any pattern that is found could be used in a positive enforcement program designed to investigate the most likely areas of price fixing. Section I reviews the academic literature which has dealt with the problem of horizontal conspiracy; Section II describes the sample and the methodology used in the study; and Section III summarizes the results

An Empirical Survey of Price Fixing Conspiracies

This paper reports on a study of recent Antitrust Division horizontal price fixing cases. The objective of the study was to determine if there has been a specific set of characteristics associated with the product or product markets that have been the subjects of price fixing. If such a pattern exists, it might provide empirical insight into some aspects of oligopoly behavior. From a policy point of view, any pattern that is found could be used in a positive enforcement program designed to investigate the most likely areas of price fixing. Section I reviews the academic literature which has dealt with the problem of horizontal conspiracy; Section II describes the sample and the methodology used in the study; and Section III summarizes the results

Effects of exercise on BMI z-score in overweight and obese children and adolescents: a systematic review with meta-analysis

Background: Overweight and obesity are major public health problems in children and adolescents. The purpose of this study was to conduct a systematic review with meta-analysis to determine the effects of exercise (aerobic, strength or both) on body mass index (BMI) z-score in overweight and obese children and adolescents. Methods: Studies were included if they were randomized controlled exercise intervention trials ≥ 4 weeks in overweight and obese children and adolescents 2 to 18 years of age, published in any language between 1990–2012 and in which data were available for BMI z-score. Studies were retrieved by searching eleven electronic databases, cross-referencing and expert review. Two authors (GAK, KSK) selected and abstracted data. Bias was assessed using the Cochrane Risk of Bias Assessment Instrument. Exercise minus control group changes were calculated from each study and weighted by the inverse of the variance. All results were pooled using a random-effects model with non-overlapping 95% confidence intervals (CI) considered statistically significant. Heterogeneity was assessed using Q and I 2 while funnel plots and Egger’s regression test were used to assess for small-study effects. Influence and cumulative meta-analysis were performed as well as moderator and meta-regression analyses. Results: Of the 4,999 citations reviewed, 835 children and adolescents (456 exercise, 379 control) from 10 studies representing 21 groups (11 exercise, 10 control) were included. On average, exercise took place 4 x week for 43 minutes per session over 16 weeks. Overall, a statistically significant reduction equivalent to 3% was found for BMI z-score Χ; −0:06; 95% CI; ‐0:09 to ‐0:03;Q ¼ 24:9; p ¼ 0:01; I 2 ¼ 59:8%. No small-study effects were observed and results remained statistically significant when each study was deleted from the model once. Based on cumulative meta-analysis, results have been statistically significant since 2009. None of the moderator or meta-regression analyses were statistically significant. The number-needed-to treat was 107 with an estimated 116,822 obese US children and adolescents and approximately 1 million overweight and obese children and adolescents worldwide potentially improving their BMI z-score by participating in exercise. Conclusions: Exercise improves BMI z-score in overweight and obese children and adolescents and should be recommended in this population group. However, a need exists for additional studies on this topic

Brief Report: Exercise and Anxiety in Adults with Arthritis and Other Rheumatic Diseases: Support for Evidential Value

Objective. Given the high prevalence of anxiety in adults with arthritis and other rheumatic diseases (AORD) and the subsequent need for interventions to reduce anxiety, this brief report sought to determine if evidential value exists to support the role of exercise for reducing anxiety in adults with AORD. Methods. Utilizing data from a prior meta-analysis, a recently developed approach, P- curve, was used to determine evidential value by assessing for publication bias and p-hacking. Binomial tests as well as the more robust Stouffer’s test were used to examine for evidential value. To examine the influence of selected studies on p-curve results, findings were also examined by dropping the highest and lowest p values from the analysis. Results. The binomial test for evidential value was not statistically significant (p = 0.11) while the more robust Stouffer’s test satisfied both conditions for evidential value (p = 0.002). Power analyses suggested a good fit for the observed p-curve. Results were generally robust when the least and most extreme values were excluded. Conclusions. The results of this study provide evidential support for the benefits of exercise on anxiety in adults with AORD

Exercise and Adiposity in Overweight and Obese Children and Adolescents: A Systematic Review with Network Meta-analysis of Randomised Trials

Objectives Determine both the effects and hierarchy of effectiveness for exercise interventions (aerobic, strength training or both) on selected measures of adiposity (body mass index (BMI) in kg/m2 , fat mass and per cent body fat) in overweight and obese children and adolescents. Design Network meta-analysis of randomised exercise intervention trials. Setting Any setting where a randomised trial could be conducted. Participants Overweight and obese male and/or female children and adolescents 2–18 years of age. Interventions Randomised exercise intervention trials\u3e4 weeks, published between 1 January 1973 and 22 August 2018, and which included direct and/or indirect evidence for aerobic, strength training or combined aerobic and strength training. Primary outcomes Changes in BMI in kg/m2 , fat mass and per cent body fat. Results Fifty-seven studies representing 127 groups (73 exercise, 54 control) and 2792 participants (1667 exercise, 1125 control) met the criteria for inclusion. Length of training (‍ − X ± SD) averaged 14.1±6.2 weeks, frequency, 3.3±1.1 days per week and duration 42.0±21.0min per session. Significant and clinically important reductions in BMI, fat mass and per cent body fat were observed in aerobic versus control comparisons (BMI, mean, 95%CI -1.0, 1.4 to −0.6; fat mass -2.1, –3.3 to −1.0 kg; per cent fat -1.5, –2.2 to −0.9%) and combined aerobic and strength versus control comparisons (BMI -0.7, –1.4 to −0.1; fat mass -2.5, –4.1 to −1.0 kg; per cent fat, -2.2, –3.2 to −1.2%). A significant reduction in per cent fat was also found for strength vs control comparisons (-1.3,–2.5 to −0.1%). Combined aerobic and strength training was ranked first for improving both fat mass (kg) and per cent body fat while aerobic exercise was ranked first for improving BMI. Conclusions Aerobic and combined aerobic and strength training are associated with improvements in adiposity outcomes in overweight and obese children and adolescents. PROSPERO registration number CRD42017073103