Exercise-Induced Hypoalgesia in Healthy Individuals and People With Chronic Musculoskeletal Pain: A Systematic Review and Meta-Analysis

Exercise-induced hypoalgesia (EIH) is a reduction in pain that occurs during or following exercise. Randomized controlled studies published from 1980 to January 2020 that examined experimentally induced pain before and during/following a single bout of exercise in healthy individuals or people with chronic musculoskeletal pain were systematically reviewed. Data were analyzed using random-effects meta-analyses and studies were appraised using the Cochrane Risk of Bias tool and GRADE. Five thousand eight hundred twenty-nine records were screened, with 13 studies ultimately included. In healthy individuals, aerobic exercise caused large EIH (7 studies, 236 participants; g = −.85 [−1.58, −.13]), dynamic resistance exercise caused small EIH (2 studies, 23 participants; g = −.45 [−.69, −.22]), and isometric exercise did not cause EIH (3 studies, 177 participants; g = −.16 [−.36,.05]). In chronic musculoskeletal pain, isometric exercise did not cause EIH (3 studies, 114 participants; g = −.41 [−1.08,.25]); aerobic (0 studies) and dynamic resistance (1 study) exercise were not analyzed. We conclude that, based on small studies with unclear risk of bias, aerobic and dynamic resistance exercise reduce experimental pain in healthy individuals. Further research is needed to determine whether EIH exists for experimental and clinical pain in people with chronic musculoskeletal pain. Registration: PROSPERO ID: CRD42018085886. Perspective: Based on low-quality data from small samples, a single bout of aerobic exercise reduces experimental pain in healthy individuals. The evidence is unclear in people with chronic musculoskeletal pain but warrants further investigation due to the limited number of studies in these populations

The effectiveness and safety of isometric resistance training for adults with high blood pressure: a systematic review and meta-analysis

High blood pressure (BP) is a global health challenge. Isometric resistance training (IRT) has demonstrated antihypertensive effects, but safety data are not available, thereby limiting its recommendation for clinical use. We conducted a systematic review of randomized controlled trials comparing IRT to controls in adults with elevated BP (systolic ≥130 mmHg/diastolic ≥85 mmHg). This review provides an update to office BP estimations and is the first to investigate 24-h ambulatory BP, central BP, and safety. Data were analyzed using a random-effects meta-analysis. We assessed the risk of bias with the Cochrane risk of bias tool and the quality of evidence with GRADE. Twenty-four trials were included (n = 1143; age = 56 ± 9 years, 56% female). IRT resulted in clinically meaningful reductions in office systolic (–6.97 mmHg, 95% CI –8.77 to –5.18, p < 0.0001) and office diastolic BP (–3.86 mmHg, 95% CI –5.31 to –2.41, p < 0.0001). Novel findings included reductions in central systolic (–7.48 mmHg, 95% CI –14.89 to –0.07, p = 0.035), central diastolic (–3.75 mmHg, 95% CI –6.38 to –1.12, p = 0.005), and 24-h diastolic (–2.39 mmHg, 95% CI –4.28 to –0.40, p = 0.02) but not 24-h systolic BP (–2.77 mmHg, 95% CI –6.80 to 1.25, p = 0.18). These results are very low/low certainty with high heterogeneity. There was no significant increase in the risk of IRT, risk ratio (1.12, 95% CI 0.47 to 2.68, p = 0.8), or the risk difference (1.02, 95% CI 1.00 to 1.03, p = 0.13). This means that there is one adverse event per 38,444 bouts of IRT. IRT appears safe and may cause clinically relevant reductions in BP (office, central BP, and 24-h diastolic). High-quality trials are required to improve confidence in these findings. PROSPERO (CRD42020201888); OSF (https://doi.org/10.17605/OSF.IO/H58BZ)

If exercise is medicine, why don’t we know the dose? An overview of systematic reviews assessing reporting quality of exercise interventions in health and disease

Objective To determine how well exercise interventions are reported in trials in health and disease. Design Overview of systematic reviews. Data sources PubMed, EMBASE, CINAHL, SPORTDiscus and PsycINFO from inception until June 2021. Eligibility criteria Reviews of any health condition were included if they primarily assessed quality of exercise intervention reporting using the Consensus on Exercise Reporting Template (CERT) or the Template for Intervention Description and Replication (TIDieR). We assessed review quality using a modified version of A MeaSurement Tool to Assess systematic Reviews. Results We identified 7804 studies and included 28 systematic reviews. The median (IQR) percentage of CERT and TIDieR items appropriately reported was 24% (19%) and 49% (33%), respectively. TIDieR items 1, Brief name (median=100%, IQR 4) and 2, Why (median=98%, IQR 6), as well as CERT item 4, Supervision and delivery (median=68%, IQR 89), were the best reported. For replication of exercise interventions, TIDieR item 8, When and how much, was moderately well reported (median=62%, IQR 68) although CERT item 8, Description of each exercise to enable replication (median=23%, IQR 44) and item 13, Detailed description of the exercise intervention (median=24%, IQR 66) were poorly reported. Quality of systematic reviews ranged from moderate to critically low quality. Conclusion Exercise interventions are poorly reported across a range of health conditions. If exercise is medicine, then how it is prescribed and delivered is unclear, potentially limiting its translation from research to practice

Interactive video games to reduce paediatric procedural pain and anxiety: a systematic review and meta-analysis

Background: Procedural pain and anxiety in children can be poorly controlled, leading to significant short- and long-term sequelae, such as longer procedure times or future healthcare avoidance. Caregiver anxiety can exacerbate these effects. We aimed to evaluate the effect of interactive video game interventions on children's procedural pain and anxiety, including the effect of different types of video games on those outcomes. Methods: We conducted a systematic review and meta-analysis of the effectiveness of interactive video games compared with standard care in children (0–18 yr) undergoing painful procedures. We searched the databases MEDLINE, Embase, and PsycINFO. We conducted random-effects meta-analysis using ‘R’ of children's procedural pain and anxiety and caregivers' anxiety. Results: Of 2185 studies screened, 36 were eligible (n=3406 patients). Studies commonly involved venous access (33%) or day surgery (31%). Thirty-four studies were eligible for meta-analyses. Interactive video games appear to reduce children's procedural pain (standardised mean difference [SMD]=–0.43; 95% confidence interval [CI]: –0.67 to –0.20), anxiety (SMD=0.61; 95% CI: –0.88 to –0.34), and caregivers' procedural anxiety (SMD=–0.31; 95% CI: –0.58 to –0.04). We observed no difference between preparatory and distracting games, or between virtual reality and non-virtual reality games. We also observed no difference between interactive video games compared with standard care for most medical outcomes (e.g. procedure length), except a reduced need for restraint. Studies reported minimal adverse effects and typically had high intervention acceptability and satisfaction. Conclusions: Our findings support introducing easily available video games, such as distraction-based conventional video games, into routine practice to minimise paediatric procedural pain and child/caregiver anxiety

The Effect of Resistance Training in Healthy Adults on Body Fat Percentage, Fat Mass and Visceral Fat: A Systematic Review and Meta-Analysis

Background: Resistance training is the gold standard exercise mode for accrual of lean muscle mass, but the isolated effect of resistance training on body fat is unknown. Objectives: This systematic review and meta-analysis evaluated resistance training for body composition outcomes in healthy adults. Our primary outcome was body fat percentage; secondary outcomes were body fat mass and visceral fat. Design: Systematic review with meta-analysis. Data Sources: We searched five electronic databases up to January 2021. Eligibility Criteria: We included randomised trials that compared full-body resistance training for at least 4 weeks to no-exercise control in healthy adults. Analysis: We assessed study quality with the TESTEX tool and conducted a random-effects meta-analysis, with a subgroup analysis based on measurement type (scan or non-scan) and sex (male or female), and a meta-regression for volume of resistance training and training components. Results: From 11,981 records, we included 58 studies in the review, with 54 providing data for a meta-analysis. Mean study quality was 9/15 (range 6–15). Compared to the control, resistance training reduced body fat percentage by − 1.46% (95% confidence interval − 1.78 to − 1.14, p < 0.0001), body fat mass by − 0.55 kg (95% confidence interval − 0.75 to − 0.34, p < 0.0001) and visceral fat by a standardised mean difference of − 0.49 (95% confidence interval − 0.87 to − 0.11, p = 0.0114). Measurement type was a significant moderator in body fat percentage and body fat mass, but sex was not. Training volume and training components were not associated with effect size. Summary/Conclusions: Resistance training reduces body fat percentage, body fat mass and visceral fat in healthy adults. Study Registration: osf.io/hsk32

Emotion regulation skills-focused interventions for chronic pain: A systematic review and meta-analysis

Objectives: To investigate the effect of emotion regulation skills-focused (ERSF) interventions to reduce pain intensity and improve psychological outcomes for people with chronic pain and to narratively report on safety and intervention compliance. Methods: Six databases and four registries were searched for randomized controlled trials (RCTs) up to 29 April 2022. Risk of bias was evaluated using the Cochrane RoB 2.0 tool, and certainty of evidence was assessed according to the Grading, Assessment, Development and Evaluation (GRADE). Meta-analyses for eight studies (902 participants) assessed pain intensity (primary outcome), emotion regulation, affect, symptoms of depression and anxiety, and pain interference (secondary outcomes), at two time points when available, post-intervention (closest to intervention end) and follow-up (the first measurement after the post-intervention assessment). Results: Compared to TAU, pain intensity improved post-intervention (weighted mean difference [WMD] = −10.86; 95% confidence interval [CI] [−17.55, −2.56]) and at follow-up (WMD = −11.38; 95% CI [−13.55, −9.21]). Emotion regulation improved post-intervention (standard mean difference [SMD] = 0.57; 95% CI [0.14, 1.01]), and depressive symptoms improved at follow-up (SMD = −0.45; 95% CI [−0.66, −0.24]). Compared to active comparators, anxiety symptoms improved favouring the comparator post-intervention (SMD = 0.10; 95% CI [0.03, 0.18]), and compared to CBT, pain interference improved post-intervention (SMD = −0.37; 95% CI [−0.69, −0.04]). Certainty of evidence ranged from very low to moderate. Significance: The findings provide evidence that ERSF interventions reduce pain intensity for people with chronic pain compared to usual treatment. These interventions are at least as beneficial to reduce pain intensity as the current gold standard psychological intervention, CBT. However, the limited number of studies and certainty of evidence mean further high-quality RCTs are warranted. Additionally, further research is needed to identify whether ERSF interventions may be more beneficial for specific chronic pain conditions

Efficacy, acceptability, and safety of muscle relaxants for adults with non-specific low back pain: Systematic review and meta-analysis

AbstractObjective To investigate the efficacy, acceptability, and safety of muscle relaxants for low back pain. Design Systematic review and meta-analysis of randomised controlled trials. Data sources Medline, Embase, CINAHL, CENTRAL, ClinicalTrials.gov, clinicialtrialsregister.eu, and WHO ICTRP from inception to 23 February 2021. Eligibility criteria for study selection Randomised controlled trials of muscle relaxants compared with placebo, usual care, waiting list, or no treatment in adults (≥18 years) reporting non-specific low back pain. Data extraction and synthesis Two reviewers independently identified studies, extracted data, and assessed the risk of bias and certainty of the evidence using the Cochrane risk-of-bias tool and Grading of Recommendations, Assessment, Development and Evaluations, respectively. Random effects meta-analytical models through restricted maximum likelihood estimation were used to estimate pooled effects and corresponding 95% confidence intervals. Outcomes included pain intensity (measured on a 0-100 point scale), disability (0-100 point scale), acceptability (discontinuation of the drug for any reason during treatment), and safety (adverse events, serious adverse events, and number of participants who withdrew from the trial because of an adverse event). Results 49 trials were included in the review, of which 31, sampling 6505 participants, were quantitatively analysed. For acute low back pain, very low certainty evidence showed that at two weeks or less non-benzodiazepine antispasmodics were associated with a reduction in pain intensity compared with control (mean difference -7.7, 95% confidence interval-12.1 to-3.3) but not a reduction in disability (-3.3, -7.3 to 0.7). Low and very low certainty evidence showed that non-benzodiazepine antispasmodics might increase the risk of an adverse event (relative risk 1.6, 1.2 to 2.0) and might have little to no effect on acceptability (0.8, 0.6 to 1.1) compared with control for acute low back pain, respectively. The number of trials investigating other muscle relaxants and different durations of low back pain were small and the certainty of evidence was reduced because most trials were at high risk of bias. Conclusions Considerable uncertainty exists about the clinical efficacy and safety of muscle relaxants. Very low and low certainty evidence shows that non-benzodiazepine antispasmodics might provide small but not clinically important reductions in pain intensity at or before two weeks and might increase the risk of an adverse event in acute low back pain, respectively. Large, high quality, placebo controlled trials are urgently needed to resolve uncertainty. Systematic review registration PROSPERO CRD42019126820 and Open Science Framework https://osf.io/mu2f5/