Safety of exercise training in multiple sclerosis: a protocol for an updated systematic review and meta-analysis

BACKGROUND

There has been an exponential growth in the number of clinical research studies regarding exercise training in multiple sclerosis, and literature reviews and meta-analyses have documented the many benefits of exercise training. This research further requires careful review for documenting the safety of exercise training in multiple sclerosis, as clarity on safety represents a major hurdle in the clinical prescription of exercise behaviour.

OBJECTIVES

To enhance understanding of the feasibility of exercise in multiple sclerosis, we (1) provide a protocol of a systematic review and meta-analysis that summarises rates and risks of clinical relapse, adverse events (i.e., an unfavourable outcome that occurs during the intervention delivery time period), and serious adverse events (i.e., an untoward occurrence that results in death or is life threatening, requires hospitalisation, or results in disability during the intervention delivery time period), as well as retention, adherence, and compliance, from randomised controlled trials of exercise training in persons with multiple sclerosis; and (2) identify moderators of relapse, adverse events, and serious adverse event rates.

METHODS

Eight field-relevant databases will be searched electronically. Studies that involve a randomised controlled trial of exercise training (with non-exercise, non-pharmacological, comparator), report on safety outcomes, and include adults with multiple sclerosis will be included. Rates and relative risks of the three primary outcomes (relapse, adverse event, and serious adverse event) will be calculated and reported each with standard error and 95% confidence interval. Random-effects meta-analysis will estimate mean population relative risk for outcomes. Potential sources of variability, including participant characteristics, features of the exercise stimulus, and comparison condition, will be examined with random-effects meta-regression with maximum likelihood estimation.

DISCUSSION

The results from this systematic review and meta-analysis will inform and guide healthcare practitioners, researchers, and policymakers on the safety of exercise training in persons with multiple sclerosis. Where possible, we will identify the impact of exercise type, exercise delivery style, participant disability level, and the prescription of exercise guidelines, on the safety of exercise training. The result will identify critical information on the safety of exercise in persons with multiple sclerosis, while also identifying gaps in research and setting priorities for future enquiries.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 2020 CRD42020190544.

Associations of physical activity with anxiety symptoms and status: results from The Irish longitudinal study on ageing

AIMS

Anxiety is debilitating and associated with numerous mental and physical comorbidities. There is a need to identify and investigate low-risk prevention and treatment strategies. Therefore, the purpose of this study was to investigate cross-sectional and longitudinal associations between different volumes of moderate-to-vigorous physical activity (PA) and anxiety symptoms and status among older adults in Ireland.

METHODS

Participants (n = 4175; 56.8% female) aged ⩾50 years completed the International PA Questionnaire (IPAQ) at baseline, and the anxiety subscale of the Hospital Anxiety and Depression Scale at baseline and follow-up (2009-2013). Participants were classified according to meeting World Health Organisation PA guidelines, and divided into IPAQ categories. Respondents without anxiety at baseline (n = 3165) were included in prospective analyses. Data were analysed in 2017.

RESULTS

Anxiety symptoms were significantly higher among females than males (p < 0.001). Models were adjusted for age, sex, waist circumference, social class, smoking status and pain. In cross-sectional analyses, meeting PA guidelines was associated with 9.3% (OR = 0.91, 95% confidence interval 0.78-1.06) lower odds of anxiety. Compared with the inactive group, the minimally- and very-active groups were associated with 8.4% (OR = 0.92, 0.76-1.10) and 18.8% (OR = 0.81, 0.67-0.98) lower odds of anxiety, respectively. In prospective analyses, meeting guidelines was associated with 6.3% (OR = 0.94, 0.63-1.40) reduced odds of anxiety. Compared with the inactive group, the minimally and very-active groups were associated with 43.5% (OR = 1.44, 0.89-2.32) increased, and 4.3% (OR = 0.96, 0.56-1.63) reduced odds of anxiety. The presence of pain, included in models as a covariate, was associated with a 108.7% (OR = 2.09, 1.80-2.42) increase in odds of prevalent anxiety, and a 109.7% (OR = 2.10, 1.41-3.11) increase in odds of incident anxiety.

CONCLUSION

High volumes of PA are cross-sectionally associated with lower anxiety symptoms and status, with a potential dose-response apparent. However, significant associations were not observed in prospective analyses. The low absolute number of incident anxiety cases (n = 109) potentially influenced these findings. Further, as older adults may tend to experience and/or report more somatic anxiety symptoms, and the HADS focuses primarily on cognitive symptoms, it is plausible that the HADS was not an optimal measure of anxiety symptoms in the current population.

Physical activity correlates among older adults with probable generalized anxiety disorder: Results from The Irish Longitudinal Study on Ageing

OBJECTIVES

This study assessed physical activity (PA) correlates among 1237 (69.0% female; age ≥ 50 years) community-dwelling adults with probable-generalized anxiety disorder (GAD).

METHODS

Wave 1 data from The Irish Longitudinal Study on Ageing were analysed. PA was measured using the short-form International PA Questionnaire. Probable-GAD caseness was indicated by a score of ≥23 on the abbreviated Penn State Worry Questionnaire. Potential correlates were analysed using binomial logistic regression. Hierarchical logistic regression consisting of three blocks (sociodemographic variables; quality of life (QoL) variables; physical health and performance variables) examined the proportion of the variance for PA that was explained at each step of the regression model.

RESULTS

Five hundred thirty-five participants (43.2%) met PA guidelines. After adjustment for age and sex, younger age and being male were associated with increased likelihood of meeting PA guidelines. Significant correlates of PA were in employment, higher QoL (CASP-19), social connectedness, and grip-strength. Additionally, polypharmacy (i.e., taking ≥five medications), antidepressant use, at-risk waist circumference (i.e., Males: >94 cm; Females >80 cm), up-and-go time, and number of self-reported physical limitations were significantly negatively associated with meeting PA guidelines. Physical health and performance variables explained significant variation (8.4%) in meeting physical activity guidelines beyond that of sociodemographics, and QoL variables.

CONCLUSIONS

This study identified a range of sociodemographic, physical, and psychological variables that were associated with meeting or not meeting PA guidelines among older adults with probable-GAD.

Associations of physical activity and depression: Results from the Irish Longitudinal Study on Ageing

Physical activity (PA) can protect against depression, but few studies have assessed whether meeting PA guidelines is sufficient, or if benefits can be derived from greater volumes of PA. The present study examines cross-sectional and prospective associations between different volumes of moderate-to-vigorous PA (MVPA) and walking, and depressive symptoms and status. Participants (n = 4556; 56.7% female) aged ≥ 50 years completed the International PA Questionnaire (IPAQ) at baseline and the Center for Epidemiological Studies Depression Scale at baseline and two years later. Prevalence and incidence of depression were 9.0% (n = 410) and 5.0% (n = 207), respectively. After full adjustment, odds of prevalent depression were: 40% (OR = 0.60, 95%CI: 0.48-0.76) lower among those meeting PA guidelines; 23% (OR = 0.77, 0.49-1.21) and 43% (OR = 0.57, 0.45-0.73) lower among those in moderate and high categories, respectively; and, 22% (OR = 0.78, 0.61-1.01) and 44.0% (OR = 0.56, 0.42-0.74) lower among those in moderate and high walking tertiles, respectively. Odds of incident depression were: 23% (OR = 0.77, 0.58-1.04) lower among those meeting PA guidelines; 37% (OR = 0.63, 0.32-1.22) and 20.0% (OR = 0.80, 0.59-1.09) lower among those in moderate and high categories, respectively; and, 21% (OR = 0.79, 0.56-1.12) and 25% (OR = 0.75, 0.52-1.07) lower among those in moderate and high walking tertiles, respectively. Moderate and high volumes of MVPA were significantly associated with lower odds of concurrent depression, and significantly and non-significantly associated with reduced odds of incident depression, respectively. Meeting recommended levels of MVPA and walking were associated with significantly lower odds of concurrent depression, and non-significantly reduced odds of the development of depression over two years.

The cross-sectional associations between objectively measured sedentary time and cardiometabolic health markers in adults - a systematic review with meta-analysis component

Sedentary time is viewed as an independent risk factor for adverse cardiometabolic health (CMH). No systematic review and meta-analysis on the cross-sectional associations between objectively measured sedentary time and CMH markers has been conducted. PubMed, Scopus and Web of Science Core Collection were searched for papers that examined the cross-sectional association between objectively measured sedentary time and CMH markers in adults. Forty-six papers met the inclusion criteria. The included papers had a combined sample size of 70,576 and an age range of 18-87 years. To examine the effect of increased levels of sedentary time on CMH markers, data on effect sizes and moderators were extracted, where possible. By pooling the unadjusted data from the included papers, increased sedentary time was shown to have a significant detrimental association with fasting glucose (Δ = 0.12, 95% confidence interval [CI]: 0.02, 0.23), fasting insulin (Δ = 0.19, 95% CI: 0.06, 0.32), triglycerides (Δ = 0.25, 95% CI: 0.14, 0.37), high-density lipoprotein cholesterol (Δ = -0.20, 95% CI: -0.28, -0.13) and waist circumference (Δ = 0.25, 95% CI: 0.15, 0.35). How sedentary time was quantified and the device used to measure sedentary time significantly influence the size of the effect reported. Future interventions focused on both decreasing sedentary time and increasing physical activity may be the most effective strategy to improve CMH.

Sedentary behavior and anxiety: Association and influential factors among 42,469 community-dwelling adults in six low- and middle-income countries

OBJECTIVE

This study investigated the association between sedentary behavior (SB) and anxiety, and explored factors that influence this relationship in six low- and middle-income countries.

METHOD

Cross-sectional data were analyzed from the World Health Organization's Study on Global Ageing and Adult Health. Multivariable linear and logistic regression analyses were conducted to assess the association between anxiety and self-reported SB. Potentially influential factors were examined with mediation analysis.

RESULTS

The sample consisted of 42,469 adults aged≥18years (50.1% female; mean age 43.8years). After adjusting for sociodemographics and country, people with anxiety engaged in 24 (95%CI=7-41) more minutes per day of SB than non-anxious individuals; the corresponding figure for the elderly (≥65years) was much higher (55min; 95% CI=29-81). Anxiety was associated with a 2.0 (95%CI=1.5-2.7) times higher odds for high SB (i.e., ≥8h/day). Overall, the largest proportion of the high SB-anxiety relationship was explained by mobility limitations (46.8%), followed by impairments in sleep/energy (44.9%), pain/discomfort (31.7%), disability (27.0%), cognition (13.3%), and physical activity levels (6.3%).

CONCLUSIONS

Anxiety was significantly associated with high SB, particularly among older adults. Future longitudinal studies are warranted to disentangle the potentially complex interplay of factors that may influence the anxiety-SB relationship.

Eating and arterial endothelial function: a meta-analysis of the acute effects of meal consumption on flow-mediated dilation

Given that endothelial dysfunction precedes atherosclerotic cardiovascular disease, exploring the parameters that modify postprandial flow-mediated dilation (FMD) is important for public health. The objectives of the study are to estimate the population effect of meal ingestion on FMD and to determine how the effect varied based on patient characteristics and modifiable methodological features. Articles published before June 2015 were located using MEDLINE, PubMed and Web of Science. One hundred fifty-four effects were derived from 78 articles involving 2,548 subjects were selected. Included articles required measurement of FMD in adults before and after meal ingestion. Effects were analysed using an unstandardized mean gain random effects model, and significant moderators were analysed using meta-regression. Meal consumption significantly reduced FMD by a heterogeneous mean effect size delta (Δ) of -2.03 (95% CI: [-2.28, -1.77]), an ~2% reduction in FMD. FMD reductions were larger among normal weight individuals, males, those with a cardio-metabolic disorder, those with elevated baseline FMD, and individuals with impaired glucose tolerance at baseline. Macronutrient meal ingestion significantly reduced FMD, an effect that was moderated by body mass index, sex and two-way interactions between disease status and both baseline FMD and baseline blood glucose levels.

Genetic factors in exercise adoption, adherence and obesity

Physical activity and exercise play critical roles in energy balance. While many interventions targeted at increasing physical activity have demonstrated efficacy in promoting weight loss or maintenance in the short term, long term adherence to such programmes is not frequently observed. Numerous factors have been examined for their ability to predict and/or influence physical activity and exercise adherence. Although physical activity has been demonstrated to have a strong genetic component in both animals and humans, few studies have examined the association between genetic variation and exercise adherence. In this review, we provide a detailed overview of the non-genetic and genetic predictors of physical activity and adherence to exercise. In addition, we report the results of analysis of 26 single nucleotide polymorphisms in six candidate genes examined for association to exercise adherence, duration, intensity and total exercise dose in young adults from the Training Interventions and Genetics of Exercise Response (TIGER) Study. Based on both animal and human research, neural signalling and pleasure/reward systems in the brain may drive in large part the propensity to be physically active and to adhere to an exercise programme. Adherence/compliance research in other fields may inform future investigation of the genetics of exercise adherence.