Abstract
Introduction
With the popularity of yoga increasing as a means to improve overall well-being, this umbrella review aimed to evaluate the potential effects of yoga on chronic disease outcomes by synthesizing previously published systematic reviews, including meta-analyses, of randomized controlled trials in adult populations.
Content
PubMed, Scopus, Cochrane, Web of Science, and CINAHL for systematic reviews published up to 31st March 2023. Systematic reviews examining the effectiveness of yoga interventions compared with controllable groups on chronic disease outcomes were searched from adults aged above 18 years old. Fifty-one systematic reviews, of which 34 were with meta-analyses, were eligible. The included reviews yielded 579 individual studies with 28403 reported participants. Most studies (n=45, 86.5 %) were conducted with general adult participants, other six studies were with women diagnosed with breast cancer. Yoga interventions had strong effects on depression, blood pressure, blood glucose, and fatigue management, while weak evidence was found for pain management and arthritis.
Summary
Yoga intervention may have an effect on improvements on depression, hypertension, type 2 diabetes, and fatigue management but not beneficial for physically disordered chronic diseases.
Outlook
Future studies with larger sample sizes and longer durations are necessary to validate the effect of yoga on chornic diseases. Further exploration on yoga implementation are expected.
Primary Funding Source
JIF201036Y and JIF201018Y (PROSPERO: CRD42023417841).
Keywords: yoga, chronic disease, umbrella review, systematic review, meta-analysis
Introduction
Chronic disease is a health condition that is not contagious, typically lasting for at least one year, and requiring ongoing health care for rehabilitation [1]. According to the 2019 Global Health Estimates report, the top seven causes of death were chronic or noncommunicable diseases, with 17 million people dying from these diseases before the age of 70 each year [2]. The prevalence of cardiovascular disease has nearly doubled from 1990 to 2019 [3]. As people live longer, the prevalence and cost of chronic diseases continue to increase. It is estimated that the cost of chronic disease will reach $47 trillion worldwide by 2030 [4]. Additionally, having multiple chronic conditions, such as obesity, cancer, cardiovascular disease, diabetes, and stroke, can significantly reduce both life quality and life expectancy [5].
Despite the varying quality of evidence, studies on yoga or yoga-related activities have been published across a range of chronic diseases, including low back pain [6], Parkinson’s disease [7], arthritis [8], lung disease [9], and psychological conditions [10]. While most studies suggest that yoga may have beneficial effects [8], 11], others report no effects of yoga on certain diseases such as Chronic Obstructive Pulmonary Disease (COPD) [12]. The diversity in disease outcomes and study designs, as well as the difficulty of supervising and monitoring yoga in non-clinical settings, have hindered a broader understanding of yoga practices among people with chronic diseases.
With the popularity of yoga increasing as a means to improve overall well-being, there has been surge in review articles focusing on yoga interventions for chronic diseases in recent years. Additionally, there have been meta-analyses of yoga interventions conducted in randomized controlled trials (RCTs) [13], [14], [15], [16], [17], which have specifically targeted chronic diseases such as Type 2 Diabetes (T2DM) or specific population subgroups like individuals suffering from chronic pain. It is important to consolidate and summarize the findings regarding the effectiveness of yoga in managing chronic diseases as reported in previous systematic reviews and meta-analyses, as existing reviews have utilized varying review designs, non-standardized yoga interventions among diverse populations [18], 19].
Umbrella reviews are systematic reviews of systematic reviews, offering a way to synthesize a vast amount of research evidence. By conducting an umbrella review of systematic reviews and meta-analyses of RCTs, we aimed to 1) summarize the high-quality evidence of yoga interventions on chronic diseases or conditions; 2) assess the effectiveness of yoga interventions on components of chronic diseases or conditions; and 3) provide useful suggestions on how yoga interventions benefit chronic conditions.
Methodology
The umbrella review was conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines [20]. The protocol was prospectively registered on PROSPERO with the registration number CRD42023417841. The PRISMA checklist can be found in Supplementary Material 1.
Eligibility criteria
We selected systematic reviews, whether they performed meta-analyses or not, evaluating the effectiveness of yoga practices for chronic health conditions or diseases from quasi-experimental (pre-intervention and post-intervention) and RCTs. To be considered eligible for inclusion, participants had to be above 18 years old. We excluded meta-analyses of pooled cross-sectional studies due to their weak level of evidence by design. Additionally, we excluded cohort studies because they lack empirical evidence. Systematic reviews that did not involve exercise-oriented yoga programs were excluded, as body movement and physical activity are known to be beneficial for chronic health conditions and non-communicable diseases. To ensure the quality of included systematic reviews, those without quality appraisal were also excluded. Additionally, reviews including perinatal females were excluded due to their unique life status, which may introduce bias compared to the general population. The Population, Intervention, Comparison, Outcomes and Study (PICOS) framework [21] was utilized to clarify the population (adults with chronic diseases), interventions (yoga), comparators (without yoga as control group), outcomes of interest (chronic disease or related symptoms), study design (e.g., systematic reviews), and additional search criteria. Detailed inclusion and exclusion criteria can be found in Table 1.
Table 1:
Inclusion and exclusion criteria.
| Items | Eligibility criteria | |
|---|---|---|
| Inclusion criteria | Exclusion criteria | |
| Patients/population | 1. Adults aged>18years old | 1. Teenager or adolescent population |
| 2. A combination of all age groups | ||
| 2. Both female and/or male population | 3. Pregnancy or perinatal women | |
| Intervention | 1. Yoga or yoga exercise related interventions were included | 1. Breathing-orientated exercises |
| 2. Mindful therapies | ||
| 3. Yoga with non-yoga compared groups | ||
| Comparison | 1. With comparators or waiting-list group | 1. Without control groups or comparators |
| Outcomes | 1. Chronic disease related symptoms | 1. Outcomes as chronic symptoms |
| 2. Outcome without specified chronic disease | ||
| 3. Outcomes of no interest | ||
| Study design | 1. Only systematic review and/or meta-analysis of RCTs were included | 1. Other review types (e.g., rapid reviews, scoping reviews, state-of-art reviews, umbrella reviews) |
| 2. Studies without quality control | ||
| 3. Studies without risk assessment of bias | ||
| 4. Preprints, protocols, communications with editor | ||
| Additional items | 1. Cochrane reviews with duplicated information are excluded | |
| 2. Study with inaccurate data was not considered | ||
Chronic health outcomes
Given the large degree of variation in the use of the term “chronic disease”, the search scope for chronic diseases referred to a study that explored the prevalence of chronic disease using National Health and Nutrition Examination Survey (NHANES) data (1999–2004) [22]. This study classified a collection of chronic health outcomes [22] and supported the chronic disease definition that lasts a year or more, requireing ongoing medical attention and/or limited activities of daily living [23]. Chronic diseases can range from mild to more significant conditions such as coronary heart disease, hypertension, and diabetes etc. If more than one relevant outcome was reported in a systematic review on yoga, each outcome was included separately.
Search and identification of studies
We searched five electronic databases PubMed, Scopus, Cochrane, Web of Science and CINAHL from inception untill March 31, 2023. Two researchers (FW, WY) independently screened all titles and abstracts of identified systematic reviews. Any discrepancies were resolved through discussion with a third independent researcher (KW) until a consensus was reached. The search string combined relevant keywords and MeSH terms for chronic diseases and study design. Search results were restricted to articles published in English. The search terms (“Yoga” AND (“Chronic disease” OR “Noncommunicable disease” OR “Cardiovascular disease” OR “Hypertension” OR “Diabetes” OR” Hypercholesterolemia” OR “Asthma” OR “COPD” OR “Heart disease” OR “Cancer” OR “Stroke” OR “Obesity” OR” Arthritis” OR “Alzheimer’s disease” OR “Depression” OR” Kidney disease” OR” HIV”) AND “Review”) were used to search each individual database. One researcher (FW) independently used citation pearl growing to hand search references of eligible systematic reviews.
Data extraction and methodological quality assessment
Two researchers (FW, WY) independently extracted data from each included systematic review. The extracted data was double-checked through discussion with the third researcher (KW). The main characteristics extracted from each systematic review included the number of searched databases, the number of included studies, the number of total participants, effect sizes, p-values, heterogeneity, and chronic health outcomes. The overlap of evidence was assessed by comparing the list of primary studies in each review.
The assessment of methodological quality of the included systematic reviews was conducted using A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2), an updated version of AMSTAR that allows for a more detailed assessment of systematic reviews including randomized or non-randomized studies of healthcare interventions, or both [24]. The AMSTAR two consists of 16 items for evaluating methodological aspects of systematic reviews and is used to address risks of bias and provide an overall appraisal of a systematic review. The methodological quality of included systematic reviews is categorized as high (13–16), moderate (9−12), low (5–8), or critically low (1–4) by calculating an overall score. The scoring methods and rating rules were described elsewhere [25]. Only reviews with quality from moderate to high were selected for meta-analysis.
Certainty of evidence
The certainty of evidence for systematic reviews of RCTs (without meta-analysis) was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) framework, which is a consensus on rating the quality of evidence and strength of recommendations [26]. The GRADE is rated in four categories: 1) Very low: the true effect is probably markedly different from the estimated effect; 2) Low: the true effect might be markedly different from the estimated effect; 3) Moderate: the authors believe that the true effect is probably close to the estimated effect; and 4) High: the authors have high confidence that the true effect is similar to the estimated effect. For meta-analysis, we classified three levels of evidence certainty based on published statistical metrics [27], [28], [29]: Level I (strong evidence): heterogeneity I2<50 % (p>0.10) and significance of the overall effect p<10−5; Level II (moderate evidence): heterogeneity I2<50 % (p>0.10) or significance of the overall effect p<10−5; and Level III (weak evidence): heterogeneity I2>50 % (p<0.10) or significance of the overall effect p>10−5.
Data synthesis and analysis
Chronic diseases or related symptoms were categorized based on clinical status and conditions. The primary outcome of this umbrella review was to summarize chronic diseases or conditions that have been treated by yoga interventions. The secondary outcome was to synthesize meta-analysis results assessing the effectiveness of yoga interventions on chronic diseases or conditions. Qualitative analysis was performed for systematic reviews without meta-analysis and quantitative analysis was performed for systematic reviews with meta-analysis in this umbrella review.
For qualitative analysis, we presented the results of yoga and its impact on health outcomes through synthesized tables. In quantitative analysis, associations between yoga interventions and chronic diseases/conditions were examined by extracting effect-sizes from each meta-analysis, and then calculating pooled effect sizes with 95 % confidence intervals (CIs) using fixed or random-effects models. Forest plots and funnel plots were generated for meta-analyses reporting standardized mean differences (SMD) using RevMan (version 5.3). Heterogeneity was assessed using Cochran’s I2 statistic, with I2 values of 25 %, 50 % and 75 % indicating low, medium, and high heterogeneity, respectively [30]. If there were more than two systematic reviews, a random-effects model was used when heterogeneity was medium to high (I2>50 %), otherwise, a fixed effect model was used. When only two systematic reviews were available, a fixed-effects model was considered for an accurate estimate of between-studies variance. A p-value >0.10 was deemed statistically significant for heterogeneity tests [31]. Egger’s regression test was utilized to evaluate the small study effect in each health outcome category [32], where p<0.10 indicated biased evidence. Stata (version 16.0) was employed for Egger’s regression test. A p-value <0.05 was considered significant for all other tests.
Equity, diversity and inclusion statement
The author group consists of junior, mid-career and senior researchers. Our study included male and female adults from various socioeconomic and cultural backgrounds.
Results
Summary of included systematic reviews
We identified 2,218 records from PubMed (n=917), Scopus (n=202), Cochrane (n=91), Web of Science (n=993) and CINAHL (n=13). No eligible reviews were detected from records or citations that appeared to meet the inclusion criteria. After excluding duplicates, ineligible study designs, ineligible outcomes, and studies conducted with non-adult populations, 51 articles were included in this umbrella review (Figure 1). Among the included articles, 34 studies performed meta-analysis of RCTs (Supplementary Material 3). The summarized characteristics of the included studies with meta-analysis and without meta-analysis are presented in Supplementary Material 2 eTable 1 (n=34) and eTable 2 (n=17).
Figure 1:
The flow chart of study selection process.
The included reviews yielded 579 RCTs with 28,403 reported participants. Of those, 22,243 reported participants from 428 RCTs were included in the meta-analysis. The included systematic reviews were published from 2010 to 2023 with a minimum of four included individual studies and a maximum of 37 included individual studies (eTable 1 & eTable 2 ). After extracting the disease information from the included articles, we identified 12 chronic health outcomes from systematic reviews conducted meta-analysis. These outcomes include hypertension, type 2 diabetes mellitus (T2DM), chronic obstructive pulmonary disease (COPD), cardiovascular diseases, arthritis, asthma, metabolic syndrome, Parkinson’s disease, and diseases (e.g., cancer) that cause health symptoms such as fatigue, anxiety, depression, and pain, as shown in Supplementary Material 2 eTable 3. Most of the studies (n=45, 86.5 %) were conducted with both men and women, while the remaining six studies involved only women with breast cancer or menstrual disorders. Patients with hypertension (n=5) and T2DM (n=4) took yoga practice as an adjunctive treatment to ameliorate physical and mental discomforts. Yoga was popularly used as a therapeutic strategy to alleviate depression (n=10) and anxiety (n=7). Additionally, yoga was also used for management of fatigue (n=3), chronic obstructive pulmonary disease (n=2), arthritis (n=2), asthma (n=2), metabolic syndrome (n=2), Parkinson’s disease (n=1), pain (n=3), and post-traumatic stress disorder (n=1).
More than half of the included systematic reviews (n=51) were ranked as high quality (n=32) according to the AMSTAR2 score. The remaining included reviews were ranked as moderate quality (n=17) and low quality (n=2), with no study being ranked as critically low quality. Details of the methodological quality assessment rated by AMSTAR2 can be found in Supplementary Material 2 eTable 4.
Findings of systematic reviews without meta-analysis
Seventeen systematic reviews (without meta-analysis) investigated pain, heart disease, mental disorder, dysmenorrhea, hypertension, type 2 diabetes, asthma, fatigue and irritable bowel syndrome. These reviews comprised a total of 165 RCTs, with the number of included RCTs in each review ranging from four to 28. According to the GRADE evaluation system, the studies ranked moderate to high in terms of evidence indicating that yoga may have a potential therapeutic role in addressing symptomatic conditions such as fatigue, nausea/vomiting, sleep quality, anxiety, depression, and distress in breast cancer patients [33], 34] and patients with type 2 diabetes [35]. Yoga-based interventions were also found to have beneficial effects on cognition and mental disorders [36]. Moderate evidence supported the effects of yoga on reducing body weight [37] and hypertension [38]. The key findings of systematic reviews (without meta-analysis) are outlined in Supplementary Material 2 eTable 2.
Meta-analysis of yoga and health outcomes
The systematic reviews included in this umbrella review utilized a variety of effect size indicators. Most reviews presented effect sizes using SMD (n=24) or unstandardized mean difference (MD) (n=9), with only one study reporting effect size using relative risk (RR) among the included reviews (eTable 1). The overall pooled SMD between the yoga group and the control group was −0.61 (95 % CI: −0.73 to −0.49) (Figure 2). There was relatively high heterogeneity among the studies (I2=72 %, p<0.001). Studies presenting SMD showed no risk of bias according to Egger’s test (p=0.29) (Supplementary Material 2 eTable 5), and a Funnel plot was presented in eFigure 1. Health outcomes reported by at least two studies using SMD as the effect size were included for subgroup analysis. Health outcomes were categorized into four subgroups: Mental disorders, Hypertension, T2DM, and Physical dysfunction (pain, fatigue, arthritis). Forest plots calculating the pooled SMD of yoga groups and control groups were created for each outcome category (Figure 3–6). Asthma was reported by two studies and the pooled SMD was shown in eFigure 2. Levels of evidence certainty for the meta-analysis of yoga and mental disorders, hypertension, T2DM, and physical dysfunctions were presented in Supplementary Material 2 eTable 6. Strong evidence was found for depression, blood pressure, blood glucose, and fatigue management; moderate evidence was found for anxiety and HbA1c, and weak evidence was found for pain management and arthritis (eTable6, Figure 3–6).
Figure 2:
Forest plot of yoga vs. control for overall chronic health outcomes. CI, confidence interval; IV, inverse variance; SD, standard deviation.
Figure 3:
Forest plot of yoga vs. control for mental disorders. CI, confidence interval; IV, inverse variance; SD, standard deviation.
Figure 6:
Forest plot of yoga vs. control for physical dysfunctions (fatigue, pain, and arthritis). CI, confidence interval; IV, inverse variance; SD, standard deviation.
Yoga and mental disorder
Among all health outcomes, mental disorders such as depression and anxiety were the most frequently studied. The impact of yoga on depression was analyzed using a fixed-effects model. One out of 10 studies was not included in the meta-analysis due to an unstandardized effect size reported as MD [39]. The remaining nine studies with reported SMD, showed strong evidence of yoga’s effect on depression (SMD: −0.52; 95 % CI: −0.62 to −0.41) with very low heterogeneity (I2=6 %, p=0.39) and an overall effect of Z=9.45 (p<0.001). Among the seven reviews on anxiety, one study reported an effect size with MD [40], while the remaining six studies were included in the meta-analysis (Figure 3). The forest plot of yoga and anxiety indicated that yoga reduces anxiety in a random-effects model with moderately high heterogeneity (SMD= −0.55; 95 % CI: −0.74 to −0.36; I2=60 %, p=0.03; Z=5.70 (p<0.001)).
Yoga and hypertension
Among studies involving patients with hypertension or prehypertension, three studies reported SMD, and separate meta-analyses of systolic and diastolic blood pressure were conducted (Figure 4). A fixed-effects model was utilized because the heterogeneity of both systolic (I2=34 %; p>0.1) and diastolic blood pressure (I2=41 %; p>0.1) was less than 50 %. The SMD of yoga on systolic and diastolic blood pressure was −0.48 (95 % CI: −0.62 to −0.34) and −0.39 (95 % CI: −0.57 to −0.21).
Figure 4:
Forest plot of yoga vs. control for blood pressure by forest plot. CI, confidence interval; IV, inverse variance; SD, standard deviation.
Yoga and type 2 diabetes
The statistical analysis of yoga and T2DM was performed using three variables: post prandial blood sugar (PPBS) (SMD: −0.70, 95 % CI: −0.96 to −0.44), fasting blood glucose (FBG) (SMD: −1.24, 95 % CI: −1.64 to −0.85) and Glycated hemoglobin (HbA1c) (SMD: −0.72, 95 % CI: −1.16 to −0.27) (Figure 5). A fixed-effects model was used for PPBS (Heterogeneity: I2=34 %; p=0.22) and FBG (Heterogeneity: I2=0 %; p=0.42), while a random-effects model was used for HbA1c (Heterogeneity: I2=65 %; p=0.06). One study reported MD was not included in the forest plot [41].
Figure 5:
Forest plot of yoga vs. control for T2DM biomarkers. PPBS: Post prandial blood sugar; FBG: fasting blood glucose; HbA1c: glycated haemoglobin; CI, confidence interval; IV, inverse variance; SD, standard deviation.
Yoga and physical dysfunction
We categorized three health conditions as physical dysfunction including fatigue, pain, and arthritis (Figure 6). Disease related fatigue (SMD= −0.40, 95 % CI: −0.59 to −0.21) and pain (SMD= −0.72, 95 % CI: −1.04 to −0.40) were identified. The heterogeneity was low for fatigue (I2=44 %; p=0.17) and moderate for pain (I2=75 %; p=0.02). Only two reviews reported on yoga for arthritis (SMD= −1.08, 95 % CI: −1.27 to −0.88; heterogeneity: I2=98 %).
Discussion
To the best of our knowledge, this is the first review to compile the extensive evidence regarding the effectiveness of yoga on chronic diseases. This umbrella review provided the most comprehensive synthesis of evidence on yoga’s efficacy for various chronic diseases/conditions, including mental, cardiometabolic, and physical disorders, from 51 systematic reviews. Our findings suggest that yoga interventions are effective in alleviating chronic diseases/conditions, although the magnitude of effect varies. The greatest benefits were seen in people with depression, hypertension, high blood glucose, and fatigue; moderate benefits were found for people with anxiety and high HbA1c; and low or unclear benefits were found for people with pain and arthritis.
This umbrella review identified the largest number of systematic reviews investigating the efficacy of yoga on mental disorders. Recent evidence has documented the benefits of body movements (i.e., physical activity), regardless of modality and duration, for depression, anxiety, and distress [42]. Additionally, emerging studies have focused on yoga therapy in various health conditions, suggesting yoga-based interventions as a therapy for depression and anxiety disorders [43]. Our findings were in line with existing knowledge and found strong evidence certainty for mental disorder such as depression, through systematic meta-analysis. Even though previous studies have suggested yoga as a complementary and alternative treatment for both depression and anxiety [44], our findings emphasized the more beneficial effects of yoga for depression than for anxiety. This was supported by a meta-analysis study of RCTs [45] and summarized reviews [46]. A possible explanation could be the far less data available on the effects of yoga on anxiety compared to depression [47].
Our study demonstrated a stable and strong certainty of eviden regarding the efficacy of yoga in managing blood pressure. The effect is more pronounced for systolic blood pressure than diastolic blood pressure. The impact of yoga interventions on blood pressure in patients with hypertension has been extensively studies [48], [49], [50]. The mechanism behind yoga’s cardioprotective effects is still largely unknown, but potential explanations include the improvement of vagal tone, reduction of sympathetic activity, and reduction of systematic inflammation [51]. Other possible mechanisms include modulation of lipid metabolism, such as reducing levels of low-density lipoprotein (LDL) and triglycerides (TG), and increasing high-density lipoprotein (HDL) levels [52]. Consistent with this, a previous study reported a statistically significant increase in HDL levels and a low but significant effect on LDL, total cholesterol, and triglycerides during yoga intervention [53].
Our study revealed that for patients with T2DM, there is strong evidence supporting the positive impact of yoga on PPBS and FBG levels. However, the evidence supporting the effect of yoga on HbA1c is moderate due to heterogeneity among studies. Previous research has shown that yoga can improve glycemic outcomes and other risk factors (e.g., lipid profile, blood pressure, body mass index and waist/hip ratio etc.) for complications in adults with T2DM. However, the long-term efficacy of yoga has not been thoroughly examined [54]. Additional studies have suggested that regular yoga practice can enhance glycemic control without causing weight gain [55]. This may be attributed to the reduction of oxidative stress and inflammatory response through yoga practice [56]. It is important to consider potential heterogeneity when recommending the benefits of yoga for patients with type 2 diabetes mellitus [57].
For physical dysfunctions, our review only showed strong evidence for the efficacy of yoga in patients with fatigue, but weak evidence in patients with pain and arthritis. Despite variations in the frequency, time, and duration of yoga interventions tailored to physical disorders, numerous studies have been conducted on cancer-related fatigue and disease related or non-disease related chronic pain [58], 59]. Adequate evidence suggests the impact of yoga on fatigue and supports non-clinical recommendations of yoga as an adjunctive treatment for fatigue [14], 59]. However, previous studies investigating the effectiveness of yoga practice on arthritis did not consistently show qualified evidence [8], 60].
Our review evaluated the effects of yoga on a wide range of chronic diseases in the adult population. A key strength is that we only considered the highest level of evidence for inclusion, specifically, systematic reviews and meta-analyses, allowing for comparisons of relevant findings. We conducted meta-analysis of meta-analysis in subgroups to further explore the effects of yoga on each category of chronic diseases or conditions. This review categorized chronic diseases in order to better explain the effect yoga effects on health. Yogic cognitive-behavioral practices on human physiology can be classified into four transduction pathways: humoral factors, nervous system activity, cell trafficking, and bioelectromagnetism. Studies are suggested to investigate long-term effects and dose-response relationships and physiological mechanisms of yoga.
Limitations existed in this study. The review focused solely on body-oriented yoga, which helped to improve the specificity of yoga practice and reduce the potential ambiguity of other yoga types. However, this may limit the generalizability of holistic yoga practices on chronic diseases. The review excluded reviews conducted with full age groups due to the low quality of evidence. Only studies reported SMD were involved in the meta-analysis to increase the credibility of the evidence. Additionally, there is no consensus list of chronic diseases/conditions from any official websites or literature. The list of chronic diseases varies with changes in health guidelines. We referred to one that contains a relatively large coverage of chronic diseases which summarized and compared different chronic guidelines [22]. Finally, it is important to acknowledge that compared with traditional systematic reviews, umbrella reviews still lack standardization among researchers [61]. Nevertheless, future researchers should further discuss how different methods of selection and analyses influence the results of umbrella reviews [62].
Conclusions
Numerous studies have examined the impact of yoga on various chronic diseases and conditions. Though, these studies have produced conflicting results due to differences in study designs and disease outcomes. The current umbrella review synthesized existing systematic reviews and meta-analyses to offer a comprehensive summary of the positive effects of yoga on a variety of chronic disease outcomes. In conclusion, our results indicated that yoga interventions are closely linked to improvements in depression, blood pressure, blood glucose, and fatigue. There is limited evidence to support its benefits for pain and arthritis. Nevertheless, future RCTs with larger sample sizes and longer durations are necessary to validate these findings. Future studies are suggested to further explore implementation strategies to prevent progress of chronic diseases.
Supplementary Material
Supplementary Material
Supplementary Material
Supplementary Material
Acknowledgments
Thanks to Dr. Tingting Geng and Dr. Yaqi Li for their advices in data analysis.
Supplementary Material
This article contains supplementary material (https://doi.org/10.1515/mr-2024-0078).
Footnotes
Research ethics: Not applicable.
Informed consent: Not applicable.
Author contributions: FW and XG designed the study; FW, WY performed the literature search and data extraction; FW wrote the manuscript; KW double checked selected studies; LS supported the manuscript revision and performed quality assessment; DK and CW reviewed the manuscript with comments. All authors read and approved the final version.
Use of Large Language Models, AI and Machine Learning Tools: None declared.
Conflict of interest: The authors declare no competing interests.
Research funding: This umbrella review received Startup Grant (JIF201036Y and JIF201018Y).
Data availability: Data is available by request to the first author FW.
Contributor Information
Liang Sun, Email: sun_liang@fudan.edu.cn.
Xiang Gao, Email: xiang_gao@fudan.edu.cn.
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