The Dietary Inflammatory Index and Human Health: An Umbrella Review of Meta-Analyses of Observational Studies

Author(s):  
Wolfgang Marx ◽  
Nicola Veronese ◽  
Jaimon T Kelly ◽  
Lee Smith ◽  
Meghan Hockey ◽  
...  

ABSTRACT Numerous observational studies have investigated the role of the Dietary Inflammatory Index (DII®) in chronic disease risk. The aims of this umbrella review and integrated meta-analyses were to systematically synthesize the observational evidence reporting on the associations between the DII and health outcomes based on meta-analyses, and to assess the quality and strength of the evidence for each associated outcome. This umbrella review with integrated meta-analyses investigated the association between the DII and a range of health outcomes based on meta-analyses of observational data. A credibility assessment was conducted for each outcome using the following criteria: statistical heterogeneity, 95% prediction intervals, evidence for small-study effect and/or excess significance bias, as well as effect sizes and P values using calculated random effects meta-analyses. In total, 15 meta-analyses reporting on 38 chronic disease-related outcomes were included, incorporating a total population of 4,360,111 subjects. Outcomes (n = 38) were examined through various study designs including case-control (n = 8), cross-sectional (n = 5), prospective (n = 5), and combination (n = 20) study designs. Adherence to a pro-inflammatory dietary pattern had a significant positive association with 27 (71%) of the included health outcomes (P value < 0.05). Using the credibility assessment, Class I (Convincing) evidence was identified for myocardial infarction only, Class II (Highly suggestive) evidence was identified for increased risk of all-cause mortality, overall risk of incident cancer, and risk of incident site-specific cancers (colorectal, pancreatic, respiratory, and oral cancers) with increasing (more pro-inflammatory) DII score. Most outcomes (n = 31) presented Class III (Suggestive) or lower evidence (Weak or No association). Pro-inflammatory dietary patterns were nominally associated with an increased risk of many chronic disease outcomes. However, the strength of evidence for most outcomes was limited. Further prospective studies are required to improve the precision of the effect size.

2021 ◽  
Vol 8 ◽  
Author(s):  
Fang-Hua Liu ◽  
Chuan Liu ◽  
Ting-Ting Gong ◽  
Song Gao ◽  
Hui Sun ◽  
...  

Background and Aims: The dietary inflammatory index (DII) is associated with non-communicable disease. We conducted an umbrella review to systematically evaluate meta-analyses of observational studies on DII and diverse health outcomes.Methods: We comprehensively searched the PubMed, Web of Science, and Embase databases to identify related systematic reviews and meta-analyses of observational studies. Those investigating the association between DII and a wide range of health outcomes in humans were eligible for inclusion. For each meta-analysis, we estimated the summary effect size by using fixed and random effects models, the 95% confidence interval, and the 95% prediction interval. We assessed heterogeneity, evidence of small-study effects, and excess significance bias.Results: The umbrella review identified 35 meta-analyses assessing associations between DII and various health outcomes: cancer (n = 24), mortality (n = 4), metabolic (n = 4), and other (n = 3). The methodological quality was high or moderate. Of the 35 meta-analyses, we observed highly suggestive evidence for harmful associations between digestive tract cancer, colorectal cancer, overall cancer, pharyngeal cancer, UADT cancer, and CVD mortality. Moreover, 11 harmful associations showed suggestive evidence: hormone-dependent cancer, rectal cancer, colon cancer, breast and prostate cancer, gynecological cancer, breast cancer, ovarian cancer, colorectal cancer, prostate cancer, all-cause mortality, and depression.Conclusion: DII is likely to be associated with harmful effects in multiple health outcomes. Robust randomized controlled trials are warranted to understand whether the observed results are causal.Systematic Review Registration: CRD42021218361


BMJ Open ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. e031951
Author(s):  
Liqun Li ◽  
Jinjing Tan ◽  
Lijian Liu ◽  
Jianfeng Li ◽  
Guangwen Chen ◽  
...  

ObjectiveSystematic reviews and meta-analyses have revealed the associations betweenH. pyloriinfection and various health outcomes. We aimed to evaluate the strength and breadth of evidence on the associations.DesignUmbrella review of systematic reviews and meta-analyses.SettingNo settings.ParticipantsNo patients involved.Data sourcesEmbase, PubMed, Web of Science, Cochrane Library Databases, CNKI, VIP database and Wangfang database from inception to February 1, 2019.Outcomes measuresDiverse diseases (such as cancer and ischaemic heart disease).ResultsSixty articles reporting 88 unique outcomes met the eligible criteria. 74 unique outcomes had nominal significance (p<0.05). Of the outcomes with significance, 61 had harmful associations and 13 had beneficial associations. Furthermore, 73% (64) of the outcomes exhibited significant heterogeneity . Of the these meta-analyses, 32 had moderate to high heterogeneity (I2=50%–75%) and 24 had high heterogeneity (I2>75%). Moreover, 20% exhibited publication bias (p<0.1). In addition, 97% of the methodological qualities were rated ‘critically low’. 36% of the evidence qualities of outcomes were rated ‘low’, 56% of the evidence qualities were rated ‘very low’ and 8% of the evidence qualities were rated ‘moderate’.H. pyloriinfection may be associated with an increased risk of five diseases and a decreased risk of irritable bowel syndrome.ConclusionAlthough 60 meta-analyses explored 88 unique outcomes, moderate quality evidence only existed for six outcomes with statistical significance.H. pyloriinfection may be associated with a decreased risk of irritable bowel syndrome and an increased risk of hypertriglyceridemia, chronic cholecystitis and cholelithiasis, gestational diabetes mellitus, gastric cancer and systemic sclerosis.Trial registrationCRD42019124680.


2021 ◽  
Vol 8 ◽  
Author(s):  
Yin-hao Wang ◽  
Chen Huang ◽  
Yu-lin Tseng ◽  
Jing Zhong ◽  
Xue-min Li

Purpose: To explore the associations between refractive errors and multiple eye health outcomes.Methods: This is an umbrella review based on systematic reviews with meta-analyses. In our study, refractive errors included myopia, hyperopia, astigmatism, and anisometropia. We reconducted the meta-analyses whose primary data were available in sufficient detail by random effect model. Heterogeneity was assessed by I2. The main outcomes included myopic macular degeneration (MMD), retinal detachment (RD), cataract, open-angle glaucoma (OAG), strabismus, age-related macular degeneration (AMD), and diabetic retinopathy (DR).Results: Myopia was associated with increased risk of MMD (relative risk = 102.11, 95% CI 52.6–198.22), RD (3.45, 1.08–11.00), nuclear cataract (2.15, 1.53–3.03), posterior subcapsular (PSC) cataract (1.74, 1.41–2.15), OAG (1.95, 1.74–2.19), exotropia (5.23, 2.26–12.09), but decreased risk of DR (0.83, 0.66–1.04), and early AMD (0.80, 0.67–0.94). From mild-to-high myopia, the association strengthened for MMD, RD, nuclear cataract, PSC cataract, OAG, and DR. Hyperopia was associated with an increased risk of early AMD (1.09, 1.01–1.18) and esotropia (22.94, 10.20–51.62). Astigmatism and anisometropia were associated with increased risk of both exotropia and esotropia.Conclusions: Myopia, especially high myopia, demonstrated the highest risk for eye health outcomes, such as MMD, RD, OAG, nuclear and PSC cataracts, and exotropia. However, myopia was associated with a lower risk of early AMD and DR. Individuals with hyperopia are more likely to suffer early AMD and esotropia. Astigmatism and anisometropia predispose to strabismus. A lot of research studies on the mechanism of the associations are needed.Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=239744; identifier: 239744


2021 ◽  
Vol 8 ◽  
Author(s):  
Ya-Shu Liu ◽  
Qi-Jun Wu ◽  
Jia-Le Lv ◽  
Yu-Ting Jiang ◽  
Hui Sun ◽  
...  

Background and Aims: The associations between dietary carbohydrate and diverse health outcomes remain controversial and confusing. To summarize the existing evidence of the association between dietary carbohydrate intake and diverse health outcomes and to evaluate the credibility of these sources of evidence. We performed this umbrella review of evidence from meta-analyses of observational studies.Methods: PubMed, Embase, Web of Science databases, and manual screening of references up to July 2020 were searched. Systematic reviews with meta-analyses of observational studies in humans investigating the association between dietary carbohydrate intake and multiple health outcomes were identified. We assessed the evidence levels by using summary effect sizes, 95% prediction intervals, between-study heterogeneity, evidence of small-study effects, and evidence of excess significance bias for each meta-analysis.Results: We included 43 meta-analyses of observational research studies with 23 health outcomes, including cancer (n = 26), mortality (n = 4), metabolic diseases (n = 4), digestive system outcomes (n = 3), and other outcomes [coronary heart disease (n = 2), stroke (n = 1), Parkinson's disease (n = 1), and bone fracture (n = 2)]. This umbrella review summarized 281 individual studies with 13,164,365 participants. Highly suggestive evidence of an association between dietary carbohydrate intake and metabolic syndrome was observed with adjusted summary odds ratio of 1.25 [95% confidence interval (CI) 1.15–1.37]. The suggestive evidences were observed in associations of carbohydrate consumption with esophageal adenocarcinoma (0.57, 95% CI = 0.42–0.78) and all-cause mortality (adjusted summary hazard ratio 1.19, 95% CI = 1.09–1.30).Conclusions: Despite the fact that numerous systematic reviews and meta-analyses have explored the relationship between carbohydrate intake and diverse health outcomes, there is no convincing evidence of a clear role of carbohydrate intake. However, there is highly suggestive evidence suggested carbohydrate intake is associated with high risk of metabolic syndrome, suggestive evidence found its association with increased risk of all-cause mortality and decreased risk of esophageal adenocarcinoma.Systematic Review Registration: CRD42020197424.


2019 ◽  
Vol 70 (9) ◽  
pp. 1809-1815 ◽  
Author(s):  
Igor Grabovac ◽  
Nicola Veronese ◽  
Sinisa Stefanac ◽  
Sandra Haider ◽  
Sarah E Jackson ◽  
...  

Abstract Background Our aim was to assess both the credibility and strength of evidence arising from systematic reviews with meta-analyses of observational studies and physical health outcomes associated with human immunodeficiency virus (HIV) but not acquired immunodeficiency syndrome. Methods We performed an umbrella review of observational studies. Evidence was graded as convincing, highly suggestive, suggestive, weak, or nonsignificant. Results From 3413 studies returned, 20 were included, covering 55 health outcomes. Median number of participants was 18 743 (range 403–225 000 000). Overall, 45 (81.8%) of the 55 unique outcomes reported nominally significant summary results (P &lt; .05). Only 5 outcomes (9.0%; higher likelihood of presence of breathlessness, higher chronic obstructive pulmonary disease [COPD] prevalence, maternal sepsis, higher risk of anemia, and higher risk of all fractures among people living with HIV [PLWHIV]) showed suggestive evidence, with P values &lt; 10–3; only 3 (5.5%; higher prevalence of cough in cross-sectional studies, higher incidence of pregnancy-related mortality, and higher incidence of ischemic heart disease among PLWHIV in cohort studies) outcomes showed stronger evidence using a stringent P value (&lt;10–6). None of the unique outcomes presented convincing evidence (Class I), yet 3 outcomes presented highly suggestive evidence, 5 outcomes presented suggestive evidence, and 37 outcomes presented weak evidence. Conclusions Results show highly suggestive and suggestive evidence for HIV and the presence of a cough, COPD, ischemic heart disease, pregnancy-related mortality, maternal sepsis, and bone fractures. Public health policies should reflect and accommodate these changes, especially in light of the increases in the life expectancy and the incidence of comorbidities in this population.


2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
K Giannakou ◽  
T Pittara ◽  
D Lamnisos

Abstract Background Preeclampsia (PE) is a common pregnancy disease, linked with several complications during and after pregnancy. Although its pathogenesis is not completely understood, evidence suggests that PE has long-term health effects of both the mother and the offspring. Methods An umbrella review was performed to identify systematic reviews and meta-analyses on the association of PE with long-term health outcomes in women and infants born to pregnancies complicated with PE. We searched PubMed, EMBASE, Scopus and ISI Web of Science from inception to March 2019. For each meta-analysis we estimated the summary effect size by random-effects and fixed-effects models, the 95% confidence interval, the 95% prediction interval (PI), the between-study heterogeneity, evidence of small-study effects and evidence of excess significance bias. To evaluate the credibility of the published evidence we preferred state-of-the-art approaches of predefined criteria. Results Twenty-two eligible meta-analyses were identified providing data on 71 associations. Forty-nine (69%) associations had nominally statistically significant findings at P &lt; 0.05, while nineteen (27%) remain significant at P &lt; 10-6 under the random-effects model. Forty (56%) associations had large or very large heterogeneity. Evidence for small-study effects and excess significance bias was found in 4 (6%) and 7 (10%) associations, respectively. Only five associations presented robust evidence: cerebrovascular disease (cohort studies), cerebrovascular disease (overall), cardiac disease, cardiovascular mortality and attention deficit hyperactivity disorder (ADHD). These were supported by &gt; 1000 cases, 95% PI excluding the null, no large heterogeneity, small-study effects, or excess of significance. Conclusions Our findings suggest an increased risk for women to develop cerebrovascular, cardiovascular and cardiac diseases after a pregnancy complicated by PE, while offspring exposed to PE are at higher risk for ADHD. Key messages Our findings highlight the importance of promoting ongoing patient assessment practices for prevention and early diagnosis of these comorbidities. More research is required for the elevated risks of the reported outcomes to improve maternal health.


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