Table 2.
Characteristics of meta-analyses on egg intake and CVD and/or type 2 diabetes
| Reference | Objective | Database/Publ. years | Search terms*/Inclusion criteria | Included Studies | Statistical Analysis | Results | Quality rating† |
|---|---|---|---|---|---|---|---|
| Xu et al. 2018(39) | Update MAs on the associations of egg consumption with all-cause mortality and CVD-specific outcomes. |
Database: PubMed/MEDLINE Years: Jan. 2013–Aug. 2016. (to update previous MA by Li et al. 2013) |
Terms: egg, IHD, CHD, stroke, MI, CAD, all-cause, mortality Criteria: PC studies investigating egg intake and risk of IHD, stroke, or all-cause mortality |
Nine PC on IHD, nine PC on all stroke, five PC on haemorrhagic stroke, six PC on ischemic stroke. |
RR comparing highest to lowest intakes; fixed effect model when heterogeneity was low and random effects model when heterogeneity was high; Stata version 14.0 | No significant association of 7+ egg/week v. <1 egg/week for mortality from CVD [HR: 0·99 (0·76, 1·27)], IHD [HR: 0·92 (0·63, 1·36)], or stroke, [HR: 0·88 (0·57, 1·35)]. 7+eggs/week was not associated with risk of IHD [HR:0·97 (0·90, 1·05), ischemic stroke [HR: 0·91 (0·82, 1·01), or haemorrhagic stroke [HR: 0·88 (0·68, 1·14)], but a small reduction in risk of total stroke [HR: 0·91 (0·85, 0·98)]. | PRISMA: 79 % ROBIS: Low Bias AMSTAR2: 25 % |
| Zhang et al. 2018(31) | Examine the associations of red meat, poultry, and egg consumption with the risk of HTN |
Database: PubMed, Web of Science, Embase Years: through August 2017 |
Terms: HTN, blood pressure, meat, poultry, egg, poultry, cohort, incidence Criteria: PC studies reporting on red meat (unprocessed or processed), poultry, or egg intake and HTN |
Three PC on egg | Compared the highest to lowest egg intake; Stata version 11 | Egg consumption was significantly associated with lower risk of HTN [RR 0·79 (0·68, 0·91)]. | PRISMA: 96 % ROBIS: Low Bias AMSTAR2: 56 % |
| Bechthold et al. 2017(27) | Synthesize the data on twelve major food groups (whole grains, refined grains, vegetables, fruits, nuts, legumes, eggs, dairy, fish, red meat, processed meat, and sugar-sweetened beverages) and the risk of CHD, stroke, and HF |
Database: PubMed, Embase Years: through March 2017 (cross-referenced studies in other SR/MAs) |
Terms: food, whole grain, refined grain, cereal, pasta, rice, potato, vegetable, fruit, nut, legume, bean, egg, dairy, milk, yogurt, cheese, fish, seafood, meat, sugar sweetened beverage, CV, coronary, stroke, vascular, MI, HF Criteria: PC reporting association for at least one food group of interest in adults (≥18 y) and a CV outcome |
Eleven PC on CHD‡ten PC on stroke‡,§
four PC on HF‡ |
Compared different levels of intakes with Greenland and Longnecker method; random-effects model; Review Manager 5.3 and Stata version 14 software. | No association of egg intake and CHD risk [RR: 0·99 (0·94, 1·05)] or stroke [RR: 0·99 (0·93, 1·05)]. Positive association of egg intake and HF risk [RR: 1·25 (1·12, 1·39)]. No association for 50 g increments of daily egg intake and CHD risk [RR: 1·00 (0·95, 1·06)] or stroke [RR: 0·99 (0·93, 1·05)], but association with HF risk [RR: 1·16 (1·03, 1·31)]. | PRISMA: 100 % ROBIS: Low Bias AMSTAR2: 63 % |
| Khawaja et al. 2017(28) | Examine the association of egg consumption with incident HF in humans |
Database: PubMed, Cochrane, Google Scholar Years: published through May 2016. |
Terms: eggs, nutrition, heart failure Criteria: human, population-based PC published in English that compared incident HF event rates between two or more groups of egg intake |
Four PC on HF‡ | RR comparing the highest to the lowest category of egg consumption, random effects model, Comprehensive Meta-Analysis version 2.2.064 | Frequent egg intake (≥1/d) associated with increased HF incidence [RR: 1·25 (1·12, 1·39)]. | PRISMA: 83 % ROBIS: Low Bias AMSTAR2: 25 % |
| Schwingshackl et al. 2017(30) | Summarize the evidence on the relation of the intakes of twelve major food groups: whole grains, refined grains, vegetables, fruits, nuts, legumes, eggs, dairy, fish, red meat, processed meat, and sugar-sweetened beverages (SSB) with the risk of HTN. |
Database: PubMed, Scopus, Web of Science, Google Scholar Years: Published through June 2017 |
Terms: grain (whole, refined, etc.) cereal, vegetable, fruit, nut, legume, bean, egg, dairy, fish, seafood, meat, SSB, HTN, MetS, blood pressure Criteria: prospective, peer-reviewed, full-text available, includes ≥1 selected food group and HTN risk |
1 PC | RR comparing highest v. lowest egg intake; Random effect model; Dose-response analysis per Greenland and Longnecker; Review Manager 5.3 and Stata version 14 | Inverse association for highest v. lowest egg intake with HTN incidence [RR: 0·54 (0·32, 0·91)], or for each additional of 50 g/d [RR: 0·25 (0·08, 0·74)]. | PRISMA: 100 % ROBIS: Low Bias AMSTAR2: 56 % |
| Alexander et al. 2016(26) | Conduct an updated, comprehensive meta-analysis to estimate summary associations between egg consumption and CHD and stroke risk based on high v. low intakes |
Database: PubMed, Embase, Cochrane Years: published through August 2015.(update of Shin et al. 2013) |
Terms: eggs, dietary cholesterol, CVD, CHD, IHD, CAD, MI, HF, cerebrovascular, stroke, cholesterol Criteria: human PC or RCT published in English with RR and measures of variance for egg intake CV outcomes including CHD or stroke |
Nine PC on stroke§,||,¶, eight PC on CHD||,¶,** |
RR comparing highest v. lowest intake, Random-effects models, dose–response analysis, Comprehensive MA Software version 3.2.00089 | Consumption of approximately one egg a day was not associated with CHD risk [SRRE: 0·97 (0·88, 1·07)] and was instead, associated with decreased risk of stroke [SRRE: 0·88 (0·81, 0·97)]. | PRISMA: 88 % ROBIS: Low Bias AMSTAR2: 44 % |
| Rong et al. 2013(29) | To investigate and quantify the potential dose-responseassociation between egg consumption and risk of coronary heart disease and stroke |
Database: PubMed, Embase Years: Published prior to June 2012 |
Terms: CVD, CHD, MI, stroke, coronary disease, egg Criteria: PC on egg consumption and CHD or stroke relevant outcome reporting risks with 95 % CI for at least three quantitative categories of egg intake |
General population: seven PC on CHD||,¶,**, seven PC on stroke§,||. T2DM population: two PC on CHD||,¶, three PC on stroke¶. |
Risks for increases of 1 egg/d; Fixed effect model with negligible heterogeneity, Random effect model with significant heterogeneity; dose-response using Greenland and Longnecker method; Stata version 11.0 | No association of an increase of 1 egg/d with risks of CHD [RR: 0·99 (0·85, 1·15), total stroke [RR: 0·91 (0·81, 1·02)], fatal stroke [RR: 0·94 (0·80, 1·10)], or ischemic stroke [RR: 0·91 (0·82, 1·01)]. Increase of 1 egg/d significantly decreased haemorrhagic stroke risk [RR: 0·75 (0·57, 0·99)]. In T2DM population, increase of 1 egg/d significantly increased CHD risk [RR: 1·54 (1·14, 2·09)]. No significant effect of 1 egg/d increase on total stroke [RR: 0·80 (0·29, 2·15)]. |
PRISMA: 92 % ROBIS: Low Bias AMSTAR2: 63 % |
| Shin et al. 2013(15) | Quantitatively summarize the literature on egg consumption and risk of CVD, cardiac mortality, and type 2 diabetes | Database: PubMed, Embase Years: Published through March 2012 |
Terms: egg, CVD, CHD, MI, stroke, mortality/death, diabetes mellitus Criteria: human PC study published in English reporting HR with 95 % CI on egg intake (as per egg or g/d, not continuous) and CVD, mortality, or T2DM providing |
General population: two PC on CVD, five PC on IHD**, five PC on stroke, five PC on T2DM. T2DM population:four PC on CVD††. |
HRs comparing highest v. lowest egg intake; Random-effects model; Stata version 11 | No significant effect of high egg intake (≥1 egg/d) on risks of overall CHD [HR: 0·96 (0·88, 1·05)], IHD [HR: 0·97 (0·86, 1·09)], stroke [HR: 0·93 (0·81, 1·07)], IHD mortality [HR: 0·98 (0·77, 1·24)], or stroke mortality [HR: 0·92 (0·56, 1·50)]. In T2DM population, significant association of high egg intake with increased overall CVD risk [HR: 1·69 (1·09, 2·62). Increased risk for T2DM with high egg consumption [RR: 1·68 (1·41, 2·00)]. |
PRISMA: 92 % ROBIS: Low Bias AMSTAR2: 44 % |
| Li et al. 2013(14) | Assess the dose-response relationship between egg consumption and the risk of CVD and diabetes |
Database: MEDLINE Years: Published through Dec 2012 |
Terms: egg or egg consumption, diet cholesterol, CVD, diabetes, mortality, coronary heart disease, heart failure Criteria: cohort, case-control or cross-sectional on CVD (e.g. CHD, IHD, HF) or diabetes risk, reporting multi-variable adjusted risks with 95 % CI using lowest egg intake as reference; excluded studies in special populations (e.g. pregnant women) |
General population: ten PC¶,** and one cross-sectional on CVD, three PC‡‡,§§, one cross-sectional‖‖, and one case-control on T2DM. T2DM population: six PC** on CVD. |
RR of highest v. lowest egg intake; Fixed effect model with negligible heterogeneity, Random effect model with significant heterogeneity; dose-response using Greenland and Longnecker method; Stata version 10.0 | Significant association of high v. low egg intake on increased CVD risk [RR: 1·19 (1·02, 1·38)]. In T2DM population, significant association of high egg intake with increased overall CVD risk [RR: 1·83 (1·42, 2·37)]. Increased T2DM risk with high egg intake [HR: 1·42 (1·09, 1·86)]. No differences between studies conducted in US v. non-US populations. |
PRISMA: 88 % ROBIS: High Bias AMSTAR2: 44 % |
| Djousse et al. 2016(34) | Evaluate the relation of egg consumption with the risk of T2DM |
Database: PubMed, Ovid, Cochrane, Google Scholar Years: Published through October 2015. |
Terms: egg(s), diabetes/ diabetic Criteria: human PC studies published in English and reporting association between egg intake and incident T2DM |
Nine PC‡‡,§§,‖‖,¶¶ | RR comparing highest v. lowest egg intake; Both fixed and random estimates of effects; Stata version 13.1 | No association of high (<4 eggs/week) egg intake with T2DM risk [RR: 1·09 (0·99, 1·20, fixed-effect; RR: 1·06 (0·86, 1·30, random-effect]. Stratified analysis showed increased T2DM risk with ≥3 eggs/week for US-based studies [RR: 1·39 (1·21, 1·60)], but not in non-US-studies [RR: 0·89 (0·79, 1·02)]. | PRISMA: 88 % ROBIS: Low Bias AMSTAR2: 31 % |
| Tamez et al. 2016(36) | Quantify the association betweenhabitual egg intake and risk of T2DM |
Database: MEDLINE, Embase, EBSCOhost Years: Published through June 2015. |
Terms: egg(s), animal food, diabetes mellitus, diabetes Criteria: PC studies reporting multi-variable-adjusted RR on egg intake and T2DM risk in adults |
Twelve PC‡‡,§§,***,††† | RR for an increased intake of one egg per day for each report, random-effects model, Stata 11.2 for Mac | Increases of 1 egg/d associated with 13 % higher T2DM risk [RR: 1·13 (1·32, 1·64)]. Stratified analysis indicated 47 % higher risk with US studies [RR: 1·47 (1·32, 1·64)], but not significant for non-US studies [RR: 0·95 (0·83, 1·10)]. | PRISMA: 92 % ROBIS: Low Bias AMSTAR2: 63 % |
| Wallin et al. 2016(38) | Summarize available prospective evidence on the association between egg consumption and T2DM risk | Database: PubMed Years: Published through December 2015. |
Terms: egg, diabetes Criteria: PC studies reporting T2DM risk estimates by egg intake amounts |
13 PC‡‡,§§,‖‖,¶¶ | HR for each 3×/week egg increments; Random-effects model, Stata (version not reported) | No association between 3 eggs/week and T2DM [HR: 1·03 (0·96, 1·10)] overall, but significant when only studies in US included in analysis [HR: 1·18 (1·13, 1·24)] v. non-US studies [HR: 0·97 (0·90, 1·05)]. | PRISMA: 88 % ROBIS: High Bias AMSTAR2: 38 % |
| Tian et al. 2017(37) | Clarify the association of protein consumption with risk of T2DM | Database: PubMed, Embase Years: Published through 2017 | Terms: protein (dietary, plant, animal), diabetes, T2DM, human, red meat, processed meat, fish, seafood, egg, dairy, milk, yogurt, soy, legume, soy Criteria: cohort on T2DM incidence or mortality reporting RR and 95 % CI, intakes of dietary protein or other high-protein foods such as meat, fish, egg, dairy, soy |
6 PC‡‡,§§ | Summary RRs and 95 % CI comparing highest to lowest dietary protein intakes; Fixed model with no heterogeneity; Random model heterogeneity present; Comprehensive MA V2 | High v. low egg intakes were not associated with T2DM risk [RR: 1·03 (0·64, 1·67)]. | PRISMA: 88 % ROBIS: Low Bias AMSTAR2: 31 % |
| Schwingshackl et al. 2017(35) | Synthesize the knowledge about the relation between intake of twelve major food groups and risk of T2DM |
Database: PubMed/ MEDLINE (Ovid), Embase, Cochrane Central, Google Scholar Years: Published through Feb. 2017 |
Terms: grain (whole, refined, etc.) cereal, vegetable, fruit, nut, legume, bean, egg, dairy, fish, seafood, meat, SSB, diabetes Criteria: prospective, peer-reviewed, full-text available, includes ≥1 selected food group and T2DM risk; subjects ≥18 y free of T2DM at onset |
13 PC‡‡,§§ | RR comparing highest v. lowest egg intake; Random effect model; Dose-response analysis per Greenland and Longnecker; Review Manager 5.3 and Stata version 14 | No significant association for highest v. lowest egg intake [RR: 1·08 (0·95, 1·22)], or for each additional of 30 g/d [RR: 1·08 (0·95, 1·22)] with T2DM risk. Positive association for US-only studies in dose–response analysis, but not for Asian and European studies. |
PRISMA: 96 % ROBIS: Low Bias AMSTAR2: 69 % |
| Rouhani et al. 2017(32) | Conduct a meta-analysis of published RCTs to explore the quantitative effect of egg consumption on serum lipid concentrations |
Database: Medline, Proquest, Google Scholar Years: Published from Jan. 1999 to Nov. 2016. |
Terms: egg(s), cholesterol, HDL, LDL, TG, lipoprotein, hypercholesterolemia, Criteria: compared egg intake with egg substitute or no-egg diet for whole eggs (no egg whites only), regular eggs (not enriched), in healthy adults reporting fasting lipid profile (not postprandial lipid) |
27 RCTs | Effect size, Random-effects model, Stata version 11.0. | Significant association of egg intake with increased tChol [ES: 5·60 mg/dl (3·11, 8·09)], LDL-C [ES: 5·55 mg/dl (3·41, 7·69)], and HDL-C [ES: 2·13 mg/dl (1·10, 3·16)]. No significant association for tChol/HDL-C [ES: -0·01 (−0·08, 0·07)], LDL-C/HDL-C [ES: 0·16 (−0·28, 0·59)], or TG [ES: −0·43 mg/dl (−3·77, 2·92)]. | PRISMA: 96 % ROBIS: Low Bias AMSTAR2: 56 % |
| Schlesinger 2019(33) | Investigate the potential associations between twelve predefined food groups, including eggs, and the risk of overweight/obesity, abdominal obesity, and weight gain |
Database: PubMed, Web of Science
Years: Published through Aug. 2018 |
Terms: grain (whole, refined, etc.) cereal, pasta, rice, vegetable, fruit, nut, legume, bean, egg, dairy, yogurt, milk, cheese, fish, seafood, meat, SSB, body weight, obesity, overweight, adiposity, waist circumference, abdominal fat, waist to hip Criteria: prospective, peer-reviewed, full-text available, includes ≥1 selected food group and general overweight/obesity, abdominal obesity, or weight gain; subjects ≥18 y |
1 PC | RR comparing highest v. lowest egg intake; Random effect model; Dose-response analysis per Greenland and Longnecker; Review Manager 5.3 and Stata version 14 | No significant association for highest v. lowest egg intake [RR: 0·97 (0·59, 1·59)], or for each additional of 50 g/d [RR: 0·95 (0·63, 1·43)] with abdominal obesity. | PRISMA: 100 % ROBIS: Low Bias AMSTAR2: 63 % |
CAD, coronary artery disease; CV, cardiovascular; d, day; dL, deciliter; ES, effect size; g, gram; HDL-C, high-density lipoprotein cholesterol; HF, heart failure; HR, hazard ratio; HTN, hypertension; LDL-C, low-density lipoprotein cholesterol; MA(s), meta-analysis(es); mg, milligram; PC, prospective cohort; PRISMA, preferred reporting items for systematic reviews and meta-analyses; RCT, randomized controlled trial; ROBIS, risk of bias in systematic reviews; RR, relative risk; SSB, sugar-sweetened beverage; SR, systematic review; SRRE, summary relative risk estimates; T2DM, type-2 diabetes mellitus; tChol, total-cholesterol; TG, triglycerides.
*
Terms summarized for comparison of scope or search. See specific reports for full list of search terms and combinations.
†
Each PRISMA and AMSTAR2 required checklist items were assigned 1 point if reported in the manuscript and 0 if not, with maximum achievable scores of 24 and 16 points, respectively. The scores were adjusted as a percentage of the maximum available points.
‡
Two cohorts (Swedish Mammography Cohort and Cohort of Swedish Men) were analysed separately and included in one report (Larsson et al., 2013).
§
Two cohorts (Health Professionals Follow-Up Study and Nurses’ Health Study) were analysed separately and included in one report (Bernstein et al. 2012).
||
Males and females from the same cohort were analysed separately in one report (Nakamura et al. 2004).
¶
Males and females from the same cohort were analysed separately in one report (Scrafford et al. 2010).
**
Two cohorts (Health Professionals Follow-Up Study and Nurses’ Health Study) were analysed separately and included in one report (Hu et al. 1994).
††
Males and females from the same cohort were analysed separately in one report (Qureshi et al. 2007).
‡‡
Two cohorts (Physicians’ Health Study I and Women’s Health Study) were analysed separately and included in one report (Djousse et al. 2009).
§§
Males and females from the same cohort were analysed separately in one report (Djousse et al. 2010).
||||
Males and females from the same sample were analysed separately in one report (Shi et al. 2011).
¶¶
Males and females from the same cohort were analysed separately in one report (Djousse et al. 2015).
***
Males and females from the same cohort were analysed separately in one report (Kurotani et al. 2014).
†††
Two cohorts were analysed together and included in one report (Vang et al. 2008).