Vitamin D status and cognitive performance in community-dwelling adults: A dose-response meta-analysis of observational studies.

Low vitamin D status is linked with poorer cognition in adults while findings in relation to high levels are mixed.We performed a systematic review and meta-analyses to examine dose-response associations between 25-hydroxyvitamin D (25OHD) levelsand cognitive performance in community-dwelling adults. Thirty-eight observational studies were included in dose-response meta-analyses. Positive, nonlinear associations were identified between baseline25OHD levels and global cognition incross-sectional and longitudinal analyses, and for performance in memory and executive function in longitudinal analyses. When restricted to studies involving older adults, thepattern emerged forspecific domains in cross-sectional analyses. Poorer performance was associated with low 25OHD levels, while a sharp improvement was associated withlevels up to 60-70 nM/L. Further improvement was observed only for longitudinal global cognition. Our findings support the association between low vitamin D and poorer cognition and suggest levels of at least 60 nM/L are associated with better cognition during ageing.

The influence of n-3 polyunsaturated fatty acids on cognitive function in individuals without dementia: a systematic review and dose-response meta-analysis.

BACKGROUND: Omega-3 polyunsaturated fatty acids (n-3 PUFA) have been suggested as a cognitive enhancing agent, though their effect is doubtful. We aimed to examine the effect of n-3 PUFA on the cognitive function of middle-aged or older adults without dementia. METHODS: We reviewed randomized controlled trials of individuals aged 40 years or older. We systematically searched PubMed/MEDLINE, EMBASE, CINAHL, PsycINFO, and Cochrane Library databases. We used the restricted cubic splines model for non-linear dose-response meta-analysis in terms of the standardized mean difference with 95% confidence intervals. RESULTS: The current meta-analysis on 24 studies (n 9660; follow-up 3 to 36 months) found that the beneficial effect on executive function demonstrates an upward trend within the initial 12 months of intervention. This effect is prominently observed with a daily intake surpassing 500 mg of n-3 PUFA and up to 420 mg of eicosapentaenoic acid (EPA). Furthermore, these trends exhibit heightened significance in regions where the levels of blood docosahexaenoic acid (DHA) + EPA are not very low. CONCLUSIONS: Supplementation of n-3 PUFA may confer potential benefits to executive function among the middle-aged and elderly demographic, particularly in individuals whose dietary DHA + EPA level is not substantially diminished.

Postoperative pain and neurocognitive outcomes after noncardiac surgery: a systematic review and dose-response meta-analysis.

BACKGROUND: Postoperative delirium (POD) and postoperative cognitive dysfunction (POCD) are common after noncardiac surgery. Postsurgical pain is frequent and can persist as chronic postsurgical pain (CPSP). The association between postsurgical pain and POD or POCD is biologically plausible. We conducted this systematic review to evaluate the association between acute postsurgical pain or CPSP and POD or POCD in adults undergoing noncardiac surgery. METHODS: We followed Preferred Reporting Items for Systematic Review and Meta-Analyses. We searched MEDLINE, EMBASE, Cochrane, CINAHL and PSYCHINFO up to May 2023. We included cohort, case-control, and cross-sectional studies of any language. Pairs of reviewers independently screened studies, extracted data and assessed the risk of bias using the CLARITY tool and the Joanna Briggs Institute checklist. We assessed the certainty of evidence using the Grading of Recommendations Assessment, Development, and Evaluation approach. Where possible, we conducted random-effects meta-analyses to summarise our findings. RESULTS: We analysed 30 studies (>9000 participants) that assessed the association between acute postoperative pain and POD/POCD. Dose-response meta-analyses found that postoperative pain intensity was associated with occurrence of POD (adjusted relative risk [aRR]/unit of pain intensity: 1.26; 95% confidence interval [CI]: 1.17-1.35; low certainty of evidence) and risk of developing POD (aRR/unit of pain intensity: 1.18; 95% CI: 1.08-1.30; low certainty of evidence). There was very low certainty of evidence regarding the association between postoperative pain and POCD. No studies assessed the association between CPSP and POCD. Residual confounding and substantial methodological variability between studies prevented pooling data from many of the included studies and lowered certainty of evidence. CONCLUSIONS: Dose-response meta-analyses found that postoperative pain intensity was associated with occurrence of and risk of developing POD. SYSTEMATIC REVIEW PROTOCOL: PROSPERO-CRD42021192105.

Cadmium exposure and risk of hypertension: a systematic review and dose-response meta-analysis.

BACKGROUND: Exposure to environmental toxic metals represents a significant global public health concern. Many studies have reported that cadmium (Cd) exposure increases the risk of hypertension. Since the shape of such relation has not been well characterized, we assessed it by performing a systematic review and dose-response meta-analysis of human studies. METHODS: We searched the literature through September 5, 2024 to identify papers related to Cd, hypertension, and blood pressure. Inclusion criteria were: observational design, adult population, assessment of exposure using Cd biomarkers, and availability of exposure category-specific risk estimates for hypertension. We performed a dose-response meta-analysis of the results from included studies. RESULTS: Of the 18 studies published between 2006-2024, most had a cross-sectional design. Cd was measured in whole blood and/or urine in almost all studies, whereas only two studies measured Cd in serum. The dose-response meta-analysis indicated an almost linear relation between urinary Cd concentrations and hypertension risk with RR=1.18, 95% CI 1.02-1.37 at 2.0 µg/g creatinine compared with no exposure. In contrast, the association between blood Cd concentrations and hypertension risk was non-linear: there was a steep monotonic increase in risk for Cd concentrations below 2 µg/L, reaching a RR of 1.48 (95% CI 1.17-1.86) at 2.0 µg/L, after which a plateau seemed reached. We found similar trends when restricting to studies of Asian population, while when considering North American studies, hypertension risk increased above 1.0 µg/g creatinine. CONCLUSIONS: In this dose-response meta-analysis, risk of hypertension showed a non-linear positive association with blood Cd concentrations and a linear positive association with urinary Cd concentrations. Inconsistency in the shape of associations could relate to the different timing of exposure assessed by the biomarkers or the alteration Cd excretion at increasing exposure levels. Mitigation of Cd exposure is confirmed as a public health priority for chronic disease prevention.

Artificially sweetened beverage consumption and all-cause and cause-specific mortality: an updated systematic review and dose-response meta-analysis of prospective cohort studies.

BACKGROUND: Artificially sweetened beverages (ASB) are consumed globally, but their impact on overall health remains uncertain. We summarized published associations between ASB intake with all-cause and cause-specific mortality. METHODS: We searched Medline, Embase, Web of Science, and Cochrane CENTRAL databases until August 2023. Random effect meta-analysis was conducted to calculate pooled risk ratios (RRs) and 95% confidence intervals (95%CIs) for highest versus lowest categories of ASB consumption in relation to all-cause and cause-specific mortality. Linear and non-linear dose-response analyses were also performed. RESULTS: Our systematic review and meta-analysis included 11 prospective cohort studies. During a median/mean follow-up period of 7.0 to 28.9 years, 235,609 deaths occurred among 2,196,503 participants. Intake of ASB was associated with higher risk of all-cause and CVD mortality with pooled RRs (95%CIs) of highest vs. lowest intake categories of 1.13 (1.06, 1.21) (I2 = 66.3%) for all-cause mortality and 1.26 (1.10, 1.44) (I2 = 52.0%) for CVD mortality. Dose-response analysis revealed a non-linear association of ASB with all-cause mortality (pnon-linearity = 0.01), but a linear positive association with CVD mortality (pnon-linearity = 0.54). No significant association was observed for ASB intake and cancer mortality. Moreover, a secondary meta-analysis demonstrated that replacing 1 serving/day of sugary sweetened beverages (SSB) with ASB was associated with 4-6% lower risk of all-cause and CVD mortality. Per NutriGrade, the evidence quality for associations between ASB intake with all-cause and CVD mortality was moderate. CONCLUSIONS: Higher intake of ASB was associated with higher risk of all-cause and CVD mortality, albeit a lower risk than for SSB. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration no. CRD42022365701.

The severity of intrahepatic cholestasis during pregnancy increases risks of adverse outcomes beyond stillbirth: evidence from 15,826 patients.

BACKGROUND: What kinds of fetal adverse outcomes beyond stillbirth directly correlate to the severity of intrahepatic cholestasis during pregnancy (ICP) remained tangled. Herein, we conducted a retrospective cohort study and a dose-response meta-analysis to speculate the association between the severity of ICP and its adverse outcomes. METHODS: We retrospectively collected a cohort of ICP patients from electronic records from Guangzhou Women and Children's Medical Center between Jan 1st, 2018, and Dec 31st, 2022. Also, we searched PubMed, Cochrane, Embase, Scopus, and Web of Science to extract prior studies for meta-analysis. The Kruskal-Wallis test, a one-way or two-way variants analysis (ANOVA), and multi-variant regression are utilized for cohort study. One stage model, restricted cubic spline analysis, and fixed-effect model are applied for dose-response meta-analysis. The data analysis was performed using the R programme. RESULTS: Our cohort included 1,289 pregnant individuals, including 385 mild ICP cases, 601 low moderate ICP cases, 282 high moderate ICP cases, and 21 severe ICP cases. The high moderate bile acid levels were correlated to preterm birth [RR = 2.14, 95%CI 1.27 to 3.62), P < 0.01], and preterm premature rupture of membranes [RR = 0.34, 95%CI 0.19 to 0.62), P < 0.01]. We added our cases to cases reported by other studies included in the meta-analysis. There were 15,826 patients included in dose-response meta-analysis. The severity of ICP was associated with increased risks of stillbirth, spontaneous preterm birth, iatrogenic preterm birth, preterm birth, admission to neonatal intensive care unit, and meconium-stained fluid (P < 0.05). CONCLUSIONS: Our study shows the correlation between the severity of ICP and the ascending risks of stillbirth, preterm birth, and meconium-stained fluid, providing new threshold TBA levels. PROSPERO REGISTRATION NUMBER: CRD42023472634.

Effects of selected dietary supplements on migraine prophylaxis: A systematic review and dose-response meta-analysis of randomized controlled trials.

BACKGROUND: The existing evidence on the effect of dietary supplements for preventing migraines has generated conflicting results. METHODS: We assessed alterations in migraine clinical features corresponding to the intake of dietary supplements. Our main outcomes included the frequency (number of attacks), duration (in hours), the severity (intensity) and the monthly migraine days. Using a dose-response meta-analysis, we estimated the dose-dependent impact. The certainty of evidence was evaluated using the GRADE tool. RESULTS: Finally, twenty-two trials were included in the systematic review and meta-analysis. Magnesium supplementation reduced migraine attacks (mean difference (MD) = -2.51), severity (MD = -0.88), and the monthly migraine days (MD = -1.66) compared with the control group. CoQ10 decreased the frequency (MD = -1.73), severity (MD = -1.35), and duration of migraine (MD = -1.72). Riboflavin decreased attack frequency (MD = -1.34). Alpha-lipoic acid decreased attack frequency (MD = -1.24) and severity (MD = -0.38). Probiotics decreased the frequency (MD = -1.16), severity (MD = -1.07) and the monthly migraine days (MD = -3.02). Vitamin D reduced migraine frequency (MD = -1.69) and the monthly migraine days (MD = -2.41). In adults, compared with placebo, these supplements did not significantly affect other outcomes, and omega-3 supplementation did not yield a statistically significant reduction in any of these outcomes. CONCLUSION: The use of certain dietary supplements has resulted in a significant decrease in migraine prophylaxis. Further clinical trials of high quality appear to be beneficial.

Aerobic exercise training and obstructive sleep apnea: dose-response meta-analyses.

PURPOSE: Several studies have shown that aerobic exercise training improves obstructive sleep apnea (OSA) severity. However, a dose-response relationship has never been shown. This study aimed to quantify any dose-response relationships between time spent per week in aerobic exercise and key sleep apnea outcomes. METHODS: Randomized controlled trials (RCT) were selected from literature search studying the effects of supervised aerobic exercise training on patients with OSA. Dose-response meta-analyses were performed, where the 'dose' was the total weekly duration of aerobic exercise training. Primary outcomes were apnea hypopnea index (AHI), cardiorespiratory fitness (maximum oxygen consumption or VO2peak) and Epworth Sleepiness Scale (ESS). RESULTS: Analysis of data from 11 RCTs showed a non-linear dose-response relationship between the total weekly duration of aerobic exercise training and mean differences in AHI. Maximum effects on AHI (-10.92 (95%CIs: -15.57; -6.27)) were observed when the weekly duration of aerobic exercise reached 100 min/week. Similar non-linear dose-response trend was observed in the mean differences in VO2peak. Studies in which aerobic exercise training lasted ≥ 12 weeks showed greater proportional changes in mean AHI differences with maximal effects reaching a peak at ∼ 70 min/week of aerobic exercise training. ESS and total weekly duration of aerobic exercise training showed a linear dose-response relationship based on 4 RCTs. CONCLUSIONS: Based on these analyses, aerobic exercise training of 70-100 min/week over 3 or 5 days a week should be recommended as adjunctive treatment for patients with OSA.

Association of dietary glycemic index and glycemic load with the risk of gestational diabetes mellitus: a systematic review and dose-response meta-analysis.

OBJECTIVE: To comprehensively assess the dose-response association between dietary glycemic index (GI) and glycemic load (GL) and gestational diabetes mellitus (GDM) risk. METHODS: PubMed, Embase, Cochrane Library, Web of Science, CNKI, WanFang, and VIP databases were searched up to May 29, 2024. Studies with at least three exposure categories were included. Dose-response analysis was also performed when covariates were adjusted in the included studies. RESULTS: Thirteen studies involving 39,720 pregnant women were included. A linear relationship was found between GI and the risk of GDM (χ2 = 4.77, Pnon-linearity = .0923). However, association was not significant (χ2 = 0.06, p = .8000). For every unit increase in GI (range 0-30), GDM risk increased by 0.29%. After adjusting for covariates, the linear relationship persisted (χ2 = 4.95, Pnon-linearity = .084) with no significant association (χ2 = 0.08, p = .7775). For GL, a linear relationship was also found (χ2 = 4.17, Pnon-linearity =.1245), but GL was not significantly associated with GDM risk (χ2 = 2.63, p = .1049). The risk of GDM increased by 0.63% per unit increase in GL. After covariate adjustment, a significant association was observed (χ2 = 6.28, p = .0122). CONCLUSION: No significant association between GI and GDM risk was found. After adjusting for covariates, GL shows a significant association with GDM risk. Our findings emphasize the importance of considering dietary GL in managing the risk of GDM. Future research should continue to explore these relationships with standardized diagnostic criteria and robust adjustment for potential confounders.

Night shift work and female breast cancer: a two-stage dose-response meta-analysis for the correct risk definition.

INTRODUCTION: The hypothesis of this study is night shift work exposure can increase the risk of female breast cancer. To validate this hypothesis, the authors conducted a two-stage dose-response meta-analysis with improved quality on this topic. METHODS: The medical librarian searched PubMed, EMBASE, and the Cochrane Library on December 30th, 2022. The eight inclusion criteria were determined and strictly applied to the selection process. A reliable dose-response meta-analysis methodology was applied. RESULTS: Reliable 10 cohort (total cases: 15,953, and total person-years: 6,812,138) and 11 case-control reports (total cases: 9196, and total controls:12,210) were included in the final analysis. The pooled risk ratio (RR) of female breast cancer (from cohort studies) for 1, 10, 20, and 30 years of night shift work exposure was 1.0042 (95% CI 1.0014-1.0070), 1.0425 (95% CI 1.0138-1.0719), 1.0867 (95% CI 1.0278-1.1490), and 1.1328 (95% CI 1.0419-1.2317), respectively. The pooled odds ratio (OR) of female breast cancer (from case-control studies) for 1, 10, 20, and 30 years of night shift work exposure was 1.0213 (95% CI 1.0108-1.0319), 1.2346 (95% CI 1.1129-1.3695), 1.5242 (95% CI 1.2386-1.8756), and 1.8817 (95% CI 1.3784-2.5687), respectively. DISCUSSION: This study has several strengths from the perspective of a dose-response meta-analysis: Strictly applied eight inclusion criteria, separately synthesized RRs from cohort studies and ORs from case-control studies, clearly defined exposure dose, years of night shift work for each risk estimate, a reliable dose-response meta-analysis methodology, and careful considering of selection, exposure, and outcome biases and confounder adjustment for each study. This careful consideration of potential biases and confounding led to the exclusion of unreliable two cohort and five case-control studies.

Exposure to disinfection by-products and risk of cancer: A systematic review and dose-response meta-analysis.

Disinfection by-products (DBPs), including trihalomethanes (THMs) and haloacetic acids (HAAs), have attracted attention due to their carcinogenic properties, leading to varying conclusions. This meta-analysis aimed to evaluate the dose-response relationship and the dose-dependent effect of DBPs on cancer risk. We performed a selective search in PubMed, Web of Science, and Embase databases for articles published up to September 15th, 2023. Our meta-analysis eventually included 25 articles, encompassing 8 cohort studies with 6038,525 participants and 10,668 cases, and 17 case-control studies with 10,847 cases and 20,702 controls. We observed a positive correlation between increased cancer risk and higher concentrations of total trihalomethanes (TTHM) in water, longer exposure durations, and higher cumulative TTHM intake. These associations showed a linear trend, with relative risks (RRs) and 95 % confidence intervals (CIs) being 1.02 (1.01-1.03), 1.04 (1.02-1.06), and 1.02 (1.00-1.03), respectively. Gender-specific analyses revealed slightly U-shaped relationships in both males and females, with males exhibiting higher risks. The threshold dose for TTHM in relation to cancer risk was determined to be 55 µg/L for females and 40 µg/L for males. A linear association was also identified between bladder cancer risk and TTHM exposure, with an RR and 95 % CI of 1.08 (1.05-1.11). Positive linear associations were observed between cancer risk and exposure to chloroform, bromodichloromethane (BDCM), and HAA5, with RRs and 95 % CIs of 1.02 (1.01-1.03), 1.33 (1.18-1.50), and 1.07 (1.03-1.12), respectively. Positive dose-dependent effects were noted for brominated THMs above 35 µg/L and chloroform above 75 µg/L. While heterogeneity was observed in the studies for quantitative synthesis, no publication bias was detected. Exposure to TTHM, chloroform, BDCM, or HAA5 may contribute to carcinogenesis, and the risk of cancer appears to be dose-dependent on DBP exposure levels. A cumulative effect is suggested by the positive correlation between TTHM exposure and cancer risk. Bladder cancer and endocrine-related cancers show dose-dependent and positive associations with TTHM exposure. Males may be more susceptible to TTHM compared to females.

The effects of citrus flavonoids supplementation on endothelial function: A systematic review and dose-response meta-analysis of randomized clinical trials.

The present systematic review and dose-response meta-analysis was conducted to synthesize existing data from randomized clinical trials (RCTs) concerning the impact of citrus flavonoids supplementation (CFS) on endothelial function. Relevant RCTs were identified through comprehensive searches of the PubMed, ISI Web of Science, and Scopus databases up to May 30, 2023. Weighted mean differences and their corresponding 95% confidence intervals (CI) were pooled utilizing a random-effects model. A total of eight eligible RCTs, comprising 596 participants, were included in the analysis. The pooled data demonstrated a statistically significant augmentation in flow-mediated vasodilation (FMD) (2.75%; 95% CI: 1.29, 4.20; I2 = 87.3%; p < 0.001) associated with CFS compared to the placebo group. Furthermore, the linear dose-response analysis indicated that each increment of 200 mg/d in CFS led to an increase of 1.09% in FMD (95% CI: 0.70, 1.48; I2 = 94.5%; p < 0.001). The findings from the nonlinear dose-response analysis also revealed a linear relationship between CFS and FMD (Pnon-linearity = 0.903, Pdose-response <0.001). Our findings suggest that CFS enhances endothelial function. However, more extensive RTCs encompassing longer intervention durations and different populations are warranted to establish more precise conclusions.

Plasma total cholesterol concentration and risk of higher-grade prostate cancer: A nested case-control study and a dose-response meta-analysis.

Our previous publication found an increased risk of higher-grade (Gleason sum ≥7) prostate cancer for men with high total cholesterol concentration (≥200 mg/dl) in the Health Professionals Follow-up Study (HPFS). With additional 568 prostate cancer cases, we are now able to investigate this association in more detail. For the nested case-control study, we included 1260 men newly diagnosed with prostate cancer between 1993 and 2004, and 1328 controls. For the meta-analyses, 23 articles studied the relationship between total cholesterol level and prostate cancer incidence were included. Logistic regression models and dose-response meta-analysis were performed. An increased risk of higher-grade (Gleason sum ≥4 + 3) prostate cancer for high vs low quartile of total cholesterol level was observed in the HPFS (ORmultivariable = 1.56; 95% CI = 1.01-2.40). This finding was compatible with the association noted in the meta-analysis of highest vs lowest group of total cholesterol level, which suggested a moderately increased risk of higher-grade prostate cancer (Pooled RR =1.21; 95%CI: 1.11-1.32). Moreover, the dose-response meta-analysis indicated that an increased risk of higher-grade prostate cancer occurred primarily at total cholesterol levels ≥200 mg/dl, where the RR was 1.04 (95%CI: 1.01-1.08) per 20 mg/dl increase in total cholesterol level. However, total cholesterol concentration was not associated with the risk of prostate cancer overall either in the HPFS or in the meta-analysis. Our primary finding, as well as the result of the meta-analysis suggested a modest increased risk of higher-grade prostate cancer, at total cholesterol concentrations exceeding 200 mg/dl.

Association of soft drinks and 100% fruit juice consumption with risk of cancer: a systematic review and dose-response meta-analysis of prospective cohort studies.

BACKGROUND: Studies of the associations between soft drinks and the risk of cancer showed inconsistent results. No previous published systematic reviews and meta-analysis has investigated a dose-response association between exposure dose and cancer risk or assessed the certainty of currently available evidence. Therefore, we aim to demonstrate the associations and assessed the certainty of the evidence to show our confidence in the associations. METHODS: We searched Embase, PubMed, Web of Science, and the Cochrane Library from inception to Jun 2022, to include relevant prospective cohort studies. We used a restricted cubic spline model to conduct a dose-response meta-analysis and calculated the absolute effect estimates to present the results. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess the certainty of the evidence. RESULTS: Forty-two articles including on 37 cohorts enrolled 4,518,547 participants were included. With low certainty evidence, increased consumption of sugar-sweetened beverages (SSBs) per 250 mL/day was significantly associated with a 17% greater risk of breast cancer, a 10% greater risk of colorectal cancer, a 30% greater risk of biliary tract cancer, and a 10% greater risk of prostate cancer; increased consumption of artificially sweetened beverages (ASBs)re per 250 mL/day was significantly associated with a 16% greater risk of leukemia; increased consumption of 100% fruit juice per 250 mL/day was significantly associated with a 31% greater risk of overall cancer, 22% greater risk of melanoma, 2% greater risk of squamous cell carcinoma, and 29% greater risk of thyroid cancer. The associations with other specific cancer were no significant. We found linear dose-response associations between consumption of SSBs and the risk of breast and kidney cancer, and between consumption of ASBs and 100% fruit juices and the risk of pancreatic cancer. CONCLUSIONS: An increment in consumption of SSBs of 250 mL/day was positively associated with increased risk of breast, colorectal, and biliary tract cancer. Fruit juices consumption was also positively associated with the risk of overall cancer, thyroid cancer, and melanoma. The magnitude of absolute effects, however, was small and mainly based on low or very low certainty of evidence. The association of ASBs consumption with specific cancer risk was uncertain. TRIAL REGISTRATION: PROSPERO: CRD42020152223.

Intake of legumes and cardiovascular disease: A systematic review and dose-response meta-analysis.

AIMS: To summarize the evidence on the association between the intake of legumes and the risk of cardiovascular disease (CVD) overall, coronary heart disease (CHD) and stroke, and to identify optimal intake levels for reduced disease risk through a systematic review and dose-response meta-analysis. DATA SYNTHESIS: We have systematically searched PubMed, Scopus and Web of Science up to March, 2022 for the retrieval of intervention and observational studies (PROSPERO Reg. number: CRD42021247565). Pooled relative risks (RRs) comparing extreme categories of intake were computed using random-effects models. One-stage dose-response meta-analyses were also performed using random-effects models. 22 831 articles were screened resulting in 26 eligible observational studies (21 prospective cohort and 5 case-control studies). When comparing extreme categories of intake, the consumption of legumes was inversely associated with CVD (n = 25: RR = 0.94; 95%CI:0.89,0.99) and CHD (n = 16: RR = 0.90; 95%CI:0.85,0.96), but not with stroke (n = 9: RR = 1.00; 95%CI:0.93,1.08). We further found evidence for an inverse dose-response association with CHD, increasing in magnitude up to an intake of 400 g/week, after which the benefit seems to level-off. CONCLUSIONS: The intake of legumes was associated with a reduced risk of CVD and CHD, but not with stroke, among individuals with the highest consumption levels. An intake level of 400 g/week seemed to provide the optimal cardiovascular benefit. Further research is needed to better understand the role of legumes in stroke subtypes.

Glycosylated haemoglobin and prognosis in 10,536 people with cancer and pre-existing diabetes: a meta-analysis with dose-response analysis.

AIMS: To assess whether glycaemic control is associated with prognosis in people with cancer and pre-existing diabetes. METHODS: In this pre-registered systematic review (PROSPERO: CRD42020223956), PubMed and Web of Science were searched on 25th Nov 2021 for studies investigating associations between glycosylated haemoglobin (HbA1c) and prognosis in people with diabetes and cancer. Summary relative risks (RRs) and 95% Confidence Intervals (CIs) for associations between poorly controlled HbA1c or per 1-unit HbA1c increment and cancer outcomes were estimated using a random-effects meta-analysis. We also investigated the impact of potential small-study effects using the trim-and-fill method and potential sources of heterogeneity using subgroup analyses. RESULTS: Fifteen eligible observational studies, reporting data on 10,536 patients with cancer and pre-existing diabetes, were included. Random-effects meta-analyses indicated that HbA1c ≥ 7% (53 mmol/mol) was associated with increased risks of: all-cause mortality (14 studies; RR: 1.14 [95% CI: 1.03-1.27]; p-value: 0.012), cancer-specific mortality (5; 1.68 [1.13-2.49]; p-value: 0.011) and cancer recurrence (8; 1.68 [1.18-2.38; p-value: 0.004]), with moderate to high heterogeneity. Dose-response meta-analyses indicated that 1-unit increment of HbA1c (%) was associated with increased risks of all-cause mortality (13 studies; 1.04 [1.01-1.08]; p-value: 0.016) and cancer-specific mortality (4; 1.11 [1.04-1.20]; p-value: 0.003). All RRs were attenuated in trim-and-fill analyses. CONCLUSIONS: Our findings suggested that glycaemic control might be a modifiable risk factor for mortality and cancer recurrence in people with cancer and pre-existing diabetes. High-quality studies with a larger sample size are warranted to confirm these findings due to heterogeneity and potential small-study effects. In the interim, it makes clinical sense to recommend continued optimal glycaemic control.

Association of Egg Consumption with Risk of All-Cause and Cardiovascular Disease Mortality: A Systematic Review and Dose-Response Meta-Analysis of Observational Studies.

BACKGROUND: Recent studies have reported conflicting associations between egg consumption and the risk of all-cause or cardiovascular disease (CVD) mortality, including ischemic heart disease (IHD) mortality and stroke mortality. With accumulating evidence, up-to-date evidence about the association should be synthesized. OBJECTIVES: We aimed to assess the association of the risk of all-cause and CVD mortality with egg consumption. METHODS: We searched the PubMed, Embase, and Web of Science databases through 3 November, 2021 for observational studies conducted in participants ≥18 y of age and which provided ORs, RRs, or HRs and 95% CIs for ≥3 egg consumption categories or for increased intake of egg addressing the associations of interest. A random-effects model was used to pool the reported risk estimates. Restricted cubic splines were used to examine the dose-response association. RESULTS: Twenty-four articles with 48 reports (25 for all-cause mortality, 11 for CVD mortality, 6 for IHD mortality, and 6 for stroke mortality) involving 11,890,695 participants were included. Intake of each 1-egg/d increment was associated with increased risk of all-cause mortality (RR: 1.06; 95% CI: 1.02, 1.10; P = 0.008), but the association was restricted to women, Americans, and studies with adjustments for hyperlipidemia. Egg consumption was linearly associated with CVD mortality only in participants >60 y of age, Americans, studies with follow-up duration ≥15 y, and studies with adjustments for hyperlipidemia (P ≤ 0.018). No significant association was found between egg consumption and IHD or stroke mortality (P ≥ 0.080). CONCLUSIONS: Egg consumption was linearly associated with a modestly increased risk of all-cause mortality and, in older participants, Americans, and studies with longer follow-up or adjustments for hyperlipidemia, CVD mortality. These findings suggest that it may be prudent to avoid high egg consumption.

Optimal dose of aripiprazole for augmentation therapy of antidepressant-refractory depression: preliminary findings based on a systematic review and dose-effect meta-analysis.

BACKGROUND: Aripiprazole augmentation is proven effective for antidepressant-refractory depression, but its licensed dose range is wide and optimal dosage remains unclear. AIMS: To find the optimal dosage of aripiprazole augmentation. METHOD: Multiple electronic databases were searched (from inception to 16 February 2021) to identify all assessor-masked randomised controlled trials evaluating aripiprazole augmentation therapy in adults (≥18 years old, both genders) with major depressive disorder showing inadequate response to at least one antidepressant treatment. A random-effects, one-stage dose-effect meta-analysis with restricted cubic splines was conducted. Outcomes were efficacy (treatment response: ≥50% reduction in depression severity), tolerability (drop-out due to adverse effects) and acceptability (drop-out for any reason) after 8 weeks of treatment (range 4-12 weeks). RESULTS: Ten studies met the inclusion criteria. All were individually randomised, placebo-controlled, multi-centre, parallel studies including 2625 participants in total. The maximum target dose-efficacy curve showed an increase up to doses between 2 mg (odds ratio OR = 1.46, 95% CI 1.15-1.85) and 5 mg (OR = 1.93, 95% CI 1.33-2.81), and then a non-increasing trend through the higher licensed doses up to 20 mg (OR = 1.90, 95% CI 1.52-2.37). Tolerability showed a similar trend with greater uncertainty. Acceptability showed no significant difference through the examined dose range. Certainty of evidence was low to moderate. CONCLUSIONS: Low-dose aripiprazole as augmentation treatment might achieve the optimal balance between efficacy, tolerability and acceptability in the acute treatment of antidepressant-refractory depression. However, the small number of included studies and the overall moderate to high risk of bias seriously compromise the reliability of the results. Further research is required to investigate the benefits of low versus high dose.

White rice consumption and risk of cardiometabolic and cancer outcomes: A systematic review and dose-response meta-analysis of prospective cohort studies.

White rice is the food more than half of the world's population depends on. White rice intake can significantly increase the glycemic load of consumers and bring some adverse health effects. However, the quality of evidence implicating white rice in adverse health outcomes remains unclear. To evaluate the association between white rice consumption and the risk of cardiometabolic and cancer outcomes, a systematic review and dose-response meta-analysis of the relevant publications were performed. Twenty-three articles including 28 unique prospective cohorts with 1,527,198 participants proved eligible after a comprehensive search in four databases. For the risk of type 2 diabetes mellitus (T2DM), the pooled RR was 1.18 (16 more per 1000 persons) for comparing the highest with the lowest category of white rice intake, with moderate certainty evidence. Females presented a higher risk (23 more per 1000 persons) in subgroup analysis. And every additional 150 grams of white rice intake per day was associated with a 6% greater risk of T2DM (5 more per 1000 persons) with a linear positive trend. We found no significant associations between white rice intake and risk of cardiovascular diseases (CVD), CVD mortality, cancer, and metabolic syndrome. In conclusion, moderate certainty evidence demonstrated that white rice intake was associated with T2DM risk, with a linear positive trend. However, low to very low certainty of evidence suggested that no substantial associations were found between white rice intake and other cardiometabolic and cancer outcomes. More cohorts are needed to strength the evidence body.

Longitudinal association of dietary carbohydrate and the risk cardiovascular disease: a dose-response meta-analysis.

Previous findings on the association of dietary carbohydrate with cardiovascular disease (CVD) events and mortality are inconsistent. We aimed to assess the relationship between dietary carbohydrate and the incidence of cardiovascular events and mortality. A comprehensive literature search of MEDLINE (PubMed), Scopus, ISI Web of Science, and EMBASE, was performed up to June 2019. Prospective cohort studies which examined dietary carbohydrate in relation to fatal and non-fatal myocardial infarction, fatal and non-fatal stroke, heart failure, and sudden cardiac death were included in our study. Summary HRs and 95% CIs were estimated using a random-effects model. A total of 19 cohort studies including 15,663,111 participants were identified. Combining 27 effect sizes with 1,577,225 CVD cases led to a significant association between dietary carbohydrate and total CVD events (HR= 1.05, 95% CI: 1.00, 1.10; I2 = 38.5%), but no association was observed between dietary carbohydrate and CVD mortality (HR = 1.02; 95% CI: 0.91, 1.14; I2=27.1%, derived from 8 effect sizes with 106,412 events), and CHD events (HR = 1.03, 95% CI: 0.98, 1.09; I2 = 46.6%, derived from 18 effect sizes with 1,549,281 events). Moreover, using 8 effect sizes with 6,829 cases, higher carbohydrate intake was associated with increased risk of stroke (HR = 1.13; 95% CI: 1.01, 1.27; I2= 0.0%). In subgroup analysis by sex, higher carbohydrate intake increased the risk of total CVD events (HR: 1.10; 95% CI: 1.03, 1.17; I2 = 0.0%), and CHD (HR: 1.10; 95% CI: 1.01, 1.20; I2= 15.0%), but not stroke and CVD mortality in women. No significant association was found in men. Low- to very-low-certainty evidence suggests that higher carbohydrate intake is directly but slightly associated with CVD and stroke risk, while no association was found for CHD and CVD mortality. We also found sex-specific associations.