Meta-analysis Of Prospective Observational Studies Research Articles

Dietary Antioxidants, Circulating Antioxidant Concentrations, Total Antioxidant Capacity, and Risk of All-Cause Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Observational Studies.

The associations of various dietary or circulating antioxidants with the risk of all-cause mortality in the general population have not been established yet. A systematic search was performed in PubMed and Scopus, from their inception up to October 2017. Prospective observational studies reporting risk estimates of all-cause mortality in relation to dietary intake and/or circulating concentrations of antioxidants were included. Random-effects meta-analyses were conducted. Forty-one prospective observational studies (total n=507,251) involving 73,965 cases of all-cause mortality were included. The RRs of all-cause mortality for the highest compared with the lowest category of circulating antioxidant concentrations were as follows: total carotenes, 0.60 (95% CI: 0.46, 0.74); vitamin C, 0.61 (95% CI: 0.53, 0.69); selenium, 0.62 (95% CI: 0.45, 0.79); β-carotene, 0.63 (95% CI: 0.57, 0.70); α-carotene, 0.68 (95% CI: 0.58, 0.78); total carotenoids, 0.68 (95% CI: 0.56, 0.80); lycopene, 0.75 (95% CI: 0.54, 0.97); and α-tocopherol, 0.84 (95% CI: 0.77, 0.91). The RRs for dietary intakes were: total carotenoids, 0.76 (95% CI: 0.66, 0.85); total antioxidant capacity, 0.77 (95% CI: 0.73, 0.81); selenium, 0.79 (95% CI: 0.73, 0.85); α-carotene, 0.79 (95% CI: 0.63, 0.94); β-carotene, 0.82 (95% CI: 0.77, 0.86); vitamin C, 0.88 (95% CI: 0.83, 0.94); and total carotenes, 0.89 (95% CI: 0.81, 0.97). A nonsignificant inverse association was found for dietary zinc, zeaxanthin, lutein, and vitamin E. The nonlinear dose-response meta-analyses demonstrated a linear inverse association in the analyses of dietary β-carotene and total antioxidant capacity, as well as in the analyses of circulating α-carotene, β-carotene, selenium, vitamin C, and total carotenoids. The association appeared to be U-shaped in the analyses of serum lycopene and dietary vitamin C. The present study indicates that adherence to a diet with high antioxidant properties may reduce the risk of all-cause mortality. Our results confirm current recommendations that promote higher intake of antioxidant-rich foods such as fruit and vegetables.

Association of Serum Leptin with All-Cause and Disease Specific Mortality: A Meta-Analysis of Prospective Observational Studies.

Leptin levels may affect mortality through its link to inflammation and obesity. However, data are inconclusive. This meta-analysis was performed to investigate the association of leptin with mortality. The PubMed, Scopus, Google scholar, and reference lists of the included studies were searched for all published prospective observational studies that described the associations of serum leptin and mortality up to August 2017. Two reviewers independently assessed all potentially relevant studies for inclusion and methodological quality using standardized abstraction forms. Of 518 studies identified, 19 studies considered the association of leptin with all-cause mortality (16 208 subjects) and 12 studies evaluated the association of leptin with disease-specific mortality (13 680 subjects). In the overall analysis, no significant association was found between leptin and all-cause mortality (HR=1.028; 95% CI: 0.908-1.165; p=0.659), with a high between study heterogeneity (p˂0.001, I2=61). Subgroup analysis found that high leptin is associated with increased all-cause mortality in healthy people (HR=1.159 (95% CI, 1.032, 1.302), p=0.012), in men (HR=1.162; 95% CI: 1.036-1.302; p=0.010), and in subjects with ≥60 years old (HR=1.129; 95% CI: 1.030-1.238; p=0.010); whereas, increased leptin levels was related to the decreased cancer-specific mortality ((HR=0.550; 95% CI: 0.418-0.724), p˂0.001). Higher leptin levels in healthy people, old people, and males were associated with increased all-cause mortality, while increased leptin level was related to the reduced risk of death among patients with cancer.

Fish consumption and risk of all-cause and cardiovascular mortality: a dose-response meta-analysis of prospective observational studies.

There are some indications of regional differences in the association between fish consumption and clinical outcomes. We aimed to test the linear and potential non-linear dose-response relationships between fish consumption and risk of all-cause and cardiovascular (CVD) mortality, and possible confounding by region. Systematic review and dose-response meta-analysis. Systematic search using PubMed and Scopus, from inception up to September 2016. Prospective observational studies reporting the estimates of all-cause and CVD mortality in relation to three or more categories of fish intake were included. Random-effects dose-response meta-analysis was conducted. Fourteen prospective cohort studies (ten publications) with 911 348 participants and 75 451 incident deaths were included. A 20 g/d increment in fish consumption was significantly and inversely associated with the risk of CVD mortality (relative risk=0·96; 95 % CI 0·94, 0·98; I 2=0 %, n 8) and marginally and inversely associated with the risk of all-cause mortality (relative risk=0·98; 95 % CI 0·97, 1·00; I 2=81·9 %, n 14). Subgroup analysis resulted in a significant association only in the subgroup of Asian studies, compared with Western studies, in both analyses. Analysis of Western studies suggested a nearly U-shaped association, with a nadir at fish consumption of ~20 g/d in analysis of both outcomes. Meanwhile, the associations appeared to be linear in Asian studies. There was potential evidence of regional differences in the association between fish consumption and mortality. It may be helpful to examine the associations by considering types of fish consumed and methods of fish preparation.

GW28-e0393 Association between circulating oxidized low-density lipoprotein and atherosclerotic cardiovascular disease: a meta-analysis of prospective observational studies

GW28-e0393 Association between circulating oxidized low-density lipoprotein and atherosclerotic cardiovascular disease: a meta-analysis of prospective observational studies

Normal values for Doppler echocardiographic assessment of prosthetic valve function after transcatheter aortic valve replacement: a systematic review and meta-analysis.

Transcatheter aortic valve replacement has emerged as valuable treatment modality for patients with severe aortic stenosis and an unacceptable risk/benefit ratio for open heart surgery, but particularities specific to TAVR and a rapidly growing number of available TAVR prosthesis make post-procedural assessment of valve function challenging. Aim of the present analysis was to collect and pool all available data currently in the literature regarding normal doppler values for transcatheter prosthetic heart valves and to provide a comprehensive overview. A PRISMA checklist-guided systematic review and meta-analysis of prospective observational studies or national and device specific registries or randomized clinical trials was conducted. Studies were identified by searching PUBMED, SCOPUS, Cochrane Central Register of Controlled Trials and LILACs from January 2000 to March 2017. Out of 240 abstracts, 155 studies reporting echocardiographic parameter for twelve different valves prosthesis in a total of 27,159 patients were in included in this meta-analysis. The means and standard deviations of peak velocity, peak gradient, mean gradient and effective orifice were extracted and pooled from the included studies. The pooled means and standard deviations for all available TAVR prosthesis were classified according to implanted valve size and time since implantation. The present study firstly describes a pooled analysis of normal values for all available TAVR prosthesis in order to empower treating physicians with a reliable tool to perform follow-up echocardiographic assessment in TAVR patients and to safely identify patients with prostheses dysfunction.

Smoking and the risk of type 2 diabetes in Japan: A systematic review and meta-analysis.

Cigarette smoking is the leading avoidable cause of disease burden. Observational studies have suggested an association between smoking and risk of type 2 diabetes mellitus (T2DM). We conducted a meta-analysis of prospective observational studies to investigate the association of smoking status, smoking intensity, and smoking cessation with the risk of T2DM in Japan, where the prevalence of smoking has been decreasing but remains high. We systematically searched MEDLINE and the Ichushi database to December 2015 and identified 22 eligible articles, representing 343,573 subjects and 16,383 patients with T2DM. We estimated pooled relative risks (RRs) using a random-effects model and conducted subgroup analyses by participant and study characteristics. Compared with nonsmoking, the pooled RR of T2DM was 1.38 (95% confidence interval [CI], 1.28–1.49) for current smoking (19 studies) and 1.19 (95% CI, 1.09–1.31) for former smoking (15 studies). These associations persisted in all subgroup and sensitivity analyses. We found a linear dose-response relationship between cigarette consumption and T2DM risk; the risk of T2DM increased by 16% for each increment of 10 cigarettes smoked per day. The risk of T2DM remained high among those who quit during the preceding 5 years but decreased steadily with increasing duration of cessation, reaching a risk level comparable to that of never smokers after 10 years of smoking cessation. We estimated that 18.8% of T2DM cases in men and 5.4% of T2DM cases in women were attributable to smoking. The present findings suggest that cigarette smoking is associated with an increased risk of T2DM, so tobacco control programs to reduce smoking could have a substantial effect to decrease the burden of T2DM in Japan.

Is sarcopenia associated with an increased risk of all-cause mortality and functional disability?

BackgroundWhile a recent meta-analysis of observational studies reported a statistically significant association between sarcopenia and both all-cause mortality and functional decline, a recently developed inverse heterogeneity (IVhet) model has been shown to be more valid than the traditional random-effects model used. ObjectiveThe objective of this short report was to use a previous meta-analysis to compare the two approaches. MethodsAggregate data meta-analysis of prospective observational studies conducted in any setting. Men and women 60years of age and older in which all-cause mortality (12 studies, 14,169 participants) or functional decline (6 studies, 8561 participants) was assessed. Using the IVhet model, pooling of previous studies regarding the association between sarcopenia and all-cause mortality as well as functional decline. Absolute and relative differences between IVhet and random-effects results were also calculated as well as influence analysis with each study deleted once. Non-overlapping 95% confidence intervals (CI) for odds ratios (OR) were considered statistically significant. ResultsSarcopenia was associated with an increased risk for all-cause mortality (OR=3.64, 95% CI=2.94 to 4.51) and functional decline (OR=2.58, 95% CI=1.33 to 4.99). Compared to the random-effects model, the OR was slightly higher (0.04 or 1.1%) but with wider CI (0.16 or 11.3%) for all-cause mortality and 0.45 (14.9%) lower with a CI that was 0.34 (10.2%) wider for functional decline. With each study deleted from the model once, results remained statistically significant for both all-cause mortality and functional decline. ConclusionThese results provide additional and more accurate evidence in support of an association between sarcopenia and an increased risk for both all-cause mortality and functional decline.

First-trimester artemisinin derivatives and quinine treatments and the risk of adverse pregnancy outcomes in Africa and Asia: A meta-analysis of observational studies.

BackgroundAnimal embryotoxicity data, and the scarcity of safety data in human pregnancies, have prevented artemisinin derivatives from being recommended for malaria treatment in the first trimester except in lifesaving circumstances. We conducted a meta-analysis of prospective observational studies comparing the risk of miscarriage, stillbirth, and major congenital anomaly (primary outcomes) among first-trimester pregnancies treated with artemisinin derivatives versus quinine or no antimalarial treatment.Methods and findingsElectronic databases including Medline, Embase, and Malaria in Pregnancy Library were searched, and investigators contacted. Five studies involving 30,618 pregnancies were included; four from sub-Saharan Africa (n = 6,666 pregnancies, six sites) and one from Thailand (n = 23,952). Antimalarial exposures were ascertained by self-report or active detection and confirmed by prescriptions, clinic cards, and outpatient registers. Cox proportional hazards models, accounting for time under observation and gestational age at enrollment, were used to calculate hazard ratios. Individual participant data (IPD) meta-analysis was used to combine the African studies, and the results were then combined with those from Thailand using aggregated data meta-analysis with a random effects model.There was no difference in the risk of miscarriage associated with the use of artemisinins anytime during the first trimester (n = 37/671) compared with quinine (n = 96/945; adjusted hazard ratio [aHR] = 0.73 [95% CI 0.44, 1.21], I2 = 0%, p = 0.228), in the risk of stillbirth (artemisinins, n = 10/654; quinine, n = 11/615; aHR = 0.29 [95% CI 0.08–1.02], p = 0.053), or in the risk of miscarriage and stillbirth combined (pregnancy loss) (aHR = 0.58 [95% CI 0.36–1.02], p = 0.099). The corresponding risks of miscarriage, stillbirth, and pregnancy loss in a sensitivity analysis restricted to artemisinin exposures during the embryo sensitive period (6–12 wk gestation) were as follows: aHR = 1.04 (95% CI 0.54–2.01), I2 = 0%, p = 0.910; aHR = 0.73 (95% CI 0.26–2.06), p = 0.551; and aHR = 0.98 (95% CI 0.52–2.04), p = 0.603. The prevalence of major congenital anomalies was similar for first-trimester artemisinin (1.5% [95% CI 0.6%–3.5%]) and quinine exposures (1.2% [95% CI 0.6%–2.4%]). Key limitations of the study include the inability to control for confounding by indication in the African studies, the paucity of data on potential confounders, the limited statistical power to detect differences in congenital anomalies, and the lack of assessment of cardiovascular defects in newborns.ConclusionsCompared to quinine, artemisinin treatment in the first trimester was not associated with an increased risk of miscarriage or stillbirth. While the data are limited, they indicate no difference in the prevalence of major congenital anomalies between treatment groups. The benefits of 3-d artemisinin combination therapy regimens to treat malaria in early pregnancy are likely to outweigh the adverse outcomes of partially treated malaria, which can occur with oral quinine because of the known poor adherence to 7-d regimens.Review registrationPROSPERO CRD42015032371

Is orthostatic hypotension related to falling? A meta-analysis of individual patient data of prospective observational studies.

orthostatic hypotension (OH) is one out of many risk factors believed to contribute to an increased fall risk in elderly subjects but it is unclear whether an independent association between OH and falling exists. to perform an individual patient data (IPD) meta-analysis of prospective observational studies investigating the relationship between OH and falling. MEDLINE, EMBASE, the Cochrane Library and the abstracts of annual meetings of selected hypertension societies were searched. Both one-stage (analysing all IPD from all studies simultaneously) and two-stage (analysing IPD per study, and then pooling the results) methods were used, and both logistic and cox regression analyses were performed. The study protocol was published on PROSPERO (2015:CRD42015019178). from 34 selected abstracts, 6 studies were included. IPD were provided in 1,022 patients from 3 cohorts and were included in the IPD meta-analysis. The one-stage meta-analysis showed a significant relationship between OH and time to first fall incident (hazard ratio (HR) 1.52 (95% Confidence Interval (CI) 1.23-1.88)). No significant relationship between OH and falling was found in the one-stage logistic regression analysis and the two-stage logistic and cox regression analyses. this IPD meta-analysis of prospective observational studies showed a clear and significant relationship between OH and time to first fall incident. Although the ORs of falling was not significantly different for patients with and without OH, a the cox regression analyses reporting HRs and including time to incident provided more clinically relevant information in present meta-analysis.

Psoriasis increases risk of new-onset atrial fibrillation: a systematic review and meta-analysis of prospective observational studies

Background: Psoriasis is a common chronic immune-mediated dermatological disease that increases the risk of cardiovascular disease. We conducted a systematic review and meta-analysis to evaluate the association between psoriasis and atrial fibrillation from prospective observational studies.Methods: A comprehensive search of the databases of the MEDLINE and EMBASE was performed from inception through November 2015. The inclusion criterion was the prospective observational study that assessed the risk of new-onset atrial fibrillation in adults with psoriasis. Outcome was the adjusted hazard ratio (HR) of atrial fibrillation comparison between patients with psoriasis and controls. Pooled HR and 95% confidence intervals (CI) were calculated using a random-effects model.Results: The initial search yielded 176 articles. Fifteen articles underwent full-length review and data were extracted from 4 observational studies. Incidence of atrial fibrillation was ascertained by cardiologist-reviewed electrocardiograms. There was a significant increased risk of new-onset atrial fibrillation in patients with psoriasis compared to controls with a pooled HR 1.42 (95%CI 1.22–1.65).Conclusion: Our meta-analysis of prospective studies demonstrated that patients with psoriasis have increased risk of new-onset atrial fibrillation. Future interventional studies addressing the impact of psoriasis treatment and prevention of atrial fibrillation should be performed.

Abstract 13943: Psoriasis Increases Risk of New Onset Atrial Fibrillation: A Systematic Review and Meta-Analysis of Prospective Observational Studies

Introduction: Psoriasis is a common dermatological disease that increases risk of cardiovascular disease. Previous studies have shown possible evidence that patients with psoriasis may also have increased risk of new-onset atrial fibrillation. Hypothesis: We assessed a hypothesis that psoriasis increases risk of atrial fibrillation by performing a systematic review and meta-analysis of prospective observational studies. Methods: A comprehensive search of the databases of the MEDLINE and EMBASE was performed from inception through April 2016. The inclusion criterion was the prospective observational study that assessed risk of new-onset atrial fibrillation in adults with psoriasis. Outcome was the adjusted hazard ratio (HR) of atrial fibrillation comparing between patient with psoriasis and controls. Pooled HR and 95% confidence interval (CI) were calculated using a random-effects model. Results: The initial search yielded 176 articles. Fifteen articles underwent full-length review and data was extracted from 4 observational studies. All studies had prospective designs, involving totally 12,755 participants with a median follow-up time between 2.5 to 5 years. Psoriasis was identified by a medical code associated with clinic visits to a dermatologist. Incidence of atrial fibrillation was ascertained by cardiologist reviewed of electrocardiograms. There was a significant increased risk of new-onset atrial fibrillation in patients with psoriasis compared to controls with a pooled HR 1.42 (95%CI 1.22 -1.65, I 2 =68%). Conclusions: Our meta-analysis of prospective studies demonstrated that patient with psoriasis has increased risk of new-onset atrial fibrillation. Inflammation is likely an important factor in the pathophysiology of both atrial fibrillation and psoriasis. Future interventional studies addressing the impact of psoriasis treatment and prevention of atrial fibrillation should be performed.

Coffee and cancer risk: A meta-analysis of prospective observational studies.

Meta-analyses on coffee and cancer incidence mainly restricted to limited cancers. We carried out a more comprehensive meta-analysis of cohort studies to explore association between coffee and most cancer types. We conducted comprehensive search and summarized relative risk (RR) and 95% confidence intervals for the highest versus lowest coffee intake and cancer using STATA12. We conducted dose-analysis if result suggested significant association. The publication bias was evaluated with begg’s and egger’s test. Finally, 105 individual prospective studies were included. Inverse associations were observed on oral, pharyngeal, colon, liver, prostate, endometrial cancer and melanoma, with RR 0.69 (95% CI = 0.48–0.99, I2 = 73.4%, P = 0.044), 0.87 (95% CI = 0.78–0.96, I2 = 28.4%, P = 0.007), 0.46 (95% CI = 0.37–0.57, I2 = 0%, P = 0), 0.89 (95% CI = 0.84–0.93, I2 = 30.3%, P = 0.003), 0.73 (95% CI = 0.67–0.80, I2 = 0%, P = 0) and 0.89 (95% CI = 0.80–0.99, I2 = 0%, P = 0.031) respectively. However, the relative risk for lung cancer is 2.18 (95% CI = 1.26–3.75, I2 = 63.3%, P = 0.005). The summary relative risk for increment of 2 cups of coffee were RR = 0.73, 95% CI = 0.67–0.79 for liver cancer, RR = 0.97, 95% CI = 0.96–0.98 for prostate cancer and RR = 0.88, 95% CI = 0.85–0.92 for endometrial cancer. Accordingly, coffee intake was associated with reduced risk of oral, pharynx, liver, colon, prostate, endometrial cancer and melanoma and increased lung cancer risk.

Cheese consumption and risk of cardiovascular disease: a meta-analysis of prospective studies.

Cheese contains a high content of saturated fatty acids but also lists of potentially beneficial nutrients. How long-term cheese consumption affects the development of cardiovascular disease (CVD) is unclear. A meta-analysis of prospective observational studies was conducted to evaluate the risks of total CVD, coronary heart disease (CHD), and stroke associated with cheese consumption. Potentially eligible studies were identified by searching PubMed and EMBASE databases and by carefully reviewing the bibliographies of retrieved publications and related reviews. The summary relative risks (RRs) with 95% confidence intervals (CIs) were calculated using the random-effects model. The final analyses included 15 prospective studies. Most of the studies excluded prevalent CVD at baseline (14/15) and had a duration >10years (13/15). The summary RR for high vs. low cheese consumption was 0.90 (95% CI 0.82-0.99) for total CVD (7 studies, 8076 events), 0.86 (95% CI 0.77-0.96) for CHD (8 studies, 7631 events), and 0.90 (95% CI 0.84-0.97) for stroke (7 studies, 10,449 events), respectively. The restricted cubic model indicated evidence of nonlinear relationships between cheese consumption and risks of total CVD (P nonlinearity<0.001) and stroke (P nonlinearity=0.015), with the largest risk reductions observed at the consumption of approximately 40g/d. This meta-analysis of prospective studies suggests a nonlinear inverse association between cheese consumption and risk of CVD.

Abstract 124: Association Between Low Bone Mineral Density and Risk of Peripheral Vascular Disease: A Systematic Review and Meta-analysis

Background: Previous studies have suggested that osteoporosis and coronary heart disease have shared common risk factors. Some studies also suggested that low bone mineral density (BMD) also increased risk of peripheral vascular disease (PVD) or stroke. However, few longitudinal studies did not find significant association between these two conditions. We performed a systematic review and meta-analysis to explore association between low BMD and risk of PVD or stroke from prospective studies. Methods: We comprehensively searched the databases of PubMed/MEDLINE, EMBASE, and Cochrane Databases from their dates of inception to December 2015. The inclusion criteria were published prospective observational studies of PVD, stroke, BMD, osteoporosis, or fractures. Two authors independently assessed the quality of the articles and extracted the data. The primary outcome of interest was risk of new PVD or stroke events comparing between low BMD and normal BMD groups. Results: From 36 full-text articles, five observational studies involving 3,287 participants were included in the meta-analysis based on the random-effects model. There was increased risk of new peripheral vascular disease or stroke events in groups with low BMD compared with normal BMD controls with pooled hazard risk (HR) of 3.10 (95% CI: 1.32-7.23). In the subgroup analysis of fracture as a risk factor, there was no significant difference in risk of PVD or stroke in group with pooled HR of 1.17 (95% CI: 0.78-1.75). Conclusions: Low BMD is associated with increased risk of PVD and stroke from the meta-analysis of prospective observational studies. Clinicians should be aware of the close association between these two conditions. Early identification of PVD in patients with low BMD should be performed.

The effect of statins on mortality in heart failure with preserved ejection fraction: a meta-analysis of propensity score analyses.

Nearly half of patients with heart failure (HF) have preserved ejection fraction (EF) and the mortality and morbidity of patients with HF with preserved EF (HFpEF) are high. However, no pharmacological therapy has been shown to improve survival in HFpEF patients. Previous retrospective and prospective observational studies have examined the prognostic impact of hydroxymethylglutaryl-coenzyme A reductase inhibitors (statins) in patients with HFpEF. However, the results are inconsistent due to limited power with small sample sizes and/or lack of adjustment for known prognostic factors and differences in baseline characteristics between patients treated with and without statins. We aimed to conduct a meta-analysis of prospective observational studies examining the effect of statin therapy on mortality in HFpEF patients with the use of propensity score analysis. A total of 4 studies with 5,536 patients (2,768 patients [50%] on statins; mean age, 65-77 years; male, 43-66%; coronary artery disease, 42-64%; hypertension, 61-82%; diabetes, 20-29%; follow-up duration, 12-36 months) were included in this meta-analysis. The pooled analysis showed that statin therapy was associated with reduced mortality (odds ratio [95% CI] = 0.690 [0.493-0.965], P=0.030). Our meta-analysis suggests the potential mortality benefit of statins in HFpEF. Further prospective observational studies and randomized controlled trials should be planned to confirm our observed potential survival benefit of statins in HFpEF.

Perceived job insecurity, unemployment and depressive symptoms: a systematic review and meta-analysis of prospective observational studies.

It was shown that both job insecurity and unemployment are strongly and consistently associated with depressive symptoms. It is, however, less clear whether perceived job insecurity and unemployment constitute a comparable risk for the onset of depressive symptoms. A meta-analysis was conducted to explore this issue. In December 2014, relevant records were identified through the databases MEDLINE, Embase and PsychINFO. Articles were included if they had been published in the last 10 years and contained a quantitative analysis on the prospective link between job insecurity and unemployment with depressive symptoms. In 20 cohort studies within 15 articles, job insecurity and unemployment were significantly related to a higher risk of depressive symptoms, with the odds ratio (OR) being modestly higher for job insecurity (1.29, 95% CI 1.06-1.57) than for unemployment (1.19, 95% CI 1.11-1.28). Sensitivity analyses revealed that the effects were strongest in studies that examined younger respondents (<40 years) and used an unadjusted statistical model. By considering the length of the observational period, it was shown that unemployment ORs were higher in shorter time lags (under 1 year), while ORs for job insecurity were increased in longer exposure-outcome intervals (3-4 years). Specifically for unemployment, ORs were highest in studies that did not control for potential health selection effects and that ascertained enduring unemployment. A statistically significant publication bias was found for studies on unemployment, but not for job insecurity. The analyses revealed that both perceived job insecurity and unemployment constitute significant risks of increased depressive symptoms in prospective observational studies. By comparing both stressors, job insecurity can pose a comparable (and even modestly increased) risk of subsequent depressive symptoms.

Early age at natural menopause and risk of cardiovascular and all-cause mortality: A meta-analysis of prospective observational studies

Menopause is defined as the permanent cessation of menstruation because of loss of ovarian follicular function. Menopause is a marker of the end of a woman's reproductive life. The age at menopause varies in different ethnic populations [ [1] Baber R.J. East is east and West is west: perspectives on the menopause in Asia and the West. Climacteric. 2014; 17: 23-28 Crossref PubMed Scopus (19) Google Scholar ]. Menopause between the ages of 40 and 45 years is usually described as early menopause [ [2] Miro F. Parker S.W. Aspinall L.J. Coley J. Perry P.W. Ellis J.E. Sequential classification of endocrine stages during reproductive aging in women: the FREEDOM study. Menopause. 2005; 12: 281-290 Crossref PubMed Scopus (34) Google Scholar ], while occurring before the age of 40 years is defined as premature menopause [ [3] Luborsky J.L. Meyer P. Sowers M.F. Gold E.B. Santoro N. Premature menopause in a multi-ethnic population study of the menopause transition. Hum. Reprod. 2003; 18: 199-206 Crossref PubMed Scopus (302) Google Scholar ]. Early or premature menopause can be naturally spontaneous or induced by medical interventions including chemotherapy or bilateral oophorectomy. Some epidemiologic studies [ 4 Snowdon D.A. Kane R.L. Beeson W.L. Burke G.L. Sprafka J.M. Potter J. et al. Is early natural menopause a biologic marker of health and aging?. Am. J. Public Health. 1989; 79: 709-714 Crossref PubMed Scopus (279) Google Scholar , 5 Cooper G.S. Sandler D.P. Age at natural menopause and mortality. Ann. Epidemiol. 1998; 8: 229-235 Abstract Full Text Full Text PDF PubMed Scopus (219) Google Scholar , 6 Jacobsen B.K. Knutsen S.F. Fraser G.E. Age at natural menopause and total mortality and mortality from ischemic heart disease: the Adventist Health Study. J. Clin. Epidemiol. 1999; 52: 303-307 Abstract Full Text Full Text PDF PubMed Scopus (195) Google Scholar , 7 Mondul A.M. Rodriguez C. Jacobs E.J. Calle E.E. Age at natural menopause and cause-specific mortality. Am. J. Epidemiol. 2005; 162: 1089-1097 Crossref PubMed Scopus (184) Google Scholar , 8 Cooper G.S. Baird D.D. Weinberg C.R. Ephross S.A. Sandler D.P. Age at menopause and childbearing patterns in relation to mortality. Am. J. Epidemiol. 2000; 151: 620-623 Crossref PubMed Scopus (49) Google Scholar , 9 Jacobsen B.K. Heuch I. Kvale G. Age at natural menopause and all-cause mortality: a 37-year follow-up of 19,731 Norwegian women. Am. J. Epidemiol. 2003; 157: 923-929 Crossref PubMed Scopus (208) Google Scholar , 10 Amagai Y. Ishikawa S. Gotoh T. Kayaba K. Nakamura Y. Kajii E. Age at menopause and mortality in Japan: the Jichi Medical School Cohort Study. J. Epidemiol. 2006; 16: 161-166 Crossref PubMed Scopus (44) Google Scholar , 11 Hong J.S. Yi S.W. Kang H.C. Jee S.H. Kang H.G. Bayasgalan G. et al. Age at menopause and cause-specific mortality in South Korean women: Kangwha Cohort Study. Maturitas. 2007; 56: 411-419 Abstract Full Text Full Text PDF PubMed Scopus (72) Google Scholar , 12 Tom S.E. Cooper R. Wallace R.B. Guralnik J.M. Type and timing of menopause and later life mortality among women in the Iowa Established Populations for the Epidemiological Study of the Elderly (EPESE) cohort. J. Womens Health (Larchmt). 2012; 21: 10-16 Crossref PubMed Scopus (21) Google Scholar , 13 Li S. Rosenberg L. Wise L.A. Boggs D.A. LaValley M. Palmer J.R. Age at natural menopause in relation to all-cause and cause-specific mortality in a follow-up study of US black women. Maturitas. 2013; 75: 246-252 Abstract Full Text Full Text PDF PubMed Scopus (37) Google Scholar , 14 Wu X. Cai H. Kallianpur A. Gao Y.T. Yang G. Chow W.H. et al. Age at menarche and natural menopause and number of reproductive years in association with mortality: results from a median follow-up of 11.2 years among 31,955 naturally menopausal Chinese women. PLoS One. 2014; 9: e103673 Crossref PubMed Scopus (57) Google Scholar , 15 Jacobsen B.K. Heuch I. Kvale G. Age at natural menopause and stroke mortality: cohort study with 3561 stroke deaths during 37-year follow-up. Stroke. 2004; 35: 1548-1551 Crossref PubMed Scopus (46) Google Scholar ] suggested that women who experienced early natural menopause or premature menopause were at increased risk of all-cause mortality. However, findings from these studies are conflicting. Therefore, we conducted this meta-analysis on all available prospective studies to quantitatively evaluate the early age at natural menopause and risk of cardiovascular or all-cause mortality.

Egg intake and cancers of the breast, ovary and prostate: a dose-response meta-analysis of prospective observational studies.

Evidence suggests that egg intake may be implicated in the aetiology of sex hormone-related cancers. However, dose-response relationships between egg intake and such cancers are unclear. Thus, we conducted a dose-response meta-analysis to summarise the dose-response relationships between egg consumption and the risk of breast, prostate and gynaecological cancers. A literature search was performed using PubMed and Embase up to April 2015 to identify relevant prospective observational studies. Summary relative risk (RR) and 95% CI were estimated using a random-effects model. For breast cancer, the linear dose-response meta-analysis found a non-significantly increased risk (RR for an increase of 5 eggs consumed/week: 1·05, 95% CI 0·99, 1·11, n 16,023 cases). Evidence for non-linearity was not statistically significant (P non-linearity= 0·50, n 15,415 cases) but consuming ≥ 5 eggs/week was significantly associated with an increased risk of breast cancer compared with no egg consumption, with the summary RR being 1·04 (95% CI 1·01, 1·07) for consuming 5 eggs/week and 1·09 (95% CI 1·03, 1·15) for consuming about 9 eggs/week. For other cancers investigated, the summary RR for an increase of 5 eggs consumed/week was 1·09 (95% CI 0·96, 1·24, n 2636 cases) for ovarian cancer; 1·47 (95% CI 1·01, 2·14, n 609 cases) for fatal prostate cancer, with evidence of small-study effects (P Egger= 0·04). No evidence was found for an association with the risk of total prostate cancer. While our conclusion was tempered by the potential for publication bias and confounding, high egg intake may be associated with a modestly elevated risk of breast cancer, and a positive association between egg intake and ovarian and fatal prostate cancers cannot be ruled out.

Alcohol intake and associated risk of major cardiovascular outcomes in women compared with men: a systematic review and meta-analysis of prospective observational studies.

BackgroundThe prevalence of alcohol intake is increasing among women in some populations. Alcohol consumption plays an important role in the risk of major cardiovascular outcomes and total mortality. Here, we conducted a meta-analysis to estimate the association between alcohol intake and major cardiovascular outcomes or total mortality in women compared with men.MethodsWe searched the PubMed, Embase, and the Cochrane Library databases for relevant articles published prior to June 2014. Among these potential included prospective studies, the different dose categories of alcohol intake were compared with the lowest alcohol intake or non-drinkers between women and men for the outcomes of major cardiovascular or total mortality.ResultsWe included 23 prospective studies (18 cohorts) reporting data on 489,696 individuals. The summary relative risk ratio (RRR; female to male) for total mortality was significantly increased with moderate alcohol intake compared with the lowest alcohol intake (RRR, 1.10; 95 % confidence interval [CI]: 1.00–1.21; P = 0.047); no such significance was observed with other levels of alcohol intake (low intake: RRR, 1.07; 95 % CI: 0.98–1.17; P = 0.143; heavy intake: RRR, 1.09; 95 % CI: 0.99–1.21; P = 0.084). There was no evidence of a sex difference in the relative risk for coronary disease, cardiac death, stroke, or ischemic stroke between participants with low to heavy alcohol intake compared with those who never consumed alcohol or had the lowest alcohol intake.ConclusionsWomen with moderate to heavy alcohol intake had a significantly increased risk of total mortality compared with men in multiple subpopulations. Control of alcohol intake should be considered for women, particularly for young women who may be susceptible to binge drinking.Electronic supplementary materialThe online version of this article (doi:10.1186/s12889-015-2081-y) contains supplementary material, which is available to authorized users.

Selenium status and cardiovascular diseases: meta-analysis of prospective observational studies and randomized controlled trials.

Selenium was thought to have a role in cardiovascular disease (CVD) owing to its antioxidant properties; however, evidence from observational studies and randomized controlled trials (RCTs) has been inconsistent and controversial. We thus conducted a meta-analysis to assess the discrepancies between observational and randomized trial evidence. We searched MEDLINE and EMBASE for eligible prospective studies regarding the relationship between selenium and CVD up to 15 December 2013 and finally included 16 prospective observational studies and 16 RCTs. Random effects model was used to estimate the pooled relative risk (RR). Generalized least-squares trend test and restricted cubic spline model were performed to assess a linear and a nonlinear dose-response relationship. Our meta-analysis of prospective studies showed a nonlinear relationship of CVD risk with blood selenium concentrations across a range of 30-165 μg/l and a significant benefit of CVD within a narrow selenium range of 55-145 μg/l. Our meta-analyses of RCTs showed that oral selenium supplements (median dose: 200 μg/day) for 2 weeks to 144 months significantly raised the blood selenium concentrations by 56.4 μg/l (95% confidence interval (CI): 40.9, 72.0 μg/l), whereas oral selenium supplements (median: 100 μg/day) for 6 to 114 months caused no effect on CVD (RR=0.91; 95% CI: 0.74, 1.10). Our meta-analysis in prospective studies demonstrated a significant inverse association between selenium status and CVD risk within a narrow selenium range and a null effect of selenium supplementation on CVD was observed in RCTs. These findings indicate the importance of considering selenium status, dose and safety in health assessment and future study design.