Metabolic syndrome and stroke: A meta-analysis of prospective cohort studies

Background and aimThe relationships between metabolic syndrome (MetS) and risk of incident stroke are inconsistent. We summarized the evidence by a meta-analysis of prospective cohort studies.Methods and resultsWe searched the PubMed, EMBASE, and Google Scholar databases from their inception until June 2016 for prospective cohort studies investigating this research question, relevant information was extracted by two independent investigators, and then aggregated using the fixed-effects models.We identified 16 studies, including 116,496 participants who were initially free of cardiovascular diseases. Comparing the persons without MetS, those with MetS have a significantly higher risk of incident stroke, and the pooled relative risk (RR) was 1.70 (95% confidence interval (CI): 1.49–1.95). Subgroup analyses suggested that women were more sensitive to this effect (with an RR of 1.83, 95% CI: 1.31–2.56) than men (RR = 1.47 (95% CI: 1.22–1.78). And those with MetS have a significantly higher risk of ischemic stroke (RR = 2.12, 95% CI: 1.46–3.08) than hemorrhagic stroke (RR = 1.48, 95% CI: 0.98–2.24).ConclusionsThis meta-analysis suggests that metabolic syndrome might be an important risk factor of stroke, particularly among women and those with ischemic stroke.     

Migraine and the risk of stroke: an updated meta-analysis of prospective cohort studies

Dozens of observational studies and two meta-analyses have investigated the association of migraine with the risk of stroke, but their results are inconsistent. We aimed to quantitatively evaluate the relationship between migraine and stroke risk by performing a meta-analysis of prospective cohort studies. PubMed and Embase were searched through July 2016 to identify studies that met pre-stated inclusion criterion and reference lists of retrieved articles were also reviewed. Information on the characteristics of the included study, risk estimates, and control for possible confounding factors were extracted independently by two authors. The random-effects model was used to calculate the pooled risk estimates. Eleven prospective cohort studies involving 3371 patients with stroke and 2,221,888 participants were included in this systematic review. Compared with non-migraineurs, the pooled relative risks of total stroke, hemorrhagic stroke, and ischemic stroke for migraineurs were 1.55 [95% confidence interval (CI) 1.38–1.75], 1.15 (95% CI 0.85–1.56), and 1.64 (95% CI 1.22–2.20), respectively. Exception of any single study did not materially alter the combined risk estimate. Integrated epidemiological evidence supports that migraine should be associated with the increased risk of total stroke and ischemic stroke, but the relationship between migraine and the risk of hemorrhagic stroke is not of certainty.     

Schizophrenia and the risk of cardiovascular diseases: A meta-analysis of thirteen cohort studies

Background

Numerous studies have investigated the relationship between schizophrenia and the incidence of cardiovascular disease (CVD), but their results were not entirely consistent. Our study aimed to elucidate the association between schizophrenia and the risk of CVD by a meta-analysis of cohort studies.

Methods

PubMed, the Cochrane Library, and EMBASE databases were searched to identify relevant studies that met the prespecified inclusion criteria. We also reviewed reference lists from the retrieved articles. Relative risks (RRs) and 95% confidence intervals (CIs) were extracted and pooled using the fixed-effect or random-effects models.

Results

Thirteen studies involving 3,549,950 participants, with outcomes of CVD reported for 422,698, were included in the meta-analysis. The follow-up period ranged from 1.6 to 36.0 years. The meta-analysis found that the pooled RRs for schizophrenia compared with the reference group were 1.53 (95% CI: 1.27–1.86) for the incidence of CVD, 1.20 (95% CI: 0.93–1.53) for coronary heart disease (CHD), 1.71 (95% CI: 1.19–2.46) for stroke, and 1.81 (95% CI: 1.42–2.29) for congestive heart failure (CHF). Sensitivity analysis after the exclusion of a single cohort or using the unadjusted RRs yielded similar results to the primary overall estimations. No evidence of publication bias was observed.

Conclusions

Schizophrenia is associated with increased incidence of CVD, stroke and CHF, and might also increase the risk of CHD. Greater attention should be paid to schizophrenia patients to prevent the occurrence of CVD and to decrease the risk of cardiac morbidity.     

Coffee,caffeine, and risk of completed suicide: Results from three prospective cohorts of American adults

Objective.To evaluate the association between coffee and caffeine consumption and suicide risk in three large-scale cohorts of US men and women. Methods. We accessed data of 43,599 men enrolled in the Health Professionals Follow-up Study (HPFS, 1988–2008), 73,820 women in the Nurses’ Health Study (NHS, 1992–2008), and 91,005 women in the NHS II (1993–2007). Consumption of caffeine, coffee, and decaffeinated coffee, was assessed every 4 years by validated food-frequency questionnaires. Deaths from suicide were determined by physician review of death certificates. Multivariate adjusted relative risks (RRs) were estimated with Cox proportional hazard models. Cohort specific RRs were pooled using random-effect models. Results. We documented 277 deaths from suicide. Compared to those consuming ≤ 1 cup/week of caffeinated coffee (< 8 oz/237 ml), the pooled multivariate RR (95% confidence interval [CI]) of suicide was 0.55 (0.38–0.78) for those consuming 2–3 cups/day and 0.47 (0.27–0.81) for those consuming ≥ 4 cups/day (P trend < 0.001). The pooled multivariate RR (95% CI) for suicide was 0.75 (0.63–0.90) for each increment of 2 cups/day of caffeinated coffee and 0.77 (0.63–0.93) for each increment of 300 mg/day of caffeine. Conclusions. These results from three large cohorts support an association between caffeine consumption and lower risk of suicide.     

Cigarette smoking and the incidence of Parkinson's disease in two prospective studies.

An inverse association between cigarette smoking and idiopathic Parkinson's disease has been reported in several retrospective studies, but prospective evidence is available only for men. We assessed the association between the incidence of Parkinson's disease and smoking in two large prospective cohort studies comprising men and women. New cases of Parkinson's disease were identified in the Nurses' Health Study for 1976-1996, and in the Health Professionals Follow-up Study for 1986-1996. Smoking history was assessed at baseline and updated on subsequent biennial questionnaires. In women, the age-adjusted rate ratios (95% confidence intervals) for Parkinson's disease relative to never-smokers were 0.7 (0.5, 1.0) for past smokers, and 0.4 (0.2, 0.7) for current smokers. In men, the age-adjusted rate ratios for Parkinson's disease relative to never-smokers were 0.5 (0.4, 0.7) for past smokers, and 0.3 (0.1, 0.8) for current smokers. In both cohorts, the strength of the association decreased with time since quitting (among past smokers), increased with number of cigarettes per day (among current smokers), and increased with pack-years of smoking. These prospective findings confirm that an inverse association between smoking and the incidence of Parkinson's disease exists in both men and women.     

Psychotic (delusional) depression and completed suicide: a systematic review and meta-analysis

Background

It remains unclear whether psychotic features increase the risk of completed suicides in unipolar depression. The present systematic review coupled with a meta-analysis attempts to elucidate whether unipolar psychotic major depression (PMD) compared to non-PMD presents higher rates of suicides.

Methods

A systematic search was conducted in Scopus, PubMed, and “gray literature” for all studies providing data on completed suicides in PMD compared to non-PMD, and the findings were then subjected to meta-analysis. All articles were independently extracted by two authors using predefined data fields.

Results

Nine studies with 33,873 patients, among them 828 suicides, met our inclusion criteria. PMD compared to non-PMD presented a higher lifetime risk of completed suicides with fixed-effect pooled OR 1.21 (95% CI 1.04–1.40). In a sub-analysis excluding a very large study (weight?=?86.62%), and comparing 681 PMD to 2106 non-PMD patients, an even higher pooled OR was found [fixed-effect OR 1.69 (95% CI 1.16–2.45)]. Our meta-analysis may provide evidence that the presence of psychosis increases the risk of suicide in patients suffering from severe depression. The data are inconclusive on the contribution of age, mood congruence, comorbidity, and suicide method on PMD’s suicide risk. The lack of accurate diagnosis at the time of suicide, PMD’s diagnostic instability, and the use of ICD-10 criteria constitute the main study limitations.

Conclusions

The presence of psychosis in major depression should alert clinicians for the increased risk of completed suicide. Thus, the implementation of an effective treatment both for psychotic depression and patients’ suicidality constitutes a supreme priority.

     

Prevalence of exposure to suicide: A meta-analysis of population-based studies

Those exposed to suicide are at increased risk of adverse outcomes including mental illness, impaired social functioning, and fatal and non-fatal suicidal behavior. However, it is unclear how many people are exposed to suicide in the general community. This first meta-analysis of population-based studies aimed to provide pooled estimates of past-year and lifetime prevalence of exposure to suicide among family, friends/peers, and all relationships. In addition, the study examined prevalence of exposure to suicide by age group: adolescents and adults. Systematic searches of the literature in Embase, Medline and PsycINFO identified eighteen studies that were included in the analysis. Pooled past-year prevalence was 4.31% (CI: 2.50 to 6.58) and life-time prevalence 21.83% (CI: 16.32 to 27.90). Both past-year and lifetime prevalences of exposure to suicide among friends and peers were significantly higher than the prevalence of exposure within families; there were no differences in the prevalence of exposure to suicide between adolescents and adults. Heterogeneity was highly significant. Future research should be conducted with large national representative samples and use standardised assessment instruments. Given the increased risks of adverse outcomes among those exposed to suicide, the high rate of exposure to suicide reported here has important ramifications for public health and mental health service delivery.     

Cigarette smoking and risk of primary intracerebral haemorrhage

From September 1985 to December 1989 a total of 158 patients had primary intracerebral haemorrhage in the population of 116000 in the Jyväskylä Region, Central Finland. All had the diagnosis confirmed by either computerised tomography or necropsy, and information on cigarette smoking habits was available in 155 patients, 20% of whom were current cigarette smokers. One control was selected for each of the 155 patients matched on sex, age, and residence from the census of Central Finland. The odds ratio of primary intracerebral haemorrhage of current cigarette smokers compared with current non-smokers was estimated on basis of the number of discordant pairs as 1.4 (95% confidence interval 0.7 to 2.8). Adjustment for hypertension or diabetes did not change this estimate. Our data did not show evidence of an positive association of cigarette smoking and risk of primary intracerebral haemorrhage. This assumption was strenghtened when the results of previous studies and the present study were pooled giving an odds ratio of 1.0 (95% confidence interval 0.8 to 1.3).     

Social disorganization and completed suicide

Summary It has been found in Edinburgh, Scotland that the incidence of completed suicide is very common in areas of the city where there is a high degree of social disorganization, such as overcrowding and juvenile delinquency. A study in the city of Buffalo in the United States failed to replicate this finding. It appears possible, therefore, that the types of people who kill themselves (at least as determined by ecological studies) may differ considerably in Edinburgh and in Buffalo. The implications of this study are important since preventative measures for suicide would have to differ for the two countries were this true. Overcoming social disorganization would be expected, for example, to have an ameliorative effect on suicidal behavior in Edinburgh but not in Buffalo.

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Zusammenfassung In Edinburgh, Schottland, wurde gefunden, daß der vollendete Suicid in Innenstädten, wo ein hoher Grad sozialer Zerrüttung, wie Überbevölkerung und Jugenddeliquenz herrscht, sehr verbreitet ist. Eine Untersuchung in der Innenstadt von Buffalo in den Vereinigten Staaten bestätigte dies allerdings nicht. Es erscheint daher als möglich, daß die Wesensart der Leute, die sich umbringen (so wie sie wenigstens durch ökologische Untersuchungen bestimmt werden), in Edinburgh und in Buffalo verschieden ist. Die Folgerungen aus dieser Studie sind bedeutsam, da die präventiven Maßnahmen für Suicid sich in den beiden Ländern unterscheiden müßten, wenn sich das so verhielte. Man würde erwarten, daß die Überwindung der sozialen Zerrüttung sich beispielsweise in Edinburgh auf suicidales Verhalten heilsam auswirken würde, aber nicht in Buffalo.

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Résumé A Edinburgh, en Ecosse, on a trouvé que l'incidence des suicides réussis est très fréquente dans les zones urbaines où règne une grande désorganisation sociale (surpopulation, délinquance juvénile, etc.). Une étude réalisée dans la ville de Buffalo aux USA n'a pas confirmé ce résultat. Il semble donc possible que les genres de personnes qui se tuent (du moins tels qu'ils sont déterminés par les études écologiques) diffèrent considérablement à Edinburgh et à Buffalo. Les implications de cette étude sont importantes puisque, si c'est vrai, les mesures préventives du suicide devraient alors différer dans les deux pays. On pourrait s'attendre par exemple à ce qu'une organisation sociale améliorée ait un effet favorable sur le comportement suicidaire à Edinburgh, mais pas à Buffalo.

     

The impact of parental status on the risk of completed suicide

BACKGROUND: Although some studies suggest that parenthood is associated with a reduced suicide risk, the impact of children on parental suicide has rarely been documented. METHODS: This study investigates the impact of parental status on the risk of completed suicide in the context of other risk factors. A nested case-control design is used, matching for age, sex, and calendar time. The study is based on 4 Danish longitudinal registers, including 18 611 suicides of individuals aged 18 to 75 years from January 1, 1981, to December 31, 1997, and 372 220 matched control subjects. Information about children and subject's individual background is retrieved and merged. Data are analyzed using conditional logistic regression, yielding odds ratios interpreted as incidence rate ratios. RESULTS: The presence of children is protective against suicide in parents in terms of having children and, to a higher degree, having a young child; these effects exist even when adjusted for marital, socioeconomic, and psychiatric status; and their influences are much stronger in women than in men. At the same time, parents of children with a hospitalized psychiatric disorder and parents of children who have died are at an increased risk for suicide. A child dying during early childhood has a strong effect on suicide in parents, and a suicidal death of a child increases the risk of parental suicide more than a nonsuicidal death. The suicide risk is particularly high in the first month after losing a child. CONCLUSIONS: The impact of children on parental suicide can be protective because of having children. It can also be negative, for example, when losing a child, particularly if the child dies during early childhood; the risk is particularly high during the first month after the loss.     

Alzheimer's disease and smoking: bias in cohort studies

The discrepancy between cohort and case-control studies regarding the association between smoking and Alzheimer's disease (AD) has been attributed to the competing risk of early mortality of smokers. A simulation study was conducted to show that the bias favoring smokers acts also on cohort studies. In the model, individuals {grow older} and have smoking habits according to published year-age-gender-specific patterns, with morbidity and mortality according to their demographic and smoking profiles. Those individuals dying of smoking-related causes ("phantoms") remain at risk of AD and of death from other causes. Three scenarios were considered: no association of AD and smoking, increased risk for smokers, and decreased risk for smokers. For each simulation of a cohort study, two incidence density ratios (IDR) were computed: one including the phantoms that developed AD (thus ignoring smoking-related deaths) and another excluding them (thus mimicking real-life studies). For all scenarios, the simulations show that smoking-related death creates a bias, resulting in smokers having an understated risk of AD compared to non-smokers. The speculation that the conflicting results of case-control and cohort studies are solely due to the increased mortality in smokers thus appears unjustified. Other factors must also be considered to explain the discrepancy in results.     

Spatial navigation and risk of cognitive impairment: A prospective cohort study

Introduction

Spatial navigation deficits are reported in dementia, but their temporal relationship to cognitive decline is not established.