scholarly journals Vitamin B12 status, cognitive decline and dementia: a systematic review of prospective cohort studies

2012 ◽  
Vol 108 (11) ◽  
pp. 1948-1961 ◽  
Author(s):  
Fiona O'Leary ◽  
Margaret Allman-Farinelli ◽  
Samir Samman
Keyword(s):  
Systematic Review ◽  
Cohort Studies ◽  
Cognitive Decline ◽  
Quality Assessment ◽  
Prospective Cohort ◽  
Methylmalonic Acid ◽  
Serum Vitamin ◽  
Assessment Tools ◽  
Vitamin B ◽  
Prospective Cohort Studies

Poor vitamin B12 status may lead to the development of cognitive decline and dementia but there is a large variation in the quality, design of and results reported from these investigations. We have undertaken a systematic review of the evidence for the association between vitamin B12 status and cognitive decline in older adults. A database search of the literature to 2011 was undertaken, using keywords related to vitamin B12 and cognition. All prospective cohort studies assessing the association of serum vitamin B12 or biomarkers were included. Quality assessment and extraction of the data were undertaken by two researchers. The quality assessment tool assigns a positive, neutral or negative rating. Of 3772 published articles, thirty-five cohort studies (n 14 325 subjects) were identified and evaluated. No association between serum vitamin B12 concentrations and cognitive decline or dementia was found. However, four studies that used newer biomarkers of vitamin B12 status (methylmalonic acid and holotranscobalamin (holoTC)) showed associations between poor vitamin B12 status and the increased risk of cognitive decline or dementia diagnosis. In general, the studies were of reasonable quality (twenty-one positive, ten neutral and four negative quality) but of short duration and inadequate subject numbers to determine whether an effect exists. Future studies should be of adequate duration (at least 6 years), recruit subjects from the seventh decade, choose markers of vitamin B12 status with adequate specificity such as holoTC and/or methylmalonic acid and employ standardised neurocognitive assessment tools and not screening tests in order to ascertain any relationship between vitamin B12 status and cognitive decline.

Association between anaemia and adult depression: a systematic review and meta-analysis of observational studies

2020 ◽  
pp. jech-2020-213842
Author(s):  
Yong-Jae Lee ◽  
Hong-Bae Kim
Keyword(s):  
Systematic Review ◽  
Cohort Studies ◽  
Prospective Cohort ◽  
Observational Studies ◽  
Methodological Quality ◽  
Meta Analysis ◽  
Assessment Tools ◽  
Cochrane Library ◽  
Prospective Cohort Studies ◽  
Adult Depression

BackgroundSeveral observational studies have been conducted to investigate the link between anaemia and adult depression but have shown inconsistent results. This systematic review and meta-analysis was performed to investigate this association.MethodsA comprehensive search of four electronic databases (PubMed, EMBASE, PsycINFO and the Cochrane Library) was conducted to identify relevant papers published up to November 2019 for the systematic review and meta-analysis. The Newcastle-Ottawa Scale was used to assess the methodological quality of selected studies. A random-effects model was used to draw metaestimates of the relationship between anaemia and adult depression.ResultsA total of 9706 papers were retrieved, and 14 observational epidemiological studies (9 case–control studies and 5 prospective cohort studies) comprising 10 764 cases of depression were finally included in this meta-analysis. The mean age of the participants ranged from 38.4 to 75.0 years. A significant association was identified between low haemoglobin levels and adult depression (OR or relative risk 1.43; 95% CI 1.23 to 1.65). Subgroup analyses according to study design, mean age, diagnostic criteria of anaemia, geographical region, number of participants, methodological quality and adjustment for various confounding factors such as education, smoking, comorbid disorders, physical activity, alcohol intake and medication use showed similar results.ConclusionsThe current study showed that anaemia was related to an increased risk of adult depression. One of the important limitations of our study was a moderate degree of heterogeneity due to the variety of assessment tools used to identify depression and the existence of publication bias. Another limitation of this meta-analysis was the lack of prospective cohort studies.

scholarly journals Customary physical activity and odds of depression: a systematic review and meta-analysis of 111 prospective cohort studies

2021 ◽  
pp. bjsports-2020-103140
Author(s):  
Rodney K Dishman ◽  
Cillian P McDowell ◽  
Matthew Payton Herring
Keyword(s):  
Physical Activity ◽  
Systematic Review ◽  
Depressive Symptoms ◽  
Cohort Studies ◽  
Prospective Cohort ◽  
Observational Studies ◽  
Meta Analysis ◽  
Vigorous Physical Activity ◽  
Prospective Cohort Studies ◽  
Over Time

ObjectiveTo explore whether physical activity is inversely associated with the onset of depression, we quantified the cumulative association of customary physical activity with incident depression and with an increase in subclinical depressive symptoms over time as reported from prospective observational studies.DesignSystematic review and meta-analysis.Data sourcesMEDLINE, PsycINFO, PsycARTICLES and CINAHL Complete databases, supplemented by Google Scholar.Eligibility criteriaProspective cohort studies in adults, published prior to January 2020, reporting associations between physical activity and depression.Study appraisal and synthesisMultilevel random-effects meta-analysis was performed adjusting for study and cohort or region. Mixed-model meta-regression of putative modifiers.ResultsSearches yielded 111 reports including over 3 million adults sampled from 11 nations in five continents. Odds of incident cases of depression or an increase in subclinical depressive symptoms were reduced after exposure to physical activity (OR, 95% CI) in crude (0.69, 0.63 to 0.75; I2=93.7) and adjusted (0.79, 0.75 to 0.82; I2=87.6) analyses. Results were materially the same for incident depression and subclinical symptoms. Odds were lower after moderate or vigorous physical activity that met public health guidelines than after light physical activity. These odds were also lower when exposure to physical activity increased over time during a study period compared with the odds when physical activity was captured as a single baseline measure of exposure.ConclusionCustomary and increasing levels of moderate-to-vigorous physical activity in observational studies are inversely associated with incident depression and the onset of subclinical depressive symptoms among adults regardless of global region, gender, age or follow-up period.

Risk of hypertension among different metabolic phenotypes: a systematic review and meta-analysis of prospective cohort studies

2018 ◽  
Vol 33 (5) ◽  
pp. 365-377 ◽  
Author(s):  
Atieh Mirzababaei ◽  
Hadis Mozaffari ◽  
Sakineh Shab-Bidar ◽  
Alireza Milajerdi ◽  
Kurosh Djafarian
Keyword(s):  
Systematic Review ◽  
Cohort Studies ◽  
Prospective Cohort ◽  
Meta Analysis ◽  
Metabolic Phenotypes ◽  
Prospective Cohort Studies
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