Population baseline numbers|
descriptive Length of follow up
|Type of study main outcome||Measurements Of cognition or hand grip||Measurements Of anemia||Adjusted for:||Relationship between anemia and cognitive||Statistics|
|Trevisa-n et al 2016 ||e Progetto Veneto Anziani project on, Italian population, 1227 participants older than 65 years old, without cognitive impairment mean follow up 4.4 (1.2SD) years||Cohort the onset of the cognitive impairment||the 30-item Mini-Mental State Examination (MMSE)||
Based on WHO criteria|
Samples were Divided into the gender-specific Hb tertiles using the following cut-offs: 13.9 and 14.9 g/dL for men; and 12.8 and 13.7 g/dL for women.
|Age, sex, education, smoking, alcohol, monthly income, living alone, physical activity, BMI, hearing loss, vision loss, hypertension, CVD, COPD, OAD, diabetes, cancer||Low hg concentration Increases the risk of cognitive impairment in the elderly, apparently with a stronger association in men than in women.||
Participants with the lowest Hb concentrations had a significant 37% higher risk (95% confidence interval [CI]: 1.08–1.75; p = 0.01) of being diagnosed with cognitive impairment.|
Considering the gender separately, the risk of cognitive impairment only increased significantly, by 60%, for men in the lowest Hb tertile (95% CI: 1.06–2.41; p = 0.02), but not for women (hazard ratio = 1.32; 95% CI: 0.97–1.79; p = 0.08).
|Dlugaja et al 2015 ||
4033 participants from mandatory city registries in the Ruhr area in Germany, participant 45 to 75 years of age|
Five years follow up
Anemia and mild cognitive impairment
verbal memory measured by a word list consisting of eight words from the Nuremberg Geriatric Inventory|
Speed of processing/executive functioning was measured using the labyrinth test, a paper-pencil test from the NAI
For mild cognitive impairment diagnosis: Participants were asked if their cognitive performance changed during the past two years, then statistical manual of mental disorders,
|WHO criteria hemoglobin level < 13 g/dl in men and < 12 g/dl in women||Age, gender, BMI, education, diabetes, blood pressure hypertension, stroke, cancer, depression scale, smoking status, total cholesterol||Anemic participants showed lower performances in verbal memory and executive functions||Adjusted Odds ratios (OR) for mild cognitive impairment (MCI), amnestic- MCI, and non-amnestic-MCI in anemic versus non-anemic participants were 1.92 (95%-CI, 1.09–3.39), 1.96 (1.00–3.87), and 1.88 (0.91–3.87).|
|Payne et al 2018 ||4499 men and women aged 40 and over||cross-sectional data from a population-based study of rural South African men and women physical and cognitive performance||
Grip strength was measured twice in both hands, using a Smedley digital dynamometer (12–0286).|
Walk speed was measured by asking participants to walk a 2.5 m course twice, with the time taken timed to the nearest 0.1 s.
Cognitive performance was assessed with a cognitive battery adapted for language, cultural, and educational appropriateness from validated measures used in the U.S. Health and Retirement Study.
|Hg concentration < 12 g/dL for women and < 13 g/dL for men||Age, sex, education, Median C reactive protein concentration, HIV, hypertension, diabetes mellitus, mean body mass index, and self-reported angina, chronic bronchitis, and stroke||
There was no association between hemoglobin levels and walk speed or cognitive score|
Hemoglobin concentration Was independently associated With grip strength
|Hemoglobin concentration Was independently associated With grip strength in women when covariates were included in the model (B = 0.391; 95% CI 0.177 to 0.605), but this association was not statistically significant in men (B = 0.266; 95% CI − 0.019 to 0.552|
|Qin et al 2019 ||9324 adults aged 45 years or older from the China Health and Retirement Longitudinal Study||
Association between Anemia and cognitive decline among Chinese middle-aged and elderly
|Cognitive performance assessed by memory recall (episodic memory), mental status (TICS), and global cognitive function at baseline survey||WHO criteria hemoglobin level < 13 g/dl in men and < 12 g/dl in women||Age, gender, education, marital status, cigarette, smoking, body mass index, hypertension, diabetes, abdominal adiposity, chronic pain, dyslipidemia, CRP, HDL, and cholesterol||
This study found a cross-sectional and longitudinal association between Anemia and accelerated decline in cognitive functions in Chinese middle-aged and elderly|
The hemoglobin concentration Was associated with global cognitive function global -cognitive function and episodic- memory was associated with anemia independent of covariates
|After adjusting for socio-demographic and health-related covariates, the cross-sectional association between anemia and global cognitive function [β (95%CI) = − 0.49(− 0.69 ~ − 0.29)], episodic memory [β (95%CI) = − 0.14(− 0.23 ~ − 0.05)], and TICS [β (95%CI) = − 0.23(− 0.38 ~ − 0.08)] were significant and did not differ by gender.|
|Joosten Et al 2016 ||220 patients aged 70 years and older||
The relationship Between Anemia and handgrip and walking speed
|Handgrip strength was assessed with a hydraulic hand dynamometer. Gait speed (in meters per second) was calculated after a 4.5 m walk ADL score||WHO criteria hemoglobin level < 13 g/dl in men and < 12 g/dl in women||Sex, age, BMI, ADL, CRP, GFR, MMSE mean, cancer, gastrointestinal diseases, −Neuropsychiatric diseases, Falls-fractures-osteoporosis||Handgrip, ADL score, and gait speed were not significantly different in anemic and non-anemic person||No significant correlation was found between the hemoglobin values and the hand-grip strength (Spearman’s rho 0.112, p = 0.1) and walking speed (Spearman’s rho 0.04, p = 0.69)|
|Hong- bae et al 2019 .||16 observational studies, including eight case-control studies and eight cohort studies, were included in the final analysis In total, 16,765 cognitive impairment cases were surveyed in the meta-analysis.||Meta-Analyzed Studies reporting a relationship between Anemia and cognitive impairment from 1964 to July 10, 2019||cognitive impairment in four articles was diagnosed using a cut-off score of 24 on the MMSE, and one article used the International Working Group (IWS) criteria||anemia was defined according to the WHO criteria of hemoglobin level < 13 g/dl in men and < 12 g/dl in women||gender, mean age, duration of follow-up in cohort studies, number of participants, methodological quality, and studies that adjusted for education, cardiovascular risks, smoking status, apolipoprotein E carrier status, alcohol consumption, and physical activity were used in Sub-group meta-analyses||According to this meta-analyzed, There is a relationship between Anemia and cognitive impairment||Anemia was significantly linked to cognitive impairment (OR or RR 1.51; 95% CI: 1.32–1.73) in a random-effects meta-analysis|
et al 2020 
|13,624 participants (mean ages = 51.6 years±9)||Cross-sectional study base on ELSA-Brazil Cohort||scores for verbal learning, late recall, word recognition, a semantic verbal fluency test, and the Trail-Making Test, Part B (TMT-B)||WHO criteria hemoglobin level < 13 g/dl in men and < 12 g/dl in women||Education, race, monthly family income, excessive alcohol use, thyroid function, smoking status, hypertension, diabetes, dyslipidemia, body mass index, Antipsychotic, antiparkinsonian, or anticonvulsant drug use||Hemoglobin levels were not associated with global cognitive scores,||Global cognitive scores were similar between participants with and without anemia in adjusted models for the entire sample (b = − 0.004; 95% CI = –0.052, 0.044) or separately, for men (b = 0.047; 95% CI = –0.053, 0.146) and women (b = − 0.015; 95% CI = –0.070, 0.040)|
|Jiang et al 2020 ||4838 participants 65 years old and over||Cross-sectional||CognitivefunctionwasevaluatedusingtheMini-MentalStateExamination (MMSE) and neuropsychological test battery||WHO criteria hemoglobin level < 13 g/dl in men and < 12 g/dl in women||Demographic factors, lifestyle, and clinical condition||Anemia was associated with cognitive performance There was no relationship between Anemia and dementia||Anemia was associated with a multiple-adjusted odds ratio of 1.28 (95%CI:1.041.57) for MCI and 1.27 (95% CI: 0.87–1.85) for dementia, and a multiple-adjusted β coefficient of − 0.60 (95% CI: − 0.94 to − 0.27) for MMSE score|
|Brenda et al 2004 ||1156 participants aged 65 and older from CHIANTI Study (Italy)||Used data from the Italian National Research Council of Aging||
ADL (6 item questioner)|
IADL (8 items)
Walking speed: was defined as the best performance (time in seconds) of two 4-m walks.
Standing balance: participants were asked to stand with the feet side by side, a semi tandem position, and a full-tandem position.
Chair stand test: participants were asked to stand up from and sit down in a chair five times without using hands
|World Health Organization (WHO) criteria hemoglobin level < 13 g/dl in men and < 12 g/dl in women||Age, sex, BMI, smoke, MMSE, diabetes mellitus, myocardial infection, Angina pectoris, Peripheral artery disease, Congestive heart failure, stroke, cancer, lung disease, Gastric ulcer, Hospitalization in the past year, Creatinine, mg/dL||Anemia is associated with disability, poorer physical performance, and lower muscle strength||
anemic persons had more disabilities (1.71 vs 1.04, P = 0.002) and poorer performance (8.8 vs 9.6, P = 0.003), than persons without Anemia.|
Anemic persons also had significantly lower knee extensor strength (14.1vs 15.2 kg, P = 0.02) and lower handgrip strength (25.3vs27.1 kg, P = 0.04) than persons without Anemia
|Hirani et al 2016 ||
1705 Australian men aged 70 years old and over from the Concord Health and Ageing in Men Project|
Five years follow up
|Cross-sectional study, The relationship between HG levels, and sarcopenia, low muscle strength, functional and activities of daily living (ADL), and instrumental ADL (IADL) disabilities in older||
muscle strength was assessed by handgrip and participate divided in|
grip strength less than 26.0 kg versus grip strength 26.0 kg and more.
Walking speed: was measure 4 mm speed. Participants with a walking speed of 0.8 m/s or less were classified as having low walking speed.
ADL: was assessed by seven items from a modified version of the Katz ADL scale
IADL: asks participants how much help they need to perform ten tasks considered necessary for independent living
|World Health Organization (WHO) criteria Hb level less than 13 g/dL in men||age, income, body mass index, measures of health, estimated glomerular function, inflammatory markers, and medication use||
Low hemoglobin concentration over time is associated with poor functional performance|
for every 1 g/dL increase in Hb, there was a significant reduction in risk of sarcopenia, slow walking speed, poor grip strength, inability to perform chair stands, and ADL and IADL disabilities
there was a association between Hb and grip strength|
β coefficient = 1.52, 95% CI = 1.27, 1.78 for unadjusted
β coefficient = 1.05, 95% CI = 0.80, 1.30 for age-adjusted
and β coefficient = 0.82; 95% CI = 0.55, 1.08, for multivariate-adjusted
for walking speed:
β coefficient = 0.03, 95% CI = 0.02, 0.03; for unadjusted
β coefficient = 0.01, 95% CI = 0.01, 0.02; for age-adjusted
and β coefficient = 0.01, 95% CI = 0.004, 0.02,, for multivariate-adjusted.
|Thein et al 2009 ||328 participants 65 years and older||
To determine the relationship between HG concentration and functional status, depression, disability, and physical strength, independent of chronic disease
IADL (consists of 13 questions)|
Handgrip strength: with a handheld dynamometer (in kg), using the mean value after performing the task three times
|WHO criteria hemoglobin level < 13 g/dl in men and < 12 g/dl in women||Age, sex, diabetes, hypertension, chronic inflammation, or rheumatoid arthritis||There was a significant association of Anemia with declines in health-related quality of life, functional status, and physical strength||Anemia was associated with greater fatigue (P < 0.001), lower handgrip strength (P = 0.014), and increased number of disabilities (P = 0.005)|