Factors involved in the anaemia of chronic disorders in elderly patients

Anemia in Association with Cognitive Impairment: A Systematic Review and Meta-Analysis

BACKGROUND

Prevalence of both anemia and cognitive impairment tends to increase with age. Individual studies have recently shown that anemia could be associated with cognitive impairment.

OBJECTIVE

To investigate the association between anemia and cognitive impairment including dementia.

METHODS

Two of the authors systematically searched PubMed, EMBASE, and the Cochrane library to retrieve observational studies reporting a relationship between anemia and cognitive impairment from 1964 to July 10, 2019. Case-control and cohort studies were included, and odds ratios (ORs) or relative risks (RRs) with 95% confidence intervals (CIs) for the risk of cognitive impairment were calculated using a random-effects model.

RESULTS

In total, 16 observational studies including eight case-control studies and eight cohort studies were included in the final analysis. Anemia was significantly linked to cognitive impairment (OR or RR 1.51; 95% CI: 1.32-1.73) in a random-effects meta-analysis, albeit with medium heterogeneity (I2 = 47.8%). Meta-estimates of dementia from prospective population-based cohort studies were similar (RR 1.46; 95% CI: 1.22-1.76) without substantial heterogeneity (I2 = 23.2%).

CONCLUSION

Our meta-analysis indicates that anemia is associated with cognitive impairment. Further prospective research is warranted to determine the cause-effect relationship of anemia with cognitive impairment and whether treatment of anemia might reduce the risk of dementia.

Relationship between anaemia and cognitive functions in elderly people

BACKGROUND

The primary goal of the present study was to investigate the effects of anaemia on the cognitive functions and daily living activities in elderly people.

METHODS

This sectional study was performed using 180 elderly people. Face-to-face interviews and questionnaires were conducted to evaluate daily activities. To evaluate cognitive functions we used the Folstein's Mini-Mental State Examination (MMSE).

RESULTS

The mean age of the anaemic group and the nonanaemic group were 76.0+/-11.7 and 72.5+/-15.2 years, respectively. The average haemoglobin level among the anaemic population was 10.4 g/dL compared with 13.6 g/dL among the nonanaemic population; a statistically significant difference. There was more impairment in functional status (Katz ADL) (6.8+/-4.3 vs 9.3+/-3.7) and cognition (MMSE) (17.9+/-6.4 vs 21.7+/-6.7) in anaemic than nonanaemic groups, respectively. Albumin and body mass index were lower and the percentage of two or more comorbidities was higher in anaemic group compared to the nonanaemic group, which was a statistically significant variation. The anaemic group was more dependent in terms of bathing, dressing, toileting and transferring.

CONCLUSION

In the elderly anaemic group, the dependency for daily activities that require physical effort was higher compared to the nonanaemic group. The MMSE score in the elderly anaemic group was lower than subjects who had normal haemoglobin levels. We conclude that anaemia may impair cognitive functions and some daily living activities in the elderly.

Longitudinal trends of hemoglobin levels in a Japanese population--RERF's Adult Health Study subjects

Conflicting results have been reported on the long-term relationship between hemoglobin (Hb) level and age. We analyzed that relationship over a 40-yr period in a Japanese population, adjusting for the effects of sex, birth cohort, smoking, and anemia-associated diseases. We used Hb levels measured biennially between 1958 and 1998 for 4858 Adult Health Study subjects of the Radiation Effects Research Foundation. Using the mixed-effects model, we showed that the aging Hb profile varied by sex (P < 0.001) and birth cohort (P < 0.001). Male Hb levels peaked in the third and fourth decades and then decreased while female Hb levels dipped slightly in the third decade, peaked in the sixth and seventh, and then decreased. Levels were higher in younger cohorts. The rate of Hb decline after the sixth decade of life was greater for subjects with anemia-associated diseases (P = 0.002). The annual rate of decline between 70 and 80 yr of age for disease-free men ranged from 0.083 to 0.042 g/dL and for disease-free women from 0.049 to 0.036 g/dL. Levels were higher for ever-smokers (P < 0.001), more so for women than men. A decreasing trend in Hb concentration with advancing age was detected for elderly men and women after controlling for anemia-associated diseases, suggesting that anemia in the elderly is due not only to disease but also to aging. Cohort and smoking effects on Hb levels were also observed.