Clinical Investigation
Relations of Anemia With the All-Cause Mortality and Cardiovascular Mortality in General Population: A Meta-Analysis

https://doi.org/10.1016/j.amjms.2019.05.016Get rights and content

Abstract

Background

Anemia may be an independent risk factor of death. Therefore, the current meta-analysis aimed to explore the relationship of anemia with all-cause mortality (ACM) and cardiovascular mortality (CVM) to provide evidence-based medical facts.

Methods

Three major electronic databases, the National Library of Medicine of the USA (PubMed), Cochrane Library and Embase, were searched from inception to October 2018. Relevant studies were screened in strict accordance with the inclusion and exclusion criteria, and the pooled hazard ratios (HRs) together with the 95% confidence intervals (CIs) were performed to assess the statistically significant difference of anemia compared with ACM and CVM.

Results

A total of 15 related studies were included. Our results suggested that among the mixed population regardless of sex, age and cardiovascular diseases (CVD), the ACM and CVM of anemia patients were increased, with the HRs and 95% CIs of 1.41 (1.33, 1.50) and 1.33 (1.23, 1.45), respectively. Meanwhile, the ACM of anemia patients with the mean age of over 65 or below 65 years was increased irrespective of sex and CVD, with the HRs and 95% CIs of 1.43 (1.26, 1.61) and 1.41 (1.32, 1.50), separately. Moreover, the risks of ACM were increased in male, female and mixed sex anemia patients despite age and CVD, with the HRs and 95% CIs of 1.39 (1.29, 1.49), 1.25 (1.20, 1.30) and 1.53 (1.39, 1.68), respectively. All patients with CVD and no CVD were associated with an increased risk of ACM regardless of age and sex, with the HRs and 95% CIs of 1.42 (1.33, 1.51) and 1.38 (1.16, 1.63), respectively.

Conclusions

Anemia is a risk factor to predict ACM and CVM among the general population, which is independent of sex, age, and history of CVD.

Section snippets

INTRODUCTION

Anemia is more common among clinical patients, especially for patients with cardiovascular diseases (CVD). It is suggested in numerous studies that anemia may be an independent risk factor of hospitalization and death.1, 2, 3, 4, 5 In addition, some studies indicate that hemoglobin shows a parabolic rather than linear relationship with mortality at both a very high or very low concentration level, which is associated with an increased risk.6, 7, 8 Currently, the vast majority of studies

Search Strategy

This meta-analysis was carried out based on the PRISMA 2009 flow diagram, the preferred guideline for systematic meta-analysis (www.prisma-statement.org).9 Three major electronic databases, the National Library of Medicine of the USA (PubMed), Cochrane Library and Embase, were searched from inception to October 2018 with no language restrictions. Two sets of keywords including hemoglobin and mortality are retrieved, the detailed search strategies are listed in the Appendix Table 1.

RESULTS

The literature retrieval process and search results are displayed in Figure 1. In this meta-analysis, a total of 10,430 studies (including 6,651 from the PubMed, 1,732 from the Cochrane library and 2,047 from the Embase) were retrieved from the global e-medical databases. After removing the duplicates, 9,994 studies remained. Moreover, 9,702 studies were clearly unrelated after further reading titles and abstracts. Then, the full texts of the remaining 292 studies were reviewed in detail. Two

DISCUSSION

Anemia is a common clinical disease, which is particularly common among the elderly.15, 24 Results of our meta-analysis suggested that anemia would increase the risks of ACM and CVM, which was not related to sex, age or CVD in patients, indicating that anemia was an independent risk factor of ACM and CVM. Our results were consistent with the study by Mamas et al in 2016.19 Moreover, the study of Puurunen et al published in 2014 found that anemia was an independent predictor of ACM in their

CONCLUSIONS

Anemia is a risk factor to predict the ACM and CVM among the general population, which is independent of sex, age and the history of CVD.

References (24)

  • S Hamaguchi et al.

    Anemia is an independent predictor of long-term adverse outcomes in patients hospitalized with heart failure in Japan. A report from the Japanese Cardiac Registry of Heart Failure in Cardiology (JCARE-CARD)

    Circ J

    (2009)
  • A Martinsson et al.

    Anemia in the general population: prevalence, clinical correlates and prognostic impact

    Eur J Epidemiol

    (2014)
  • Cited by (20)

    • Effect of Chronic Kidney Disease or Anemia or Both on Cardiovascular Mortality in a 25-Year Follow-Up Study of Japanese General Population (From NIPPON DATA90)

      2022, American Journal of Cardiology
      Citation Excerpt :

      A large, globally pooled analysis showed a 1.1- to 1.8-fold increased risk for CVD mortality in patients with CKD compared with that in patients without CKD.26 In a large meta-analysis, the risk for CVD mortality in patients with anemia increased by 1.3- to 1.4-fold.27 The previous results concerning the relationship between CKD and CVD are consistent with those of the present study.

    • Diagnosis and prediction of COVID-19 severity: can biochemical tests and machine learning be used as prognostic indicators?

      2021, Computers in Biology and Medicine
      Citation Excerpt :

      All developed ML-based models (ANN, PLS-DA, KNN, and DT) highlighted that the differences in the levels of these two biomarkers were critical, both for the prediction of COVID-19 diagnosis and disease severity. Recent studies have indicated anaemia and hyperferritinaemia to be strong biomarkers for the prognosis of mortality due to SARS-CoV-2, in addition to other serious respiratory diseases [45–50]. Ferritin is a protein found mainly in the liver, bone marrow, and spleen and is the body's main source of iron storage.

    • Eliminating race-based reference ranges in haematology: a call to action

      2021, The Lancet Haematology
      Citation Excerpt :

      We are well versed in the physiology of haemoglobin, anaemia, and iron metabolism and have no scientific or biological basis for tolerating anaemia or iron deficiency more liberally simply because of an individual's race or ethnicity. This is not simply a matter of semantics, because anaemia is a common and serious health condition, associated with all-cause mortality,61 cardiovascular mortality,62 mortality post-stroke,63 maternal and perinatal morbidity and mortality,64 and decreased survival for several malignancies.65 Similarly, iron deficiency is a condition with substantial morbidity, including not only fatigue and a decreased quality of life, but also neurodevelopmental and cognitive impairments in undiagnosed or inadequately treated young children.66

    • Treatment outcomes of drug resistant tuberculosis patients with multiple poor prognostic indicators in Uganda: A countrywide 5-year retrospective study

      2021, Journal of Clinical Tuberculosis and Other Mycobacterial Diseases
      Citation Excerpt :

      Among the poor prognostic indicators, anaemia, a modifiable poor prognostic indicator, was identified as a risk factor for an unsuccessful treatment outcome in a dose-dependent fashion (the risk increased with severity of anaemia). In the general population, anaemia is a recognised independent predictor of all-cause mortality regardless of age, sex and cardiovascular disease (HR: 1.41) [30]. Similar to our finding, anaemia has been reported to predict poor treatment outcomes of DR – TB patients in Ethiopia [11].

    View all citing articles on Scopus

    Funding: None.

    Competing Interests: The authors have no conflicts of interest to disclose.

    #

    Zhou Liu and Rong Sun are co-first authors with equal contribution.

    View full text