An estimated one in four of the world’s population was affected by anaemia in 2013. Limited progress has been made since the 1990s, despite wide recognition of its harmful impacts. The World Health Organization (WHO) thresholds for diagnosis of anaemia include adjustments for altitude, but there is concern they are not a reliable indicator at very high altitudes such as the Andean region.
In January 2021, the UK Academy of Medical Sciences held a virtual workshop with the National Academy of Sciences, Peru, to identify gaps in the knowledge that could be addressed by research in order to support a public health response to anaemia in the Andean region.
The WHO thresholds for diagnosis of anaemia take into account factors such as age and sex, with a further adjustment for altitude. However, for altitudes above 3,000 metres they are estimates based on modelling, rather than measurements. As a result, there are suggestions that anaemia is being over-diagnosed at altitude. This could be leading to over-treatment, and also absorbing resources that could be used to tackle other public health challenges.
Today [Friday 7 May 2021], we have published a report from the workshop ‘Addressing the challenges of anaemia in the Andean region’, summarising priority research questions that need to be answered to close the evidence gaps in causes, consequences and treatments of anaemia at high altitude, identified by the participants.
Key issues highlighted in the report include:
- Causes and contributory factors: Participants identified a need to gain a deeper understanding of how distal risk factors (such as poverty) and proximal risk factors (such as nutrition, infections, inflammation and hypoxia) interact to influence the risk of anaemia at high altitude.
- Mechanisms of iron homeostasis and anaemia: More information is needed on iron metabolism in high-altitude Andean populations.
- Diagnosis of iron deficiency: More appropriate thresholds of haemoglobin levels need to be developed and validated across different age groups in high-altitude populations, to diagnose anaemia.
- Consequences of anaemia: A better understanding of the consequences of mild anaemia at altitude would help to determine whether interventions are necessary, and more information is needed on the impact of anaemia on vulnerable populations such as pregnant women at high altitude.
- Treatment and prevention: The most appropriate iron dosing schedule needs to be identified. Research is needed into the advantages of supplements and fortification of foods, and the best sources of iron for interventions. More information is also needed on the potential detrimental effects of iron supplementation on the gut microbiome, and treatment approaches not focused on iron should be evaluated.
- Methodologies: A range of approaches that could be taken to address these questions were identified by workshop participants. Collaborations were seen as important to generate comparative data, and engagement with communities was identified as vital to ensure that communities have an opportunity to shape research studies.
Workshop participants felt that there is an urgent need to address whether high levels of anaemia in the region reflect a true disease burden or stem in large part from the adjustments in diagnostic thresholds recommended by WHO. They called for the evidence gaps to be closed to ensure that interventions are targeted at those most in need, use the most effective approaches and minimise unnecessary harm to vulnerable populations.
For more information, please download the full workshop report, which is available to the right of this page.
This workshop was funded by the Global Challenges Research Fund that aims to support cutting-edge research that addresses the challenges faced by developing countries. Visit our GCRF webpage to read more about the fund and further policy workshops.