Addressing the Challenges of Anaemia in the Andean Region
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Addressing the Challenges of Anaemia in the Andean Region Online 20-21 January 2021 The Academy of Medical Sciences is the independent body in the UK representing the diversity of medical science. Our mission is to promote medical science and its translation into benefits for society. The Academy’s elected Fellows are the United Kingdom’s leading medical scientists from hospitals, academia, industry and the public service. We work with them to promote excellence, influence policy to improve health and wealth, nurture the next generation of medical researchers, link academia, industry and the NHS, seize international opportunities and encourage dialogue about the medical sciences. This workshop is funded by the Academy, through the Global Challenges Research Fund (GCRF). Meeting Background Low and middle income countries (LMICs) account for 89% of all anaemia-related disability. However, despite several interventions, the number of people diagnosed as anaemic rose from 25% of the world’s population between 1993-2005 to 27% by 2013.1,2 In Africa 37% of children aged between 6-14 years are anaemic largely due to 3 malnutrition and parasitic infections. Despite a high prevalence of anaemia also in Meeting Background Latin America there is little understanding of the main cause in this region. A particular consideration regarding anaemia should be given to the Andean region. The Andean region constitutes a complex geographical area with coast, mountain and jungle and includes different countries whose capitals or important cities are located in highland settings, as Quito (Ecuador), Bogota (Colombia), San Jose (Costa Rica), Mexico DF (Mexico) among others. In Peru and Bolivia, a high proportion of the whole population lives over 3000m altitude. Anaemia persists in the Andean region despite governmental effort to reduce the burden. Worryingly, anaemia rates have not decreased since the early 2010’s. Children living at high altitude are at a particular risk of anaemia. In Bolivia for example, despite iron supplementation over an 18-year period, the prevalence of anaemia on the whole remained unchanged whereas it increased in children living at high altitude. Iron deficiency appears to explain only a small proportion of childhood anaemia and there is an urgent need to better understand its other causes to develop appropriate and effective interventions.4 Anaemia is not only a question of iron deficiency. Haemoglobin measurements continue to be used to diagnose anaemia despite this being an unreliable marker as haemoglobin levels vary substantially with age, sex, smoking and altitude. Much of the Andean region is located over 2500 metres above sea level and rates of anaemia increase after adjustment of haemoglobin by altitude. The World Health Organization (WHO) recommends adjustment of Haemoglobin by altitude from 1000m.5 There is an on-going debate of whether or not the altitude-adjustment, recommended by the WHO, is appropriate since it has been found to overestimate anaemia rates.6,7 Despite major breakthroughs in iron metabolism, guidelines established in the late 1950s have not been updated to reflect this increase in understanding. 1. Kassebaum NJ & GBD 2013 Anemia Collaborators (2016). The Global Burden of Anemia. Hematol Oncol Clin North Am 30(2), 247-308. 2. De Benoist B et al (2008). Worldwide prevalence of anaemia 1993-2005. WHO Global database on anaemia 2008. 3. Tariku EZ et al (2019). Anemia and its associated factors among school-age children living in different climatic zones of Arba Minch Zuria 4. District, Southern Ethiopia. BMC Hematol 19:6. 4. Cordero D et al. (2019). Anemia in Bolivian children: a comparative analysis among three regions of different altitudes. Ann N Y Acad Sci 1450(1), 281–290. 5. World Health Organization (2011). Haemoglobin concentrations for the diagnosis of anaemia and assessment of severity. Vitamin and Mineral Nutrition Information System. 6. Sarna K, et al (2018). WHO hemoglobin thresholds for altitude increase the prevalence of anemia among Ethiopian highlanders. Am J Hematol 93(9), E229–E231. 7. Gonzales GF, Begazo J, & Alarcón-Yaquetto D (2019). Suitability of hemoglobin adjustment to define anaemia at high altitudes. Acta Hematol 19, 1-2. Meeting Background (contd.) Increasing evidence points to intestine-microbiota metabolic crosstalk that is important for systemic iron homeostasis.8 Iron supplementation in toddlers may generate an imbalance between commensal and enteropathogenic bacteria and lead to the development of local and systematic inflammatory processes. Both of which will have 9 consequences in the development of anaemia. Furthermore, most cases of anaemia Meeting Background are mild yet it is not well understood how and whether mild anaemia affects health. Indeed, several studies have demonstrated that haemoglobin values associated with mild anaemia result in better reproductive outcomes for mother and child and improved growth in pre-school children.10 Many research questions and knowledge gaps remain to be addressed to understand the complex association/interaction between anaemia and high altitude. As evidence mounts that iron supplementation may be counterproductive, we should tread carefully in recommending a supplementation in children diagnosed with anaemia despite a lack of stunting and clinical signs of anaemia. As we now better understand anaemia it may be time to update the way anaemia is diagnosed using direct iron status marker measurements instead of indirect markers such as haemoglobin. However, research is needed to understand how feasible it is to use new measures to solve the current anaemia problem. More research is needed to establish the main cause of anaemia in the Andean region in order to tackle the problem effectively. 8. Das NK, et al (2020). Microbial Metabolite Signaling Is Required for Systemic Iron Homeostasis. Cell Metab 31(1), 115–130.e6. 9. Verma S & Cherayil BJ (2017). Iron and inflammation–the gut reaction. Metallomics 9(2), 101-111. 10. Gonzales GF, et al (2018). Correcting the cut-off point of hemoglobin at high altitude favors misclassification of anemia, erythrocytosis and excessive erythrocytosis. Am J Hematol 93(1), E12-E16. Meeting Background (Español) Los países de bajos y medianos ingresos (LMIC) representan el 89 % de toda la discapacidad relacionada con la anemia. No obstante, a pesar de diversas intervenciones, la cantidad de personas diagnosticadas con anemia aumentó del 25 % en la población mundial entre 1993 y 2005 al 27 % para 2013.1,2, En África, el 37 % de los niños de entre 6 y 14 años tienen anemia debido, en gran parte, a desnutrición e 3 infecciones parasitarias. A pesar de una gran prevalencia de la anemia también Meeting Background presente en América Latina, no se conoce en profundidad la razón principal de su presencia en esta región. Debe tenerse en cuenta un aspecto particular de la anemia en relación con la región Andina. La región Andina abarca un área geográfica compleja que incluye costas, montañas y selvas, y diferentes países cuyas capitales o ciudades importantes se ubican en tierras elevadas, como Quito (Ecuador), Bogotá (Colombia), San José (Costa Rica), Ciudad de México (México), entre otras. En Perú y Bolivia, una gran parte de toda la población vive por encima de los 3000 m de altitud. La anemia persiste en la región Andina a pesar de los esfuerzos gubernamentales por reducirla. Es preocupante que los índices de anemia no hayan disminuido desde comienzos de la década de 2010. Los niños que viven en altitudes elevadas se enfrentan a un mayor riesgo de tener anemia. En Bolivia, por ejemplo, a pesar de la complementación con hierro durante un período de 18 años, la prevalencia general de la anemia se mantuvo sin cambios, aunque aumentó en los niños que viven en altitudes elevadas. La deficiencia de hierro pareciera explicar únicamente una pequeña proporción de la anemia infantil, y existe una urgente necesidad de comprender mejor sus otras causas para desarrollar intervenciones apropiadas y eficaces.4 La anemia no se trata únicamente de la deficiencia de hierro. Las mediciones de hemoglobina siguen utilizándose para diagnosticar la anemia, a pesar de ser un marcador poco confiable, dado que los niveles de hemoglobina varían sustancialmente según la edad, el género, la altitud, y en función de si la persona es o no fumadora. Gran parte de la región Andina se ubica por encima de los 2500 metros sobre el nivel del mar, y los índices de anemia aumentan luego de ajustar la hemoglobina según la altitud. La Organización Mundial de la Salud (OMS) recomienda ajustar la hemoglobina según la altitud a partir de los 1000 m.5 Existe un debate continuo sobre si el ajuste según la altitud recomendado por la OMS es apropiado, dado que se ha demostrado que sobrevolara los índices de anemia.6,7 A pesar de los grandes descubrimientos en términos del metabolismo del hierro, los lineamientos establecidos a fines de la década de 1950 no han sido actualizados para reflejar este aumento en el conocimiento. 1. Kassebaum NJ & GBD 2013 Anemia Collaborators (2016). The Global Burden of Anemia. Hematol Oncol Clin North Am 30(2), 247-308. 2. De Benoist B et al (2008). Worldwide prevalence of anaemia 1993-2005. WHO Global database on anaemia 2008. 3. Tariku EZ et al (2019). Anemia and its associated factors among school-age children living in different climatic zones of Arba Minch Zuria 4. District, Southern Ethiopia. BMC Hematol 19:6. 4. Cordero D et al. (2019). Anemia in Bolivian children: a comparative analysis among three regions of different altitudes. Ann N Y Acad Sci 1450(1), 281–290. 5. World Health Organization (2011). Haemoglobin concentrations for the diagnosis of anaemia and assessment of severity. Vitamin and Mineral Nutrition Information System. 6. Sarna K, et al (2018). WHO hemoglobin thresholds for altitude increase the prevalence of anemia among Ethiopian highlanders. Am J Hematol 93(9), E229–E231. 7. Gonzales GF, Begazo J, & Alarcón-Yaquetto D (2019).