Influence of gender, age and residence altitude on haemoglobin levels and the prevalence of anaemia

Abstract

Introduction: There are gaps in our knowledge of the normative levels of haemoglobin and the prevalence of anaemia in our geographical area, and in certain population subgroups.

Objectives: To study the mean values of haemoglobin in a mountainous Spanish region, according to sex, age range and residence altitude, and the prediction of anaemia according to the WHO thresholds and other proposals.

Material and methods: Cross-sectional descriptive study of all patients aged >14 residents in the Huesca healthcare Sector with ≥1 laboratory report in the 5 years of inclusion; multivariate analysis to determine the influence of demographic factors on haemoglobin values.

Results: 583,856 laboratory reports of 90,800 patients (coverage 89.1%) residing between 281 and 1305 meters: 54.6% female; mean age 52.6 years. Hb mean: 14.1 g/dl (males:15.0/females:13.4). Prevalence of anaemia: 8.99% (males: 7.8%/females:10.0%). It was more frequent in women (1.6 times) and increased markedly with age: >65 years:16.5%; ≥75 years: 21.7%; ≥80 years: 25.7%; >90 years 35%. It increased 1.02 times per year, and 0.99 times per meter of altitude. In residents ≥1000 m, anaemia prevalence fell by half.

Conclusions: We obtained data from sub-populations that were previously not well described; anaemia in the elderly requires consideration. The influence of altitude does not seem to be fully considered within the correction framework proposed by WHO. Broader studies should be planned in order to obtain adequate parameters for the elderly and residents at high altitudes in Spain, as both groups represent an important proportion of the population, to avoid potential underdiagnosis of anaemia and overdiagnosis of other pathologies.

Keywords: Ageing; Altitud; Altitude; Anaemia; Anemia; Diagnostic threshold; Envejecimiento; Haemoglobin; Hemoglobina; Prevalence; Prevalencia; Umbral diagnóstico.