The decline in haemoglobin (Hb) levels with advanced age is a widely known event. Nevertheless, it remains unclear whether this is a normal consequence of aging or a feature of age-related comorbidities. The World Health Organisation (WHO) definition of anaemia, although commonly used, was based on small epidemiological data and did not include individuals over 64-years-old. The aim of the present study is to evaluate haemoglobin levels and establish a reference range for a Brazilian population of the oldest old with active aging.
This was a cross-sectional study of community-dwelling independent elderly aged 80 years or older in the city of São Paulo, Brazil. Patients were excluded if they were institutionalised, diagnosed with dementia, Parkinson's disease or current cancer, were undergoing dialysis or had been hospitalised in the last 3 months. Chronic diseases had to be under control. The reference range was calculated excluding patients with transferrin saturation below 16%, serum ferritin levels below 10 μg/L or eGFR < 30 ml/min/1.73 m2. Values were obtained according to recommendations of the International Federation of Clinical Chemistry (IFCC).
Of the 256 subjects included in this study, 182 (71%) were women, and the median age was 85-years-old (80-99). A total of 47 individuals met the exclusion criteria for statistical analysis. The median haemoglobin level was 13.9 g/dL in men and 13.3 g/dL in women. The calculated 0.95 reference range of haemoglobin concentration was 11.2-16.7 g/dL for men and 11.3-15.7 g/dL in women.
A lower threshold of haemoglobin was found for both men and women when compared to levels set by the WHO. Further studies must indicate the normal level of haemoglobin concentration in the elderly in the Brazilian population.