Blood haemoglobin declines in the elderly: implications for reference intervals fromage 70 to 88

Abstract: The objective was to determine whether Hb declines in healthy elderly men and women and if this influences health‐related reference intervals. A representative population sample, comprising 30% of all 70‐yr‐old subjects in a Swedish city with 420,000 inhabitants ( n =1148, participation rate 85%), was followed at 1–5‐yr intervals for 18 yr within a longitudinal population study. Age‐related changes in Hb were calculated after exclusion of non‐healthy probands and by multivariate analyses in the total study group. Mean Hb declined between age 70 and 88 from 149 to 138 g/L in men (annual decline 0.69 g/L, p =0.000), and from 139 to 135 g/L in women (annual decline 0.06 g/L, n.s.). Healthy men declined from 152 to 141 g/L (annual decline 0.53 g/L, p =0.038), for women from 140 to 138 g/L (annual decline 0.05 g/L, n.s.). Age and body mass index correlated, in multivariate analysis, independently to Hb in both men and women, as did variables indicating a non‐healthy state. Epidemiological decision limits for anaemia declined for men from 128 to 116 g/L, for women from 118 to 114 g/L. Anaemia, thus defined, occurred in 3.2 to 9.7% of the subjects, whereas 28.3% of the 88‐yr‐old men had anaemia according to the WHO definition. In conclusion, there is a significant age‐related decline in Hb from age 70 to 88 among healthy men, and a less pronounced decline among women. This justifies the use of lower epidemiological decision limits for anaemia of about 115 g/L for both men and women from age 80–82.