Haemoglobin concentrations appear to be lower in indigenous Greenlanders than in Danes: assessment of haemoglobin in 234 Greenlanders and in 2804 Danes

OBJECTIVE: To compare haemoglobin concentrations in Greenlanders and Danes.

METHODS: Haemoglobin was measured in a population survey in 1993-1994 comprising 234 indigenous Greenlandic individuals (115 men) aged 19-82 yr. and in Copenhagen County 1983-1984 comprising 2804 Caucasian Danes (1444 men) aged 30-60 yr. The Greenlandic participants were residents in the capital Nuuk (n=70), the town Ilulissat (n=74), and four settlements in the Uummannaq district (n=90). The significance of differences was assessed by Student's t-test, and the xi2-test. Correlations were assessed by Spearman's correlation coefficient (rs).

RESULTS: Greenlanders: Haemoglobin levels were not correlated with age or consumption of traditional foods, and were not significantly different in the three residential areas. Mean haemoglobin was higher in men, 146+/-9.6 (SD) g/L, than in women, 132+/-9.6 g/L (p<0.0001). Mean haemoglobin in iron-replete men with serum ferritin >32 microg/L (n=104) was 146+/-9.3 g/L, and in iron-replete women (n=68) 133+/-10.4 g/L (p<0.0001). The 5th percentile for haemoglobin in iron-replete men was 133 g/L (8.3 mmol/L) and in women 118 g/L (7.3 mmol/L). The prevalence of iron deficiency anaemia (i.e. ferritin <13 microg/L and Hb <5th percentile for iron-replete men and women) was 0% in men, 2.78% in women < or =50 yr of age and 0% in women >50 yr of age. Danes: Mean haemoglobin in men was 154+/-10.0 g/L and in women 138+/-10.4 g/L (p<0.0001). Haemoglobin in iron-replete men (n=1379) (i.e. serum ferritin >32 microg/L) was 154+/-10.7 g/L, and in iron-replete women (n=1003) 140+/-9.6 g/L (p<0.0001). Mean haemoglobin was lower in premenopausal than in postmenopausal women (p<0.0001). The 5th percentile for haemoglobin in iron-replete men was 137 g/L (8.5 mmol/L) and in women 124 g/L (7.7 mmol/L). The prevalence of iron deficiency anaemia (i.e. ferritin <13 microg/L and Hb <5th percentile for iron replete men and women) was 0% in men, 1.92% in women < or =50 yr of age and 0% in women >50 yr of age.

CONCLUSION: Haemoglobin concentrations in Greenlanders were significantly lower than in Danes both in men (p<0.0001) and in women (p<0.0001). Delta(mean haemoglobin) in men was 8.0 g/L (0.5 mmol/L) and in women 6.2 g/L (0.4 mmol/L). Variations in haemoglobin levels may be due to genetic differences.