Iron stores in 1359, 30- to 60-year-old Danish women: Evaluation by serum ferritin and hemoglobin

Summary

Iron status, including serum (S-)ferritin and hemoglobin (Hb), was assessed in a population survey comprising 1359 nonpregnant Danish women in age cohorts of 30, 40, 50, and 60 years. S-ferritin levels were similar in 30- and 40-year-old women; they displayed a significant increase in 50-year-old women and a further significant increase in 60-year-old women. In the 30- and 40-year-old women, median S-ferritin was 38μg/l, 5–95 percentile 6–135μg/l; 17.2% had values < 15,μg/l (i.e., depleted iron stores), 22.7% values from 15 to 30μg/l (i.e., small iron stores), and 60.1% values > 30μg/l (i.e., replete iron stores). In the 50-year-old women, median S-ferritin was 54μg/l, 5–95 percentile 10–164μg/l; 10.3% had values < 15μg/l, 16.5% values from 15 to 30μg/l, and 73.2% values > 30μg/l. For the 60-year-old women, median S-ferritin was 84μg/l, 5–95 percentile 25–249μg/l; 1.6% had values < 15μg/l, 8.6% values from 15 to 30μg/l, and 89.8% values > 30μg/l. Blood donors (n=180) had lower S-ferritin than nondonors in all age-groups (p<0.001). In the entire series, Hb levels were similar in 30- and 40-year-old women, median 137 g/l (8.5 mmol/l), 5–95 percentile 121–152 g/1 (7.5–9.4 mmol/l), and higher in 50- and 60-year-old women, median 140 g/l (8.7 mmol/l), 5–95 percentile 123-158 g/l (7.6–9.8 mmol/l) (p<0.0001). Hb values < 121 g/l (7.5 mmol/l) were observed in 3.8% of the women. Women with S-ferritin < 15 μg/l (n=161) had lower Hb, median 134 g/l (8.3 mmol/l), than those with S-ferritin > 15 μg/l, median 139 g/l (8.6 mmol/l) (p<0.001). Iron deficiency anemia (S-ferritin < 15 μg/l and Hb < 121 g/l) was seen in 2.3% of 30- and 40-year-old women, and in 1.1% of 50- and 60-year-old women.