Elements in autopsy liver tissue samples from Greenlandic Inuit and Danes.II. Iron measured by X-ray fluorescence spectrometry

The purpose of this study was to measure the content of iron (Fe) in liver tissue samples from urbanized Greenlandic Inuit using X-ray fluorescence sp ectrometry, and compare the results with those obtained in liver tissue sam ples from urbanized Danes. Normal liver tissue samples were obtained at aut opsy from 50 Greenlandic Inuit (27 men, 23 women) with a median age of 61 y ears (range 23-83) and from 72 Danes (42 men, 30 women) with a median age o f 62 years (range 15-87). In the entire series, there was no significant di fference between liver iron in Inuit compared with Danes. Likewise, there w as no significant gender difference concerning liver iron content, either i n Inuit or in Danes. The median iron content (with 5-95 percentile) in Inui t was 17.23 mmol/kg dry liver (5.80-91.80) and in Danes 16.51 mmol/kg dry l iver (7.83-39.05). However, when stratified according to age, a trend was r evealed showing that Inuit men and women less than or equal to 50 years had a lower liver iron content than Danes (p = 0.05 and p = 0.08) whereas Inui t men and women >50 years had a higher liver iron content than Danes (p = 0 .18 and p = 0.02). There was a significant correlation between liver iron c ontent and age in both Inuit men (r(s) = 0.49, p = 0.01) and in women (r(s) = 0.64, p = 0.003), but not in Danes. In Inuit, the median hepatic iron in dex (liver iron content divided by age) was 0.33 in men and 0.32 in women. The median estimated iron content in the whole liver was 6.54 mmol (365 mg) in Inuit men and 5.41 mmol (302 mg) in Inuit women (p = 0.6). There was no correlation between hepatic iron index and age. In Danes, the median hepat ic iron index was 0.46 in men and 0.29 in women (p = 0.01). There was a sig nificant inverse correlation between hepatic iron index and age in the two genders and in the entire series (r(s) = -0.71, p = 0.0001). The results in dicate that young and middle-aged urbanized Inuit have slightly smaller iro n stores than urbanized Danes, whereas elderly Inuit have higher iron store s than Danes. In Danes, iron stores plateau at 30 to 40 years of age in men and some years after the menopause in women. In Inuit, iron stores continu e to increase in old age, probably to due a lifelong dietary intake of haem iron.