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

Abstract

Objective: To measure the content of copper (Cu) in liver tissue samples from Greenlandic Inuit and compare the results with those obtained in Caucasian Danes. Materials and methods: Normal liver tissue samples were obtained at autopsy from 50 Inuit (27 men, 23 women) with a median age of 61 years (range 23 - 83) and from 74 Danes (44 men, 30 women) with a median age of 60 years (range 15 - 87). Total liver copper content was measured by X-ray fluorescence spectrometry. Results: The content of copper given as median and 5 - 95 percentile was in Inuit 0.2982 mmol/kg dry liver (0.1810 -0.6531), and in Danes 0.3777 mmol/kg dry liver (0.1889 - 0.7550) (p = 0.02). This difference was due to a higher median liver copper content in Danish men compared with Danish women (p = 0.04), Inuit men (p = 0.005) and Inuit women (p = 0.05), and was based solely on the 3 highest liver copper values in Danish men. Inuit displayed no gender difference concerning liver copper content. There was no correlation between liver copper content and age either in Inuit or in Danes. In Inuit, the median hepatic copper index (liver copper content divided by age) was 0.0045 in men and 0.0066 in women (p = 0. 14). There was an inverse correlation between hepatic copper index and age in the entire Inuit series (r s = -0.63, p < 0.0001). In Danes, the median hepatic copper index was 0.0082 in men and 0.0046 in women (p = 0.005). There was an inverse correlation between hepatic copper index and age in the entire Danish series (r s = -0.76, p < 0.0001). Conclusion: There is no evidence to suggest that the prevalence of copper deficiency or copper overload in adults differ in Inuit and Danes. Inuit have a hepatic copper content, which is similar to that found in Caucasian Danes and other populations from the Western societies.