[Investigation and analysis of plasma trace elements of oldest elderly in longevity areas in China]

To investigate the levels and differences of plasma selenium, manganese, iron, copper, zinc among oldest elderly in longevity areas in China.

446 oldest elderly including 208 centenarians, 238 aged 90 and over, who lived in Xiayi county of Henan province (110 persons), Zhongxiang city of Hubei province (111 persons), Mayang county of Hunan province (60 persons), Sanshui district of Guangdong province (113 persons), Yongfu county of Guangxi Zhuang autonomous region (52 persons) in China, were selected. The contents of plasma selenium, manganese, iron, copper, zinc were detected and compared among these elderly who were classified into different genders, different regions and different age groups.

In oldest elderly, the median (inter-quartile range) of content of plasma selenium was 1.44 (0.91) micromol/L, content of manganese was 0.54 (0.94) micromol/L, content of iron was 69.17 (102.85) micromol/L, content of copper was 20.19 (8.73) micromol/L, content of zinc was 31.66 (32.51) micromol/L. Contents of plasma selenium of oldest elderly in Xiayi, Zhongxiang, Mayang, Sanshui, Yongfu region were 1.46 (0.66), 1.30 (0.80), 1.06 (0.51), 2.39 (1.53) and 1.35(0.55) micromol/L; contents of plasma manganese were 0.56 (0.51), 1.40 (1.11), 0.35 (0.71), 0.44 (0.55) and 0.15 (0.21) micromol/L; contents of plasma iron were 86.77 (86.87), 141.42 (101.83), 38.88 (36.28), 31.38 (46.19) and 79.64 (75.34) micromol/L; contents of plasma copper were 22.16 (8.11), 19.46 (9.26), 21.36 (12.38), 18.12 (6.74) and 21.47 (7.85) micromol/L; contents of plasma zinc were 36.85 (26.18), 36.59 (35.94), 39.98 (56.91), 25.05 (24.92) and 16.74 (16.81) micromol/L. Contents of plasma trace elements among oldest elderly in different longevity areas were significantly different (F values were 29.76, 38.75, 47.18, 11.51 and 13.47, P values were all less than 0.05). Contents of plasma trace elements in different gender groups (contents of plasma selenium were 1.38 (0.83) micromol/L in male and 1.45 (0.91) micromol/L in female; contents of plasma manganese were 0.52 (0.95) and 0.54 (0.91) micromol/L; contents of plasma iron were 69.23 (104.06) and 69.11 (101.05) micromol/L; contents of plasma copper were 20.28 (8.72) and 20.06 (8.76) micromol/L; contents of plasma zinc were 28.39 (32.58) and 31.85 (34.26) micromol/L) were not significantly different (t(Se) = -1.82, P = 0.07; t(Mn) = 0.64, P = 0.52; t(Fe) = 0.65, P = 0.52; t(Cu) = -1.90, P = 0.06; t(Zn) = -0.96, P = 0.34). The contents of plasma selenium, iron, copper in centenarians were higher than those aged 90 and over (contents of plasma selenium were 1.63 (0.94) micromol/L and 1.30 (0.82) micromol/L, contents of plasma iron were 112.63 (119.78) and 60.13 (58.43) micromol/L, contents of plasma copper were 21.07 (9.03) and 18.81 (8.86) micromol/L, F value were 41.99, 27.32, 24.45, P values were less than 0.01). Content of plasma manganese in centenarians was lower than those aged 90 and over (0.44 (0.76) and 0.64 (0.93) micromol/L, F = 10.76, P < 0.01). No significant differences were detected in plasma zinc between concentration and those aged 90 and over (31.78 (34.06) and 31.11 (33.85) micromol/L; F = 1.32, P = 0.25).

The concentrations of plasma selenium, manganese, iron, copper and zinc were high in oldest elderly in the longevity areas. The contents of plasma selenium, iron, copper increased with age.