2010 年 21 巻 1 号 p. 32-37
We developed the ratio of apo/holo activities of angiotensin converting enzyme (ACE ratio) in the serum as an index of the zinc nutrition status. The zinc nutrition in patients with taste impairment was then estimated by dietary zinc intake, zinc concentration and ACE ratio in the serum. The results obtained in a series of our studies suggested that zinc deficiency is predominant factor underlying taste impairment even when zinc concentrations are within normal ranges in the serum and that ACE ratio is a more sensitive indicator of the zinc nutrition status than measuring zinc concentration in the serum. There were no differences of dietary intake of zinc after adjusting for energy and zinc concentration in the serum between patients and age-matched healthy subjects. But, ACE ratio in patients with taste impairment was significantly higher than that in age-matched healthy subjects. It is suggested that zinc deficiency in patients with taste impairment is due to malabsorption of dietary zinc from the duodenum and jejunum, but not low intake of dietary zinc.