Physiological changes in circulating mannose levels in normal, glucose-intolerant, and diabetic subjects.
Mannose is an essential hexose that is required for glycoprotein synthesis. Although circulating mannose levels are known to be influenced by metabolic disorders, how physiological levels of mannose fluctuate in normal and diabetic subjects is largely unknown. We describe a new accurate and sensitive assay for determining circulating mannose levels, which we used to measure plasma mannose levels in 273 normal and diabetic (DM) subjects. Our results revealed a clear correlation (r = 0.754) between fasting plasma mannose (FPM) and fasting plasma glucose (FPG) levels. Our mannose assay showed sensitivity and specificity comparable to that seen for hemoglobin A(1c) (HbA(1c)) assay in subjects with impaired glucose tolerance (IGT) or DM whose FPG levels were normal. Mannose levels were found to increase less than glucose levels in response to an oral glucose tolerance test (OGTT). Furthermore, plasma mannose levels did not significantly change following a meal and more closely correlated with the coefficient of variation (CV) of daily glucose levels than did glucose itself. In conclusion, the close correlation between FPM and FPG levels taken together with the small fluctuations seen in plasma mannose in response to glucose suggests that the measurement of mannose using our assay could potentially play a supplementary role in the diagnosis and screening of patients with mild DM.
Sone
Hirohito
H
Department of Endocrinology and Metabolism, Laboratory of Medicine, Institute of Clinical Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan.
Shimano
Hitoshi
H
Ebinuma
Hiroyuki
H
Takahashi
Akimitsu
A
Yano
Yoshihiro
Y
Iida
Kaoruko Tada
KT
Suzuki
Hiroaki
H
Toyoshima
Hideo
H
Kawakami
Yasushi
Y
Okuda
Yukichi
Y
Noguchi
Yuichi
Y
Ushizawa
Koji
K
Saito
Kazunori
K
Yamada
Nobuhiro
N
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D003124:Colorimetry; D004396:Coloring Agents; D003920:Diabetes Mellitus / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood; D004435:Eating / Q000502:physiology; D005215:Fasting / Q000378:metabolism; D005260:Female; D019270:Fructosamine / Q000378:metabolism; D018149:Glucose Intolerance / Q000097:blood*; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D008297:Male; D008358:Mannose / Q000097:blood*; D008875:Middle Aged
D001786:Blood Glucose; D004396:Coloring Agents; D019270:Fructosamine; D006442:Glycated Hemoglobin; D008358:Mannose