title: Monitoring of liver glycogen synthesis in diabetic patients using carbon-13 MR spectroscopy.
abstract: To investigate the relationship between liver glucose, glycogen, and plasma glucose in diabetic patients, in vivo liver carbon-13 magnetic resonance spectroscopy ((13)C MRS) with a clinical 3.0T MR system was performed. Subjects were healthy male volunteers (n=5) and male type-2 diabetic patients (n=5). Pre- and during oral glucose tolerance tests (OGTT), (13)C MR spectra without proton decoupling were acquired in a monitoring period of over 6h, and in total seven spectra were obtained from each subject. For OGTT, 75g of glucose, including 5g of [1-(13)C]glucose, was administered. The MR signals of liver [1-(13)C]glucose and glycogen were detected and their time-course changes were assessed in comparison with the plasma data obtained at screening. The correlations between the fasting plasma glucose level and liver glycogen/glucose rate (Spearman: rho=-0.68, p<0.05, n=10) and the fasting plasma glucose level and liver glycogen peak/fasting rate (Spearman: rho=-0.67, p<0.05, n=10) indicated that (13)C MRS can perform noninvasive measurement of glycogen storage/degradation ability in the liver individually and can assist in tailor-made therapy for diabetes. In conclusion, (13)C MRS has a potential to become a powerful tool in diagnosing diabetes multilaterally.
authors.affiliation: Department of Biophysics, Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage, Chiba city, Chiba 263-8555, Japan. moyo@fml.nirs.go.jp <moyo@fml.nirs.go.jp>
authors.forename: Moyoko
authors.initials: M
authors.lastname: Tomiyasu
authors.forename: Takayuki
authors.initials: T
authors.lastname: Obata
authors.forename: Yukio
authors.initials: Y
authors.lastname: Nishi
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Nakamoto
authors.forename: Hiroi
authors.initials: H
authors.lastname: Nonaka
authors.forename: Yukihisa
authors.initials: Y
authors.lastname: Takayama
authors.forename: Joonas
authors.initials: J
authors.lastname: Autio
authors.forename: Hiroo
authors.initials: H
authors.lastname: Ikehira
authors.forename: Iwao
authors.initials: I
authors.lastname: Kanno
mesh_terms: D002247:Carbon Isotopes / Q000032:analysis; D003924:Diabetes Mellitus, Type 2 / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*; D006003:Glycogen / Q000096:biosynthesis*; D006801:Humans; D008099:Liver / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008297:Male; D008657:Metabolic Clearance Rate
chemical_list: D002247:Carbon Isotopes; D006003:Glycogen; D005947:Glucose