title: Serum glycerophosphate levels are increased in Japanese men with type 2 diabetes.
abstract: OBJECTIVE
  To identify metabolites showing changes in serum levels among Japanese male with diabetes.
  
  
  METHODS
  We performed metabolite profiling by coupling capillary electrophoresis with electrospray ionization time-of-flight mass spectrometry using fasting serum samples from Japanese male subjects with diabetes (n=17), impaired glucose tolerance (IGT; n=5) and normal glucose tolerance (NGT; n=14).
  
  
  RESULTS
  Other than the expected differences in characteristics related to abnormal glucose metabolism, the percent body fat was significantly different among subjects with diabetes, IGT and NGT (27.3±6.2, 22.2±4.5 and 19.2±6.0%, respectively, p=0.0022). Therefore, percent body fat was considered as a possible confounding factor in subsequent analyses. Of 560 metabolites detected using our platform, the levels of 74 metabolites were quantified in all of the serum samples. Significant differences between diabetes and NGT were observed for 24 metabolites. The top-ranked metabolite was glycerol-3-phophate (glycerophosphate), which was significantly higher in subjects with diabetes than in those with NGT, even after Bonferroni correction for multiple testing (11.7±3.6 vs. 6.4±1.9 µM, respectively; corrected p=0.0222). Stepwise multiple regression analyses revealed that serum glycerophosphate levels were significantly correlated with 2-h plasma glucose after a 75-g oral glucose tolerance test (r=0.553, p=0.0005), independently of other characteristics, including FPG and HbA1c.
  
  
  CONCLUSIONS
  Serum glycerophosphate levels were found to be elevated in Japanese men with diabetes, and correlated with 2-h PG, independent of FPG and HbA1c. Namely, serum glycerophosphate level at fasting condition can be a marker for predicting glucose intolerance. These results warrant further studies to evaluate the relevance of glycerophosphate in the pathophysiology of diabetes.
authors.affiliation: Department of Neurology, Hematology, Metabolism, Endocrinology and Diabetology (DNHMED), Yamagata University School of Medicine, Japan. mdaimon@med.id.yamagata-u.ac.jp
authors.forename: Makoto
authors.initials: M
authors.lastname: Daimon
authors.forename: Tomoyoshi
authors.initials: T
authors.lastname: Soga
authors.forename: Atsushi
authors.initials: A
authors.lastname: Hozawa
authors.forename: Toshihide
authors.initials: T
authors.lastname: Oizumi
authors.forename: Wataru
authors.initials: W
authors.lastname: Kaino
authors.forename: Kaoru
authors.initials: K
authors.lastname: Takase
authors.forename: Shigeru
authors.initials: S
authors.lastname: Karasawa
authors.forename: Yumi
authors.initials: Y
authors.lastname: Jimbu
authors.forename: Kiriko
authors.initials: K
authors.lastname: Wada
authors.forename: Wataru
authors.initials: W
authors.lastname: Kameda
authors.forename: Shinji
authors.initials: S
authors.lastname: Susa
authors.forename: Takamasa
authors.initials: T
authors.lastname: Kayama
authors.forename: Kaori
authors.initials: K
authors.lastname: Saito
authors.forename: Masaru
authors.initials: M
authors.lastname: Tomita
authors.forename: Takeo
authors.initials: T
authors.lastname: Kato
mesh_terms: D050154:Adiposity; D000368:Aged; D000886:Anthropometry; D001786:Blood Glucose / Q000032:analysis; D001794:Blood Pressure; D001823:Body Composition; D015986:Confounding Factors, Epidemiologic; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000503:physiopathology; D019075:Electrophoresis, Capillary; D018149:Glucose Intolerance / Q000097:blood; D005951:Glucose Tolerance Test; D006442:Glycated Hemoglobin / Q000032:analysis; D005994:Glycerophosphates / Q000097:blood*; D006801:Humans; D007333:Insulin Resistance; D007564:Japan; D008055:Lipids / Q000097:blood; D008297:Male; D008875:Middle Aged; D019518:Postprandial Period; D021241:Spectrometry, Mass, Electrospray Ionization
chemical_list: D001786:Blood Glucose; D006442:Glycated Hemoglobin; D005994:Glycerophosphates; D008055:Lipids