title: Isoprostanes, a marker of lipid peroxidation, may not be involved in the development of glucose intolerance.
abstract: We investigated whether isoprostanes, as a marker of lipid peroxidation, may be involved in the development of impaired glucose tolerance (IGT) or diabetes. Using a nested case-control study, we tracked the changes in isoprostane levels, insulin sensitivity (IS) and beta-cell function (BCF) in Afro-Jamaicans who progressed to IGT and diabetes over 3.9 years. Anthropometry, glucose tolerance, insulin levels, blood pressure and urinary isoprostane concentration were measured at baseline and follow-up. IS and BCF were estimated by the method of homeostasis assessment. Fifty-two individuals who progressed to IGT or diabetes and 44 age, sex and body mass index (BMI) matched controls were studied. Progression to glucose intolerance was significantly related with baseline BCF (p< or =0.01), but not isoprostane levels or IS. Glucose concentrations (fasting and 2 h) on follow-up were significantly correlated to baseline IS, baseline BCF, follow-up IS and follow-up BCF (p-values<0.05). In multiple regression analysis, only follow-up IS and BCF (p-values< or =0.001) independently predicted fasting glucose and 2h glucose levels at follow-up. Isoprostanes were not significantly associated with IS or BCF (p-values>0.1). We concluded that isoprostanes may not be causally involved in the development of glucose intolerance, insulin resistance or deteriorating BCF.
authors.affiliation: Tropical Medicine Research Institute, University of the West Indies, Mona, Jamaica. michael.boyne@uwimona.edu.jm
authors.forename: Michael S
authors.initials: MS
authors.lastname: Boyne
authors.forename: Lincoln A
authors.initials: LA
authors.lastname: Sargeant
authors.forename: Franklyn I
authors.initials: FI
authors.lastname: Bennett
authors.forename: Rainford J
authors.initials: RJ
authors.lastname: Wilks
authors.forename: Richard S
authors.initials: RS
authors.lastname: Cooper
authors.forename: Terrence E
authors.initials: TE
authors.lastname: Forrester
mesh_terms: D000328:Adult; D000368:Aged; D000886:Anthropometry; D015415:Biomarkers / Q000652:urine; D044383:Black People / Q000208:ethnology; D001786:Blood Glucose / Q000032:analysis; D001794:Blood Pressure; D015992:Body Mass Index; D016022:Case-Control Studies; D015331:Cohort Studies; D005215:Fasting; D005500:Follow-Up Studies; D018149:Glucose Intolerance / Q000209:etiology*; D005951:Glucose Tolerance Test; D006801:Humans; D007328:Insulin / Q000097:blood; D050417:Insulin-Secreting Cells / Q000378:metabolism; D028421:Isoprostanes / Q000032:analysis / Q000652:urine*; D007563:Jamaica / Q000453:epidemiology; D015227:Lipid Peroxidation; D008875:Middle Aged; D012044:Regression Analysis; D012189:Retrospective Studies; D013997:Time Factors; D014505:Urban Population / Q000706:statistics & numerical data
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D007328:Insulin; D028421:Isoprostanes