title: Elevated plasma nonesterified fatty acids are associated with deterioration of acute insulin response in IGT but not NGT.
abstract: High concentrations of nonesterified fatty acids (NEFA) are a risk factor for developing type 2 diabetes in Pima Indians. In vitro and in vivo, chronic elevation of NEFA decreases glucose-stimulated insulin secretion. We hypothesized that high fasting plasma NEFA would increase the risk of type 2 diabetes by inducing a worsening of glucose-stimulated insulin secretion in Pima Indians. To test this hypothesis, fasting plasma NEFA concentrations, body composition, insulin action (M), acute insulin response (AIR, 25-g IVGTT), and glucose tolerance (75-g OGTT) were measured in 151 Pima Indians [107 normal glucose tolerant (NGT), 44 impaired glucose tolerant (IGT)] at the initial visit. These subjects, participants in ongoing studies of the pathogenesis of obesity and type 2 diabetes, had follow-up measurements of body composition, glucose tolerance, M, and AIR. In NGT individuals, cross-sectionally, high fasting plasma NEFA concentrations at the initial visit were negatively associated with AIR after adjustment for age, sex, percent body fat, and M (P = 0.03). Longitudinally, high fasting plasma NEFA concentrations at the initial visit were not associated with change in AIR. In individuals with IGT, cross-sectionally, high fasting plasma NEFA concentrations at the initial visit were not associated with AIR. Longitudinally, high fasting plasma NEFA concentrations at the initial visit were associated with a decrease in AIR before (P < 0.0001) and after adjustment for sex, age at follow-up, time of follow-up, change in percent body fat and insulin sensitivity, and AIR at the initial visit (P = 0.0006). In conclusion, findings in people with NGT indicate that fasting plasma NEFA concentrations are not a primary etiologic factor for beta-cell failure. However, in subjects who have progressed to a state of IGT, chronically elevated NEFA seem to have a deleterious effect on insulin-secretory capacity.
authors.affiliation: Clinical Diabetes and Nutrition Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Phoenix, Arizona 85016, USA. nstefan@mail.nih.gov
authors.forename: Norbert
authors.initials: N
authors.lastname: Stefan
authors.forename: Michael
authors.initials: M
authors.lastname: Stumvoll
authors.forename: Clifton
authors.initials: C
authors.lastname: Bogardus
authors.forename: P Antonio
authors.initials: PA
authors.lastname: Tataranni
mesh_terms: D000293:Adolescent; D000328:Adult; D001823:Body Composition / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D003430:Cross-Sectional Studies; D003920:Diabetes Mellitus / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000097:blood / Q000150:complications; D005230:Fatty Acids, Nonesterified / Q000097:blood*; D005260:Female; D015309:Glucose Clamp Technique; D018149:Glucose Intolerance / Q000097:blood*; D005951:Glucose Tolerance Test; D006801:Humans; D007198:Indians, North American; D007333:Insulin Resistance / Q000502:physiology*; D016014:Linear Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009765:Obesity
chemical_list: D005230:Fatty Acids, Nonesterified