Istituto Scientifico di Medicina Interna dell'Universit~ degli Smdi di Genova Cattedra di Patologia Medica Cattedra di Maiattie del Ricambio I.V. GLUCOSE TOLERANCE TEST: CORRELATION BETWEEN FFA, GLUCOSE AND IRI IN NORMAL, OBESE AND DIABETIC SUBJECTS ROMANO PRANDO RENZO CORDERA ALBERTO DE MICHELI ~vIICHELE MAIELLO PATRIZIO ODETTI GIORGIO VIVIANI LAURA CORS! LUCIANO ADEZATt Insulin secretion in response to glucose follows a biphasic pattern; therefore, the existence of two functional pools has been suggested, one responsible for the rapid phase, the other for the late or chronic phase z3,36, 37,38.6s. In recent years, interest has been concentrated mainly on the early phase of insulin release, the qualitative and quantitative changes which seem to be the pathogenetic basis of reduced carbo- hydrate tolerance 16 In diabetes mellitus, glucose infusion reveals a more marked impairment of acute insulin secretion 12. 32, 76, 78 (although some of the evidence is conflicting 45, 69, 71) compared to the late phase 1s. 19, 25, 3s, sl,82. In obesity, there is an overall increase of insulin secretion in response to stimulation ,_6, 29, ~, 47,48,o3 but this is more marked and consistent in the late phase 3,53,s7 and extremely variable and inconsistent in the early one 5s'78'79'82 (related above all to the degree and type of obesity and carbohydrate tolerance). An obvious connection between impaired early insulin response and Kgl ..... (Kc) during i.v. glucose tolerance test (IVGTT) has been reported in a number of patho- physiological and experimental conditions 12,16,18, :o,21, 32, 36, 38, 4s,6< 6s, 69, 7L 74, 76, 78, 83, ~ but it is still doubtful whether there is a true and significant correlation between these two parameters l, I1,12,14, 50, 52, 70, 80 Similarly, recent research has confirmed the existence of a significant correlation between variations of FFA concentration and peripheral glucose utilization in basal Key-words: Diabetes, FFA; Glucose; Insulin; Obesity, Tolerance test. Received: August 8, 1977. Acta diabet, lat. I5, 259, 1978. 259