ACTA ENDOCRINOLOGICA (BUC)

The qualitative influence of free fatty acids (FFAs) on glucose metabolism is well documented while there is no data quantifying this relationship. An attempt to measure this correlation was made by employing a prospective, cross-sectional study involving 21 patients grouped in 5 categories established after a standard 2h Oral Glucose Tolerance Test (OGTT): normal glucose tolerance (N); insulin resistant (IR; IR2); impaired glucose tolerance (IGT) and diabetes (D). Two OGTTs were performed for each patient, separated by two weeks during which dietary supplements were taken along with restriction of saturated fat ingestion; levels of FFAs, aminoacids, etc., were measured on both patient visits. Glucose metabolism was quantified as the area under the curve and named glucose metabolic index (GMI). FFAs influence on GMI was dependent on their degree of saturation, with saturated and monounsaturated fats impairing glucose tolerance and polyunsaturated fats (especially tetraenoic and hexaenoic acids) improving it. Short chain FFAs (up to 14 C) had a negative effect; 16 and 18 C were weakly correlated and 20-26 C had a positive effect on glucose tolerance. Levels of aminoacids and metabolic intermediaries suggested involvement of aminoacids in energy production and showed mitochondrial energy overproduction. Glucose and energy metabolism were altered in IR, IGT and D patients in a similar fashion; those alterations were more pronounced in D than in the IR while none was present in the N group. Glucose tolerance was improved upon restriction of saturated fats intake along with administration of antioxidants in D, IGT and IR groups.