ABSTRACT
<p><b>OBJECTIVE</b>To investigate the influence of short-term high-fat diet (HFD) on glucose and lipid metabolism in male Han Chinese with type 2 diabetes mellitus (T2DM).</p><p><b>METHODS</b>Middle-aged T2DM men supported with solely diet or diet and metformin were enrolled into the study. The design was an unblinded crossover design. Each of the subjects randomly received one from two types of isocalorie (8786.4 kJ/d) standard diet for three consecutive days on two occasions, with a 6-week wash-out period in between. The component ratios of fat, carbohydrate, and protein were 50%, 35%, and 15% vs. 25%, 60%, and 15% in patients administered with HFD or high carbohydrate diet (HCD). The 24-hour blood samples during the third day were collected. On the morning of the forth day an intravenous glucose tolerance test (IVGTT) was conducted with 25g of glucose.</p><p><b>RESULTS</b>According to the determination results of 24-hour profile samples, HFD resulted in a markedly increased circulating level of non-esterified fatty acid (NEFA) as compared to HCD (P < 0.001). Nearly significant higher (P = 0.056) FPG was observed 72 hours after the administration of HFD. Circulating insulin levels were comparable between the two diets. A significantly higher HDL-C was also observed after HFD administration (P < 0.05). As assessed by the IVGTT, acute insulin response of glucose (AIRg) tended to increase after the HFD administration (P = 0.06). Fasting plasma glucagons (GLG) level and AUC(Glucagon) during breakfast period (8:00-12:00) were significantly higher after HFD administration than that of after HCD administration.</p><p><b>CONCLUSIONS</b>Short-term HFD induced the increase of NEFA with lower glucose exposure to the patietns. Fasting plasma glucose increased at the fourth day without remarkable changes of insulin levels which may be due to the increase of hepatic glucose output after HFD administration. The short-term HFD in our study induced early stage of insulin resistance. GLG seemed to play a role in this procedure. beta-cell dysfunction may need a longer high NEFA exposure.</p>