OBJECTIVES: The influence of body fat reduction on adipocyte fatty acid-binding protein (A-FABP) in obese patients with type 1 diabetes mellitus (T1DM) was investigated to examine whether it relates to the etiopathogenesis of insulin resistance (IR) and obesity. METHODS: We studied 14 obese patients with T1DM and IR (42.6±9.4 years, BMI 32.4±2.1 kg/m2) and 13 non-obese control patients with T1DM (36.9±13.9 years, BMI 22.6±2.1 kg/m2). Plasma FABP was measured by ELISA and plasma free fatty acids (FFA) were measured spectrophotometrically before weight reduction, immediately after 7 days of fasting and after 21 days on a low-calorie diet. The control group was studied only after overnight fasting. Body composition was examined using bioimpedance spectroscopy. The means ± SD, T-test, one-way ANOVA and Spearman's correlation were used for statistical evaluation. RESULTS: All patients tolerated the period of fasting. Obese T1DM patients lost 6.1±1.1 kg. There was a significant decrease in body mass index and body fat measured 21 days after weight reduction (p<0.05). Plasma FABP and FFA concentrations in obese T1DM patients before weight reduction were significantly higher than in controls, further increased significantly after fasting (p<0.05) and were restored thereafter. Significant positive correlations between FABP and FFA and between FABP and BMI (p<0.05) were found. CONCLUSION: Increased plasma FABP indicates insulin resistance in obese patients with T1DM. Weight reduction in T1DM patients is associated with a desirable decrease of body fat and transiently increased FABP. This increase might be a temporary adaptation of metabolism to non-stress fasting.

3rd Department of Medicine 1st Faculty of Medicine Charles University and General University Hospital Prague Czech Republic

3rd Department of Medicine Metabolic Care and Gerontology Charles University in Hradec Králové Czech Republic