[Changes of bone metabolism in diabetics]. / Zmeny kostního metabolizmu u diabetiku

The effect of impaired regulation of the glucose metabolism on the bone tissue metabolism is many-sided and very complicated. In most cases we observe an increased risk of fracture in people with diabetes. The reasons causing this condition are varied. Its main cause in diabetic patients is typically not the decrease in bone mineral density, it is rather deterioration of bone tissue and its structure. An important role of insulin and insulin resistance is beyond dispute, with numerous other factors at work, such as increased glycation of proteins, including increased glycation of collagen in bones, change in sclerostin production and levels, intervention in the pluripotent stem cells differentiation and reversal of their differentiation toward adipocytes and many more. Some antidiabetics, mainly oral, may also significantly contribute to the increased risk of fracture. Given the increasing incidence of both diseases, diabetes and osteoporosis, it will be also necessary to examine in greater detail their mutual relations and effects.Key words: antidiabetics - bone metabolism - diabetes mellitus - insulin resistance - osteoporosis.

Effects of body fat reduction on plasma adipocyte fatty acid-binding protein concentration in obese patients with type 1 diabetes mellitus.

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.