[The effects of glucose fluctuation on resistin].

Objective: To explore the effect of glucose fluctuation on resistin.
Methods: The phorbol-12-myristate-13-acetate(PMA)-activated and differentiated U937 cells were exposed to experimental condition for 3 days, three groups of cells were formed, each one receiving the following fresh medium every 6 hours, respectively: (1) continuous 11.1 mmol/L glucose concentration medium (Con group), (2) continuous 22.2 mmol/L glucose concentration medium (CHG group), (3) alternating 11.1 mmol/L glucose concentration and 22.2 mmol/L glucose concentration medium every 6 hours (IHG group). The supernatants of cell median at the last 6 hours were collected to test resistin concentration. Besides, 92 subjects were selected and classified into three groups according to the results of oral glucose tolerance test: normal glucose tolerance group (NGT group, n=30), impaired glucose tolerance patients (IGT group, n=31) and newly diagnosed type 2 diabetes patients (T2DM group, n=31). Blood glucose and serum resistin levels were measured at 0 h and 1 h during oral glucose tolerance test (OGTT) to compare the glucose fluctuation (ΔGlu1-0) and the change of serum resistin level (ΔlnRes1-0) among the three groups.
Results: Resistin concentration in the Con, CHG and IHG group was (73.62±5.07) ng/L, (97.78±7.00) ng/L and (212.49±28.81) ng/L respectively and in IHG group it was higher as compared with the other two groups (P<0.05). ΔGlu1-0 in NGT, IGT and T2DM group was (2.31±2.30) mmol/L, (5.70±2.08) mmol/L and (8.41±2.63) mmol/L respectively; ΔGlu1-0 increased gradually in all the three groups (P<0.05). Serum resistin level from 0 h to 1 h in the NGT group was 6.41 (1.52-15.76) µg/L to 6.96 (1.52-22.70) µg/L, in the IGT group 5.47 (1.49-24.09) µg/L to 9.12 (1.27-21.94) µg/L and in the T2DM group 5.77 (1.11-30.10) µg/L to 9.27(1.02-48.15) µg/L. In the IGT and T2DM group serum resistin level increased from 0 h to 1 h (P<0.05), but no difference was observed in the NGT group (P>0.05). ΔlnRes1-0 in these 3 groups was (0.05±0.05) µg/L, (0.25±0.04) µg/L and (0.37±0.03) µg/L respectively and the change in the T2DM group was significant as compared with that in the NGT group, ΔlnRes1-0 was positively correlated with ΔGlu1-0 (r=0.23, P=0.02).
Conclusion: Glucose fluctuation induced monocyte/macrophage to secrete resistin, greater the glucose fluctuation, greater the change of amplitude of serum resistin.