Clinical Significance And Changes In Serum Leptin And Leptin-R Levels Of Patients After Trauma

Background: Leptin, a 16 kDa non-glycosylated polypeptide product of the obese (ob) gene, is an adipocyte-derived hormone which has long been recognized as a key factor in regulating a wide range of biological responses including energy homeostasis, neuroendocrine function, angiogenesis, bone formation and reproduction. In addition to its critical involvement in these physiological functions, leptin has been increasingly recognized as a cytokine-like hormone with pleiotropic actions in modulating immune responses, interacted with insuline, glucocorticosteroid, and the cotykines such as IL-1, IL-2, IL-6, IL-10 and TNF-α. It combines with the specific receptor located at hypothalamus. The physiology state at the course of the acute stress state and functional recovery is associated with the biological responses of leptin. If we can identify the change regularity and the affect mechanism of leptin after trauma, we can treat the trauma patients at the earlier period through adjusting the level of leptin. In the study, we decided to observe the changes of leptin and leptin-R in peripheral blood after trauma, and investigate the interrelation of leptin and leptin receptor (leptin-R) with clinical index and trauma complication, so as to explore the effect mechanism and clinical significance of leptin and leptin-R at the course of restoration process after trauma and provide theoretical basis for the clinical application of leptin and leptin-R.Methods52 samples of trauma patients serum who had admission from July 2007 to March 2008 were collected at first day(D1), third day (D3)and sixth day (D6) after trauma. The basic data such as age and sex of patients, the characteristics and location of injury, complication after trauma such as systemic inflammatory response syndrome(SIRS), sepsis and multiple organ dysfunction syndrome (MODS) were recorded in detail. 52 patients were divided into three groups according to the AIS-ISS score: ISS<16 or AIS≤2 for mild injury group(21 cases) and 16≤ISS<25 or AIS=3 for moderate injury group (17 cases)and ISS≥25 or AIS>3 for severe injury group(14 cases). At the same time, we selected 7 healthy adults as control group, gathering the peripheral vein blood at the state of empty stomach, extraction the blood serum after centrifugalization for 15 minutes at 3200 rpm, conservation at -70℃for measure after stuff and tag. The concentrations of leptin and leptin-R were quantified with enzyme linked immunosordent assay (ELISA).ResultsThe sex and age had no significant difference in all groups. The hospital day, ICU day, and day of mechanical ventilation prolonged with increasing of the injure severity. The severe injury group is much longer than the moderate injury group (P <0.05), so was the modiate injury group compared to the mild injury group (P <0.05). The incidence of SIRS, SEPSIS and MODS were higher in severe injury group than that of other groups(P <0.05). The two death cases were serious injury: the one succumb to serious the craniocerebral injury, the other to the hemorrhagic shock.The level of leptin in serum of patients were higher than control group at three phases(P <0.05). It reached the peak at D3,and is higher than control group and D1(P <0.05). The level of leptin at D6 is significantly lower than of D3 (P <0.05). The level of OB-R in trauma patients raised gradually and were all significantly higher than control group at all phases(P <0.05). It was much higher at D6 than other phases (P <0.05).The level of leptin raised with the increasing of the severity of trauma. There was no significant change in the mild injury group contrast to the control group, it is recovery at the D6. The levels of leptin in moderate injury group at D1 are higher lightly,and there was also no significant difference compared to the control group (P>0.05), but it is higher significantly than control group and mild injury group at D3 (P<0.05). It decrease gradually at D6 to the level at D1. The level of leptin in serious groups was higher significantly than other groups (P<0.05).The level of leptin-R in trauma patients serum was higher significantly than control group at all phase (P<0.05), and increased gradually with increasing of the degree of injure (P<0.05). The mild injury group was higher than control group (P<0.05), the moderate injury proup was higher than mild injury group and control groups (P<0.05), Severity trauma group was significant higher than other groups (P<0.05).The incidence of trauma complication was significantly positively correlated with the level of leptin and leptin-R level (P<0.05). It elevated as the increasing of levels of leptin and leptin-R after trauma.Conclusion1. As the injure degree aggravate, the serum leptin and leptin-R levels of patients increase significantly after trauma, and the time that the level of leptin-R recover to the normal is longer.2. The serum leptin and leptin-R level was positively correlated with the incidence of trauma complication. With the increase of the serum leptin and leptin-R level, the incidence of trauma complication elevates.