The Correlation Of Serum Leptin Level With Insulin Resistance In Patients With Systemic Lupus Erythematosus

Objective To detect the serum levels of leptin in systemic lupus erythematosus patients, and analyze the corrlation between leptin and other clinical and biochemical data, further explore the corrlation between leptin and insulin resistance.Method61SLE patients and24healthy, age and sex matched controls were studied. All qualified patients fulfilled the1997revised American College of Rheumatology criteria. Patients’ disease activity was assessed at time of enrollment in the study using the SLE Disease Activity Index(SLEDAI). In all the participants, height, weight, waist, hips and other clinical data and fasting blood glucose and insulin were measured to calculate insulin resistance index(HOMA-IR), Homa-β cell function index(HBCI) and insulin sensitivity index(ISI). Serum leptin was measured by enzyme-linked immunosorbent assay(ELISA). clinical and biochemical data, and leptin levels were compared between the SLE group and healthy control group. Beside, we divided the SLE patients into remission and active group, the obese group and non-obese group, high FINS group and the normal FINS group, IR group and no-IR group. Serum leptin levels and other clinical and biochemical data were compared between these SLE groups. Linear correlation analysis and multiple regression analysis were conducted to investigate the correlation between leptin and insulin resistance(IR).Results1. SLE patients had significantly higher WHR, BF%, TG, and lower HDL than healthy controls, these suggest that SLE patients have body fat, abdominal obesity and abnormal lipid metabolism.2. Compared with control subjects, SLE patients showed significantly higher FINS, HOMA-IR and HOMA-HBCI, and lower ISI, it’s suggest that SLE patients have IR and β cell dysfunction.3. The level of serum leptin in the SLE group elevated compared to the controls, which suggest leptin may take part in the pathology of SLE.4. Compared with non-obese group, obese group showed significantly higher FINS and HOMA-IR, and lower ISI, suggest that IR more common in obese patients.5. Compared with remission group, activity group showed significantly higher TC and TG levels. leptin levels did not differ between SLE activity group and remission group.6. Compared with the normal FINS group, high FINS group showed significantly higher FBG and HOMA-IR, and lower ISI, suggest that IR was more common in high FINS patients. Leptin levels were higher in group with high FINS levels than normal FINS group.7. In IR group, BMI, WHR, FBG and FINS were significantly higher than that in no-IR group, meanwhile, ISI was significantly lower in IR group. These suggested that IR was more common in obese patients, especially the patients with abdominal obesity. Leptin levels were also higher in patients with IR compared with patients with no-IR.8. In SLE patients, leptin levels were positively correlated with CRP、BMI、WHR、 BF%、FBG、FINS and HOMA-IR. While, leptin levels were not correlated with age、 disease activity index(SLEDAI, C3, ds-DNA) in SLE patients. The resullt of multiple regression analysis is that HOMA-IR、ISI and CRP is independent factors to serum leptin levels in SLE paientsConclusion1. SLE patients have a higher risk of insulin resistance and abnormal lipid metabolism.2. Serum leptin levels were higher in SLE patients than controls, and free from age, and disease activity. In SLE patients, Leptin levels positively correlated with BMI、 HOMA-IR and FINS, patients with IR showed significantly higher leptin levels than patients without IR, HOMA-IR was the independent factors for serum leptin levels.3. High leptin levels and decreased leptin effects coexist in SLE patients. All above paradoxical would imply the existence of leptin resistance in SLE.