Abstract： ObjectiveTo study insulin resistance in the NG T first-degree relatives of type 2 diabetics and the relationship of anthropometr ic, blood lipids, TNF-α, FFA and leptin with insulin resistance.Meth odsA total of 58 NGT first-degree relatives of type 2 diabetics and 3 4 sex-, age- and BMI-matched control subjects without a family history of dia betics were joined, All subjects underwent a 75 g OGTT for determinations of 0, 60, 90, 120 minutes glucose, insulin and C-peptide, and baseline blood lipids, TNF-α, FFA, leptin. Insulin resistance was estimated using the homeostasis as sessment (HOMA).The relationship between HOMA-IR and the other variables was as sessed.Results(1) TC and TG were higher in relatives than in controls (P<0.05,P<0.01). Ins and CP at 0 minute and glucose at 60, 90, 12 0 minutes after OGTT were significantly higher in relatives (P<0 01). The m ean glucose(AUC) in relatives was higher than that in controls(P<0.01),an d the mean Ins(AUC) had no difference between the relatives and the controls . T he HOMA-IR in relatives (3.70±1.94)was higher than that in controls (2.73 ±0.59)(P<0.01). The mean TNF-α concentration in relatives was higher tha n that in controls (P<0.01). (2) The first-degree relatives were classified three subgroups according to BMI<23, 23≤BMI<25, BMI≥25. With BMI increasing , TG, 0, 60, 90, 120 minutes glucose, Ins, CP, HOMA-IR , leptin were signifi cantly increased (P<0.001).(3) HOMA-IR is significantly correlated with BMI , WHR, TG, Glu0, Ins 0, CP 0, Glu(AUC), Ins(AUC) (P<0.001). A significant co rrelation can be found between FFA and Glu(AUC)(r=0.31, P=0.019). ConclusionsHyperinsulinemia and insulin resistance could appear early in normoglycemic first-degree relatives of type 2 diabetics. With BMI increasin g, the severities of insulin resistance and dyslipidemia are increased in the fi rst-degree relatives. Circulating TNF-α is correlated with insulin resistance . FFA is correlated with deteriorated glucose tolerance.