Comparison Of The Associations Of Complement C3 And High Sensitive C-reactive Protein With Insulin Resistance

Objective: To compare the associations of complement C3 (C3) and high sensitive C-reactive protein (hs-CRP) with insulin resistance (IR).Methods: 587 urban community residents were recruited, aged above 20 years. The present illness, past history, personal medical history, family history, dietary habits and lifestyle characteristics, including smoking, alcohol consumption and physical activity were collected. Weight, height, blood pressure, waist circumference, fasting plasma glucose (FPG), fasting serum insulin (Fins), total cholesterol(TC), triglyceride(TG), high-density lipoprotein cholesterol (HDL-c), low-density lipoprotein cholesterol (LDL-c), Apolipoprotein A1, Apolipoprotein B, C3 and hs-CRP were measured. Body mass index (BMI), ApoB/ApoA1 ratio and HOMA index (HOMA-IR) were calculated.Results:①Subjects in the high-C3 and high-hs-CRP group (C3≥1.34 g/L and hs-CRP≥0.5 mg/L) had greater values for age, BMI, waist circumference, systolic blood pressure (SBP), diastolic blood pressure (DBP), TG, TC, LDL-c, ApoB, Fins, FPG, and HOMA-IR, along with lower values for HDL-c and ApoA1, compared with those in low-C3 and low-hs-CRP group (C3 < 1.34 g/L and hs-CRP < 0.5 mg/L)(P < 0.05). Multivariate linear regression analysis found that C3 was independently correlated with waist circumference (β= 1.31), DBP (β= 0.08), TG (β= 0.21), LDL-c (β= 0.05), Fins (β= 0.26) and hs-CRP (β= 0.44); hs-CRP was independently associated with waist circumference (β= 0.09), SBP (β= 0.07), DBP (β= -0.06) and C3 (β= 0.31).②With the HOMA-IR increasing, both C3 and hs-CRP were significantly increased (P < 0.01). HOMA-IR was positively associated with C3 (r = 0.43, P < 0.01) and hs-CRP (r = 0.24, P < 0.01). After adjustment for gender, age and waist circumference, C3 was highly independently associated with HOMA-IR [β95%Cl: 0.57 (0.41 - 0.73), P < 0.01], but the association of hs-CRP and HOMA-IR was weakened [β95%Cl: 0.05 (0.004 - 0.10), P < 0.05], by multivariate linear regression analysis. As C3 increased, subjects were 3.22 [OR95%Cl: 3.22(1.35-7.64), P < 0.01] times more likely to be with IR, after adjustment for age, gender, SBP, DBP, TG, HDL-c and waist circumference; However, hs-CRP was no longer correlated with IR.Conclusion: C3 and hs-CRP were significantly associated with IR associated factors. Compared with hs-CRP, serum C3 might be a better inflammatory marker of IR in non-diabetic Chinese population.