BackgroundInsulin resistance is closely associated with metabolic profiles, including obesity and dyslipidemia. However, there are few studies to demonstrate a relationship between lipid profiles and insulin resistance, categorized by BMI, especially in Chinese. The aim of the present study was to examine how lipid profiles were associated with insulin resistance in non-obese middle-aged and elderly Chinese population.MethodsThis cross-sectional study included 1608 (596 men and 1012 women)

more »

... cts, without prior known diabetes mellitus and lipid regulating therapy history, older than 45 years. Insulin resistance was defined by homeostasis model assessment of insulin resistance (HOMA-IR) of at least 2.5. The areas under the curve of the receiver operating characteristic curves (AROC) were used to compare the power of these serum markers. SPSS 17.0 software was used for the statistical analysis.ResultsIn non-obese subjects (BMI < 25 kg/m2, n= 996), triglyceride (TG) to high-density lipoprotein cholesterol (HDL-C) ratio (OR = 1.43, 95% CI 1.13-1.81, P = 0.003), and SBP (OR = 1.01, 95% CI 1.00-1.02, P = 0.03) were independently risk factors for the insulin resistance. The best marker for insulin resistance in non-obese subjects was triglyceride (TG) to high-density lipoprotein cholesterol (HDL-C) ratio with the AROC of 0.73 (95% CI 0.68-0.77, P < 0.001), and the positive likelihood ratio was greatest for TG/HDL-C ratio in the metabolic profiles including BMI. The optimal cut-off point to identifying insulin resistance for TG/HDL-C ratio was ≥ 1.50 in the non-obese population. The BMI, TG, total cholesterol (TC)/HDL-C ratio and HDL-C also discriminated insulin resistance, as the values for AROC were 0.70 (95% CI 0.66-0.75, P < 0.001), 0.71 (95% CI 0.67-0.76, P < 0.001), 0.70 (95% CI 0.65-0.74, P < 0.001), 0.34 (95% CI 0.29-0.38, P < 0.001), respectively. In overweight subjects (BMI ≥ 25.0 kg/m2, n = 612), BMI was still the best marker for insulin resistance with the AROC of 0.65 (95% CI 0.60-0.69, P < 0.001). ConclusionsTG/HDL-C ratio may be the best reliable marker for insulin resistance in the non-obese population.