Reference Values for Serum Lipid Profiles in Iranian Adults: Tehran Lipid and Glucose Study

Background: Lipid abnormalities are major risk factors for cardiovascular diseases. In addition to age and sex, other variables can affect serum lipid levels, warranting the determination of population-specific reference values. This study aimed to determine age- and sex-specific reference values for serum total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), and triglycerides (TG) in healthy Tehranian adults. Methods: TC, TG, and HDL-C were measured using the enzymatic colorimetric method and the Friedewald equation (LDL-C = TC − HDL-C − TG/5) was used to calculate LDL-C concentrations in individuals with TG <400 mg/dL. After applying the exclusion criteria, 1147 participants (548 men and 599 women) aged ≥20 years were included. For determining reference values, the International Federation of Clinical Chemistry guidelines (non-parametric method) and the robust method were used for sample sizes ≥120 and <120, respectively. Results: Reference values for serum TC, LDL-C, HDL-C, and TG were 121.0–261.0, 54.1–175.2, 30.9–71.9, and 46.9–301.2 mg/ dL in men and 117.8–235.9, 49.9–160.9, 36.0–83.9, and 38.1–184.2 mg/dL in women, respectively. All parameters except HDL-C were higher in men than women and showed an increasing trend with age. Conclusion: Reference values for serum TC, LDL-C, HDL-C, and TG in healthy Tehranian adults were determined, and these values could provide the basis for better decision making in both prevention and clinical settings.